Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Foreign currency forward contracts
Liabilities
Foreign currency forward contracts	$ 26	$ 14
Recurring Basis
Investments:
Total assets	467	493
Recurring Basis \| Foreign currency forward contracts
Liabilities
Foreign currency forward contracts	26	14
Recurring Basis \| Money market funds
Cash equivalents:
Cash equivalents:	257	147
Recurring Basis \| Mutual Fund
Cash equivalents:
Cash equivalents:	24
Recurring Basis \| Term deposits
Cash equivalents:
Cash equivalents:	48	49
Investments:
Investments:	11	24
Recurring Basis \| U.S. treasury securities
Cash equivalents:
Cash equivalents:		150
Recurring Basis \| Marketable equity securities
Investments:
Investments:	127	123
Recurring Basis \| Level 1
Investments:
Total assets	408	420
Recurring Basis \| Level 1 \| Foreign currency forward contracts
Liabilities
Foreign currency forward contracts	0	0
Recurring Basis \| Level 1 \| Money market funds
Cash equivalents:
Cash equivalents:	257	147
Recurring Basis \| Level 1 \| Mutual Fund
Cash equivalents:
Cash equivalents:	24
Recurring Basis \| Level 1 \| Term deposits
Cash equivalents:
Cash equivalents:	0	0
Investments:
Investments:	0	0
Recurring Basis \| Level 1 \| U.S. treasury securities
Cash equivalents:
Cash equivalents:		150
Recurring Basis \| Level 1 \| Marketable equity securities
Investments:
Investments:	127	123
Recurring Basis \| Level 2
Investments:
Total assets	59	73
Recurring Basis \| Level 2 \| Foreign currency forward contracts
Liabilities
Foreign currency forward contracts	26	14
Recurring Basis \| Level 2 \| Money market funds
Cash equivalents:
Cash equivalents:	0	0
Recurring Basis \| Level 2 \| Mutual Fund
Cash equivalents:
Cash equivalents:	0
Recurring Basis \| Level 2 \| Term deposits
Cash equivalents:
Cash equivalents:	48	49
Investments:
Investments:	11	24
Recurring Basis \| Level 2 \| U.S. treasury securities
Cash equivalents:
Cash equivalents:		0
Recurring Basis \| Level 2 \| Marketable equity securities
Investments:
Investments:	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value as of the balance sheet date of all foreign currency derivative liabilities not designated as hedging instruments.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
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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

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
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