Summary of Significant Accounting Policies (Self-Insurance) - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2016 USD ($)
Commitments and Contingencies Disclosure [Abstract]
General liability insurance claims deductible	$ 10,000,000
Auto liability insurance claims deductible	10,000,000
Worker's compensation claims per occurrence	5,000,000
Employer's liability claims subject to deductible per occurrence	1,000,000
Employee health care benefit plans subject to deductible per claimant	$ 400,000