Derivative and Financial Instruments - Cost Basis to Fair Value (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	$ 472	$ 472	$ 241
Fair Value	475	475	241
Proceeds from sales and redemptions of investments in debt securities classified as available for sale	126	189
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	276	276	159
Fair Value	278	278	159
Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	130	130	38
Fair Value	130	130	38
US Government Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	25	25	25
Fair Value	26	26	25
U.S. Government Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	4	4	0
Fair Value	4	4	0
Asset-backed Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost Basis	37	37	19
Fair Value	$ 37	$ 37	$ 19

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of cash inflow from sale, maturity, prepayment and call of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3151-108585

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 230
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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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No definition available.

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