Workers Compensation Assets and Liabilities - Summary of Workers' Compensation Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Insurance [Abstract]
Collateral paid to carriers and offset against loss reserves	$ (26,470)	$ (31,611)
Total loss reserves, net of carrier collateral offset	233,838	223,003
Payable in less than 1 year (net of collateral paid to carriers of $5,831 and $9,234 as of March 31, 2017 and December 31, 2016, respectively)	69,167	63,702
Payable in more than 1 year (net of collateral paid to carriers of $20,639 and $22,377, as of March 31, 2017 and December 31, 2016, respectively)	164,671	159,301
Collateral paid to insurance carriers, net of workers' compensation loss reserves, current	5,831	9,234
Collateral paid to insurance carriers, net of workers' compensation loss reserves, noncurrent	$ 20,639	$ 22,377