Accounts And Notes Receivable Net Note receivable secured by real estate Accounts Payable Accrued Liabilities And Other Liabilities Disclosure Noncurrent [Text Block] Notes Payable and Other Noncurrent Liabilities Accounts Payable Current Accounts payable Accounts Receivable Net Current Accounts receivable, net of allowance for doubtful accounts of $8,657 and $11,706 at December 31, 2012 and 2011, respectively Accrual For Taxes Other Than Income Taxes Current Tax reserves, non-income tax related Accrued Income Taxes Current Income taxes payable Accrued Liabilities Current Accrued liabilities Accrued liability related to royalty arrangement. Accrued Liability Related To Royalty Arrangement Accrued liability related to royalty arrangement Accrued litigation loss. Accrued Litigation Loss Accrued litigation loss Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Less accumulated depreciation and amortization Accumulated Other Comprehensive Income Loss Net Of Tax Accumulated other comprehensive loss Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Income (Loss) [Member] Additional amount authorized by board of directors. Additional Amount Authorized By Board Of Directors Additional amount authorized by board of directors Additional Borrowing Term Loan Additional Borrowing Term Loan Increase in the term loan Additional Paid In Capital Additional paid-in capital Additional Paid In Capital [Member] Additional Paid-in Capital [Member] Adjustments For Change In Accounting Principle [Axis] Adjustments for Change in Accounting Principle [Axis] Adjustments To Additional Paid In Capital Tax Effect From Share Based Compensation Excess tax benefits Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Advertising Expense Advertising costs Affiliated Entity [Member] GCUF [Member] Agreement period of Acquired source code rights for the software developed, prepaid maintenance and service fee. Agreement Period Of Acquired Source Code Rights For Software Developed Prepaid Maintenance And Service Fee Agreement period of acquired source code rights for the software developed, prepaid maintenance and service fee Agreement to pay former owner royalty amount. Agreement To Pay Former Owner Royalty Amount Agreement to pay former owner royalty amount Allocated Share Based Compensation Expense Share-based compensation expense Allowance For Doubtful Accounts [Member] Allowance for doubtful accounts receivable [Member] Allowance For Doubtful Accounts Receivable Current Allowance for doubtful accounts Amendment Flag Amendment Flag Amortization Of Financing Costs Amortization of notes payable issuance costs Amortization of other current assets under reclassification. Amortization Of Other Current Assets Under Reclassification Amortization of other current assets Amount paid to settle qui tam matter. Amount Paid To Settle Qui Tam Matter Amount agreed to pay to settle the qui tam matter as restricted cash Amounts related to options exercised. Amounts Related To Options Exercised Table [Text Block] Amounts Related to Options Exercised Annual Payment Under Agreement Annual Payment Under Agreement Payment made under the agreement Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount University's stock options outstanding were excluded from the calculation of diluted earnings Area of the company's campus. Area Of Companys Campus Area of the Company's campus in Phoenix, Arizona Arrangement expense. Arrangement Expense Arrangement expense As Changed. As Changed [Member] As Changed [Member] As Reported [Member] As Reported [Member] As Reported [Member] Assets Total assets Assets [Abstract] ASSETS: Assets Current Total current assets Assets Current [Abstract] Current assets Assets Held Under Capital Leases [Member] Equipment under capital leases [Member] Authorized to repurchase common stock including additional repurchase. Authorized To Repurchase Common Stock Including Additional Repurchase Authorized to repurchase common stock including additional repurchase Average days from the date of receipt in which funds remain as restricted cash and cash equivalents. Average Days From Date Of Receipt In Which Funds Remain As Restricted Cash And Cash Equivalents Average days from the date of receipt in which funds remain as restricted cash and cash equivalents Award Type [Axis] Award Type [Axis] Building [Member] Buildings [Member] Business Exit Costs Exit costs Capitalized interest rate on borrowing to finance improvement. Capitalized Interest Rate On Borrowing To Finance Improvement Capitalized interest rate on borrowings to finance improvements Capital lease interest rate stated percentage rate range maximum. Capital Lease Interest Rate Stated Percentage Rate Range Maximum Implicit interest rate on capital leases, Maximum Capital Lease Obligations Capital lease for equipment Capital Lease