Condensed Consolidated Statements of Earnings - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest expense:
Deposits	$ 40,703	$ 38,720	$ 21,121	$ 113,658	$ 51,306
Borrowings	6,852	7,210	3,814	21,772	7,383
Subordinated debentures	7,417	7,705	7,390	22,860	21,093
Total interest expense	54,972	53,635	32,325	158,290	79,782
Loans and leases	275,978	284,236	264,062	834,443	775,447
Investment securities	28,806	28,948	28,061	87,434	81,929
Deposits in financial institutions	2,424	1,349	519	4,423	1,555
Total interest income	307,208	314,533	292,642	926,300	858,931
Net interest income	252,236	260,898	260,317	768,010	779,149
Provision for credit losses	7,000	8,000	11,500	19,000	33,000
Net interest income after provision for credit losses	245,236	252,898	248,817	749,010	746,149
Noninterest income:
Other commissions and fees	10,855	11,590	12,397	33,453	34,429
Leased equipment income	9,615	9,182	9,120	28,079	28,497
Service charges on deposit accounts	3,525	3,771	3,979	11,026	12,418
Gain on sale of loans and leases	765	326	0	1,091	4,675
Gain on sale of securities	908	22,192	826	25,261	7,390
Other income	7,761	3,832	10,590	16,476	27,700
Total noninterest income	33,429	50,893	36,912	115,386	115,109
Noninterest expense:
Compensation	71,424	68,956	72,333	211,225	213,269
Occupancy	14,089	14,457	13,069	42,866	39,867
Data processing	7,044	6,817	6,740	20,786	20,295
Leased equipment depreciation	5,951	5,558	5,001	17,160	15,613
Intangible asset amortization	4,833	4,870	5,587	14,573	17,520
Other professional services	4,400	4,629	6,058	13,542	15,754
Insurance and assessments	4,100	4,098	5,446	12,236	16,503
Loan expense	3,628	3,451	2,249	9,964	7,578
Acquisition, integration and reorganization costs	0	0	800	618	800
Foreclosed assets expense (income), net	8	(146)	(257)	(109)	(440)
Other expense	11,332	12,737	11,127	35,662	35,238
Total noninterest expense	126,809	125,427	128,153	378,523	381,997
Earnings before income taxes	151,856	178,364	157,576	485,873	479,261
Income tax expense	(41,830)	(50,239)	(41,289)	(135,118)	(128,963)
Net earnings	$ 110,026	$ 128,125	$ 116,287	$ 350,755	$ 350,298
Earnings per share:
Net earnings (usd per share)	$ 0.92	$ 1.07	$ 0.94	$ 2.91	$ 2.79
Net earnings (usd per share)	$ 0.92	$ 1.07	$ 0.94	$ 2.91	$ 2.79