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 (loss)	$ 140,153	$ 71,746	$ 227,552	$ 221,350
Change in debt securities available-for-sale:
Unrealized holding gains (losses) for the period	(285,798)	(3,595)	(1,019,782)	(112,927)
Reclassification for securities transferred to held-to-maturity	0	0	165,473	0
Reclassification adjustment for securities (gains) losses realized in income	172	(1,207)	(85)	(3,892)
Income tax effect	68,356	627	202,999	26,404
Unrealized gains (losses) on available-for-sale securities	(217,270)	(4,175)	(651,395)	(90,415)
Change in securities held-to-maturity:
Adjustment for securities transferred from available-for-sale	0	0	(165,473)	0
Amortization of unrealized losses on securities transferred     from available-for-sale	6,772	0	10,774	0
Income tax effect	(1,651)	0	37,621	0
Changes from securities held-to-maturity	5,121	0	(117,078)	0
Change in cash flow hedges:
Net unrealized derivative gains (losses) on cash flow hedges	(36,755)	(164)	(49,679)	2,612
Reclassification adjustment for (gains) losses realized in net income	749	(1,578)	(139)	(3,483)
Income tax effect	8,846	428	12,240	214
Changes from cash flow hedges	(27,160)	(1,314)	(37,578)	(657)
Change in defined benefit pension plans:
Amortization of net (gains) losses recognized in income	(11)	49	(32)	147
Income tax effect	3	(12)	8	(36)
Changes from defined benefit pension plans	(8)	37	(24)	111
Other comprehensive income (loss), net of tax	(239,317)	(5,452)	(806,075)	(90,961)
Comprehensive income (loss)	$ (99,164)	$ 66,294	$ (578,523)	$ 130,389