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Income Taxes - Quarter information (Detail) - USD ($) $ in Millions		1 Months Ended	3 Months Ended			9 Months Ended
	Aug. 28, 2019	Sep. 30, 2018	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2018
Income Taxes
Effective tax rate of income (loss) before income taxes			19.40%		16.60%	22.20%	18.90%
Equity in net losses of unconsolidated entities			$ 14		$ 9	$ 39	$ 29
Excess tax benefits associated with equity-based compensation			5		3	22	15
Increase (decrease) to accruals and related deferred taxes			13		27	13	35
Net reduction in income tax expense due to Tax Cuts and Jobs Act		$ (12)
Tax audit settlement								$ (33)
Investment impairment				$ 52
Landfill [Member]
Income Taxes
Asset impairments					29
Investments Qualifying for Federal Tax Credits [Member]
Income Taxes
Investment consideration	$ 160
Capital obligations	140
Payment to acquire investment	$ 20
Equity in net losses of unconsolidated entities			11		5	32	17
Income tax (expense) benefit, including tax credits, from equity method investment			36		$ 18	69	$ 40
Interest expense recognized			$ 2			$ 6