CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss, Net of Tax [Member]	Unallocated Common Stock of ESOP [Member]	Unearned Restricted Stock Award Common Stock [Member]	Treasury Stock [Member]	Common Stock Held by BMP [Member]	Total
Balance at Dec. 31, 2008	$ 511	$ 213,917	$ 297,848	$ (11,111)	$ (3,933)	$ (1,790)	$ (210,471)	$ (8,007)
Increase (decrease) in stockholders' equity [Roll Forward]
Net income for the period			26,189						26,189
Shares issued in exercise of options	0	43
(Tax Cost) Excess tax benefit of stock benefit plans		(130)
Amortization of excess fair value over cost - ESOP stock and stock option expense		1,666
Amortization and reversal of net unrealized loss on securities transferred from available-for-sale to held-to-maturity, net of tax				1,975
Amortization of earned portion of ESOP stock					232
Amortization of earned portion of Restricted Stock Awards						1,030
BMP award distribution		0						0
BMP reclassification		0
Non-credit component of OTTI charge recognized during the period, net of tax				(1,648)
Reduction in non-credit component of OTTI during the peirod, net of tax				476
(Increase) Decrease in unrealized loss on available-for-sale securities during the period, net of deferred benefit (taxes)				5,241
Unrecognized (loss) gain of pension and other postretirement obligations, net of deferred benefit (tax)				1,240
Release from treasury stock for restricted stock award shares and return of shares to treasury for forfeited shares		(842)				(1,745)	2,587
Cash dividends declared and paid			(18,498)
Cumulative effect adjustment for the adoption of new accounting pronouncements			1,248	(1,255)
Balance at Dec. 31, 2009	511	214,654	306,787	(5,082)	(3,701)	(2,505)	(207,884)	(8,007)
Increase (decrease) in stockholders' equity [Roll Forward]
Net income for the period			41,389						41,389
Shares issued in exercise of options	1	1,011
(Tax Cost) Excess tax benefit of stock benefit plans		112
Amortization of excess fair value over cost - ESOP stock and stock option expense		1,688
Amortization and reversal of net unrealized loss on securities transferred from available-for-sale to held-to-maturity, net of tax				101
Amortization of earned portion of ESOP stock					231
Amortization of earned portion of Restricted Stock Awards						1,300
BMP award distribution		(28)						28
BMP reclassification		8,007	132
Non-credit component of OTTI charge recognized during the period, net of tax				(156)
Reduction in non-credit component of OTTI during the peirod, net of tax				1,374
(Increase) Decrease in unrealized loss on available-for-sale securities during the period, net of deferred benefit (taxes)				(1,042)
Unrecognized (loss) gain of pension and other postretirement obligations, net of deferred benefit (tax)				(1,547)
Release from treasury stock for restricted stock award shares and return of shares to treasury for forfeited shares		141				(1,479)	1,338
Cash dividends declared and paid			(18,640)
Cumulative effect adjustment for the adoption of new accounting pronouncements				0
Balance at Dec. 31, 2010	512	225,585	329,668	(6,352)	(3,470)	(2,684)	(206,546)	(7,979)	328,734
Increase (decrease) in stockholders' equity [Roll Forward]
Net income for the period			47,309						47,309
Shares issued in exercise of options	4	3,665
(Tax Cost) Excess tax benefit of stock benefit plans		431
Amortization of excess fair value over cost - ESOP stock and stock option expense		1,337
Amortization and reversal of net unrealized loss on securities transferred from available-for-sale to held-to-maturity, net of tax				245
Amortization of earned portion of ESOP stock					231
Amortization of earned portion of Restricted Stock Awards						1,578
BMP award distribution		0						(676)
BMP reclassification		0
Non-credit component of OTTI charge recognized during the period, net of tax				(14)
Reduction in non-credit component of OTTI during the peirod, net of tax				714
(Increase) Decrease in unrealized loss on available-for-sale securities during the period, net of deferred benefit (taxes)				(738)
Unrecognized (loss) gain of pension and other postretirement obligations, net of deferred benefit (tax)				(3,564)
Release from treasury stock for restricted stock award shares and return of shares to treasury for forfeited shares		503				(1,931)	2,104
Cash dividends declared and paid			(18,898)
Cumulative effect adjustment for the adoption of new accounting pronouncements				0
Balance at Dec. 31, 2011	$ 516	$ 231,521	$ 358,079	$ (9,709)	$ (3,239)	$ (3,037)	$ (204,442)	$ (8,655)	$ 361,034