Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income:
Interest and fees on loans	$ 229,147	$ 194,345	$ 162,519
Interest on mortgage-backed securities	19,308	15,754	14,173
Interest and dividends on investment securities
Taxable	137	321	241
Tax-exempt	4,511	4,551	3,431
Other interest income	1,623	1,607	2,212
Total interest income	254,726	216,578	182,576
Interest Expense:
Interest on deposits	14,904	9,421	7,165
Interest on Federal Home Loan Bank advances	8,263	4,707	3,008
Interest on federal funds purchased and securities sold under agreements to repurchase	972	606	360
Interest on trust preferred borrowings	1,940	1,622	1,362
Interest on senior debt	7,228	6,356	3,766
Interest on other borrowings	148	121	115
Total interest expense	33,455	22,833	15,776
Net interest income	221,271	193,745	166,800
Provision for loan losses	10,964	12,986	7,790
Net interest income after provision for loan losses	210,307	180,759	159,010
Noninterest Income:
Credit/debit card and ATM income	36,116	29,899	25,702
Deposit service charges	18,318	17,734	16,684
Wealth management income	35,103	25,691	21,884
Mortgage banking activities, net	6,293	7,434	5,896
Security gains, net	1,984	2,369	1,478
Loan fee income	2,218	2,066	1,834
Bank owned life insurance income	1,545	919	776
Other income	23,067	18,949	16,002
Total non interest income	124,644	105,061	90,256
Noninterest Expense:
Salaries, benefits and other compensation	114,376	95,983	83,908
Occupancy expense	19,409	16,646	15,121
Equipment expense	12,564	10,368	8,448
Data processing and operations expenses	6,779	6,275	5,949
Professional fees	8,597	9,142	7,737
FDIC expenses	2,216	2,606	2,853
Loan workout and OREO expenses	1,820	1,681	1,108
Marketing expense	3,083	3,020	3,002
Corporate development expense	878	8,529	7,620
Early extinguishment of debt costs	695	0	651
Provision for legal settlement	12,000	0	0
Fraud loss	2,844	0	0
Other operating expense	41,200	34,416	29,063
Total non interest expenses	226,461	188,666	165,460
Income before taxes	108,490	97,154	83,806
Income tax provision	58,246	33,074	30,273
Net income	$ 50,244	$ 64,080	$ 53,533
Basic (in dollars per share)	$ 1.60	$ 2.12	$ 1.88
Diluted (in dollars per share)	$ 1.56	$ 2.06	$ 1.85