Fair Value of Financial Instruments (Assets Measured at Fair Value Nonrecurring) (Details) - Nonrecurring Basis - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018	Dec. 31, 2017
Nonrecurring Basis
Losses on impaired loans charged through allowance for loan losses	$ 182	$ 153
Level 2
Nonrecurring Basis
Impaired loans, aggregate outstanding principal balance	31,300	31,300
Level 3
Nonrecurring Basis
Impaired loans, fair value	25,038	25,038	$ 20,602
Other Real Estate, Foreclosed Assets, and Repossessed Assets	$ 106	$ 106	$ 208