CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 71,289	$ 73,395	$ 60,352
Unrealized gains and losses:
Unrealized holding gains (losses) on available-for-sale securities arising during the period	7,005	11,286	(6,444)
Tax effect	(1,847)	(2,923)	1,638
Net of tax	5,158	8,363	(4,806)
Reclassification adjustment for realized (gains) losses included in net income	(29)	280
Tax effect	6	(79)
Net of tax	(23)	201
Unrealized (losses) gains on cash flow hedges	(3,423)	(755)	825
Tax effect	962	213	(228)
Net of tax	(2,461)	(542)	597
Reclassification adjustment for losses (gains) arising during this period	1,577	(677)	(464)
Tax effect	(443)	190	130
Net of tax	1,134	(487)	(334)
Unrealized pension plan (losses) gains:
Unrealized pension plan (losses) gains before reclassifications	(112)	(209)	236
Tax effect	31	59	(67)
Net of tax	(81)	(150)	169
Reclassification adjustment for realized losses included in net income	301	358	359
Tax effect	(84)	(101)	(101)
Net of tax	217	257	258
Total other comprehensive income (loss)	3,944	7,642	(4,116)
Total comprehensive income	$ 75,233	$ 81,037	$ 56,236