Obligations Current Current portion of capital lease obligations Less: Current portion of capital lease obligations Capital Lease Obligations [Line Items] Capital Lease Obligations [Line Items] Capital Lease Obligations [Line Items] Capital Lease Obligations Noncurrent Capital lease obligations, less current portion Capital Lease Obligations [Table] Capital Lease Obligations [Table] Capital Lease Obligations [Table] Capital lease obligations. Capital Lease Obligations Table [Text Block] Components of Capital Lease Obligations Capital Leases Future Minimum Payments Due Total Capital Leases Future Minimum Payments Due Current 2013 Capital Leases Future Minimum Payments Due In Three Years 2015 Capital Leases Future Minimum Payments Due In Two Years 2014 Capital Leases Future Minimum Payments Due Thereafter 2016 and thereafter Capital Leases Future Minimum Payments Interest Included In Payments Less: Portion representing interest Capital Leases Future Minimum Payments Present Value Of Net Minimum Payments Present value of minimum lease payments Capital Leases In Financial Statements Of Lessee Disclosure [Text Block] Capital Lease Obligations Cash And Cash Equivalents At Carrying Value Cash and cash equivalents, end of year Cash and cash equivalents, beginning of year Cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Net increase (decrease) in cash and cash equivalents Cash And Cash Equivalents Policy [Text Block] Cash and Cash Equivalents Cash And Cash Equivalents Restricted Cash And Cash Equivalents Policy Restricted Cash and Cash Equivalents Cash Flow Hedging [Member] Cash Flow Hedging [Member] Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract] Supplemental disclosure of non-cash investing and financing activities Cash flows as previously reported and as changed. Cash Flows As Previously Reported And Changed Table [Text Block] Cash Flows as Previously Reported and as Changed Change In Accounting Principle [Member] Adjustments for Change in Accounting Principle [Domain] Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Commitment And Contingencies [Line Items] Commitments And Contingencies Commitments and contingencies Commitments And Contingencies Disclosure [Text Block] Commitments and Contingencies Commitments And Contingencies Policy [Text Block] Commitments and Contingencies Common stock acquired, shares. Common Stock Acquired Shares Common stock acquired, shares Common Stock [Member] Common Stock [Member] Common Stock Par Or Stated Value Per Share Common stock, par value Common Stock Shares Authorized Common stock, shares authorized Common Stock Shares Issued Common stock, shares issued Common Stock Shares Outstanding Common stock, shares outstanding Common Stock Value Common stock, $0.01 par value, 100,000 shares authorized; 47,136 and 45,955 shares issued and 44,716 and 44,298 shares outstanding at December 31, 2012 and 2011, respectively Components Of Deferred Income Tax Assets And Liabilities [Line Items] Components Of Deferred Income Tax Assets And Liabilities [Line Items] Components Of Deferred Income Tax Assets And Liabilities [Line Items] Components Of Deferred Income Tax Assets And Liabilities [Table] Components Of Deferred Income Tax Assets And Liabilities [Table] Components Of Deferred Income Tax Assets And Liabilities [Table] Components Of Income Tax Expense Benefit [Line Items] Components Of Income Tax Expense Benefit [Line Items] Components Of Income Tax Expense Benefit [Line Items] Components Of Income Tax Expense Benefit [Table] Components Of Income Tax Expense Benefit [Table] Components Of Income Tax Expense Benefit [Table] Comprehensive Income Net Of Tax Comprehensive income Computer Equipment [Member] Computer equipment [Member] Concentration of credit risk. Concentration Of Credit Risk Policy [Text Block] Concentration of Credit Risk Consolidation Policy [Text Block] Principles of Consolidation Construction In Progress [Member] Construction in progress [Member] Contract termination fees to related party. Contract Termination Fees To Related Party Contract termination fees to related party Cost Of Sales Policy [Text Block] Instructional Costs and Services Costs And Expenses Total costs and expenses Costs And Expenses [Abstract] Costs and expenses: Costs incurred due to unanticipated delays in information processing. Costs Incurred Due To Unanticipated Delays In Information Processing Costs incurred due to unanticipated delays in information processing Credit Risk Derivative Assets At Fair Value Fair value of interest rate corridor instrument Credit Risk Derivative Liabilities At Fair Value Fair value of the interest rate swap liability, included in other noncurrent liabilities Current Federal Tax Expense Benefit Federal Current Fiscal Year End Date Current Fiscal Year End Date Current Income Tax Expense Benefit