Investment Securities - Pledged Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Amortized Cost
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged	$ 1,664	$ 22,745
Fair Value
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged	1,674	22,524
Securities sold under agreements to repurchase | Amortized Cost
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged	0	16,032
Securities sold under agreements to repurchase | Fair Value
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged	0	15,862
Federal Home Loan Bank advances | Amortized Cost
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged	1,664	6,713
Federal Home Loan Bank advances | Fair Value
Assets Sold under Agreements to Repurchase [Line Items]
Securities pledged	$ 1,674	$ 6,662