Condensed Financial Information (parent company only) - Statement of Cash Flows (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Net Income	$ 45,122,000	$ 25,252,000	$ 6,909,000
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Share-based Compensation	1,492,000	1,315,000	1,750,000
Tax Benefit From Share Based Compensation			(50,000)
Net Change In [Abstract]
Net cash provided by operating activities	70,269,000	85,484,000	81,051,000
Cash Flows from Investing Activities:
Net cash provided by (used in) investing activities	11,886,000	(28,163,000)	109,853,000
Cash Flows from Financing Activities:
Borrowings	138,127,000	306,535,000	2,382,000
Repayment of Borrowings	(271,005,000)	(252,509,000)	(65,247,000)
Preferred stock redemption under Capital Purchase Program		(69,600,000)
Preferred stock issued under Small Business Lending Fund		90,783,000
Repurchase of Common Stock Warrant under Capital Purchase Program		(368,000)
Stock Issued Under Employee Benefit Plans	449,000	669,000	582,000
Stock Issued Under Dividend Reinvestment and Stock Purchase Plan	202,000	89,000	91,000
Cash receipts of stock options exercised	78,000
Tax Benefit from Share Based Compensation			(50,000)
Stock redeemed	(235,000)	(126,000)	(76,000)
Net cash used in financing activities	(54,007,000)	(42,316,000)	(311,744,000)
Net Change in Cash and Cash Equivalents	28,148,000	15,005,000	(120,840,000)
Cash and Cash Equivalents, January 1	73,312,000	58,307,000	179,147,000
Cash and Cash Equivalents, December 31	101,460,000	73,312,000	58,307,000
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Net Income	45,122,000	25,252,000	6,909,000
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Share-based Compensation	632,000	524,000	1,750,000
Tax Benefit From Share Based Compensation			(50,000)
Ditributions in Excess of (Equity in Undistributed) Income of Subsidiaries	(21,319,000)	(29,234,000)	(16,003,000)
Net Change In [Abstract]
Other Assets	1,902,000	5,747,000	3,309,000
Other Liabilities	1,122,000	1,091,000	(744,000)
Investment in Subsidiaries - Operating Activities	(1,755,000)	(6,593,000)	(20,000)
Net cash provided by operating activities	25,704,000	(3,213,000)	(4,749,000)
Cash Flows from Investing Activities:
Investing Activities - Investment in Subsidiaries	(126,000)	704,000	(12,500,000)
Net cash provided by (used in) investing activities	(126,000)	704,000	(12,500,000)
Cash Flows from Financing Activities:
Cash Dividends	(7,442,000)	(4,729,000)	(5,920,000)
Repayment of Borrowings	(4,124,000)	(46,400,000)
Preferred stock redemption under Capital Purchase Program		(69,600,000)
Preferred stock issued under Small Business Lending Fund		90,783,000
Repurchase of Common Stock Warrant under Capital Purchase Program		(368,000)
Common Stock Issued		21,165,000	24,150,000
Stock Issued Under Employee Benefit Plans	449,000	669,000	582,000
Stock Issued Under Dividend Reinvestment and Stock Purchase Plan	202,000	89,000	91,000
Cash receipts of stock options exercised	78,000
Tax Benefit from Share Based Compensation			(50,000)
Stock redeemed	(235,000)	(126,000)	(76,000)
Other		298,000	198,000
Net cash used in financing activities	(11,072,000)	(8,219,000)	18,975,000
Net Change in Cash and Cash Equivalents	14,506,000	(10,728,000)	1,726,000
Cash and Cash Equivalents, January 1	20,654,000	31,382,000	29,656,000
Cash and Cash Equivalents, December 31	$ 35,160,000	$ 20,654,000	$ 31,382,000