Fair Value Measurements and Disclosures - Financial assets measured at fair value on non-recurring basis (Details) - Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financial assets measured at fair value on a nonrecurring basis
Impaired loans	$ 5,468	$ 5,799
Other real estate owned	120
Total	5,588	5,799
Level 3
Financial assets measured at fair value on a nonrecurring basis
Impaired loans	5,468	5,799
Other real estate owned	120
Total	$ 5,588	$ 5,799