Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest income
Interest and fees on loans	$ 159,294	$ 140,899	$ 308,222	$ 249,841
Interest on federal funds sold and other short-term investments	3,465	3,785	8,382	6,471
Interest and dividends on securities:
Taxable	13,810	8,809	25,685	16,820
Tax-exempt	1,431	1,454	2,896	2,573
Total interest income	178,000	154,947	345,185	275,705
Interest expense
Interest on deposits	19,076	12,586	34,733	21,054
Interest on short-term borrowings	464	415	885	719
Interest on long-term borrowings	9,338	5,701	16,402	10,067
Total interest expense	28,878	18,702	52,020	31,840
Net interest income	149,122	136,245	293,165	243,865
Provision for loan losses	6,204	8,251	11,382	14,150
Net interest income after provision for loan losses	142,918	127,994	281,783	229,715
Other income
Fees from brokerage services	1,953	1,882	4,177	3,738
Income from bank-owned life insurance	1,271	1,258	2,525	2,475
Net investment securities (losses) gains	(55)	747	(540)	4,687
Other income	544	954	987	1,315
Total other income	36,007	40,506	67,199	60,652
Other expense
Employee compensation	43,120	56,030	83,956	80,063
Employee benefits	9,298	9,760	18,869	16,663
Net occupancy expense	9,076	13,913	18,503	20,697
Other real estate owned (OREO) expense	556	524	1,502	1,938
Equipment expense	3,279	2,471	6,436	4,436
Data processing expense	5,817	5,331	11,667	9,374
Bankcard processing expense	480	442	946	907
FDIC insurance expense	2,842	1,771	4,690	3,522
Other expense	18,942	21,895	37,293	37,379
Total other expense	93,410	112,137	183,862	174,979
Income before income taxes	85,515	56,363	165,120	115,388
Income taxes	19,241	19,304	37,140	39,520
Net income	$ 66,274	$ 37,059	$ 127,980	$ 75,868
Earnings per common share:
Basic	$ 0.63	$ 0.37	$ 1.22	$ 0.84
Diluted	0.63	0.37	1.22	0.84
Dividends per common share	$ 0.34	$ 0.33	$ 0.68	$ 0.66
Average outstanding shares:
Basic	104,682,910	99,197,807	104,770,681	90,100,627
Diluted	104,952,788	99,620,045	105,058,014	90,570,289
Fees from Trust Services [Member]
Other income
Revenue from contract	$ 3,104	$ 2,863	$ 6,195	$ 5,893
Fees from Deposit Services [Member]
Other income
Revenue from contract	8,420	8,528	16,650	16,234
Bankcard Fees and Merchant Discounts [Member]
Other income
Revenue from contract	1,479	1,216	2,835	2,100
Other Service Charges, Commissions, and Fees [Member]
Other income
Revenue from contract	599	521	1,108	998
Mortgage Banking [Member]
Other income
Revenue from contract	$ 18,692	$ 22,537	$ 33,262	$ 23,212