Current Income Tax Expense (Benefit), Total Current Income Tax Expense Benefit Continuing Operations [Abstract] Current: Current State And Local Tax Expense Benefit State Customer Deposits Current Student deposits Debt Instrument Basis Spread On Variable Rate Interest rate of notes payable Debt instrument basis spread on variable rate, after amendment. Debt Instrument Basis Spread On Variable Rate After Amendment Interest rate on the outstanding balance, after amendment, basis points Debt instrument basis spread on variable rate, before amendment. Debt Instrument Basis Spread On Variable Rate Before Amendment Interest rate on the outstanding balance, before amendment, basis points Debt Instrument Interest Rate Stated Percentage Rate Range Maximum Interest rate of notes payable, Maximum Debt Instrument Interest Rate Stated Percentage Rate Range Minimum Interest rate of notes payable, Minimum Decreased the interest rate on the outstanding balance. Decreased Interest Rate On Outstanding Balance Decreased the interest rate on the outstanding balance Deferred Compensation Arrangement With Individual Share Based Payments By Title Of Individual [Axis] Title of Individual [Axis] Deferred Federal Income Tax Expense Benefit Federal Deferred Income Tax Expense Benefit Deferred income taxes Deferred Income Tax Expense Benefit Continuing Operations [Abstract] Deferred: Deferred Income Tax Expense Benefit Net Of Non-Cash Transactions Deferred Income Tax Expense Benefit Net Of Noncash Transactions Deferred Income Tax Expense (Benefit) Deferred Long Term Liability Charges Long-term deferred rent Deferred Revenue Current Deferred revenue Deferred State And Local Income Tax Expense Benefit State Deferred Tax Assets Liabilities Net Net deferred tax (liability) asset Deferred Tax Assets Liabilities Net Current Current deferred tax asset Deferred Tax Assets Liabilities Net Noncurrent Non-current deferred tax (liability) asset Deferred Tax Assets Net Current Deferred income taxes Deferred Tax Assets Net Current Classification [Abstract] Current deferred tax asset (liability): Deferred Tax Assets Net Noncurrent Classification [Abstract] Non-current deferred tax asset (liability): Deferred Tax Assets Other Other Deferred Tax Assets Other Tax Carryforwards Other Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost Share-based compensation Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts Accounts receivable allowance for doubtful accounts Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Deferred Rent Deferred rent Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Legal Settlements Estimated litigation loss and regulatory reserves Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets Intangibles Deferred Tax Liabilities Noncurrent Deferred income taxes, non-current Deferred tax liability depreciation and leases. Deferred Tax Liability Depreciation And Leases Depreciation and leases Deferred tax liability state taxes. Deferred Tax Liability State Taxes State taxes Defined Benefit Plan Contributions By Plan Participants University made discretionary matching contributions Denominator. Denominator [Abstract] Denominator: Depreciation And Amortization Depreciation and amortization Depreciation and Amortization Including Assets Under Capital Lease. Depreciation And Amortization Including Assets Under Capital Lease Depreciation and amortization expense including assets under capital lease Derivative And Hedging [Table] Derivative And Hedging [Table] Derivative And Hedging [Table] Derivative Contract Type [Domain] Derivative Contract Type [Domain] Derivative Higher Variable Interest Rate Range Minimum percentage of LIBOR Derivative Instrument Risk [Axis] Derivative Instrument Risk [Axis] Derivative Instruments And Hedging Activities Disclosure [Text Block] Derivative Instruments Derivative Instruments Gain Loss By Hedging Relationship [Axis] Hedging Relationship [Axis] Derivative Instruments [Line Items] Derivative Instruments [Line Items] Derivative Instruments [Line Items] Derivative Instruments [Table] Derivative Instruments [Table] Derivative Instruments [Table] Derivative [Line Items] Derivative [Line Items] Derivative Lower Variable Interest Rate Range Maximum percentage of LIBOR Derivatives Policy [Text Block] Derivatives and Hedging Dilutive Securities Included And Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Dilutive Securities Included And Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Dilutive Securities Included And Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Disclosure - Capital Lease Obligations - Components of Capital Lease Obligations [Abstract] Disclosure Capital Lease Obligations Components Of Capital Lease Obligations [Abstract] Disclosure - Capital Lease Obligations - Components of Capital Lease Obligations [Abstract] Disclosure - Capital Lease Obligations - Payments Due under Future Minimum Lease Payments under Capital Lease Obligations [Abstract] Disclosure Capital Lease Obligations Payments Due Under Future Minimum Lease Payments Under Capital Lease Obligations [Abstract] Disclosure - Capital Lease Obligations - Payments Due under Future Minimum Lease Payments under Capital Lease Obligations [Abstract] Disclosure Commitments And Contingencies Additional Information [Abstract] Disclosure Commitments And Contingencies Additional Information [Abstract] Disclosure Commitments And Contingencies Additional Information [Abstract] Disclosure - Commitments and Contingencies - Future Minimum Lease Payments under Operating Leases [Abstract] Disclosure Commitments And Contingencies Future Minimum Lease Payments Under Operating Leases [Abstract] Disclosure - Commitments and Contingencies - Future Minimum Lease Payments under Operating Leases [Abstract] Disclosure Derivative Instruments Additional Information [Abstract] Disclosure Derivative Instruments Additional Information [Abstract] Disclosure Derivative Instruments Additional Information [Abstract] Disclosure Earnings Per Share Additional Information [Abstract] Disclosure Earnings Per Share Additional Information [Abstract] Disclosure Earnings Per Share Additional Information [Abstract] Disclosure - Earnings Per Share - Summary of Weighted Average Number of Common Shares Outstanding [Abstract] Disclosure Earnings Per Share Summary Of Weighted Average Number Of Common Shares Outstanding [Abstract] Disclosure - Earnings Per Share - Summary of Weighted Average Number of Common Shares Outstanding [Abstract] Disclosure Equity Transactions Additional Information [Abstract] Disclosure Equity Transactions Additional Information [Abstract] Disclosure Equity Transactions Additional Information [Abstract] Disclosure Income Taxes Additional Information [Abstract] Disclosure Income Taxes Additional Information [Abstract] Disclosure Income Taxes Additional Information [Abstract] Disclosure - Income Taxes - Components of Income Taxes Expense (Benefit) [Abstract] Disclosure Income Taxes Components Of Income Taxes Expense Benefit [Abstract] Disclosure - Income Taxes - Components of Income Taxes Expense (Benefit) [Abstract] Disclosure - Income Taxes - Reconciliation of Unrecognized Tax Benefits [Abstract] Disclosure Income Taxes Reconciliation Of Unrecognized Tax Benefits [Abstract] Disclosure - Income Taxes - Reconciliation of Unrecognized Tax Benefits [Abstract] Disclosure - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation [Abstract] Disclosure Income Taxes Schedule Of Effective Income Tax Rate Reconciliation [Abstract] Disclosure - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation [Abstract] Disclosure - Income Taxes - Significant Components of Deferred Income Tax Assets and Liabilities [Abstract] Disclosure Income Taxes Significant Components Of Deferred Income Tax Assets And Liabilities [Abstract] Disclosure - Income Taxes - Significant Components of Deferred Income Tax Assets and Liabilities [Abstract] Disclosure Nature Of Business Additional Information [Abstract] Disclosure Nature Of Business Additional Information [Abstract] Disclosure Nature Of Business Additional Information [Abstract] Disclosure - Notes Payable and Other Noncurrent Liabilities - Additional Information [Abstract] Disclosure Notes Payable And Other Noncurrent Liabilities Additional Information [Abstract] Disclosure - Notes Payable and Other Noncurrent Liabilities - Additional Information [Abstract] Disclosure - Notes Payable and Other Noncurrent Liabilities - Notes Payable [Abstract] Disclosure Notes Payable And Other Noncurrent Liabilities Notes Payable [Abstract] Disclosure - Notes Payable and Other Noncurrent Liabilities - Notes Payable [Abstract] Disclosure - Notes Payable and Other Noncurrent Liabilities - Payments Due under Notes Payable [Abstract] Disclosure Notes Payable And Other Noncurrent Liabilities Payments Due Under Notes Payable [Abstract] Disclosure - Notes Payable and Other Noncurrent Liabilities - Payments Due under Notes Payable [Abstract] Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Share-Based Compensation Plans Disclosure Property And Equipment Additional Information [Abstract] Disclosure Property And Equipment Additional Information [Abstract] Disclosure P R O P E R T Y A N D E Q U I P M E N T Additional Information [Abstract] Disclosure - Property and Equipment - Summary of Property and Equipment [Abstract] Disclosure Property And Equipment Summary Of Property And Equipment [Abstract] Disclosure - Property and Equipment - Summary of Property and Equipment [Abstract] Disclosure - Quarterly Results of Operations (Unaudited) - Summarization of Unaudited Quarterly Results of Operations [Abstract] Disclosure Quarterly Results