Leases (Tables)

12 Months Ended

Dec. 31, 2017

Leases [Abstract]

Future Minimum Rental Commitments

Future Minimum Lease Commitments
(In millions)	Operating Leases		Financing Obligation
2018	$	67	$	666
2019	55		730
2020	54		734
2021	53		739
2022	49		745
Thereafter	1,018		36,330
Total minimum rental commitments	$	1,296	$	39,944