Fair Value Measurement of Assets and Liabilities - Financial Assets and Liabilities Measured and Recorded at Fair Value on a Non-Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity investments measured at cost minus impairment	$ 520	$ 497	$ 369	$ 293
Fair Value, measurements, not on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable equity investments measured using the Measurement Alternative	128	303
Equity investments measured at cost minus impairment	392	194
Fair Value, measurements, not on a recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-marketable equity investments measured using the Measurement Alternative	$ 128	$ 303