Sales and Other Operating Revenue - Receivables and Contract LIabilities (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Dec. 31, 2018
Revenue, Performance Obligation, Description of Payment Terms	We typically receive payment within 30 days or less (depending on the terms of the invoice) once delivery is made.
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Explanation	We expect to recognize the contract liabilities as of March 31, 2019, as revenue between the remainder of 2019 and 2022.
Contract with Customer, Liability [Abstract]
Contract with Customer, Liability Beginning Balance	$ 206
Contract with Customer, Liability, Cash Received	14
Contract with Customer, Liability, Revenue Recognized	133
Contract with Customer, Liability Ending Balance	87
Trade Accounts Receivable [Member]
Accounts Receivable, Net	2,638	$ 2,889
Short-term Contract with Customer [Member]
Contract with Customer, Liability [Abstract]
Contract with Customer, Liability Ending Balance	49
Long-term Contract with Customer [Member]
Contract with Customer, Liability [Abstract]
Contract with Customer, Liability Ending Balance	$ 38

Payment received included in balance of obligation to transfer good or service to customer.

No definition available.

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- Definition

For an unclassified balance sheet, the amount due from customers or clients for goods or services that have been delivered or sold in the normal course of business, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable.

+ References

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- References

No definition available.

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

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- Definition

Description of payment terms in contract with customer. Includes, but is not limited to, timing of payment, existence of financing component, variability of consideration and constraint on variable consideration.

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- Definition

Description of when remaining performance obligation is expected to be recognized as revenue.

+ References

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