Income Taxes (Components of deferred tax assets and liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Reserves and allowances	$ 129	$ 111
Debt cancellation and other	10	8
Net operating loss and credit carryforwards	242	371
Operating lease assets	183	182
Total deferred tax assets	564	672
Valuation allowance	(21)	(43)
Total net deferred tax assets	543	629
Property and equipment, including rental equipment	(1,962)	(2,135)
Operating lease liabilities	(183)	(182)
Intangibles	(166)	(199)
Total deferred tax liability	(2,311)	(2,516)
Total net deferred tax liability	$ (1,768)	$ (1,887)