Loans and Allowance for Loan Losses - Impaired Loans (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Unpaid Principal Balance
With no related allowance recorded	$ 3,349,000		$ 3,349,000		$ 1,474,000
With an allowance recorded	1,188,000		1,188,000		979,000
Total	4,537,000		4,537,000		2,453,000
Recorded Investment
With no related allowance recorded	3,349,000		3,349,000		1,474,000
With an allowance recorded	1,188,000		1,188,000		979,000
Total	4,537,000		4,537,000		2,453,000
Allowance for Loan Losses Allocated
Total	340,000		340,000		198,000
Average Recorded Investment
Total	4,544,000	$ 2,491,000	4,552,000	$ 2,510,000
Interest Income Recognized
Total	55,000	32,000	80,000	64,000
Cash Basis Interest Recognized
Total	20,000	32,000	42,000	63,000
Commercial
Average Recorded Investment
Total			106,000	139,000
Interest Income Recognized
Total			2,000	6,000
Cash Basis Interest Recognized
Total			2,000	6,000
Commercial Real Estate
Recorded Investment
Total	78,000		78,000
Residential Real Estate
Average Recorded Investment
Total			1,097,000	749,000
Interest Income Recognized
Total			21,000	16,000
Cash Basis Interest Recognized
Total			15,000	15,000
Commercial | Commercial
Unpaid Principal Balance
With no related allowance recorded					53,000
With an allowance recorded	105,000		105,000		7,000
Recorded Investment
With no related allowance recorded					53,000
With an allowance recorded	105,000		105,000		7,000
Allowance for Loan Losses Allocated
Total	100,000		100,000		5,000
Average Recorded Investment
Total	105,000	135,000
Interest Income Recognized
Total		3,000
Cash Basis Interest Recognized
Total		3,000
Real estate | Residential Real Estate
Unpaid Principal Balance
With no related allowance recorded	1,091,000		1,091,000		837,000
With an allowance recorded	1,000		1,000
Recorded Investment
With no related allowance recorded	1,091,000		1,091,000		837,000
With an allowance recorded	1,000		1,000
Average Recorded Investment
Total	1,094,000	747,000
Interest Income Recognized
Total	13,000	8,000
Cash Basis Interest Recognized
Total	8,000	8,000
Other | Commercial Real Estate
Unpaid Principal Balance
With no related allowance recorded	2,254,000		2,254,000		579,000
With an allowance recorded	1,066,000		1,066,000		954,000
Recorded Investment
With no related allowance recorded	2,254,000		2,254,000		579,000
With an allowance recorded	1,066,000		1,066,000		954,000
Allowance for Loan Losses Allocated
Total	239,000		239,000		192,000
Average Recorded Investment
Total	3,324,000	1,584,000	3,328,000	1,604,000
Interest Income Recognized
Total	42,000	21,000	56,000	41,000
Cash Basis Interest Recognized
Total	12,000	21,000	24,000	41,000
Other | Consumer
Unpaid Principal Balance
With no related allowance recorded	4,000		4,000		5,000
With an allowance recorded	16,000		16,000
Recorded Investment
With no related allowance recorded	4,000		4,000		5,000
With an allowance recorded	16,000		16,000		18,000
Allowance for Loan Losses Allocated
Total	1,000		1,000		$ 1,000
Average Recorded Investment
Total	$ 21,000	$ 25,000	21,000	18,000
Interest Income Recognized
Total			1,000	1,000
Cash Basis Interest Recognized
Total			$ 1,000	$ 1,000