Fair Value Measurements on a Non-Recurring Basis (Details) - Nonrecurring Measurements - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	$ 2,296	$ 7,839
Collateral-dependent impaired loans, net of ALLL	6,339	5,664
Total assets measured at fair value on a non-recurring basis	8,635	13,503
Level 1
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	0	0
Collateral-dependent impaired loans, net of ALLL	0	0
Total assets measured at fair value on a non-recurring basis	0	0
Level 2
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	0	0
Collateral-dependent impaired loans, net of ALLL	0	0
Total assets measured at fair value on a non-recurring basis	0	0
Level 3
Assets with a recorded change from re-measuring at fair value on a non-recurring basis
Other real estate owned	2,296	7,839
Collateral-dependent impaired loans, net of ALLL	6,339	5,664
Total assets measured at fair value on a non-recurring basis	$ 8,635	$ 13,503