Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 6,345	$ 5,757	$ 12,319	$ 13,310
Securities available for sale:
Unrealized holding gains on securities	1,090	14,378	2,108	14,655
Non-credit related portion of other-than-temporary impairment on securities		(9,376)		(9,376)
Reclassification adjustment for (gains) losses realized in net income	(537)	159	(1,095)	152
Amortization of unrealized holding gains on securities transferred to the held to maturity category	(91)	(221)	(193)	(390)
Total securities available for sale	462	4,940	820	5,041
Derivative instruments:
Unrealized holding losses on derivative instruments	(1,027)		(1,138)
Reclassification adjustment for gains realized in net income	(94)	(94)	(188)	(187)
Totals derivative instruments	(1,121)	(94)	(1,326)	(187)
Defined benefit pension and post-retirement benefit plans:
Net (loss) gain arising during the period
Less amortization of net actuarial loss recognized in net periodic pension cost	66	66	132	137
Total defined benefit pension and post-retirement benefit plans	66	66	132	137
Other comprehensive (loss) income	(593)	4,912	(374)	4,991
Comprehensive income	$ 5,752	$ 10,669	$ 11,945	$ 18,301