Contingencies - Activity with Respect to Claims and Contingencies (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Schedule of Claims and Contingencies [Line Items]
Payment recoveries	$ 0	$ 50	$ 103	$ 87
PEAKS Program Guarantee [Member]
Schedule of Claims and Contingencies [Line Items]
Estimated recoveries	$ 0	$ 0	$ 723	$ 0

The cash inflow from loans reinstated and recovered that were previously deemed uncollectible.

No definition available.

Name:	us-gaap_ProceedsFromRecoveriesOfLoanPreviouslyChargedOff
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration