Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Consolidated Statements of Comprehensive Income (Loss) (unaudited) [Abstract]
Net income	$ 30,072	$ 37,775	$ 63,730	$ 76,901
Securities available for sale:
Unrealized net holding (losses) arising during the period, gross	(26,783)	(44,860)	(11,058)	(135,890)
Tax effect	6,696	11,215	2,765	33,973
Unrealized net holding (losses) arising during the period, net	(20,087)	(33,645)	(8,293)	(101,917)
Reclassification adjustment for net losses in net income, gross	4,450	0	9,450	0
Tax effect	(1,113)	0	(2,363)	0
Reclassification adjustment for net losses in net income, net	3,337	0	7,087	0
Amortization of unrealized net gains for the reclassification of available for sale securities to held to maturity, gross	109	131	223	268
Tax effect	(28)	(32)	(56)	(67)
Amortization of unrealized net gains for the reclassification of available for sale securities to held to maturity, net	81	99	167	201
Total securities available for sale, net	(16,669)	(33,546)	(1,039)	(101,716)
Pension and other benefits:
Amortization of prior service cost and actuarial losses, gross	649	186	1,298	372
Tax effect	(162)	(46)	(325)	(93)
Amortization of prior service cost and actuarial losses, net	487	140	973	279
Total pension and other benefits, net	487	140	973	279
Total other comprehensive (loss)	(16,182)	(33,406)	(66)	(101,437)
Comprehensive income (loss)	$ 13,890	$ 4,369	$ 63,664	$ (24,536)