Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Consolidated Statements of Comprehensive Income (Loss) (unaudited) [Abstract]
Net income	$ 38,973	$ 37,433	$ 115,874	$ 117,575
Securities available for sale:
Unrealized net holding (losses) gains arising during the period, gross	(78,653)	(7,426)	(214,543)	(21,329)
Tax effect	19,663	1,857	53,636	5,332
Unrealized net holding (losses) gains arising during the period, net	(58,990)	(5,569)	(160,907)	(15,997)
Amortization of unrealized net gains for the reclassification of available for sale securities to held to maturity, gross	125	149	393	434
Tax effect	(31)	(38)	(98)	(109)
Amortization of unrealized net gains for the reclassification of available for sale securities to held to maturity, net	94	111	295	325
Total securities available for sale, net	(58,896)	(5,458)	(160,612)	(15,672)
Cash flow hedges:
Reclassification of net unrealized losses on cash flow hedges to interest expense, gross	0	0	0	21
Tax effect	0	0	0	(5)
Reclassification of net unrealized losses on cash flow hedges to interest expense, net	0	0	0	16
Total cash flow hedges, net	0	0	0	16
Pension and other benefits:
Amortization of prior service cost and actuarial losses, gross	185	344	557	996
Tax effect	(47)	(86)	(140)	(249)
Amortization of prior service cost and actuarial losses, net	138	258	417	747
Total pension and other benefits, net	138	258	417	747
Total other comprehensive (loss)	(58,758)	(5,200)	(160,195)	(14,909)
Comprehensive (loss) income	$ (19,785)	$ 32,233	$ (44,321)	$ 102,666