Fair Value Measurements - Significant Unobservable Inputs (Level 3) Used in Valuation of Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Fair Value	$ 4,228	$ 9,251
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Fair Value	4,228	$ 9,251
Level 3 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Fair Value	$ 4,228
Valuation Technique	Appraised value of collateral less estimated costs to sell
Significant Unobservable Inputs	Estimated costs to sell
Level 3 | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Fair Value	$ 1,636
Valuation Technique	Appraised value of property less estimated costs to sell
Significant Unobservable Inputs	Estimated costs to sell
Minimum | Level 3 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Range of Inputs	4.00%
Minimum | Level 3 | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Range of Inputs	4.00%
Maximum | Level 3 | Impaired loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Range of Inputs	10.00%
Maximum | Level 3 | OREO
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Range of Inputs	10.00%