Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest income:
Loans, including fees	$ 243,875	$ 224,332	$ 725,390	$ 645,340
Loans held for sale	592	268	1,189	784
Securities-taxable	32,724	32,482	94,107	92,566
Securities-tax exempt	5,058	5,461	15,715	16,488
Short-term investments	915	669	3,424	1,733
Total interest income	283,164	263,212	839,825	756,911
Interest expense:
Deposits	49,220	34,190	145,201	91,019
Short-term borrowings	7,729	11,780	23,658	24,547
Long-term debt	3,276	3,048	8,905	9,940
Total interest expense	60,225	49,018	177,764	125,506
Net interest income	222,939	214,194	662,061	631,405
Provision for loan losses	12,421	6,872	38,552	28,016
Net interest income after provision for loan losses	210,518	207,322	623,509	603,389
Noninterest income:
Other income	16,325	11,556	40,773	31,546
Total noninterest income	83,230	75,518	232,983	210,602
Noninterest expense:
Compensation expense	93,858	84,389	265,573	244,374
Employee benefits	18,622	18,084	57,240	55,316
Personnel expense	112,480	102,473	322,813	299,690
Net occupancy expense	13,156	11,895	38,101	35,221
Equipment expense	4,685	4,520	13,706	12,328
Data processing expense	21,532	20,492	60,951	55,214
Professional services expense	17,704	9,555	35,537	32,191
Amortization of intangible assets	4,889	5,638	15,074	16,578
Deposit insurance and regulatory fees	3,995	8,345	14,156	24,669
Other real estate and foreclosed assets (income) expense	2,055	16	1,459	(63)
Other expense	33,058	18,253	71,024	60,552
Total noninterest expense	213,554	181,187	572,821	536,380
Income before income taxes	80,194	101,653	283,671	277,611
Income taxes	12,387	17,775	48,423	50,081
Net income	$ 67,807	$ 83,878	$ 235,248	$ 227,530
Earnings per common share-basic	$ 0.77	$ 0.96	$ 2.69	$ 2.62
Earnings per common share-diluted	0.77	0.96	2.69	2.61
Dividends paid per share	$ 0.27	$ 0.27	$ 0.81	$ 0.75
Weighted average shares outstanding-basic	86,377	85,348	85,934	85,298
Weighted average shares outstanding-diluted	86,462	85,539	86,010	85,482
Service charges on deposit accounts
Noninterest income:
Service charges on deposit accounts	$ 21,892	$ 21,377	$ 62,982	$ 63,806
Trust fees
Noninterest income:
Service charges on deposit accounts	15,098	16,738	46,126	39,726
Bank card and ATM fees
Noninterest income:
Service charges on deposit accounts	17,154	14,862	49,063	44,784
Investment and annuity fees and insurance commissions
Noninterest income:
Service charges on deposit accounts	7,048	6,652	20,167	19,041
Secondary mortgage market operations
Noninterest income:
Service charges on deposit accounts	$ 5,713	$ 4,333	$ 13,872	$ 11,699