Assets Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	$ 153,468	$ 165,878
Securities Investment
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	88,896	91,744
Securities Investment | Government Sponsored Enterprises
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	84,560	87,538
Securities Investment | Trust Preferred Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	4,336	4,205
Securities Investment | U.S. Agency Obligations
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure		1
Mortgage-Backed and Related Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	64,572	74,134
Level 1
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	84,560	87,539
Level 1 | Securities Investment
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	84,560	87,539
Level 1 | Securities Investment | Government Sponsored Enterprises
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	84,560	87,538
Level 1 | Securities Investment | U.S. Agency Obligations
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure		1
Level 2
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	67,373	76,884
Level 2 | Securities Investment
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	2,801	2,750
Level 2 | Securities Investment | Trust Preferred Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	2,801	2,750
Level 2 | Mortgage-Backed and Related Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	64,572	74,134
Level 3
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	1,535	1,455
Level 3 | Securities Investment
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	1,535	1,455
Level 3 | Securities Investment | Trust Preferred Securities
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Asset Fair Value disclosure	$ 1,535	$ 1,455