Commitments and Contingencies - Narrative (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Self insurance deductible for workers compensation	$ 2,500
Self insurance deductible for general liability claims	1,000
Self insurance deductible for automobile liability	1,000
Self insurance deductible for medical and dental coverage	400
Self-insured risk accruals	$ 29,800	$ 30,800