Contingencies - Aggregate Amount of Guarantee Payments, Discharge Payments and Payments on Behalf of Borrowers (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended	2 Months Ended	3 Months Ended
	Mar. 31, 2013	Feb. 28, 2013	Mar. 31, 2013	Mar. 31, 2012
Schedule of Claims and Contingencies [Line Items]
Payments on Behalf of Borrowers			$ 1,855	$ 0
Recoveries from Charged-Off Loans			(103)	(37)
PEAKS Program [Member]
Schedule of Claims and Contingencies [Line Items]
PEAKS Guarantee	385	854	1,239	0
Payments on Behalf of Borrowers	1,323	532	1,855	0
Total	1,708	1,386	3,094	0
2009 RSA [Member]
Schedule of Claims and Contingencies [Line Items]
Regular Payments	0	0	306	229
Discharge Payments	0	0	0	0
Recoveries from Charged-Off Loans	0	0	(103)	(37)
Total	$ 1,708	$ 1,386	$ 3,297	$ 192