Loans and Leases - Impaired Loans (Details) - USD ($)	3 Months Ended		6 Months Ended		18 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2016
Impaired Loans [Abstract]
Cash collected on non accrual and impaired loan			$ 934,000	$ 1,100,000
Amount credited to principal balance outstanding			900,000	994,000
Summary of impaired loans [Abstract]
Impaired loans with a valuation allowance	$ 1,722,000		1,722,000		$ 1,722,000	$ 2,509,000
Impaired loans without a valuation allowance	3,246,000		3,246,000		3,246,000	4,446,000
Valuation allowance related to impaired loans	225,000		225,000		225,000	$ 368,000
Average recorded investment [Abstract]
Average investment in impaired loans and leases	$ 5,864,000	$ 6,278,000	6,359,000	6,598,000
Interest income recognized on a cash basis on impaired loans and leases			$ 0	$ 0	$ 0