Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Cash flows from operating activities:
Net income	$ 494,308	$ 496,049	$ 475,543
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	58,826	64,591	63,137
Provision (recovery) for credit losses	114,082	81,855	(165,273)
Deferred income taxes	1,950	123,540	67,850
Gains on sale of securities, net	(43)	(30)	(102)
Share-based compensation expense	35,861	35,638	25,721
Accretion of discount related to acquired loans	(20,801)	(36,411)	(29,658)
Extinguishment of debt cost - fair value marks			11,706
Losses on disposal of premises and equipment	66	2,876	856
Gains on sale of bank properties held for sale and repossessed real estate	(1,733)	(4,467)	(2,329)
Net amortization of premiums and discounts on investment securities	20,136	27,303	38,025
Bank properties held for sale and repossessed real estate write downs	1,571	273	2,067
Fair value adjustment for loans held for sale	(833)	6,052	6,920
Originations and purchases of loans held for sale	(881,017)	(1,411,770)	(3,045,145)
Proceeds from sales of loans held for sale	863,464	1,565,809	3,209,094
(Gains) losses on sales of loans held for sale	(3,535)	2,663	(72,124)
Increase in cash surrender value of BOLI	(25,141)	(23,058)	(18,221)
Net change in:
Accrued interest receivable	(19,806)	(32,829)	17,083
Prepaid assets	1,967	(3,090)	(1,250)
Operating leases	322	142	2,053
Bank owned life insurance	(1,595)	(1,290)	(202)
Trading securities	(57)	46,425	(35,154)
Derivative assets	38,077	207,682	399,157
Miscellaneous other assets	(6,259)	147	(79,312)
Accrued interest payable	50,590	2,609	(3,759)
Accrued income taxes	62,509	(17,218)	(53,843)
Derivative liabilities	(229,657)	741,583	(516,271)
Miscellaneous other liabilities	(6,495)	(144,181)	119,120
Net cash provided by operating activities	546,757	1,730,893	415,689
Cash flows from investing activities:
Proceeds from sales of investment securities available for sale	129,614	482,028	151,314
Proceeds from maturities and calls of investment securities held to maturity	190,825	230,003	104,958
Proceeds from maturities and calls of investment securities available for sale	590,758	575,877	805,342
Proceeds from sales and redemptions of other investment securities	214,375	13,226	1,533
Purchases of investment securities available for sale	(80,354)	(1,381,980)	(2,941,888)
Purchases of investment securities held to maturity		(1,099,691)	(975,266)
Purchases of other investment securities	(226,701)	(20,359)	(1,659)
Net (increase) decrease in loans	(2,234,274)	(3,855,268)	745,085
Net cash received from acquisitions			(39,929)
Net cash (paid in) received from acquisitions		250,115
Recoveries of loans previously charged off	15,782	19,173	13,800
Purchase of bank owned life insurance	(5,966)	(85,966)	(205,566)
Purchases of premises and equipment	(38,885)	(17,670)	(28,418)
Proceeds from redemption and payout of bank owned life insurance policies	5,956	3,267	307
Proceeds from sale of bank properties held for sale and repossessed real estate	11,575	20,706	42,657
Proceeds from sale of premises and equipment	856	6,143	8,469
Net cash used in investing activities	(1,426,439)	(4,860,396)	(2,319,261)
Cash flows from financing activities:
Net increase (decrease) in deposits	699,778	(1,780,132)	4,367,662
Net (decrease) increase in federal funds purchased and securities sold under agreements to repurchase and other short-term borrowings	(67,232)	(224,822)	1,573
Proceeds from borrowings	6,050,200		25,000
Repayment of borrowings	(5,950,200)	(13,000)	(100,878)
Common stock issuance	2,772	2,858	2,384
Common stock repurchases	(16,064)	(119,330)	(147,421)
Dividends paid on common stock	(156,184)	(146,664)	(135,337)
Stock options exercised	2,926	1,585	2,905
Net cash provided by (used in) financing activities	565,996	(2,279,505)	4,015,888
Net increase (decrease) in cash and cash equivalents	(313,686)	(5,409,008)	2,112,316
Cash and cash equivalents at beginning of period	1,312,563	6,721,571	4,609,255
Cash and cash equivalents at end of period	998,877	1,312,563	6,721,571
Cash paid for:
Interest	441,208	67,126	55,387
Income taxes	74,725	35,144	126,207
Recognition of operating lease assets in exchange for lease liabilities	1,160	12,635	9,623
Acquisitions:
Fair value of tangible assets acquired		3,500,692	34,838
Other intangible assets acquired		20,791
Liabilities assumed		3,205,694	2,343
Net identifiable assets acquired over liabilities assumed		342,021	15,816
Common stock issued in acquisition		659,772
Real estate acquired in full or in partial settlement of loans	$ 3,801	$ 1,972	$ 3,642