Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Income
Loans	$ 523,229	$ 463,331	$ 337,998
Investment securities – taxable	49,409	35,569	28,724
Investment securities – tax-exempt	5,060	6,296	8,737
Other short-term investments	4,794	4,520	2,873
Total interest income	582,492	509,716	378,332
Interest Expense
Deposits	37,774	16,184	9,863
Borrowed funds	15,388	9,100	6,313
Senior and subordinated debt	12,708	12,428	12,465
Total interest expense	65,870	37,712	28,641
Net interest income	516,622	472,004	349,691
Provision for loan losses	47,854	31,290	30,983
Net interest income after provision for loan losses	468,768	440,714	318,708
Noninterest Income
Service charges on deposit accounts	48,715	48,368	40,665
Wealth management fees	43,512	41,321	33,071
Card-based fees	17,024	28,992	29,104
Capital market products income	7,721	8,171	10,024
Mortgage banking income	7,094	8,131	10,162
Merchant servicing fees	1,465	10,340	12,533
Other service charges, commissions, and fees	9,425	9,843	9,542
Net securities gains (losses)	0
Net securities gains (losses)		(1,876)	1,420
Other income	9,636	9,859	7,282
Net gain on sale-leaseback transaction	0	0	5,509
Total noninterest income	144,592	163,149	159,312
Noninterest Expense
Salaries and wages	181,164	182,507	151,341
Retirement and other employee benefits	43,104	41,886	33,309
Net occupancy and equipment expense	53,434	49,751	41,154
Professional services	32,681	33,689	25,122
Technology and related costs	19,220	18,068	14,765
Federal Deposit Insurance Corporation (FDIC) premiums	10,584	8,987	6,268
Advertising and promotions	9,248	8,694	7,787
Amortization of Intangible Assets	7,444	7,865	4,682
Net OREO expense	1,162	4,683	3,024
Merchant card expense	0	8,377	10,782
Cardholder expense	0	7,323	5,812
Other expenses	28,236	23,956	20,152
Delivering Excellence implementation costs	20,413	0	0
Acquisition and integration related expenses	9,613	20,123	14,352
Lease cancellation fee	0	0	950
Total noninterest expense	416,303	415,909	339,500
Income before income tax expense	197,057	187,954	138,520
Income tax expense	39,187	89,567	46,171
Net income	$ 157,870	$ 98,387	$ 92,349
Per Common Share Data
Basic earnings per common share (EPS) (in dollars per share)	$ 1.52	$ 0.96	$ 1.14
Diluted earnings per common share (in dollars per share)	$ 1.52	$ 0.96	$ 1.14
Weighted-average common shares outstanding (in shares)	102,850	101,423	79,797
Weighted-average diluted common shares outstanding (in shares)	102,854	101,443	79,810