Loans and Leases - Impaired Loans (Details) - USD ($)	3 Months Ended		9 Months Ended		21 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Dec. 31, 2016
Impaired Loans [Abstract]
Cash collected on non accrual and impaired loan			$ 1,800,000	$ 1,400,000
Amount credited to principal balance outstanding			1,700,000	1,300,000
Summary of impaired loans [Abstract]
Impaired loans with a valuation allowance	$ 1,528,000		1,528,000		$ 1,528,000	$ 2,509,000
Impaired loans without a valuation allowance	3,735,000		3,735,000		3,735,000	4,446,000
Valuation allowance related to impaired loans	240,000		240,000		240,000	$ 368,000
Average recorded investment [Abstract]
Average investment in impaired loans and leases	$ 5,284,000	$ 5,835,000	5,865,000	6,332,000
Interest income recognized on a cash basis on impaired loans and leases			$ 0	$ 0	$ 0