Accounting Policies - Transfers of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Accounting Policies [Abstract] | ||
| Securities Purchased under Agreements to Resell | $ 0 | $ 0 |
| Security Owned and Sold, Not yet Purchased Fair Value, Security Sold, Not yet Purchased | $ 0 | $ 0 |