Consolidated Statements of Comprehensive Income (Loss) (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (27,586)	$ 86,818
Change in debt securities available-for-sale:
Unrealized holding gains (losses) for the period	(429,470)	(73,514)
Reclassification for securities transferred to held-to-maturity	22,163	0
Reclassification adjustment for securities (gains) losses realized in income	(342)	(1,993)
Income tax effect	96,235	16,667
Unrealized gains (losses) on available-for-sale securities	(311,414)	(58,840)
Change in securities held-to-maturity:
Adjustment for securities transferred from available-for-sale	(22,163)	0
Amortization of unrealized losses on securities transferred     from available-for-sale	310	0
Income tax effect	5,126	0
Changes from securities held-to-maturity	(16,727)	0
Change in cash flow hedges:
Net unrealized derivative gains (losses) on cash flow hedges	(9,506)	4,048
Reclassification adjustment for (gains) losses realized in net income	(669)	(149)
Income tax effect	2,500	(958)
Changes from cash flow hedges	(7,675)	2,941
Change in defined benefit pension plans:
Amortization of net (gains) losses recognized in income	(11)	49
Income tax effect	3	(12)
Changes from defined benefit pension plans	(8)	37
Other comprehensive income (loss), net of tax	(335,824)	(55,862)
Comprehensive income (loss)	$ (363,410)	$ 30,956