Acquisitions and Divestitures - Intangibles (Detail) - USD ($) $ in Millions	Jan. 08, 2016	Mar. 26, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Intangible assets
Total other intangible assets subject to amortization, Amount			$ 46	$ 212	$ 145
Covenants not-to-compete [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount			$ 7	23	8
Trade Name [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount				$ 4	$ 6
Deffenbaugh Disposal, Inc. [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount		$ 100
Total other intangible assets subject to amortization, Periods		15 years
Deffenbaugh Disposal, Inc. [Member] | Customer Relationships [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount		$ 94
Total other intangible assets subject to amortization, Periods		15 years
Deffenbaugh Disposal, Inc. [Member] | Trade Name [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount		$ 6
Total other intangible assets subject to amortization, Periods		15 years
Southern Waste Systems [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount	$ 182
Total other intangible assets subject to amortization, Periods	9 years 6 months
Southern Waste Systems [Member] | Customer Relationships [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount	$ 160
Total other intangible assets subject to amortization, Periods	10 years
Southern Waste Systems [Member] | Covenants not-to-compete [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount	$ 18
Total other intangible assets subject to amortization, Periods	5 years
Southern Waste Systems [Member] | Trade Name [Member]
Intangible assets
Total other intangible assets subject to amortization, Amount	$ 4
Total other intangible assets subject to amortization, Periods	10 years