Deposit with Regulatory Authorities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Schedule of Deposit with Regulatory Authorities [Line Items]
Assets on deposit with state and other regulatory authorities	$ 15,753	$ 15,756
Debt securities held to maturity
Schedule of Deposit with Regulatory Authorities [Line Items]
Assets on deposit with state and other regulatory authorities	14,708	14,596
Debt securities available for sale
Schedule of Deposit with Regulatory Authorities [Line Items]
Assets on deposit with state and other regulatory authorities	570	685
Short-term investments
Schedule of Deposit with Regulatory Authorities [Line Items]
Assets on deposit with state and other regulatory authorities	$ 475	$ 475