Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Interest income
Interest and fees on loans	$ 196,165	$ 182,741	$ 377,002	$ 371,414
Interest on federal funds sold and other short-term investments	4,841	1,757	7,170	3,650
Interest and dividends on securities:
Taxable	24,558	13,846	42,063	27,372
Tax-exempt	2,207	1,842	4,331	3,407
Total interest income	227,771	200,186	430,566	405,843
Interest expense
Interest on deposits	9,751	11,012	18,312	22,997
Interest on short-term borrowings	237	182	418	360
Interest on long-term borrowings	2,880	2,475	5,431	5,009
Total interest expense	12,868	13,669	24,161	28,366
Net interest income	214,903	186,517	406,405	377,477
Provision for credit losses	(1,807)	(8,879)	(5,217)	(8,736)
Net interest income after provision for credit losses	216,710	195,396	411,622	386,213
Other income
Income from bank-owned life insurance	4,120	1,658	6,314	3,061
Mortgage loan servicing income	2,328	2,386	4,715	4,741
Net investment securities gains	1,182	24	931	2,633
Other income	1,838	2,467	3,365	4,480
Total other income	43,608	62,864	89,633	155,444
Other expense
Employee compensation	62,632	68,557	125,253	140,969
Employee benefits	12,047	14,470	24,898	29,920
Net occupancy expense	11,206	10,101	22,393	21,042
Other real estate owned ("OREO") expense	46	496	228	4,055
Net gains on the sales of OREO properties	(454)	(106)	(487)	(33)
Equipment expense	7,310	5,830	14,645	11,874
Data processing expense	7,549	6,956	14,920	13,982
Mortgage loan servicing expense and impairment	1,783	3,599	3,426	6,776
Bankcard processing expense	488	478	912	878
FDIC insurance expense	3,004	1,800	5,677	3,800
Other expense	35,563	26,788	68,484	54,640
Total other expense	141,174	138,969	280,349	287,903
Income before income taxes	119,144	119,291	220,906	253,754
Income taxes	23,531	24,455	43,629	52,020
Net income	$ 95,613	$ 94,836	$ 177,277	$ 201,734
Earnings per common share:
Basic	$ 0.71	$ 0.73	$ 1.31	$ 1.56
Diluted	$ 0.71	$ 0.73	$ 1.3	$ 1.56
Average outstanding shares:
Basic	134,623,061	128,750,851	135,336,729	128,693,616
Diluted	134,863,650	129,033,988	135,634,398	128,946,280
Fees from trust services [Member]
Other income
Revenue from contract	$ 4,294	$ 4,193	$ 8,421	$ 7,956
Fees from brokerage services [Member]
Other income
Revenue from contract	4,115	3,654	8,667	7,977
Fees from deposit services [Member]
Other income
Revenue from contract	10,830	9,396	20,978	18,292
Bankcard fees and merchant discounts [Member]
Other income
Revenue from contract	1,671	1,368	3,050	2,432
Other service charges, commissions, and fees [Member]
Other income
Revenue from contract	785	775	1,544	1,534
Mortgage Banking [Member]
Other income
Revenue from contract	$ 12,445	$ 36,943	$ 31,648	$ 102,338