Of Operations Unaudited Summarization Of Unaudited Quarterly Results Of Operations [Abstract] Disclosure - Quarterly Results of Operations (Unaudited) - Summarization of Unaudited Quarterly Results of Operations [Abstract] Disclosure Regulatory Additional Information [Abstract] Disclosure Regulatory Additional Information [Abstract] Disclosure Regulatory Additional Information [Abstract] Disclosure Related Party Transactions Additional Information [Abstract] Disclosure Related Party Transactions Additional Information [Abstract] Disclosure Related Party Transactions Additional Information [Abstract] Disclosure Share Based Compensation Plans Additional Information [Abstract] Disclosure Share Based Compensation Plans Additional Information [Abstract] Disclosure Share Based Compensation Plans Additional Information [Abstract] Disclosure - Share-Based Compensation Plans - Amounts Related to Options Exercised [Abstract] Disclosure Share Based Compensation Plans Amounts Related To Options Exercised [Abstract] Disclosure - Share-Based Compensation Plans - Amounts Related to Options Exercised [Abstract] Disclosure - Share-Based Compensation Plans - Fair Value of Options as of Grant Dates Using Weighted Average Assumptions [Abstract] Disclosure Share Based Compensation Plans Fair Value Of Options As Of Grant Dates Using Weighted Average Assumptions [Abstract] Disclosure - Share-Based Compensation Plans - Fair Value of Options as of Grant Dates Using Weighted Average Assumptions [Abstract] Disclosure Share Based Compensation Plans Share Based Compensation Expense [Abstract] Disclosure Share Based Compensation Plans Share Based Compensation Expense [Abstract] Disclosure Share Based Compensation Plans Share Based Compensation Expense [Abstract] Disclosure - Share-Based Compensation Plans - Summary of Activity Related to Restricted Stock Granted Under Incentive Plan [Abstract] Disclosure Share Based Compensation Plans Summary Of Activity Related To Restricted Stock Granted Under Incentive Plan [Abstract] Disclosure - Share-Based Compensation Plans - Summary of Activity Related to Restricted Stock Granted Under Incentive Plan [Abstract] Disclosure - Share-Based Compensation Plans - Summary of Activity Related to Stock Options Granted Under Company's Incentive Plan [Abstract] Disclosure Share Based Compensation Plans Summary Of Activity Related To Stock Options Granted Under Companys Incentive Plan [Abstract] Disclosure - Share-Based Compensation Plans - Summary of Activity Related to Stock Options Granted Under Company's Incentive Plan [Abstract] Disclosure Summary Of Significant Accounting Policies Additional Information [Abstract] Disclosure Summary Of Significant Accounting Policies Additional Information [Abstract] Disclosure Summary Of Significant Accounting Policies Additional Information [Abstract] Disclosure - Summary of Significant Accounting Policies - Cash Flows as Previously Reported and as Changed [Abstract] Disclosure Summary Of Significant Accounting Policies Cash Flows As Previously Reported And As Changed [Abstract] Disclosure - Summary of Significant Accounting Policies - Cash Flows as Previously Reported and as Changed [Abstract] Disclosure - Summary of Significant Accounting Policies - Interest Cost Capitalized and Incurred [Abstract] Disclosure Summary Of Significant Accounting Policies Interest Cost Capitalized And Incurred [Abstract] Disclosure - Summary of Significant Accounting Policies - Interest Cost Capitalized and Incurred [Abstract] Disclosure - Valuation and Qualifying Accounts - Schedule of Valuation and Qualifying Accounts [Abstract] Disclosure Valuation And Qualifying Accounts Schedule Of Valuation And Qualifying Accounts [Abstract] Disclosure - Valuation and Qualifying Accounts - Schedule of Valuation and Qualifying Accounts [Abstract] Discount Rate To Determine Present Value Of Cash Flow Discount Rate To Determine Present Value Of Cash Flow Discount net cash flows Document Document and Entity Information [Abstract] Document Document And Entity Information [Abstract] Document Documentand Entity Information [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Document Information [Table] Document Information [Table] Document Period End Date Document Period End Date Document Type Document Type Due To Related Parties Current Amounts owed by related party Due to related parties Earnings Per Share [Abstract] Earnings per share: Earnings Per Share Basic Basic income per share Earnings Per Share Diluted Diluted income per share Earnings Per Share [Text Block] Earnings Per Share Effective Income Tax Rate Continuing Operations Effective income tax rate Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate Statutory U.S. federal income tax rate Effective Income Tax Rate Reconciliation Nondeductible Expense Non deductible expenses