Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest Income
Loans	$ 79,922,000	$ 62,563,000	$ 49,006,000
Investment securities:
Trading	5,187,000	4,516,000	3,579,000
Available for sale	4,531,000	3,249,000	2,361,000
Federal Home Loan Bank stock	321,000	320,000	308,000
Other	4,426,000	2,291,000	1,091,000
Total interest income	94,387,000	72,939,000	56,345,000
Interest Expense
Deposits	20,003,000	11,663,000	7,346,000
Borrowed funds	7,787,000	7,305,000	6,944,000
Total interest expense	27,790,000	18,968,000	14,290,000
Net interest income	66,597,000	53,971,000	42,055,000
Provision for loan losses	2,472,000	960,000	960,000
Net Interest Income After Provision for Loan Losses	64,125,000	53,011,000	41,095,000
Non interest Income
Gain on sale of loans	37,790,000	24,755,000	24,803,000
Loan servicing fees (costs), net	6,273,000	280,000	836,000
Mortgage warehouse fees	2,608,000	3,015,000	1,193,000
Gains on sale of investments available for sale (includes $0, $24, and $0, respectively, related to accumulated other comprehensive earnings reclassifications)		24,000
Other income	1,009,000	430,000	176,000
Total noninterest income	47,680,000	28,504,000	27,008,000
Noninterest Expense
Salaries and employee benefits	21,472,000	14,313,000	11,962,000
Loan expenses	4,097,000	4,251,000	2,735,000
Occupancy and equipment	1,602,000	1,344,000	1,248,000
Professional fees	1,516,000	1,298,000	675,000
Deposit insurance expense	930,000	1,149,000	1,077,000
Technology expense	1,171,000	985,000	702,000
Other expense	3,856,000	3,380,000	2,523,000
Total noninterest expense	34,644,000	26,720,000	20,922,000
Income Before Income Taxes	77,161,000	54,795,000	47,181,000
Provision for Income Taxes (includes $0, $10, and $0, respectively, related to income tax expense for reclassification items)	22,477,000	21,668,000	18,798,000
Net Income	54,684,000	33,127,000	28,383,000
Dividends on Preferred Stock	(3,330,000)	(2,002,000)	0
Net Income allocated to Common Shareholders	$ 51,354,000	$ 31,125,000	$ 28,383,000
Basic earnings per share (in dollar per share)	$ 2.28	$ 1.47	$ 1.35
Diluted earnings per share (in dollar per share)	$ 2.28	$ 1.47	$ 1.35
Weighted-average shares outstanding Basic (in Shares)	22,551,452	21,111,208	21,075,475
Weighted-average shares outstanding Diluted (in Shares)	22,568,154	21,113,435	21,075,475
Dividends per share	$ 0.20	$ 0.20	$ 0.20