CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Unrealized holding gain (loss) on securities available for sale arising during the period, tax	$ (4,893)	$ (20)	$ 8,001
Unrealized gain (loss) on securities available for sale for which a portion of an other than temporary impairment has been recognized in income, tax	0	0	(995)
Unrealized gain (loss) on cash flow hedges arising during the period, tax	(128)	(588)	(1,397)
Reclassification adjustment for net losses (gains) included in net income, tax	749	435	760
Defined benefit pension plans, tax	$ 809	$ (1,187)	$ 4,264