Fair Value Measurement (Tables)

9 Months Ended

Sep. 30, 2020

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value

The following table summarizes our cash equivalents and marketable securities measured at fair value and the classification by level of input within the fair value hierarchy (in millions): 

			Fair Value Measurement at Reporting Date Using
Description	September 30, 2020		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents:
Money market funds	$	4,590	$	4,590	$	—	$	—
U.S. government securities	1,272		1,272		—		—
Certificate of deposits and time deposits	254		—		254		—
Marketable securities:
U.S. government securities	21,047		21,047		—		—
U.S. government agency securities	11,063		11,063		—		—
Corporate debt securities	11,893		—		11,893		—
Total cash equivalents and marketable securities	$	50,119	$	37,972	$	12,147	$	—

			Fair Value Measurement at Reporting Date Using
Description	December 31, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable Inputs (Level 3)
Cash equivalents:
Money market funds	$	12,787	$	12,787	$	—	$	—
U.S. government securities	815		815		—		—
U.S. government agency securities	444		444		—		—
Certificate of deposits and time deposits	217		—		217		—
Corporate debt securities	81		—		81		—
Marketable securities:
U.S. government securities	18,679		18,679		—		—
U.S. government agency securities	6,712		6,712		—		—
Corporate debt securities	10,385		—		10,385		—
Total cash equivalents and marketable securities	$	50,120	$	39,437	$	10,683	$	—