Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income	$ 16,459	$ 13,446	$ 12,149
Other comprehensive income (loss):
Unrealized holding gain (loss) on available for sale securities arising during the period on securities held at end of period, net of tax of $4,703, $(6,996), and $543, respectively	8,734	(12,992)	1,009
Reclassification adjustment for prior period unrealized (gain) loss previously reported in other comprehensive income recognized during current period, net of tax of $(34), $23, and $330, respectively	63	(42)	(612)
Change in unfunded portion of postretirement benefit obligations, net of tax of $(382), $1,589, and $(92), respectively	(710)	2,953	(171)
Other comprehensive income (loss)	8,087	(10,081)	226
Comprehensive income	$ 24,546	$ 3,365	$ 12,375