Leases - Maturity of Lease Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Operating Leases
Remainder of 2019	$ 178
2020	345
2021	319
2022	283
2023	251
After 2023	1,057
Total operating lease payments	2,433
Less: Interest	276
Operating Lease, Liability	$ 2,157
Operating Leases Commitments
2019		$ 374
2020		346
2021		308
2022		258
2023		228
Due thereafter		$ 941

Amount of lessee's undiscounted obligation for lease payments for operating lease.

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Amount of lessee's undiscounted obligation for lease payments for operating lease having an initial or remaining lease term in excess of one year due in remainder of fiscal year following latest fiscal year.

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Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year 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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