Consolidated Statements of Cash Flows - USD ($)
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Operating activities      
Net income $ 14,909,000 $ 16,514,000 $ 14,139,000
Adjustments to reconcile net income to net cash provided by operating activities:      
Deferred income taxes, net (1,108,000) 1,158,000 1,389,000
Impairment of tax credit investments 3,691,000 0 0
Provision for loan and lease losses 7,818,000 3,386,000 1,236,000
Depreciation, amortization and accretion, net 1,515,000 (90,000) 1,870,000
Share-based compensation 994,000 1,063,000 887,000
Gain on sale of available-for-sale securities (10,000) 0 0
Increase in value of bank-owned life insurance policies (974,000) (960,000) (862,000)
Origination of loans for sale (71,965,000) (70,254,000) (9,392,000)
Sale of loans originated for sale 78,546,000 77,333,000 6,651,000
Gain on sale of loans originated for sale (4,990,000) (4,728,000) (392,000)
Net loss (gain) on foreclosed properties, including impairment valuation 122,000 (171,000) (10,000)
Excess tax benefit from share-based compensation (142,000) 0 0
Returns on investments in limited partnerships 250,000 0 0
Increase in accrued interest receivable and other assets (3,861,000) (1,033,000) (5,448,000)
Increase in accrued interest payable and other liabilities 1,367,000 1,002,000 1,806,000
Net cash provided by operating activities 26,162,000 23,220,000 11,874,000
Investing activities      
Proceeds from maturities, redemptions and paydowns of available-for-sale securities 43,745,000 42,899,000 44,148,000
Proceeds from maturities, redemptions and paydowns of held-to-maturity securities 3,882,000 4,349,000 2,211,000
Proceeds from sale of available-for-sale securities 5,227,000 0 0
Purchases of available-for-sale and held-to-maturity securities (61,547,000) (40,721,000) (52,947,000)
Proceeds from sale of foreclosed properties 83,000 528,000 255,000
Net increase in loans and leases (22,385,000) (155,204,000) (299,095,000)
Net cash associated with the Alterra Bank acquisition 0 0 (11,957,000)
Investments in limited partnerships (750,000) 0 (1,000,000)
Returns of investments in limited partnerships 541,000 459,000 722,000
Investment in community development entity 0 0 (7,500,000)
Investments in historic development entities (3,456,000) (578,000) 0
Investment in Federal Home Loan Bank and Federal Reserve Bank Stock (1,308,000) (1,352,000) (1,459,000)
Proceeds from the sale of Federal Home Loan Bank Stock 2,020,000 849,000 373,000
Purchases of leasehold improvements and equipment, net (584,000) (789,000) (3,190,000)
Purchases of bank owned life insurance policies (9,750,000) 0 (3,285,000)
Premium payment on bank owned life insurance policies (26,000) (25,000) (25,000)
Net cash used in investing activities (44,308,000) (149,585,000) (332,749,000)
Financing activities      
Net (decrease) increase in deposits (38,256,000) 139,469,000 308,413,000
Repayment of Federal Home Loan Bank advances (4,500,000) (1,000,000) 0
Proceeds from Federal Home Loan Bank advances 30,000,000 0 9,383,000
Net (decrease) increase in short-term borrowed funds (1,500,000) 1,500,000 1,000,000
Net increase in long-term borrowed funds 998,000 918,000 675,000
Proceeds from issuance of subordinated notes payable, net of issuance costs 0 0 14,469,000
Repayment of subordinated notes payable 0 0 (4,000,000)
Excess tax benefit from share-based compensation 0 267,000 584,000
Common stock issuance 0 0 16,557,000
Cash dividends paid (4,176,000) (3,816,000) (3,396,000)
Exercise of stock options 0 300,000 936,000
Purchase of treasury stock (467,000) (946,000) (1,795,000)
Net cash (used in) provided by financing activities (17,901,000) 136,692,000 342,826,000
Net (decrease) increase in cash and cash equivalents (36,047,000) 10,327,000 21,951,000
Cash and cash equivalents at the beginning of the period 113,564,000 103,237,000 81,286,000
Cash and cash equivalents at the end of the period 77,517,000 113,564,000 103,237,000
Supplementary cash flow information      
Interest paid on deposits and borrowings 14,790,000 13,639,000 11,048,000
Income taxes paid 5,554,000 5,668,000 7,221,000
Transfer of securities from available-for-sale to held-to-maturity 0 0 44,587,000
Transfer of loans from held-to-maturity to held-for-sale 11,504,000 4,336,000 0
Unrealized loss on transfer of securities from available-for-sale to held-to-maturity $ 0 $ 0 $ (874,000)