Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012
Available-for-sale, Amortized cost	$ 227,616		$ 251,602
Available-for-sale, Gross unrealized gains	5,819		6,312
Available-for-sale, Gross unrealized losses	763		370
Available-for-sale, Estimated fair value	232,672		257,544
Held-to-maturity Securities, Amortized Cost	1,806		1,813
Held-to-maturity Securities, Gross unrealized gains	41		50
Held-to-maturity Securities, Gross unrealized losses	0		0
Held-to-maturity Securities, Estimated fair value	1,847		1,863
U.S. Agency mortgage-backed securities (MBS) [Member]
Available-for-sale, Amortized cost	200,226	[1]	216,141	[1]
Available-for-sale, Gross unrealized gains	4,973	[1]	5,426	[1]
Available-for-sale, Gross unrealized losses	628	[1]	252	[1]
Available-for-sale, Estimated fair value	204,571	[1]	221,315	[1]
Non-agency MBS [Member]
Available-for-sale, Amortized cost	17,747		20,601
Available-for-sale, Gross unrealized gains	318		253
Available-for-sale, Gross unrealized losses	17		0
Available-for-sale, Estimated fair value	18,048		20,854
U.S. Agency asset-backed securities [Member]
Available-for-sale, Amortized cost	9,151		9,374
Available-for-sale, Gross unrealized gains	498		599
Available-for-sale, Gross unrealized losses	118		118
Available-for-sale, Estimated fair value	9,531		9,855
Commercial Paper [Member]
Available-for-sale, Amortized cost			5,000
Available-for-sale, Gross unrealized gains			0
Available-for-sale, Gross unrealized losses			0
Available-for-sale, Estimated fair value			5,000
Mutual Fund [Member]
Available-for-sale, Amortized cost	492		486
Available-for-sale, Gross unrealized gains	30		34
Available-for-sale, Gross unrealized losses	0		0
Available-for-sale, Estimated fair value	522		520
Tax Credit Investments [Member]
Held-to-maturity Securities, Amortized Cost	784		790
Held-to-maturity Securities, Gross unrealized gains	0		0
Held-to-maturity Securities, Gross unrealized losses	0		0
Held-to-maturity Securities, Estimated fair value	784		790
Us States and Political Subdivisions Debt Securities [Member]
Held-to-maturity Securities, Amortized Cost	1,022		1,023
Held-to-maturity Securities, Gross unrealized gains	41		50
Held-to-maturity Securities, Gross unrealized losses	0		0
Held-to-maturity Securities, Estimated fair value	$ 1,063		$ 1,073

[1] U.S. Agency MBS include private label MBS of approximately $13.6 million and $14.4 million at March 31, 2013 and December 31, 2012, respectively, which are supported by FHA/VA collateral.