Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 18,680	$ 29,893	$ 72,664	$ 74,457
Unrealized gains (losses) on securities available for sale:
Unrealized holding gains (losses) arising during the period, pretax	78,550	(81,515)	68,021	(77,597)
Tax (expense) benefit	(18,184)	18,871	(15,747)	18,719
Reclassification to realized losses	0	0	1,161	0
Tax expense	0	0	(269)	0
Postretirement Plans:
Amortization of unrecognized net actuarial losses	25	44	75	132
Tax benefit	(6)	(10)	(17)	(31)
Other comprehensive income (loss)	60,385	(62,610)	53,224	(58,777)
Comprehensive income (loss)	$ 79,065	$ (32,717)	$ 125,888	$ 15,680