Leases - Future Minimum Rental Commitments (Details) $ in Millions	Dec. 31, 2018 USD ($)
Leases [Abstract]
Noncancelable Operating Leases, Due 2019	$ 82
Minimum Lease Payments, Sale Leaseback Transactions, Next Twelve Months	753
Noncancelable Operating Leases, Due 2020	70
Minimum Lease Payments, Sale Leaseback Transactions, within Two Years	809
Noncancelable Operating Leases, Due 2021	57
Minimum Lease Payments, Sale Leaseback Transactions, within Three Years	822
Noncancelable Operating Leases, Due 2022	53
Minimum Lease Payments, Sale Leaseback Transactions, within Four Years	836
Noncancelable Operating Leases, Due 2023	51
Minimum Lease Payments, Sale Leaseback Transactions, within Five Years	855
Noncancelable Operating Leases, Due 2024 and thereafter	966
Minimum Lease Payments, Sale Leaseback Transactions, Thereafter	34,333
Noncancelable Operating Leases, Total minimum rental commitments	1,279
Minimum Lease Payments, Sale Leaseback Transactions	$ 38,408

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing.

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments for sale-leaseback transactions accounted for using the deposit method or as a financing due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

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