Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 146,600	$ (27,586)
Change in debt securities available-for-sale:
Unrealized holding gains (losses) for the period	24,724	(429,470)
Reclassification for securities transferred to held-to-maturity	0	22,163
Reclassification adjustment for securities (gains) losses realized in income	5,216	(342)
Income tax effect	1,146	96,235
Unrealized gains (losses) on available-for-sale securities	31,086	(311,414)
Change in securities held-to-maturity:
Adjustment for securities transferred from available-for-sale	0	(22,163)
Amortization of unrealized losses on securities transferred     from available-for-sale	5,829	310
Income tax effect	(131)	5,126
Changes from securities held-to-maturity	5,698	(16,727)
Change in hedges:
Net unrealized derivative gains (losses) on hedges	47,849	(9,506)
Reclassification adjustment for (gains) losses realized in net income	7,292	(669)
Income tax effect	(13,720)	2,500
Changes from hedges	41,421	(7,675)
Change in defined benefit pension plans:
Amortization of net (gains) losses recognized in income	(188)	(11)
Income tax effect	47	3
Changes from defined benefit pension plans	(141)	(8)
Other comprehensive income (loss), net of tax	78,064	(335,824)
Comprehensive income (loss)	$ 224,664	$ (363,410)