Investments (Tables)

9 Months Ended

Sep. 30, 2020

Investments [Abstract]

Fair value of short and long-term investments classified as available for sale

The following tables summarize the unrealized gains and losses and estimated fair value of our investments classified as available-for-sale and restricted cash (in millions):

	September 30, 2020
	Gross Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Short-term investments:
Restricted cash	$	126	$	—	$	—	$	126
Corporate debt securities	2,568		3		—		2,571
	$	2,694	$	3	$	—	$	2,697
Long-term investments:
Corporate debt securities	387		4		—		391
	$	387	$	4	$	—	$	391

	December 31, 2019
	Gross Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Short-term investments:
Restricted cash	$	21	$	—	$	—	$	21
Corporate debt securities	1,653		1		—		1,654
Government and agency securities	175		—		—		175
	$	1,849	$	1	$	—	$	1,850
Long-term investments:
Corporate debt securities	957		4		—		961
	$	957	$	4	$	—	$	961

Estimated fair values of short and long-term investments classified by date of contractual maturity

The estimated fair values of our short-term and long-term investments classified as available-for-sale and restricted cash by date of contractual maturity as of September 30, 2020 are as follows (in millions):  

	September 30, 2020
One year or less (including restricted cash of $126)	$	2,697
One year through two years	303
Two years through three years	88
	$	3,088

Schedule of equity method investments

The following table provides a summary of our equity investments (in millions):

	September 30, 2020		December 31, 2019
Equity investments without readily determinable fair values	$	264	$	307
Equity investments under the equity method of accounting	8		7
Total equity investments	$	272	$	314

Schedule of equity securities without readily determinable fair value

The following table summarizes the change in total carrying value during the three and nine months ended September 30, 2020 and 2019 related to equity investments without readily determinable fair values still held (in millions):

	Three Months Ended September 30,				Nine Months Ended September 30,
	2020		2019		2020		2019
Carrying value, beginning of period	$	261	$	105	$	307	$	107
Additions	—		160		—		160
Downward adjustments for observable price changes and impairment	—		—		(40)		—
Foreign currency translation and other	3		(3)		(3)		(5)
Carrying value, end of period	$	264	$	262	$	264	$	262