Income Taxes - Deferred Tax Assets (Liabilities) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss, capital loss and tax credit carry-forwards	$ 150	$ 258
Landfill and environmental remediation liabilities	156	143
Operating lease liabilities	114
Miscellaneous and other reserves, net	150	175
Subtotal	570	576
Valuation allowance	(162)	(261)
Deferred tax liabilities:
Property and equipment	(842)	(752)
Goodwill and other intangibles	(865)	(854)
Operating lease right-of-use assets	(108)
Net deferred tax liabilities	(1,407)	$ (1,291)
Increase (decrease) valuation allowance	$ (99)