Variable Interest Entities - Schedule of Fair Value and Carrying Value of Assets and Liabilities of the 2009 Entity (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Variable Interest Entity [Line Items]
Restricted cash	$ 5,974	$ 5,636	$ 4,989
Current portion of 2009 Entity Student Loans	10,339	7,730	7,598
2009 Entity Student Loans, excluding current portion	84,272	76,479	85,340
Total assets	767,506us-gaap_Assets	806,851us-gaap_Assets	739,302us-gaap_Assets
Current portion of 2009 Entity secured borrowing obligation	20,662us-gaap_SecuredDebtCurrent	0us-gaap_SecuredDebtCurrent	0us-gaap_SecuredDebtCurrent
Other current liabilities	27,838us-gaap_OtherLiabilitiesCurrent	42,136us-gaap_OtherLiabilitiesCurrent	57,485us-gaap_OtherLiabilitiesCurrent
2009 Entity secured borrowing obligation, excluding current portion	101,880us-gaap_SecuredLongTermDebt	0us-gaap_SecuredLongTermDebt	0us-gaap_SecuredLongTermDebt
Total liabilities	635,971us-gaap_Liabilities	691,205us-gaap_Liabilities	598,067us-gaap_Liabilities
2009 Entity [Member]
Variable Interest Entity [Line Items]
Restricted cash	2,738
Current portion of 2009 Entity Student Loans	3,406
2009 Entity Student Loans, excluding current portion	23,793
Other assets	199
Total assets	30,136
Current portion of 2009 Entity secured borrowing obligation	20,662
Other current liabilities	624
2009 Entity secured borrowing obligation, excluding current portion	101,880
Other liabilities	1,940
Total liabilities	$ 125,106

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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The aggregate carrying amounts, as of the balance sheet date, of assets not separately disclosed in the balance sheet.

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Carrying value as of the balance sheet date of the portion of long-term, collateralized debt obligations due within one year or the operating cycle, if longer. Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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