Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Cash Flows From Operating Activities: [Abstract]
Net income	$ 119,771	$ 83,694
Adjustments to reconcile net income to net cash used in operating activities: [Abstract]
Provision for credit losses	0	8,000
Change in fair value of mortgage servicing rights due to market assumption changes	7,240	(10,977)
Change in the fair value of mortgage servicing rights due to principal payments	5,918	5,447
Net unrealized (gains) losses from derivative contracts	49,111	(67,516)
Share-based compensation	5,870	4,548
Depreciation and amortization	27,284	26,392
Net amortization of discounts and premiums	(12,622)	(8,923)
Net losses (gains) on financial instruments and other losses (gains), net	725	40,792
Net loss (gain) on mortgage loans held for sale	(2,450)	(1,644)
Mortgage loans originated for sale	(159,816)	(139,176)
Proceeds from sale of mortgage loans held for sale	160,342	124,187
Capitalized mortgage servicing rights	(2,509)	(2,516)
Change in trading and fair value option securities	(952,339)	(246,669)
Change in receivables	4,337	284,991
Change in other assets	5,115	23,196
Change in other liabilities	764,282	55,394
Net cash provided by (used in) operating activities	20,259	179,220
Cash Flows From Investing Activities: [Abstract]
Proceeds from maturities or redemptions of investment securities	63,116	57,642
Proceeds from maturities or redemptions of available-for-sale securities	553,866	417,103
Purchases of available-for-sale securities	(619,755)	(1,582,902)
Proceeds from sales of available-for-sale securities	0	735,994
Change in amount receivable on unsettled available-for-sale securities transactions	(34,926)	48,195
Loans originated, net of principal collected	443,789	(271,674)
Net proceeds from derivative asset contracts	(19,041)	(5,533)
Net change in restricted equity securities	90,986	40,550
Proceeds from disposition of assets	4,918	4,624
Purchases of assets	(48,223)	(40,911)
Net cash provided by (used in) investing activities	434,730	(596,912)
Cash Flows From Financing Activities: [Abstract]
Net change in demand deposits, transaction deposits and savings accounts	159,425	1,008,959
Net change in time deposits	(68,982)	354,887
Net change in other borrowed funds	(339,662)	(839,632)
Net payments on derivative liability contracts	19,835	(1,613)
Net change in derivative margin accounts	(290,126)	(116,706)
Change in amount due on unsettled available-for-sale securities transactions	89,399	(89,807)
Issuance of common and treasury stock, net	(5,422)	(3,192)
Repurchase of common stock	(994)	(52,153)
Dividends paid	(36,468)	(35,569)
Net cash provided by (used in) financing activities	(472,995)	225,174
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Total	(18,006)	(192,518)
Cash and cash equivalents at beginning of period	1,434,701	1,348,265
Cash and cash equivalents at end of period	1,416,695	1,155,747
Supplemental Cash Flow Information: [Abstract]
Cash paid for interest	302,067	348,394
Cash paid for taxes	1,470	1,270
Net loans and bank premises transferred to repossessed real estate and other assets	0	77
Residential mortgage loans guaranteed by U.S. government agencies that became eligible for repurchase during the period	19,736	1,501
Conveyance of other real estate owned guaranteed by U.S. government agencies	755	1,371
Right-of-use assets obtained in exchange for operating lease liabilities	$ 0	$ 10,562