Investments (Tables)

3 Months Ended

Mar. 31, 2021

Debt Securities, Available-for-sale [Abstract]

Schedule of Marketable Debt Securities

The following is a summary of our available-for-sale debt securities recorded within short-term and long-term investments on the condensed consolidated balance sheets (in millions):

	March 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available-for-sale securities:
Commercial paper	$	458	$	—	$	—	$	458
Corporate notes and bonds	2,319		6		(1)		2,324
Certificates of deposit	74		—		—		74
U.S. government and agency securities	97		—		—		97
Mortgage and asset backed securities	31		—		(1)		30
Total available-for-sale securities	$	2,979	$	6	$	(2)	$	2,983

	December 31, 2020
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available-for-sale securities:
Commercial paper	$	406	$	—	$	—	$	406
Corporate notes and bonds	2,298		10		—		2,308
Certificates of deposit	23		—		—		23
U.S. government and agency securities	145		1		—		146
Total available-for-sale securities	$	2,872	$	11	$	—	$	2,883

Investments Classified by Contractual Maturity Date

The fair values of available-for-sale securities, by remaining contractual maturity, are as follows (in millions):

	March 31, 2021
Due within 1 year	$	1,635
Due in 1 year through 5 years	1,318
Instruments not due in single maturity	30
Total	$	2,983

Fair Values and Gross Unrealized Losses of Available-for-Sale Securities Aggregated by Investment Category

As of March 31, 2021, the fair values and the gross unrealized losses of these available-for-sale debt securities, classified by the length of time that the securities have been in a continuous unrealized loss position, and aggregated by investment types, excluding those securities classified within cash and cash equivalents on the condensed consolidated balance sheets (in millions), are as follows: 

	March 31, 2021
	Less than 12 Months				12 Months or Greater				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Corporate notes and bonds	$	1,027	$	(1)	$	—	$	—	$	1,027	$	(1)
Mortgage and asset backed securities	27		(1)		—		—		27		(1)
Total	$	1,054	$	(2)	$	—	$	—	$	1,054	$	(2)