Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of assets measured at fair value on a recurring basis

Assets Measured at Fair Value on a Recurring Basis

(in millions)	March 31, 2021		Level 1		Level 2		Level 3
Cash equivalents	$	6,004	$	6,004	$	—	$	—
Restricted cash equivalents	1,436		1,436		—		—
Short-term investments	5,575		3,564		2,011		—
Long-term investments	1,673		895		557		221

(in millions)	December 31, 2020		Level 1		Level 2		Level 3
Cash equivalents	$	5,755	$	5,755	$	—	$	—
Restricted cash equivalents	1,747		1,747		—		—
Short-term investments	5,789		3,919		1,870		—
Long-term investments	1,417		948		38		431