Commitments and Contingencies - Estimated Amounts of Regular, Discharge Payments Expected to Pay and Estimated Recoveries from Charged-off Loans (Parenthetical) (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Summary Of Projections Of Estimated Payments And Recoveries [Line Items]
Estimated Total Payments	$ 104,408	[1]
CUSO [Member]
Summary Of Projections Of Estimated Payments And Recoveries [Line Items]
Recoveries from charged-off loans	1,049
Amount of offset to repay	9,900
CUSO RSA [Member] | CUSO [Member]
Summary Of Projections Of Estimated Payments And Recoveries [Line Items]
Recoveries from charged-off loans	779
Sixth Amendment [Member] | CUSO RSA [Member]
Summary Of Projections Of Estimated Payments And Recoveries [Line Items]
Estimated Total Payments	$ 6,313

[1] The estimated amount of future payments under the CUSO RSA assumes that an offset that we made in 2013 of certain payment obligations under the CUSO RSA against the CUSO's obligations owed to us under the Revolving Note will not be determined to have been improper. See "- PEAKS Program and CUSO RSA Payments in Certain Periods" below for a further discussion of that offset. In the event that offset is determined to be improper, we may be required to pay the CUSO approximately $9,900, net of approximately $1,049 of recoveries from charged-off loans, which would be in addition to the estimated payment amounts set forth in this table.