Fair Value - Valuation Methodology and Unobservable Inputs (Details) - Non-Recurring Basis - Significant Unobservable Inputs (Level 3) - Third Party Appraisals	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Impaired loans carried at fair value of collateral | Minimum
Fair Value
Adjustment for differences between the comparable sales (as a percent)	(3.00%)	(16.00%)
Impaired loans carried at fair value of collateral | Maximum
Fair Value
Adjustment for differences between the comparable sales (as a percent)	(1.00%)	7.00%
Impaired loans carried at fair value of collateral | Weighted Average
Fair Value
Adjustment for differences between the comparable sales (as a percent)	(2.67%)	(4.00%)
Church | Real estate owned
Fair Value
Adjustment for differences between the comparable sales (as a percent)	(11.00%)	(6.00%)
Church | Real estate owned | Weighted Average
Fair Value
Adjustment for differences between the comparable sales (as a percent)	(10.85%)	(6.00%)