Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net change in unrealized gains (losses), tax expense (benefit)	$ (2,223)	$ 1,813	$ (2,968)
Reclassification adjustment for gains, tax expense	5	704	900
Amortization of unrealized gain on securities reclassified to held-to-maturity, tax expense	136	241	248
Change in unfunded pension liability related to unrealized (loss) gain, prior service cost and transition obligation, tax (benefit) expense	(10)	(56)	103
Net change in cash flow hedge, tax (benefit)	$ (29)	$ (113)	$ (1,086)