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]
Net change in unrealized gain (loss) on available-for-sale securities, tax effect	$ 1,212	$ 1,873	$ (4,275)
Net reclassification adjustmetn for gains included in net income, tax effect	18	1	158
Net change in unrealized gains (losses) on cash flow hedging derivatives, tax effect	343	825	2,431
Net reclassification adjustments for effective portion of cash flow hedges included in interest expense, tax effect	(709)	(593)	(600)
Net actuarial (loss) gain, tax effect	127	21	225
Reclassification of amortization of net unrecognized actuarial loss and of prior service cost included in net periodic cost, tax effect	$ (83)	$ (84)	$ (51)