Consolidated Statements of Earnings - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Loans and leases	$ 952,771	$ 924,294	$ 819,094
Investment securities	98,202	90,557	64,368
Deposits in financial institutions	1,543	1,061	476
Total interest income	1,052,516	1,015,912	883,938
Interest expense:
Deposits	45,694	31,512	41,503
Borrowings	3,638	2,259	554
Subordinated debentures	23,613	20,850	18,535
Total interest expense	72,945	54,621	60,592
Net interest income	979,571	961,291	823,346
Provision for credit losses	57,752	65,729	45,481
Net interest income after provision for credit losses	921,819	895,562	777,865
Noninterest income:
Service charges on deposit accounts	15,307	14,534	11,688
Other commissions and fees	41,422	47,126	31,586
Leased equipment income	37,700	33,919	24,023
Gain on sale of loans and leases	6,197	909	373
(Loss) gain on sale of securities	(541)	9,485	3,744
FDIC loss sharing expense, net	0	(8,917)	(18,246)
Other income	28,488	15,419	31,142
Total noninterest income	128,573	112,475	84,310
Noninterest expense:
Compensation	266,567	251,913	203,914
Occupancy	48,863	48,911	44,144
Data processing	26,575	24,356	18,617
Other professional services	17,353	16,478	13,760
Insurance and assessments	19,733	18,364	16,996
Intangible asset amortization	14,240	16,517	9,410
Leased equipment depreciation	20,767	20,899	13,603
Foreclosed assets expense (income), net	1,702	1,881	(668)
Acquisition, integration and reorganization costs	19,735	200	21,247
Loan expense	13,832	9,371	6,064
Other expense	46,294	41,211	34,952
Total noninterest expense	495,661	450,101	382,039
Earnings before income taxes	554,731	557,936	480,136
Income tax expense	(196,913)	(205,770)	(180,517)
Net earnings	$ 357,818	$ 352,166	$ 299,619
Earnings Per Share, Basic (usd per share)	$ 2.91	$ 2.90	$ 2.79
Diluted income per share (usd per share)	2.91	2.90	2.79
Dividends declared per share (usd per share)	$ 2.00	$ 2	$ 2.00