Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Interest income:
Loans, including fees	$ 272,000	$ 246,177	$ 505,617	$ 506,144
Investment securities:
Taxable	38,948	17,347	69,068	32,755
Tax-exempt	6,076	2,667	9,951	4,779
Federal funds sold, securities purchased under agreements to resell and interest-bearing deposits with banks	8,635	1,350	11,487	2,339
Total interest income	325,659	267,541	596,123	546,017
Interest expense:
Deposits	5,776	9,537	10,404	20,795
Federal funds purchased and securities sold under agreements to repurchase	781	323	1,050	673
Corporate and subordinated debentures	4,823	4,548	8,916	9,418
Other borrowings		3		3
Total interest expense	11,380	14,411	20,370	30,889
Net interest income	314,279	253,130	575,753	515,128
Provision (recovery) for credit losses	19,286	(58,793)	10,837	(117,213)
Net interest income after provision (recovery) for credit losses	294,993	311,923	564,916	632,341
Noninterest income:
Securities gains, net		36		36
Other income	7,376	6,390	13,077	10,712
Total noninterest income	88,292	79,020	174,382	175,305
Noninterest expense:
Salaries and employee benefits	137,037	137,379	274,710	277,740
Occupancy expense	22,759	22,844	44,599	46,175
Information services expense	19,947	19,078	39,140	37,867
OREO and loan related (income) expense	(3)	240	(241)	1,242
Amortization of intangibles	8,847	8,968	17,341	18,132
Supplies, printing and postage expense	2,400	2,500	4,589	5,170
Professional fees	4,331	2,301	8,080	5,575
FDIC assessment and other regulatory charges	5,332	4,931	10,144	8,772
Advertising and marketing	2,286	1,659	4,049	3,399
Extinguishment of debt cost		11,706		11,706
Merger and branch consolidation related expense	5,390	32,970	15,666	42,979
Other expense	22,843	18,807	41,692	33,337
Total noninterest expense	231,169	263,383	459,769	492,094
Earnings:
Income before provision for income taxes	152,116	127,560	279,529	315,552
Provision for income taxes	32,941	28,600	60,025	69,643
Net income	$ 119,175	$ 98,960	$ 219,504	$ 245,909
Earnings per common share:
Basic (in dollars per share)	$ 1.58	$ 1.40	$ 2.99	$ 3.47
Diluted (in dollars per share)	$ 1.57	$ 1.39	$ 2.96	$ 3.44
Weighted average common shares outstanding:
Basic (in shares)	75,461	70,866	73,465	70,937
Diluted (in shares)	76,094	71,409	74,104	71,445
Fees on deposit accounts
Noninterest income:
Noninterest income	$ 33,658	$ 23,936	$ 62,560	$ 49,218
Mortgage banking income
Noninterest income:
Noninterest income	5,480	10,115	16,074	36,995
Trust and investment services income
Noninterest income:
Noninterest income	9,831	9,733	19,549	18,311
Correspondent banking and capital market income
Noninterest income:
Noninterest income	27,604	25,877	55,598	54,625
SBA Income
Noninterest income:
Noninterest income	$ 4,343	$ 2,933	$ 7,524	$ 5,408