CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 473,840	$ 390,606	$ 309,793
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	54,934	57,615	53,317
Stock-based compensation	20,887	16,154	14,726
Provision for credit losses	32,633	125,722	24,218
Net amortization of premiums and accretion of discounts on securities and borrowings	30,251	38,315	29,512
Amortization of other intangible assets	21,827	24,645	18,080
(Gains) losses on securities transactions, net	(1,758)	(524)	150
Proceeds from sales of loans held for sale	1,180,912	1,019,841	509,448
Gains on sales of loans, net	(26,669)	(42,251)	(18,914)
Net impairment losses on securities recognized in earnings	0	0	2,928
Originations of loans held for sale	(1,003,818)	(1,211,227)	(537,985)
(Gains) losses on sales of assets, net	(901)	1,891	(78,333)
Loss on extinguishment of debt	8,406	12,036	31,995
Net deferred income tax expense (benefit)	26,827	(5,060)	15,228
Net change in:
Fair value of borrowings hedged by derivative transactions	(3,397)	0	0
Trading debt securities	(38,130)	0	0
Cash surrender value of bank owned life insurance	(8,817)	(10,083)	(8,232)
Accrued interest receivable	11,527	(593)	1,440
Other assets	122,241	(311,760)	(163,330)
Accrued expenses and other liabilities	(63,653)	58,234	57,882
Net cash provided by operating activities	837,142	163,561	261,923
Cash flows from investing activities:
Net loan originations and purchases	(1,036,949)	(2,490,937)	(2,538,909)
Equity securities:
Purchases	(4,051)	(8,337)	(14,776)
Sales	2,233	28,439	24,748
Held to maturity debt securities:
Purchases	(1,311,973)	(682,509)	(701,879)
Maturities, calls and principal repayments	802,167	824,477	424,475
Available for sale debt securities:
Purchases	(387,210)	(333,971)	(30,392)
Sales	91,978	30,020	271,901
Maturities, calls and principal repayments	462,273	555,589	316,024
Death benefit proceeds from bank owned life insurance	5,128	15,043	9,560
Proceeds from sales of real estate property and equipment	8,935	19,111	109,043
Proceeds from sales of loans held for investments	4,498	30,020	1,234,022
Purchases of real estate property and equipment	(39,428)	(24,607)	(23,375)
Cash and cash equivalents acquired in acquisitions, net	321,618	0	22,239
Net cash used in investing activities	(1,080,781)	(2,037,662)	(897,319)
Cash flows from financing activities:
Net change in deposits	2,534,826	2,749,765	1,808,148
Net change in short-term borrowings	(492,232)	54,678	(1,036,134)
Proceeds from issuance of long-term borrowings, net	295,922	838,388	950,000
Repayments of long-term borrowings	(1,168,465)	(679,775)	(921,995)
Cash dividends paid to preferred shareholders	(12,688)	(12,688)	(12,688)
Cash dividends paid to common shareholders	(179,667)	(177,965)	(146,537)
Purchase of common shares to treasury	(23,907)	(5,374)	(1,805)
Common stock issued, net	11,245	2,202	2,957
Other, net	(680)	(612)	(492)
Net cash provided by financing activities	964,354	2,768,619	641,454
Net change in cash and cash equivalents	720,715	894,518	6,058
Cash and cash equivalents at beginning of year	1,329,205	434,687	428,629
Cash and cash equivalents at end of year	2,049,920	1,329,205	434,687
Supplemental disclosures of cash flow information:
Interest on deposits and borrowings	138,364	279,042	415,649
Federal and state income taxes	163,370	148,383	106,336
Supplemental schedule of non-cash investing activities:
Transfer of loans to other real estate owned	141	4,040	5,100
Loans transferred to loans held for sale	0	30,020	1,234,022
Lease right of use assets obtained in exchange for operating lease liabilities	48,453	16,062	312,143
Non-cash assets acquired:
Equity securities	0	0	51,382
Loans, net	908,023	0	3,378,358
Premises and equipment	1,356	0	23,585
Lease right of use assets	6,745	0	0
Bank owned life insurance	28,756	0	101,896
Accrued interest receivable	2,179	0	11,781
Goodwill	76,566	0	297,777
Other intangible assets	10,277	0	20,690
Other assets	23,093	0	50,873
Total non-cash assets acquired	1,066,192	0	4,277,113
Liabilities assumed:
Deposits	1,161,984	0	2,924,716
Short-term borrowings	0	0	10,500
Long-term borrowings	0	0	430,130
Accrued expenses and other liabilities	14,692	0	98,751
Total liabilities assumed	1,176,676	0	3,464,097
Net (liabilities assumed) non-cash assets acquired	(110,484)	0	813,016
Cash and cash equivalents acquired in acquisitions, net	321,618	0	22,239
Common stock issued in acquisition	211,134	0	835,255
Available-for-sale securities
Non-cash assets acquired:
Investment securities	0	0	335,894
Held-to-maturity securities
Non-cash assets acquired:
Investment securities	$ 9,197	$ 0	$ 4,877