Intangible Assets, Net (Narrative) (Detail)	6 Months Ended
	Jun. 30, 2018
Long-term Franchise Agreements and Contracts [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period of acquired intangible assets	16 years 7 months 6 days
Customer Lists [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period of acquired intangible assets	10 years
Permits and Other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average amortization period of acquired intangible assets	40 years