Condensed Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Interest income:
Loans and leases	$ 251,085	$ 258,309	$ 224,178
Investment securities	26,138	25,712	23,039
Deposits in financial institutions	552	576	192
Total interest income	277,775	284,597	247,409
Interest expense:
Deposits	13,818	14,041	8,377
Borrowings	920	1,366	1,018
Subordinated debentures	6,537	6,234	5,562
Total interest expense	21,275	21,641	14,957
Net interest income	256,500	262,956	232,452
Provision for credit losses	4,000	6,406	24,728
Net interest income after provision for credit losses	252,500	256,550	207,724
Noninterest income:
Service charges on deposit accounts	4,174	4,574	3,758
Other commissions and fees	10,265	10,505	10,390
Leased equipment income	9,587	8,258	9,475
Gain on sale of loans and leases	4,569	1,988	712
Gain (loss) on sale of securities	6,311	(3,329)	(99)
Other income	3,653	4,799	10,878
Total noninterest income	38,559	26,795	35,114
Noninterest expense:
Compensation	71,023	71,986	64,880
Occupancy	13,223	12,715	11,608
Data processing	6,659	6,764	7,015
Other professional services	4,439	5,786	3,378
Insurance and assessments	5,727	5,384	4,791
Intangible asset amortization	6,346	5,062	3,064
Leased equipment depreciation	5,375	5,048	5,625
Foreclosed assets (income) expense, net	(122)	(475)	143
Acquisition, integration and reorganization costs	0	16,085	500
Loan expense	2,271	3,140	3,387
Other expense	12,454	11,373	12,153
Total noninterest expense	127,395	142,868	116,544
Earnings before income taxes	163,664	140,477	126,294
Income tax expense	(45,388)	(56,440)	(47,626)
Net earnings	$ 118,276	$ 84,037	$ 78,668
Earnings per share:
Net earnings (usd per share)	$ 0.93	$ 0.66	$ 0.65
Net earnings (usd per share)	0.93	0.66	0.65
Dividends declared per share (usd per share)	$ 0.50	$ 0.5	$ 0.5