CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Interest income
Loans	$ 242,230,000	$ 161,525,000	$ 122,613,000
Investment securities	26,219,000	16,982,000	11,791,000
Federal funds sold and interest-earning deposits	384,000	196,000	144,000
Total interest income	268,833,000	178,703,000	134,548,000
Interest expense
Deposits	17,569,000	12,009,000	8,404,000
Short-term borrowings	5,503,000	1,546,000	406,000
Long-term debt	8,654,000	5,998,000	5,170,000
Total interest expense	31,726,000	19,553,000	13,980,000
Net interest income	237,107,000	159,150,000	120,568,000
Provision for loan losses	10,642,000	6,245,000	3,413,000
Net interest income after provision for loan losses	226,465,000	152,905,000	117,155,000
Non-interest income
Service charges and fees on deposit accounts	21,310,000	13,750,000	9,574,000
Government-guaranteed lending	11,501,000	12,729,000	9,450,000
Mortgage banking	11,449,000	6,257,000	3,370,000
Bank-owned life insurance	4,071,000	1,873,000	1,784,000
Gain (loss) on sales of available for sale securities	(564,000)	0	126,000
Gains on sales of branches	0	88,000	415,000
Gain on sale of trust business	417,000	0	0
Other	8,364,000	5,706,000	4,198,000
Total non-interest income	56,548,000	40,403,000	28,917,000
Non-interest expense
Salaries and employee benefits	86,024,000	60,898,000	51,342,000
Occupancy and equipment	26,411,000	18,799,000	15,075,000
Data processing	10,328,000	7,599,000	5,235,000
FDIC deposit insurance premiums	4,062,000	2,892,000	2,091,000
Professional services	5,487,000	4,556,000	3,943,000
Foreclosed asset expenses, net	1,749,000	1,276,000	671,000
Loan, collection, and repossession expense	4,057,000	3,643,000	3,075,000
Merger and conversion costs	28,486,000	1,102,000	22,136,000
Impairment of purchased accounts receivable	2,927,000	0	0
Restructuring charges	46,000	3,533,000	1,142,000
Amortization of other intangible assets	5,939,000	3,098,000	2,157,000
Other	20,259,000	15,290,000	12,087,000
Total non-interest expense	195,775,000	122,686,000	118,954,000
Income before income taxes	87,238,000	70,622,000	27,118,000
Income tax expense	32,070,000	25,995,000	5,413,000
Net income	55,168,000	44,627,000	21,705,000
Dividends on preferred stock	0	822,000	1,269,000
Net income attributable to non-controlling interests	0	0	2,466,000
Net income available to common shareholders	$ 55,168,000	$ 43,805,000	$ 17,970,000
Net income per common share
Basic (in dollars per share)	$ 1.15	$ 1.39	$ 0.88
Diluted (in dollars per share)	$ 1.14	$ 1.38	$ 0.88
Weighted average common shares outstanding
Basic (in shares)	48,137,433	31,610,733	20,500,519
Diluted (in shares)	48,237,217	31,695,808	20,505,142