Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash Flows From Operating Activities: [Abstract]
Net income	$ 195,310	$ 311,415
Adjustments to reconcile net income to net cash used in operating activities: [Abstract]
Provision for credit losses	0	(60,000)
Change in fair value of mortgage servicing rights due to market assumption changes	(66,595)	(20,833)
Change in the fair value of mortgage servicing rights due to principal payments	15,317	22,143
Net unrealized (gains) losses from derivative contracts	(47,004)	40,581
Share-based compensation	2,845	4,090
Depreciation and amortization	52,971	50,185
Net amortization of discounts and premiums	6,417	9,607
Net losses (gains) on financial instruments and other losses (gains), net	7,157	(28,463)
Net gain on mortgage loans held for sale	(6,521)	(41,611)
Mortgage loans originated for sale	(779,103)	(1,597,946)
Proceeds from sale of mortgage loans held for sale	793,223	1,684,711
Capitalized mortgage servicing rights	(10,969)	(17,767)
Change in trading and fair value option securities	6,283,157	(936,759)
Change in receivables	62,029	60,286
Change in other assets	(17,067)	(16)
Change in other liabilities	(55,875)	32,611
Net cash provided by (used in) operating activities	6,435,292	(487,766)
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	26,730	23,870
Proceeds from maturities or redemptions of available for sale securities	1,365,103	1,782,153
Purchases of available for sale securities	(1,919,632)	(2,602,658)
Proceeds from sales of available for sale securities	211,301	394,146
Change in amount receivable on unsettled available for sale securities transactions	(19,793)	(19,509)
Loans originated, net of principal collected	(1,070,725)	1,621,847
Net payments on derivative asset contracts	151,559	(232,861)
Net change in restricted equity securities	(12,017)
Net change in restricted equity securities		36,506
Proceeds from disposition of assets	11,559	70,443
Purchases of assets	(119,302)	(95,077)
Net cash provided by (used in) investing activities	(1,375,217)	978,860
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	(2,288,412)	1,357,832
Net change in time deposits	(334,729)	(61,779)
Net change in other borrowed funds	(1,671,503)	(1,324,500)
Net proceeds on derivative liability contracts	(131,361)	234,074
Net change in derivative margin accounts	(1,417,338)	(649,717)
Change in amount due on unsettled available for sale securities transactions	132,781	172,638
Issuance of common and treasury stock, net	(4,907)	(4,866)
Repurchase of common stock	(72,478)	(63,868)
Dividends paid	(72,188)	(72,026)
Net cash provided by (used in) financing activities	(5,860,135)	(412,212)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	(800,060)	78,882
Cash and cash equivalents at beginning of period	2,837,410	1,180,573
Cash and cash equivalents at end of period	2,037,350	1,259,455
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	35,094	32,161
Cash paid for taxes	66,862	96,994
Net loans and bank premises transferred to repossessed real estate and other assets	4,080	289
Transfer of available for sale securities to investment securities	2,454,273	0
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	20,836	55,558
Conveyance of other real estate owned guaranteed by U.S. government agencies	3,478	3,009
Right-of-use assets obtained in exchange for operating lease liabilities	$ 15,506	$ 6,192