Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)		Dec. 31, 2022 USD ($)		Dec. 31, 2021 USD ($)
Cash Flows from Operating Activities
Net income	$ 182,956		$ 366,122		$ 350,994
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	83,021		32,998		(88,011)
Depreciation and amortization	46,989		45,088		46,508
Change in MSRs valuation(a)	(10,660)		(22,264)		(16,186)
Amortization of other intangible assets	8,811		8,811		8,844
Amortization and accretion on earning assets, funding, and other, net	38,508		14,980		15,088
Net amortization of tax credit investments	34,246		34,684		34,070
Losses on sales of investment securities, net	64,864		1,674		16
Asset (gains), net	(454)	[1]	(1,338)	[1]	(11,009)	[1]
(Gains) on sale of branches, net	0		0		(1,038)
(Gain) loss on mortgage banking activities, net	(2,919)		(3,654)		39,106
Gain (Loss) on Sale of Mortgage Loans	136,239		0		0
Mortgage loans originated and acquired for sale	(395,834)		(600,114)		(1,749,556)
Proceeds from sales of mortgage loans held for sale	367,707		715,035		1,774,791
(Increase) decrease in interest receivable	(25,120)		(63,921)		9,735
(Increase) decrease in net tax position	(77,849)		40,611		(6,177)
(Decrease) increase in interest payable	78,539		12,608		(10,675)
(Decrease) increase in expense payable	16,329		(5,297)		24,645
(Decrease) increase in net derivative position	(93,916)		269,774		120,418
Net change in other assets and other liabilities	(14,556)		(6,539)		66,201
Net cash provided by operating activities	442,740		846,566		529,551
Cash flows from investing activities
Net decrease (increase) in loans	(1,546,391)		(4,579,431)		198,631
Purchases of:
AFS securities	(1,936,635)		(959,977)		(2,744,244)
HTM securities	(38,677)		(301,052)		(622,485)
FHLB and Federal Reserve Bank stocks and equity securities	(146,308)		(128,620)		(2,760)
Proceeds from:
Proceeds from Sale of Debt Securities, Available-for-sale	715,066		110,177		158,708
Sales of FHLB and Federal Reserve Bank stocks and equity securities	202,451		528		35
Prepayments, calls, and maturities of AFS securities	397,675		494,197		1,216,657
Prepayments, calls, and maturities of HTM securities	143,001		196,605		299,761
Sales, prepayments, calls and maturities of other assets	21,267		33,795		29,833
Proceeds from Sale of Mortgage Portfolio	844,362		0		0
Premises, equipment, and software, net of disposals	(61,813)		(62,711)		(52,281)
Net change in tax credit and alternative investments	(30,255)		(58,323)		(68,455)
Net cash (used in) investing activities	(1,436,257)		(5,254,811)		(1,584,186)
Cash flows from financing activities
Net increase in deposits	3,809,948		1,169,983		2,015,423
Net decrease in deposits due to branch sales	0		0		(31,083)
Net increase (decrease) in short-term funding	(279,157)		251,674		101,946
Net increase (decrease) in short-term FHLB advances	(2,385,000)		3,125,000		0
Repayment of long-term FHLB advances	(599)		(413,558)		(18,437)
Proceeds from long-term FHLB advances	1,369		1,775		6,950
Proceeds from Issuance of Long-term Debt	292,740		0		0
(Repayment) proceeds of finance lease principal	(86)		306		(965)
Repayment of senior notes	0		0		(300,000)
Proceeds from issuance of common stock for stock-based compensation plans	4,297		11,061		25,702
Redemption of preferred shares	0		0		(164,458)
Cash dividends on common stock	(129,534)		(123,137)		(116,061)
Cash dividends on preferred stock	(11,500)		(11,500)		(17,111)
payments for repurchase of common stock for tax withholding	0		938		0
Net cash provided by financing activities	1,295,885		4,004,185		1,364,102
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	302,368		(404,060)		309,467
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Beginning Balance	621,455		1,025,515		716,048
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance	923,823		621,455		1,025,515
Restricted Cash	0		0		0
Supplemental disclosures of cash flow information
Cash paid for interest	838,828		174,675		81,604
Cash paid for income and franchise taxes	69,417		18,395		57,728
Loans and bank premises transferred to OREO	9,841		5,591		35,553
Capitalized mortgage servicing rights	3,564		7,279		16,151
Loans transferred into held for sale from portfolio, net	1,058,305		18		6,010
Transfer of AFS securities to HTM securities	0		1,621,990		0
Unsettled trades to purchase securities	0		0		4,459
Write-up of equity securities without readily determinable fair values	5,785		5,690		0
Fair value adjustment on cash flow hedges	(13,254)		3,626		0
Other Assets [Member]
Supplemental disclosures of cash flow information
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(1,757)		1,405		482
Liability
Supplemental disclosures of cash flow information
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge	(5,084)		16,163		0
Fair Value, Measurements, Recurring [Member]
Supplemental disclosures of cash flow information
Fair value adjustment on cash flow hedges	(280)		3,360		0
ABRC [Member]
Proceeds from:
Net cash received in business segment sale	0		0		2,415
Performance/Service Based RSAs, RSA, [Member]
Cash flows from financing activities
Payments for Repurchase of Common Stock	6,593		6,480		4,847
Board Authorized Purchase Program [Member]
Cash flows from financing activities
Payments for Repurchase of Common Stock	$ 0		$ 0		$ 132,955

[1] Includes the deposit premium on the sale of branches net of miscellaneous costs to sell. See Note 2 Acquisitions and Dispositions for additional details on the branch sales.