Deposits with Regulatory Authorities Deposit with Regulatory Authorities (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Schedule of Deposit with Regulatory Authorities [Line Items] | ||
| Assets on deposit with state and other regulatory authorities | $ 15,070 | $ 16,566 |
| Debt securities held to maturity | ||
| Schedule of Deposit with Regulatory Authorities [Line Items] | ||
| Assets on deposit with state and other regulatory authorities | 13,790 | 15,281 |
| Debt securities available for sale | ||
| Schedule of Deposit with Regulatory Authorities [Line Items] | ||
| Assets on deposit with state and other regulatory authorities | 805 | 810 |
| Short-term investments | ||
| Schedule of Deposit with Regulatory Authorities [Line Items] | ||
| Assets on deposit with state and other regulatory authorities | $ 475 | $ 475 |