Annual Principal Payments on Federal Home Loan Bank Advances (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Short-term Debt [Line Items]
2013	$ 5,412
2014	239
2015	178
2016	6,172
2017	20,134
Thereafter	304
Federal home loan bank, advances	$ 32,439

Amount of federal home loan bank advances. Advances are loans from the federal home loan bank system to a member (shareholder).

Amount of federal home loan bank advances maturing after the fifth fiscal year following the latest fiscal year.

Amount of federal home loan bank advances maturing in the fifth fiscal year following the latest fiscal year.

Amount of federal home loan bank advances maturing in the second fiscal year following the latest fiscal year.

Amount of federal home loan bank advances maturing in the fourth fiscal year following the latest fiscal year.

Amount of federal home loan bank advances maturing in the third fiscal year following the latest fiscal year.

Amount of federal home loan bank advances maturing in the next fiscal year following the latest fiscal year.