Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income:
Loans and leases	$ 1,097,845	$ 1,047,969	$ 952,771
Investment securities	115,569	111,619	98,202
Deposits in financial institutions	6,479	2,082	1,543
Total interest income	1,219,893	1,161,670	1,052,516
Interest expense:
Deposits	148,460	80,140	45,694
Borrowings	26,961	11,985	3,638
Subordinated debentures	29,843	28,631	23,613
Total interest expense	205,264	120,756	72,945
Net interest income	1,014,629	1,040,914	979,571
Provision for credit losses	22,000	45,000	57,752
Net interest income after provision for credit losses	992,629	995,914	921,819
Noninterest income:
Other commissions and fees	43,623	45,543	41,422
Leased equipment income	38,727	37,881	37,700
Service charges on deposit accounts	14,637	16,509	15,307
Gain on sale of loans and leases	1,114	4,675	6,197
Gain (loss) on sale of securities	25,445	8,176	(541)
Other income	19,016	35,851	28,488
Total noninterest income	142,562	148,635	128,573
Noninterest expense:
Compensation	285,862	282,568	266,567
Occupancy	57,407	53,223	48,863
Data processing	27,556	27,225	26,575
Other professional services	17,803	21,952	17,353
Insurance and assessments	16,404	20,705	19,733
Customer related expense	18,726	22,506	14,240
Loan expense	24,016	21,371	20,767
Foreclosed assets (income) expense, net	(3,555)	(751)	1,702
Customer Related Expense	13,839	10,353	8,297
Loan expense	12,931	10,569	13,832
Acquisition, integration and reorganization costs	349	1,770	19,735
Other expense	30,913	39,741	37,997
Total noninterest expense	502,251	511,232	495,661
Earnings before income taxes	632,940	633,317	554,731
Income tax expense	(164,304)	(167,978)	(196,913)
Net earnings	$ 468,636	$ 465,339	$ 357,818
Earnings Per Share, Basic (usd per share)	$ 3.90	$ 3.72	$ 2.91
Diluted income per share (usd per share)	3.90	3.72	2.91
Dividends declared per share (usd per share)	$ 2.40	$ 2.30	$ 2.00