Variable Interest Entities - Guarantee and Other Payments Related to PEAKS Program (Parenthetical) (Detail) (PEAKS Program [Member], USD $) In Thousands, unless otherwise specified	1 Months Ended	9 Months Ended
	Feb. 28, 2013	Sep. 30, 2013
PEAKS Program [Member]
Variable Interest Entity [Line Items]
Guarantee payments paid to prior consolidation	$ 854	$ 854
Payments on behalf of borrowers prior to consolidation	$ 532	$ 532