Fair Value Measurements - Quantitative Information, Level 3 (Details) - Impaired Loans - Nonrecurring $ in Thousands	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Impaired loans	$ 1,216	$ 307
Level 3
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Impaired loans	$ 1,216	$ 307
Level 3 | Comparability Adjustment | Minimum
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Range of Inputs	0.104	(0.915)
Level 3 | Comparability Adjustment | Maximum
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Range of Inputs	(0.373)	(0.144)
Level 3 | Comparability Adjustment | Weighted Average
Fair value measurements for financial instruments measured at fair value on a non-recurring basis
Range of Inputs	(0.109)	(0.440)