Securities (Non-Agency Collateralized Mortgage Obligations) (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Schedule of Held-to-maturity Securities [Line Items]
Book Value	$ 21,054	[1]
Baa2 [Member]
Schedule of Held-to-maturity Securities [Line Items]
Book Value	$ 27

[1] One acquired available for sale non-agency CMO with a June 30, 2012 book value of $27 is not included in the above table. The bond rating at acquisition was AAA and is now Baa2. This non-agency CMO is current with regards to principal and interest.