CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale securities, taxes	$ 1,476	$ 2,940	$ 473
Change in nonqualified pension plan unrecognized net gain (loss) and unrecognized prior service cost, taxes	133	38	1
Net realized gain on sale of available-for-sale securities included in net income, taxes	$ 51	$ 418	$ 630