Consolidated Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Comprehensive Income [Abstract]
Net income	$ 4,454	$ 3,702	$ 13,038	$ 10,304
Other comprehensive income (loss), net of tax:
Unrealized gains and losses on securities available-for-sale: Unrealized holding gains arising during the period	6,223	225	12,132	4,862
Unrealized gains and losses on securities available-for-sale: Reclassification adjustment on OTTI losses included in income	96	44	227	197
Unrealized gains and losses on securities available-for-sale: Reclassification adjustment for net gains arising during the period	(651)	(869)	(1,743)	(2,031)
Unrealized gains and losses on securities available-for-sale: Unrealized holding losses / gains on securities transferred from available-for-sale to held-to-maturity securities		(31)		181
Unrealized gains and losses on securities available-for-sale: Amortization of unrealized holding gains on securities transferred from available-for-sale to held-to-maturity securities	(1)	(9)	3	(14)
Unrealized gains and losses on securities available-for-sale: Net unrealized gains (losses) on investment securities	5,667	(640)	10,619	3,195
Change in minimum pension liability				(85)
Total other comprehensive income (loss)	5,667	(640)	10,619	3,110
Total comprehensive income	$ 10,121	$ 3,062	$ 23,657	$ 13,414