Consolidated Statements of Changes in Stockholders’ Equity (USD $) In Thousands	Purchase Of Common Shares Outstanding [Member] Treasury Stock [Member]	Restricted Stock Awards Repurchased To Satisfy Tax Obligations [Member] Treasury Stock [Member]	Shares Purchased To Fund Options Exercised [Member] Treasury Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Unearned Compensation [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Comprehensive Income [Member]	Total
Balance at Dec. 31, 2008				$ 1	$ 216	$ 150,662		$ (1,300)	$ 172,216	$ (20,303)
Value of shares purchased for the Treasury		(232)	(251)
Amortization of prior service costs (credit), net of taxes										26	26
OTTI charges included in income											3,278
Amortization of net actuarial losses, net of taxes										168	168
Unrecognized actuarial (losses) gains, net of taxes										203	203
Unrecognized prior service credit, net of taxes										641	641
Change in net unrealized gains on securities available for sale, net of taxes of approximately ($7,706), ($1,810) and ($8,231) for the years ended December 31, 2011, 2010 and 2009, respectively										10,187	10,187
Comprehensive income											39,285
Reclassification adjustment for losses (gains) included in net income, net of taxes										2,499	(779)
Net income									25,561		25,561	25,561
Amortization of preferred stock issuance costs, net						109
Value of stock options exercised					1	669	268		(52)
Stock-based compensation activity, net						340
Stock-based income tax (provision) benefit						(184)
Value of shares issued upon vesting of restricted stock unit awards					1	1,513	179
Cash dividends declared and paid on common shares ($0.52 per share for each of the years ended December 31, 2011, 2010 and 2009, respectively)									(11,985)
Cash dividends declared and paid on preferred shares (5.00% cumulative preferred dividends for the year ended December 31, 2009)									(3,004)
Amortization of preferred stock issuance costs including deemed dividend upon redemption of preferred shares									(1,555)
Value of shares issued					93	101,444
Preferred shares redeemed (70,000 preferred shares for the year ended December 31, 2009)				(1)		(69,597)
Value of release of shares from Employee Benefit Trust						886		725
Total Stockholders' Equity					311	185,842	(36)	(575)	181,181	(6,579)		360,144
Balance at Dec. 31, 2009					311	185,842	(36)	(575)	181,181	(6,579)		360,144
Value of shares purchased for the Treasury		(347)	(370)
Amortization of prior service costs (credit), net of taxes										(25)	(25)
OTTI charges included in income											1,145
Amortization of net actuarial losses, net of taxes										175	175
Unrecognized actuarial (losses) gains, net of taxes										(715)	(715)
Change in net unrealized gains on securities available for sale, net of taxes of approximately ($7,706), ($1,810) and ($8,231) for the years ended December 31, 2011, 2010 and 2009, respectively										2,249	2,249
Comprehensive income											41,670
Reclassification adjustment for losses (gains) included in net income, net of taxes										1,151	6
Net income									38,835		38,835	38,835
Value of stock options exercised					1	446	515		(92)
Stock-based compensation activity, net						487
Stock-based income tax (provision) benefit						12
Value of shares issued upon vesting of restricted stock unit awards					1	1,394	238		(8)
Cash dividends declared and paid on common shares ($0.52 per share for each of the years ended December 31, 2011, 2010 and 2009, respectively)									(15,788)
Value of release of shares from Employee Benefit Trust						1,167		575
Total Stockholders' Equity					313	189,348			204,128	(3,744)		390,045
Balance at Dec. 31, 2010					313	189,348			204,128	(3,744)		390,045
Value of shares purchased for the Treasury	(7,316)	(406)	(54)
Amortization of prior service costs (credit), net of taxes										(25)	(25)
OTTI charges included in income											886
Amortization of net actuarial losses, net of taxes										311	311
Unrecognized actuarial (losses) gains, net of taxes										(2,505)	(2,505)
Change in net unrealized gains on securities available for sale, net of taxes of approximately ($7,706), ($1,810) and ($8,231) for the years ended December 31, 2011, 2010 and 2009, respectively										9,890	9,890
Comprehensive income											43,905
Reclassification adjustment for losses (gains) included in net income, net of taxes										886
Net income									35,348		35,348	35,348
Value of stock options exercised					1	1,825	326		(50)
Stock-based compensation activity, net						954
Stock-based income tax (provision) benefit						292
Value of shares issued upon vesting of restricted stock unit awards					1	1,668	95		(6)
Cash dividends declared and paid on common shares ($0.52 per share for each of the years ended December 31, 2011, 2010 and 2009, respectively)									(15,910)
Value of release of shares from Employee Benefit Trust						1,541
Total Stockholders' Equity					315	195,628	(7,355)		223,510	4,813		416,911
Balance at Dec. 31, 2011					$ 315	$ 195,628	$ (7,355)		$ 223,510	$ 4,813		$ 416,911