Indicates (true false) whether practical expedient is elected to use hindsight in determining lease term and in assessing impairment of right-of-use asset.

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Indicates (true false) whether practical expedients are elected for not reassessing whether any expired or existing contract is or contains lease, lease classification for expired or existing lease, and initial direct cost for any existing lease.

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Indicates (true false) whether lessee has option to extend finance lease.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Indicates (true false) whether lessee has option to extend operating lease.

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Present value of lessee's discounted obligation for lease payments from operating lease.

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Amount of lessee's right to use underlying asset under operating lease.

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Leases (Details) - USD ($) $ in Millions	12 Months Ended
Leases (Details) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases
Stockholders' equity	$ 10,063			$ 9,796
Operating leases, existence of option to extend	true
Finance leases, existence of option to extend	true
Lease liabilities	$ 854
Operating lease right of use assets	$ 858
Lease, Practical Expedients, Package [true false]	true
Lease, Practical Expedient, Use of Hindsight [true false]	false
ASU 2016-02 Leases
Leases
Lease liabilities		$ 800
Operating lease right of use assets		$ 800
Adjustment \| ASU 2016-02 Leases
Leases
Lease liabilities			$ 800
Operating lease right of use assets			800
Retained Earnings \| Adjustment \| ASU 2016-02 Leases
Leases
Stockholders' equity			$ 14