Leases (Summary of Financial Information Associated with Leases) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets
Operating lease right-of-use assets	$ 666	$ 669
Total leased assets	892	877
Current
Accrued expenses and other liabilities	177	178
Short-term debt and current maturities of long-term debt	49	58
Long-term
Operating lease liabilities	530	533
Long-term debt	97	69
Total lease liabilities	853	838
Rental equipment
Assets
Finance lease assets, gross	296	286
Less accumulated depreciation and amortization	(87)	(89)
Finance lease assets, net	209	197
Property and equipment, net
Assets
Less accumulated depreciation and amortization	(9)	(15)
Finance lease assets, net	17	11
Non-rental vehicles
Assets
Finance lease assets, gross	8	8
Buildings
Assets
Finance lease assets, gross	$ 18	$ 18