Shareholders' Equity and Regulatory Capital Reconciliation of Bank Shareholders' Equity to Bank Regulatory Capital (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of Bank Shareholders' Equity to Bank's Regulatory Capital [Line Items]
Disallowed deferred tax asset	$ 8,975	$ 8,638
Adjustment for unrealized gains on certain available-for-sale securities	(2,112)	1,926
Total adjusted assets for Tangible and Tier 1 (Core) capital purposes	1,100,000
Total risk-weighted assets for risk-based capital purposes	775,200
Tangible [Member]
Reconciliation of Bank Shareholders' Equity to Bank's Regulatory Capital [Line Items]
Shareholders' equity of the Bank	111,201
Disallowed deferred tax asset	(8,975)
Adjustment for unrealized gains on certain available-for-sale securities	(2,112)
Other	(835)
General allowance for loan losses	0
Regulatory capital of the Bank	99,279
Total adjusted assets for Tangible and Tier 1 (Core) capital purposes	1,126,370
Core [Member]
Reconciliation of Bank Shareholders' Equity to Bank's Regulatory Capital [Line Items]
Shareholders' equity of the Bank	111,201
Disallowed deferred tax asset	(8,975)
Adjustment for unrealized gains on certain available-for-sale securities	(2,112)
Other	(835)
General allowance for loan losses	0
Regulatory capital of the Bank	99,279
Total adjusted assets for Tangible and Tier 1 (Core) capital purposes	1,126,370
Risk-Based [Member]
Reconciliation of Bank Shareholders' Equity to Bank's Regulatory Capital [Line Items]
Shareholders' equity of the Bank	111,201
Disallowed deferred tax asset	(8,975)
Adjustment for unrealized gains on certain available-for-sale securities	(2,112)
Other	(835)
General allowance for loan losses	9,721
Regulatory capital of the Bank	109,000
Total risk-weighted assets for risk-based capital purposes	$ 775,198