Commitments and Contingencies (Detail) - First Federal's loan commitments (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011
Available unused lines of credit	$ 377,473	$ 345,734	$ 344,949
Commitments to fund commercial real estate, construction and land development loans	26,401	30,531	35,145
Other unused commitments	39,055	73,835	68,929
Standby letters of credit	$ 10,792	$ 574	$ 572

The maximum amount of borrowing capacity under a line of credit that is available as of the balance sheet date for financing purchases of goods acquired for inventory or imminent delivery to a customer.

No definition available.

Name:	us-gaap_LineOfCreditFacilityCapacityAvailableForTradePurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant