Workers Compensation Assets and Liabilities - Additional Information (Details) - USD ($) $ in Thousands |
Mar. 31, 2017 |
Dec. 31, 2016 |
---|---|---|
Insurance [Abstract] | ||
Collateral held by insurance carriers | $ 65,300 | $ 65,600 |
Collateral paid to carriers and offset against loss reserves | $ (26,470) | $ (31,611) |