Financial Instruments and Fair Value Measurements - (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Summary of Financial Instruments by Significant Categories and Fair Value Measurement on a Recurring Basis

The following tables summarize our financial instruments by significant categories and fair value measurement on a recurring basis as of March 31, 2021 and December 31, 2020.

(in millions)	Level 1		Level 2		Total
March 31, 2021
Cash equivalents:
Money market mutual funds	$	127	$	—	127
Total cash equivalents	127		—		127
Investments:
Asset-backed securities	—		25		25
Corporate bonds	—		89		89
U.S. government agencies and government-sponsored agencies	—		5		5
U.S. treasuries	—		77		77
Other debt securities	—		6		6
Total investments	—		202		202
Restricted cash equivalents:
Money market mutual funds	95		—		95
Certificate of deposit	—		1		1
Commercial paper	—		—		—
Total restricted cash equivalents	95		1		96
Restricted investments:
Corporate bonds	—		34		34
U.S. government agencies and government-sponsored agencies	—		18		18
U.S. treasuries	—		182		182
Certificate of deposit	—		9		9
Total restricted investments	—		243		243
Total cash equivalents and investments and restricted cash equivalents and investments	$	222	$	446	$	668

(in millions)	Level 1		Level 2		Total
December 31, 2020
Cash equivalents
Money market mutual funds	$	2	$	—	$	2
U.S. treasuries	—		11		11
Total cash equivalents	2		11		13
Investments
Asset-backed securities	—		24		24
Corporate bonds	—		93		93
U.S. government agencies and government-sponsored agencies	—		5		5
U.S. treasuries	—		67		67
Other debt securities	—		6		6
Total investments	—		195		195
Restricted cash equivalents:
Money market mutual funds	99		—		99
Total restricted cash equivalents	99		—		99
Restricted investments:
Corporate bonds	—		35		35
U.S. government agencies and government-sponsored agencies	—		23		23
U.S. treasuries	—		198		198
Total restricted investments	—		256		256
Total investments and restricted cash equivalents and investments	$	101	$	462	$	563