Property and Equipment - Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment
Depreciation and amortization expense	$ 1,376	$ 1,301	$ 1,245
Tangible Property and Equipment [Member]
Property, Plant and Equipment
Depreciation and amortization expense	783	773	760
Landfill Airspace [Member]
Property, Plant and Equipment
Depreciation and amortization expense	497	428	409
Property and Equipment [Member]
Property, Plant and Equipment
Depreciation and amortization expense	$ 1,280	$ 1,201	$ 1,169