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
Statement of Comprehensive Income [Abstract]
Net income per consolidated statements of income	$ 42,455	$ 21,200	$ 105,950	$ 121,143
Net unrealized gains (losses) on available for sale securities and transferred securities:
Net unrealized holding gains (losses) arising during the period	(85,737)	(9,407)	(235,887)	(20,798)
Change in net unrealized holding loss on securities transferred to held to maturity	1,350	477	(23,588)	1,562
Reclassification adjustments for changes realized in net income:
Net change in prior service costs	21	21	62	63
Recognized net loss due to lump sum settlement		137		137
Change in net actuarial loss	221	333	686	1,007
Change in the accumulated gain (loss) on effective cash flow hedge derivatives	14,643		14,643
Reclassification adjustment for (gain) loss realized in net income	(482)		(482)
Other comprehensive income (loss), net of tax	(99,270)	(8,439)	(273,852)	(18,029)
Comprehensive income (loss)	$ (56,815)	$ 12,761	$ (167,902)	$ 103,114