Fair Value Measurements and Disclosures - Assets Measured on Recurring Basis or Disclosed at Fair Value (Details) - Recurring Fair Value Measurements [Member] - USD ($) $ in Millions		Mar. 31, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure		$ 480	$ 808
Short-term investments, Fair Value Measurement or Disclosure		3,026	3,105
Total assets, Fair Value Measurement or Disclosure		3,974	4,134
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure			207
Short-term investments, Fair Value Measurement or Disclosure			260
Total assets, Fair Value Measurement or Disclosure		405	627
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure		480	601
Short-term investments, Fair Value Measurement or Disclosure		3,026	2,845
Total assets, Fair Value Measurement or Disclosure		3,569	3,507
Time Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure		410	601
Short-term investments, Fair Value Measurement or Disclosure		2,058	2,165
Other assets, Fair Value Measurement or Disclosure			61
Time Deposits [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure		410	601
Short-term investments, Fair Value Measurement or Disclosure		2,058	2,165
Other assets, Fair Value Measurement or Disclosure			61
Fixed Income Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure	[1]	70	207
Short-term investments, Fair Value Measurement or Disclosure	[1]	800	784
Fixed Income Debt Securities [Member] | Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure	[1]		207
Short-term investments, Fair Value Measurement or Disclosure	[1]		104
Fixed Income Debt Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents, Fair Value Measurement or Disclosure	[1]	70
Short-term investments, Fair Value Measurement or Disclosure	[1]	800	680
Structured Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments, Fair Value Measurement or Disclosure	[2]	168
Structured Deposits [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments, Fair Value Measurement or Disclosure	[2]	168
Variable Return Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments, Fair Value Measurement or Disclosure			156
Variable Return Investments [Member] | Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Short-term investments, Fair Value Measurement or Disclosure			156
Investment in Equity Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets, Fair Value Measurement or Disclosure		405	160
Investment in Equity Securities [Member] | Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets, Fair Value Measurement or Disclosure		405	$ 160
Long-term Time Deposits [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets, Fair Value Measurement or Disclosure		63
Long-term Time Deposits [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets, Fair Value Measurement or Disclosure		$ 63

[1] Classified as held-to-maturity investments and measured at amortized cost.

[2] Represented certain structured deposits invested in the first quarter of 2021. These investments are principal-protected and provide returns in the form of both fixed and variable interests. Such variable interest rates indexed to gold prices or foreign exchange rates are considered embedded derivatives and bifurcated from host contracts, and measured at fair value on a recurring basis.