Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Cash flows from operating activities
Net income	$ 115,573	$ 81,169	$ 87,154	$ 103,360	$ 196,742	$ 190,514
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	23,008		22,100		47,009	40,071
Depreciation and amortization					24,519	22,914
Change in MSRs valuation					(2,567)	(5,135)
Amortization of other intangible assets	2,203		2,203		4,405	4,405
Amortization and accretion on earning assets, funding, and other, net					20,405	16,509
Net amortization of tax credit investments					17,788	17,227
(Gains) on sales of investment securities, net					(3,857)	0
Asset losses, net	627		299		933	35
Loss on mortgage banking activities, net					882	1,389
Mortgage loans originated and acquired for sale					(274,358)	(168,395)
Proceeds from sales of mortgage loans held for sale					228,732	151,167
Changes in certain assets and liabilities:
(Increase) in interest receivable					(3,537)	(14,736)
Increase in interest payable					13,646	44,367
(Decrease) in expense payable					(15,042)	(40,882)
Increase (decrease) in net derivative position					10,523	(37,175)
Net change in other assets and other liabilities					1,772	(43,503)
Net cash provided by operating activities					267,996	178,771
Cash flows from investing activities
Net (increase) in loans					(378,926)	(1,054,924)
Purchases of:
AFS securities					(695,457)	(948,326)
HTM securities					0	(41,524)
FHLB and Federal Reserve Bank stocks and equity securities					(99,192)	(97,622)
Proceeds from:
Sales of AFS securities					9,472	0
Sale of FHLB and Federal Reserve Bank stocks and equity securities					139,110	115,975
Prepayments, calls, and maturities of AFS securities					328,990	172,680
Prepayments, calls, and maturities of HTM securities					62,894	62,212
Sales, prepayments, calls, and maturities of other assets					1,700	17,988
Premises, equipment, and software					(20,016)	(29,663)
Net change in tax credit and alternative investments					(3,667)	(14,116)
Net cash (used in) investing activities					(655,093)	(1,817,320)
Cash flows from financing activities
Net (decrease) increase in deposits					(755,009)	2,378,308
Net increase (decrease) in short-term funding					532,759	(264,684)
Net increase (decrease) in short-term FHLB advances					735,000	(685,000)
Repayment of long-term FHLB advances					(696)	(537)
Proceeds from long-term FHLB advances					2,656	115
Proceeds from issuance of long-term funding					0	292,740
(Repayment) of finance lease principal					(44)	(43)
Proceeds from issuance of common stock for stock-based compensation plans					4,436	1,859
Cash dividends on common stock					(67,034)	(64,009)
Cash dividends on preferred stock					(5,750)	(5,750)
Net cash provided by financing activities					422,369	1,646,755
Net increase in cash and cash equivalents					35,272	8,207
Cash and cash equivalents at beginning of period		923,823		621,455	923,823	621,455	$ 621,455
Cash and cash equivalents at end of period(a)	959,094		629,662		959,094	629,662	923,823
Supplemental disclosures of cash flow information
Cash paid for interest					525,006	347,202
Cash paid for income and franchise taxes					3,413	58,985
Loans and bank premises transferred to OREO					1,340	3,632
Capitalized mortgage servicing rights					2,490	1,322	$ 3,564
Loans transferred (from) held for sale (into) portfolio, net					(84,559)	(840)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(2,522)		(22,961)		(18,848)	(12,630)
Board Authorized Purchase Program [Member]
Cash flows from financing activities
Purchase of treasury stock, open market purchases					(18,289)	0
Other Assets [Member]
Supplemental disclosures of cash flow information
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge					2,113	(704)
Other Liabilities [Member]
Supplemental disclosures of cash flow information
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge					9,779	9,651
Performance/Service Based RSAs, RSA,
Cash flows from financing activities
Purchase of treasury stock, open market purchases					(5,660)	(6,246)
Retained Earnings [Member]
Cash flows from operating activities
Net income	$ 115,573	$ 81,169	$ 87,154	$ 103,360	$ 196,742	$ 190,514