Fair Value of Assets and Liabilities - Carrying Value and Estimated Fair Value of Financial Instruments (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Assets:
Securities available for sale	$ 205,232,000	$ 219,476,000
Bank-owned life insurance	14,909,000	14,988,000
Carrying Value
Assets:
Cash and short-term investments	88,995,000	152,943,000
Securities available for sale	205,232,000	219,476,000
Loans, net	935,598,000	865,892,000
Loans held for sale	66,689,000	44,000,000
Bank-owned life insurance	14,909,000	14,988,000
Accrued interest receivable	6,551,000	6,829,000
Financial liabilities:
Demand deposits	743,234,000	733,901,000
Time deposits	345,894,000	339,732,000
Borrowings	167,204,000	177,261,000
Accrued interest payable	672,000	698,000
Total Fair Value
Assets:
Cash and short-term investments	88,995,000	152,943,000
Securities available for sale	205,232,000	219,476,000
Loans, net	942,484,000	875,341,000
Loans held for sale	66,689,000	44,000,000
Bank-owned life insurance	14,909,000	14,988,000
Accrued interest receivable	6,551,000	6,829,000
Financial liabilities:
Demand deposits	743,234,000	733,901,000
Time deposits	348,301,000	342,275,000
Borrowings	160,813,000	174,032,000
Accrued interest payable	672,000	698,000
Total Fair Value | Level 1
Assets:
Cash and short-term investments	88,995,000	152,943,000
Accrued interest receivable	6,551,000	6,829,000
Financial liabilities:
Demand deposits	743,234,000	733,901,000
Accrued interest payable	672,000	698,000
Total Fair Value | Level 2
Assets:
Securities available for sale	205,232,000	219,476,000
Loans held for sale	66,689,000	44,000,000
Bank-owned life insurance	14,909,000	14,988,000
Financial liabilities:
Time deposits	348,301,000	342,275,000
Borrowings	160,813,000	174,032,000
Total Fair Value | Level 3
Assets:
Loans, net	942,484,000	875,341,000
Interest rate lock commitments
Assets:
Derivative asset	1,250,000
Interest rate lock commitments | Carrying Value
Assets:
Derivative asset	1,251,000	744,000
Interest rate lock commitments | Total Fair Value
Assets:
Derivative asset	1,251,000	744,000
Interest rate lock commitments | Total Fair Value | Level 2
Assets:
Derivative asset	1,251,000	744,000
Interest Rate Swap | Carrying Value
Assets:
Derivative asset	815,000
Financial liabilities:
Derivative liabilities	815,000
Interest Rate Swap | Total Fair Value
Assets:
Derivative asset	815,000
Financial liabilities:
Derivative liabilities	815,000
Interest Rate Swap | Total Fair Value | Level 2
Assets:
Derivative asset	815,000
Financial liabilities:
Derivative liabilities	815,000
Cash Flow Hedges | Interest Rate Swap
Assets:
Derivative asset	815,000
Financial liabilities:
Derivative liabilities	815,000
Cash Flow Hedges | Interest Rate Swap | Carrying Value
Financial liabilities:
Derivative liabilities	603,000	175,000
Cash Flow Hedges | Interest Rate Swap | Total Fair Value
Financial liabilities:
Derivative liabilities	603,000	175,000
Cash Flow Hedges | Interest Rate Swap | Total Fair Value | Level 2
Financial liabilities:
Derivative liabilities	$ 603,000	$ 175,000