Condensed Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Interest income:
Loans and leases	$ 264,062	$ 260,300	$ 235,666	$ 775,447	$ 694,462
Investment securities	28,061	27,730	24,762	81,929	72,490
Deposits in financial institutions	519	484	538	1,555	967
Total interest income	292,642	288,514	260,966	858,931	767,919
Interest expense:
Deposits	21,121	16,367	13,071	51,306	31,653
Borrowings	3,814	2,649	188	7,383	2,272
Subordinated debentures	7,390	7,166	6,017	21,093	17,379
Total interest expense	32,325	26,182	19,276	79,782	51,304
Net interest income	260,317	262,332	241,690	779,149	716,615
Provision for credit losses	11,500	17,500	15,119	33,000	51,346
Net interest income after provision for credit losses	248,817	244,832	226,571	746,149	665,269
Noninterest income:
Service charges on deposit accounts	3,979	4,265	3,465	12,418	10,733
Other commissions and fees	12,397	11,767	9,944	34,429	30,917
Leased equipment income	9,120	9,790	8,332	28,497	29,442
Gain on sale of loans and leases	0	106	2,848	4,675	4,209
Gain on sale of securities	826	253	1,236	7,390	2,788
Other income	10,590	13,457	5,557	27,700	23,689
Total noninterest income	36,912	39,638	31,382	115,109	101,778
Noninterest expense:
Compensation	72,333	69,913	64,413	213,269	194,581
Occupancy	13,069	13,575	12,729	39,867	36,148
Data processing	6,740	6,896	6,459	20,295	19,811
Other professional services	6,058	5,257	4,213	15,754	11,567
Insurance and assessments	5,446	5,330	4,702	16,503	14,349
Intangible asset amortization	5,587	5,587	3,049	17,520	9,178
Leased equipment depreciation	5,001	5,237	4,862	15,613	15,719
Foreclosed assets (income) expense, net	(257)	(61)	2,191	(440)	2,177
Acquisition, integration and reorganization costs	800	0	1,450	800	3,650
Loan expense	2,249	3,058	3,421	7,578	10,692
Other expense	11,127	11,657	11,053	35,238	34,921
Total noninterest expense	128,153	126,449	118,542	381,997	352,793
Earnings before income taxes	157,576	158,021	139,411	479,261	414,254
Income tax expense	(41,289)	(42,286)	(37,945)	(128,963)	(140,473)
Net earnings	$ 116,287	$ 115,735	$ 101,466	$ 350,298	$ 273,781
Earnings per share:
Net earnings (usd per share)	$ 0.94	$ 0.92	$ 0.84	$ 2.79	$ 2.26
Net earnings (usd per share)	$ 0.94	$ 0.92	$ 0.84	$ 2.79	$ 2.26