Variable Interest Entities - Schedule of Fair Value and Carrying Value of Assets and Liabilities of the CUSO (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Variable Interest Entity [Line Items]
Restricted cash	$ 6,040		$ 5,636
Current portion of CUSO Student Loans	10,584		7,730
CUSO Student Loans, excluding current portion	80,292		76,479
Total assets	749,160us-gaap_Assets		806,851us-gaap_Assets
Current portion of CUSO secured borrowing obligation	20,813us-gaap_SecuredDebtCurrent		0us-gaap_SecuredDebtCurrent
Other current liabilities	27,050us-gaap_OtherLiabilitiesCurrent		42,136us-gaap_OtherLiabilitiesCurrent
CUSO secured borrowing obligation, excluding current portion	100,194us-gaap_SecuredLongTermDebt		0us-gaap_SecuredLongTermDebt
Total liabilities	601,155us-gaap_Liabilities		691,205us-gaap_Liabilities
CUSO [Member]
Variable Interest Entity [Line Items]
Restricted cash	2,517	2,738
Current portion of CUSO Student Loans	3,415	3,406
CUSO Student Loans, excluding current portion	20,390	23,793	2,500
Other assets	284	199
Total assets	26,606	30,136
Current portion of CUSO secured borrowing obligation	20,813	20,662
Other current liabilities	179	624
CUSO secured borrowing obligation, excluding current portion	100,194	101,880
Other liabilities	1,073	1,940
Total liabilities	$ 122,259	$ 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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Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future.

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An amount representing an agreement for an unconditional promise by the maker to pay the Company (holder) a definite sum of money within one year from the balance sheet date (or the normal operating cycle, whichever is longer), net of any write-downs taken for collection uncertainty on the part of the holder. Such amount may include accrued interest receivable in accordance with the terms of the debt. The debt also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. This amount does not include amounts related to receivables held-for-sale.

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An amount representing an agreement for an unconditional promise by the maker to pay the Entity (holder) a definite sum of money at a future date more than one year from the balance sheet date, net of any write-downs taken for collection uncertainty on the part of the holder. Such amount may include accrued interest receivable in accordance with the terms of the debt. The debt also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among a myriad of other features and characteristics. This amount does not include amounts related to receivables held-for-sale.

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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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The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.

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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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Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.

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