Variable Interest Entities - Additional Information (Detail) $ in Thousands		1 Months Ended	3 Months Ended									12 Months Ended
	Mar. 20, 2014 USD ($)	Jan. 31, 2014 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2013 USD ($)	Jun. 30, 2013 USD ($)	Mar. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2014 USD ($) Installment	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Feb. 28, 2013 USD ($)
Variable Interest Entity [Line Items]
Imputed interest rate												9.00%
Subordinated Note, maturity date												2026-03
Impairment charge			$ 2,454									$ 2,454	$ 0	$ 15,166
Gain (loss) on consolidation			0	$ 16,631	$ 0	$ 0	$ 0	$ 0	$ 0	$ (73,248)		16,631	(73,248)	0
Payments on Behalf of Borrowers												1,832	11,499
Offset amounts under Revolving Note												0	8,472
Carrying value of Revolving note			80,292				76,479					80,292	76,479
PEAKS Trust [Member]
Variable Interest Entity [Line Items]
Impairment charge														$ 10,300
Gain (loss) on consolidation										$ (73,248)
Payments on Behalf of Borrowers		$ 1,832
Carrying value of Revolving note			59,902				76,479					59,902	76,479		$ 104,834
PEAKS Trust [Member] | 2014 Payment [Member]
Variable Interest Entity [Line Items]
Prepayment of Senior debt	$ 40,000
PEAKS Trust [Member] | Fair Value [Member]
Variable Interest Entity [Line Items]
Amount of liabilities exceeded assets															112,748
PEAKS Trust [Member] | Carrying Value [Member]
Variable Interest Entity [Line Items]
Reduction in excess of increase in fair value of liabilities over assets															$ 39,500
CUSO [Member]
Variable Interest Entity [Line Items]
Impairment charge											$ 4,900
Gain (loss) on consolidation												$ 16,631
Number of monthly payments | Installment												10
Discount rate												10.00%
Recoveries from charged-off loans												$ 475	574
Offset amounts under Revolving Note													8,472
Amounts relating to discharge payments													6,786
Revolving note, amount owned to company			8,200				8,200					8,200	8,200
Carrying value of Revolving note			$ 20,390	23,793			$ 2,500					$ 20,390	$ 2,500
CUSO [Member] | Fair Value [Member]
Variable Interest Entity [Line Items]
Amount of liabilities exceeded assets				94,970
CUSO [Member] | Carrying Value [Member]
Variable Interest Entity [Line Items]
Amount of liabilities exceeded assets				$ 111,601