Fair Value Disclosures - Assets Measured at Fair Value on Non-recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 2,014		$ 2,234
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans held for investment	30,472	$ 43,680
Impaired leases held for investment	1,250
Other real estate owned	1,763	4,969
Total assets	33,485	48,649
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
Impaired leases held for investment	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
Impaired leases held for investment	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	30,472	43,680
Impaired leases held for investment	1,250
Other real estate owned	1,763	4,969
Total assets	$ 33,485	$ 48,649