Details of Certain Balance Sheet Accounts - Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Details Of Certain Balance Sheet Accounts [Abstract]
Workers compensation deposits	$ 400	$ 300
Health insurance deposits	500	1,200
Other miscellaneous deposit	900	1,500
Investments	27,800	25,700
Other	8,900	4,100
Other assets, net	$ 38,468	$ 32,802