Subsequent Event - Additional Information (Detail) - USD ($)		12 Months Ended
	Jan. 08, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 31, 2015
Subsequent Event [Line Items]
Total consideration, net of cash acquired, for business acquisitions closed during the year		$ 661,000,000	$ 32,000,000	$ 772,000,000
U.S. Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Credit Facility, aggregate capacity		$ 2,250,000,000			$ 2,250,000,000
Subsequent Event [Member] | Southern Waste Systems [Member]
Subsequent Event [Line Items]
Total consideration, net of cash acquired, for business acquisitions closed during the year	$ 516,000,000