Schedule of Future Minimum Rental Payments for Operating Leases (Details) $ in Millions	Dec. 31, 2018 USD ($)
Minimum Lease Payments
2019	$ 136
2020	125
2021	115
2022	103
2023	91
Thereafter	182
Net minimum lease commitments	752
Minimum Sublease Income
2019	(58)
2020	(2)
2021	(1)
2022	0
2023	0
Thereafter	(1)
Net minimum lease commitments	(62)
Operating Leases, Net Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019	78
2020	123
2021	114
2022	103
2023	91
Thereafter	181
Net minimum lease commitments	$ 690