Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Consolidated Statements of Comprehensive Income (Unaudited) [Abstract]
Net income	$ 14,083	$ 13,313
Net unrealized holding (loss) gain on securities available for sale	(6,018)	10,732
Reclassification adjustments for net gain recognized in income	0	(1,155)
Tax effect	1,557	(2,487)
Net unrealized (loss) gain on securities available for sale, net of tax	(4,461)	7,090
Amortization of net actuarial gain	(228)	(166)
Amortization of prior service credit	(52)	(49)
Tax effect	73	56
Amortization of net actuarial gain and prior service credit on pension and postretirement plans, net of tax	(207)	(159)
Other comprehensive income (loss), net of tax	(4,668)	6,931
Comprehensive income	$ 9,415	$ 20,244