Fair Value Disclosures - Assets Measured at Fair Value on Non-recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	$ 540	$ 1,187
Total assets	1,748		$ 1,895
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans held for investment	24,499	25,166
Other real estate owned	540	1,187
Total assets	25,039	26,353
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans held for investment	0	0
Other real estate owned	0	0
Total assets	0	0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans held for investment	0	0
Other real estate owned	0	0
Total assets	0	0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans held for investment	24,499	25,166
Other real estate owned	540	1,187
Total assets	$ 25,039	$ 26,353