Loans and Allowance for Loan Losses - Purchased Credit Impaired Loans (Details) - Purchased Credit Impaired Loans [Member] - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Total loans	$ 46,504	$ 48,404
Less remaining purchase discount	(13,636)	(14,246)
Total loans, net of purchase discount	32,868	34,158
Less: Allowance for loan losses	(54)	0
Carrying amount, net of allowance	32,814	34,158
Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Total loans	24,226	24,849
Consumer Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Total loans	10,464	11,108
Construction and Land Development [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Total loans	5,724	5,731
Commercial and Industrial [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Total loans	5,369	5,824
Consumer and Other [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Total loans	$ 721	$ 892