Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash Flows From Operating Activities: [Abstract]
Net income	$ 62,452	$ 144,308
Adjustments to reconcile net income to net cash used in operating activities: [Abstract]
Provision for credit losses	0	(25,000)
Change in fair value of mortgage servicing rights due to market assumption changes	(49,110)	(33,874)
Change in the fair value of mortgage servicing rights due to principal payments	7,960	11,961
Net unrealized (gains) losses from derivative contracts	(31,298)	92,502
Share-based compensation	2,835	2,724
Depreciation and amortization	26,091	24,918
Net amortization of discounts and premiums	3,216	4,853
Net losses (gains) on financial instruments and other losses (gains), net	706	(10,587)
Net gain on mortgage loans held for sale	(1,056)	(19,045)
Mortgage loans originated for sale	(418,866)	(843,053)
Proceeds from sale of mortgage loans held for sale	446,742	836,209
Capitalized mortgage servicing rights	(5,215)	(9,830)
Change in trading and fair value option securities	4,104,453	(335,624)
Change in receivables	(88,559)	15,650
Change in other assets	(19,589)	(24,991)
Change in other liabilities	(107,508)	(49,998)
Net cash provided by (used in) operating activities	3,933,254	(218,877)
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	26,363	18,624
Proceeds from maturities or redemptions of available for sale securities	723,730	877,257
Purchases of available for sale securities	(1,161,606)	(1,451,909)
Proceeds from sales of available for sale securities	55,185	56,037
Change in amount receivable on unsettled available for sale securities transactions	(99,944)	(26,130)
Loans originated, net of principal collected	(460,128)	498,667
Net payments on derivative asset contracts	34,855	(7,016)
Net change in restricted equity securities	5,724	31,777
Proceeds from disposition of assets	9,708	43,739
Purchases of assets	(37,569)	(63,110)
Net cash provided by (used in) investing activities	(903,682)	(22,064)
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	(1,626,196)	1,671,518
Net change in time deposits	(189,912)	37,228
Proceeds from (Repayments of) Other Debt	(1,271,195)	(1,078,174)
Net proceeds on derivative liability contracts	(30,779)	8,437
Net change in derivative margin accounts	(1,274,645)	2,995
Change in amount due on unsettled available for sale securities transactions	(17,198)	(101,311)
Issuance of common and treasury stock, net	(4,907)	(4,866)
Repurchase of common stock	(48,074)	(20,071)
Dividends paid	(36,295)	(36,192)
Net cash provided by (used in) financing activities	(4,499,201)	479,564
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	(1,469,629)	238,623
Cash and cash equivalents at beginning of period	2,837,410	1,180,573
Cash and cash equivalents at end of period	1,367,781	1,419,196
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	13,982	16,743
Cash paid for taxes	858	852
Net loans and bank premises transferred to repossessed real estate and other assets	64	147
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	12,568	36,496
Conveyance of other real estate owned guaranteed by U.S. government agencies	1,812	1,448
Right-of-use assets obtained in exchange for operating lease liabilities	$ 9,241	$ 1,191