Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net change in unrealized gains (losses), tax expense (benefit)	$ 13,179	$ (2,223)	$ 1,813
Reclassification adjustment for gains, tax expense	80	5	704
Amortization of unrealized gain on securities reclassified to held-to-maturity, tax expense	98	136	241
Change in unfunded pension liability related to unrealized (loss) gain, prior service cost and transition obligation, tax (benefit) expense	1,439	10	56
Net change in cash flow hedge, tax (benefit)	$ 593
Net change in cash flow hedge, tax (benefit)		$ (29)	$ (113)