CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Dividends declared per share (in dollars per share)	$ 0.80	$ 0.72	$ 0.60
Adjustment for adoption of credit losses accounting standard	$ 179,935	$ 167,263	$ 168,331
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member		us-gaap:AccountingStandardsUpdate201409Member
Cumulative Effect, Period of Adoption, Adjustment
Adjustment for adoption of credit losses accounting standard		(214)	$ 0
Accounting Standards Update 2014-09
Tax effect of new accounting standard	$ (63)
Accounting Standards Update 2016-13
Tax effect of new accounting standard	(75)
Accumulated Other Comprehensive Income (Loss)
Defined benefit pension plans, tax expense (benefit)			314
Interest rate swap, tax expense			107
Interest rate swap, tax benefit	404	(272)
Adjustment for adoption of credit losses accounting standard	(4,423)	(1,526)	1,296
Accumulated Other Comprehensive Income (Loss) | Cumulative Effect, Period of Adoption, Adjustment
Adjustment for adoption of credit losses accounting standard			168
Retained Earnings
Adjustment for adoption of credit losses accounting standard	$ 388,645	350,545	237,308
Retained Earnings | Cumulative Effect, Period of Adoption, Adjustment
Adjustment for adoption of credit losses accounting standard		$ (214)	$ (168)