Contingencies - Additional Information (Detail) - USD ($) $ in Thousands			1 Months Ended	3 Months Ended
	Nov. 12, 2014	Mar. 26, 2012	Jan. 31, 2013	Mar. 31, 2014	Mar. 31, 2013	Oct. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Apr. 30, 2013
Loss Contingencies [Line Items]
Face amount of surety bonds				$ 20,500
Letters of credit issued				2,246
Payment under settlement agreement			$ 46,000	$ 0	$ 46,000
Life of private education loan made under RSAs				10 years
Range of possible losses less than amount accrued				$ 10,000
Range of possible losses greater than portion accrued				28,000
Litigation settlement amount		$ 395
Additional payments expected in 2018				75,194
Estimated regular payment made				54,096
Discount on guarantee regular payments and recoveries				8,674
Collateral maintained with bank for education loan				8,600	8,600			$ 8,600	$ 8,600
Increase in collateral maintained in restricted bank account				2,600
Recoveries from charged-off loans				219	54
Payable in 2018 through 2027 [Member]
Loss Contingencies [Line Items]
Estimated regular payment made				97,400
Payable 2023 through 2027 [Member]
Loss Contingencies [Line Items]
Estimated regular payment made				16,600
Nonaffiliated Entity [Member]
Loss Contingencies [Line Items]
Recoveries from charged-off loans				800
Offset amounts relating to guarantee obligations					$ 538
Amount of offset to repay				8,600
Education Loan Under 2009 Loan Program [Member]
Loss Contingencies [Line Items]
Principal amount for private education loans				141,000
Maximum [Member] | Payable 2018 through 2022 [Member]
Loss Contingencies [Line Items]
Estimated regular payment made				16,400
Minimum [Member] | Payable 2018 through 2022 [Member]
Loss Contingencies [Line Items]
Estimated regular payment made				15,100
Scenario, Forecast [Member] | Fourth Amendment [Member]
Loss Contingencies [Line Items]
Discharge Payments	$ 2,577
Revolving Note [Member]
Loss Contingencies [Line Items]
Amount included in Other current liabilities offset against receivable under Revolving Note				8,500
Credit facility outstanding, amount				$ 8,200
Subsequent Event [Member]
Loss Contingencies [Line Items]
Letter of credit payable						$ 79,708	$ 106
Subsequent Event [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Letter of credit payable						$ 82,060