Consolidated Statements of Cash Flows (unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash Flows From Operating Activities
Net income	$ 449,512	$ 227,552
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	28,162	26,893
Amortization of other intangible assets	18,286	19,070
Amortization of tax credit investments	8,167	5,703
Net premium amortization on investment securities	8,673	14,625
Accretion income related to acquired loans	(17,484)	(63,472)
Share-based compensation expense	22,903	21,582
Provision for credit losses	47,292	133,391
Debt securities (gains) losses, net	5,440	(85)
Net (gains) losses on sales of loans and other assets	(727)	(5,911)
Increase in cash surrender value of company-owned life insurance	(11,624)	(11,456)
Residential real estate loans originated for sale	(366,340)	(490,288)
Proceeds from sales of residential real estate loans	366,485	531,121
(Increase) decrease in interest receivable	(18,982)	(29,088)
(Increase) decrease in other assets	(56,116)	36,049
Increase (decrease) in accrued expenses and other liabilities	(40,132)	271,625
Net cash flows provided by (used in) operating activities	443,515	687,311
Cash Flows From Investing Activities
Cash received from merger, net	0	1,912,629
Purchases of investment securities available-for-sale	(626,820)	(1,367,896)
Purchases of investment securities held-to-maturity	(1,941)	(156,378)
Purchases of Federal Home Loan Bank/Federal Reserve Bank stock	(99,158)	(115,488)
Purchases of equity securities	(20,862)	(5,843)
Proceeds from maturities, prepayments, and calls of investment securities available-for-sale	614,782	1,117,620
Proceeds from sales of investment securities available-for-sale	54,056	13,371
Proceeds from maturities, prepayments, and calls of investment securities held-to-maturity	76,276	61,172
Proceeds from sales of Federal Home Loan Bank/Federal Reserve Bank stock	47,738	108,697
Proceeds from sales of equity securities	2,610	52,034
Loan originations and payments, net	(2,269,544)	(2,481,620)
Proceeds from sales of commercial loans	679,952	0
Proceeds from company-owned life insurance death benefits	5,865	8,716
Proceeds from sales of premises and equipment and other assets	3,513	3,202
Purchases of premises and equipment and other assets	(28,074)	(28,739)
Net cash flows provided by (used in) investing activities	(1,561,607)	(878,523)
Net increase (decrease) in:
Deposits	2,251,846	235,064
Federal funds purchased and interbank borrowings	(580,571)	300,755
Securities sold under agreements to repurchase	(153,743)	(89,416)
Other borrowings	114,251	152,324
Payments for maturities of Federal Home Loan Bank advances	(1,850,150)	(1,674,875)
Proceeds from Federal Home Loan Bank advances	2,450,000	1,450,000
Cash dividends paid	(135,054)	(132,674)
Common stock repurchased	(44,266)	(70,931)
Common stock issued	797	557
Net cash flows provided by (used in) financing activities	2,053,110	170,804
Net increase (decrease) in cash and cash equivalents	935,018	(20,408)
Cash and cash equivalents at beginning of period	728,412	822,019
Cash and cash equivalents at end of period	1,663,430	801,611
Supplemental cash flow information:
Total interest paid	450,939	62,207
Total income taxes paid (net of refunds)	158,478	14,759
Issuance of common stock	0	2,446,312
Investment securities purchased but not settled	0	3,858
Securities transferred from available-for-sale to held-to-maturity	0	2,986,736
Operating lease right-of-use assets obtained in exchange for lease obligations	7,899	17,376
Finance lease right-of-use assets obtained in exchange for lease obligations	10,019	629
Preferred Stock
Supplemental cash flow information:
Issuance of common stock	$ 0	$ 243,870