Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net income	$ 20,016	$ 17,596	$ 7,026
Unrealized gains on securities:
Unrealized holding gains on available for sale securities arising during the year	4,878	244	2,101
Reclassification adjustment for gains included in net income	(1,006)	(1,382)	(2,145)
Pension liability adjustment—net actuarial losses	(8,438)	(2,006)	(1,940)
Reclassification adjustment for amortization of:
Prior service cost	21	35	36
Net actuarial losses	2,270	1,780	1,460
Other comprehensive loss	(2,275)	(1,329)	(488)
Comprehensive income	$ 17,741	$ 16,267	$ 6,538