Consolidated Statements Of Cash Flows	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Operating Activities
Net income	$ 28,476,000	$ 40,067,000	$ 20,952,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	3,035,000	5,258,000	1,936,000
Depreciation and amortization expense	3,761,000	4,426,000	3,614,000
Purchase accounting accretion, net	(2,834,000)	(5,048,000)	(367,000)
Investment securities amortization and accretion, net	3,122,000	3,135,000	2,244,000
Stock-based compensation expense	1,469,000	1,997,000	836,000
Amortization of intangible assets	1,809,000	1,903,000	1,306,000
Net gains on sale of investment securities	(855,000)	(51,000)	(4,000)
Net increase in other real estate owned valuation allowance and (gain) loss on disposition	(15,000)	35,000	362,000
Originations of mortgage loans held for sale	(211,568,000)	(236,450,000)	(72,032,000)
Proceeds from the sale of mortgage loans	224,883,000	238,351,000	62,485,000
Gain on sale of mortgage loans, net of origination costs	(6,256,000)	(6,201,000)	(1,278,000)
Cost of fixed assets disposals associated with the SBM Financial, Inc. acquisition	0	0	1,130,000
Proceeds from bank-owned life insurance death benefits	0	(507,000)	0
Proceeds from bank-owned life insurance death benefits	0	1,092,000	0
(Increase) decrease in other assets	12,060,000	11,836,000	(7,062,000)
Increase (decrease) in other liabilities	1,247,000	(1,333,000)	1,796,000
Net cash provided by operating activities	58,334,000	58,510,000	15,918,000
Investing Activities
Cash received in the SBM Financial, Inc. acquisition, net of cash paid	0	0	59,917,000
Proceeds from sales and maturities of available-for-sale securities	154,973,000	184,564,000	156,434,000
Purchase of available-for-sale securities	(170,495,000)	(220,169,000)	(111,170,000)
Purchase of securities held-to-maturity	0	(10,986,000)	(64,355,000)
Net increase in loans	(187,740,000)	(103,699,000)	(94,811,000)
Proceeds from sale of premises and equipment	137,000	90,000	0
Purchase of premises and equipment	(2,844,000)	(1,671,000)	(3,189,000)
Purchase of Federal Home Loan Bank and Federal Reserve Bank stock	(12,290,000)	(7,342,000)	(1,594,000)
Proceeds from sale of other real estate owned	11,823,000	5,652,000	471,000
Proceeds from sale of other real estate owned	808,000	730,000	2,825,000
Recoveries of previously charged-off loans	497,000	486,000	728,000
Purchase of bank-owned life insurance	(7,000,000)	(16,700,000)	0
Net cash used in investing activities	(212,131,000)	(169,045,000)	(54,744,000)
Financing Activities
Net increase in deposits	172,291,000	103,027,000	71,825,000
Net proceeds from (repayments of) borrowings less than 90 days	36,699,000	77,227,000	(18,105,000)
Repayments on Federal Home Loan Bank long-term advances	(20,000,000)	(25,000,000)	(11,039,000)
Proceeds from Federal Home Loan Bank long-term advances	0	0	10,000,000
Repayments of Other Debt	(5,000,000)	(25,000,000)	0
Issuance of subordinated debt, net of costs	0	0	14,464,000
Equity issuance costs	0	0	(612,000)
Exercise of stock options and issuance of restricted stock, net of repurchase for tax withholdings	606,000	(894,000)	(753,000)
Cash dividends paid on common stock and cash in lieu for fractional shares paid due to stock split	(14,323,000)	(12,394,000)	(9,785,000)
Net cash provided by financing activities	169,061,000	118,754,000	57,501,000
Net increase in cash and cash equivalents	15,264,000	8,219,000	18,675,000
Cash and cash equivalents at beginning of year	87,707,000	79,488,000	60,813,000
Cash and cash equivalents at end of year	102,971,000	87,707,000	79,488,000
Supplemental information
Interest paid	20,774,000	16,661,000	12,588,000
Income taxes paid	16,841,000	10,647,000	12,205,000
Transfer of loans and premises to other real estate owned	0	383,000	2,175,000
Measurement-period adjustments	0	960,000	0
Assets acquired in the acquisition of SBM Financial, Inc., excluding net cash received (not adjusted for measurement-period adjustments)	0	0	729,283,000
Liabilities assumed in the acquisition of SBM Financial Inc. (not adjusted for measurement-period adjustments)	0	0	729,500,000
Common stock and stock options issued in connection with the SBM Financial, Inc. acquisition	$ 0	$ 0	$ 110,551,000