Investments - (Tables)

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

Amortized cost, gross unrealized gains, gross unrealized losses and estimated fair values of available-for-sale investments by type of security

The amortized cost, gross unrealized gains, gross unrealized losses and fair values of interest-bearing securities, all of which are considered available-for-sale, by type of security were as follows (in millions):

Types of securities as of December 31, 2019	Amortized cost		Gross unrealized gains		Gross unrealized losses		Fair values
U.S. Treasury notes	$	359	$	1	$	—	$	360
U.S. Treasury bills	—		—		—		—
Other government-related debt securities:
U.S.	—		—		—		—
Foreign and other	—		—		—		—
Corporate debt securities:
Financial	1,108		13		—		1,121
Industrial	824		10		—		834
Other	195		3		—		198
Residential-mortgage-backed securities	181		1		—		182
Other mortgage- and asset-backed securities	—		—		—		—
Money market mutual funds	5,250		—		—		5,250
Other short-term interest-bearing securities	289		—		—		289
Total available-for-sale investments	$	8,206	$	28	$	—	$	8,234

Types of securities as of December 31, 2018	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair values
U.S. Treasury notes	$	2,710	$	—	$	(47	)	$	2,663
U.S. Treasury bills	8,191		—		—			8,191
Other government-related debt securities:
U.S.	112		—		(2		)	110
Foreign and other	972		1		(41		)	932
Corporate debt securities:
Financial	2,778		—		(81		)	2,697
Industrial	2,603		—		(99		)	2,504
Other	583		—		(21		)	562
Residential-mortgage-backed securities	1,458		—		(36		)	1,422
Other mortgage- and asset-backed securities	483		—		(14		)	469
Money market mutual funds	5,659		—		—			5,659
Other short-term interest-bearing securities	3,515		—		—			3,515
Total available-for-sale investments	$	29,064	$	1	$	(341	)	$	28,724

Fair values of available-for-sale investments by classification in the Consolidated Balance Sheets

The fair values of available-for-sale investments by location in the Consolidated Balance Sheets were as follows (in millions):

	December 31,
Consolidated Balance Sheets locations	2019		2018
Cash and cash equivalents	$	5,360	$	6,365
Marketable securities	2,874		22,359
Total available-for-sale investments	$	8,234	$	28,724

Fair values of available-for-sale interest-bearing security investments by contractual maturity

The fair values of available-for-sale investments by contractual maturity, except for mortgage- and asset-backed securities that do not have a single maturity date, were as follows (in millions):

	December 31,
Contractual maturities	2019		2018
Maturing in one year or less	$	5,629	$	17,424
Maturing after one year through three years	2,304		3,356
Maturing after three years through five years	119		5,168
Maturing after five years through ten years	—		885
Mortgage- and asset-backed securities	182		1,891
Total available-for-sale investments	$	8,234	$	28,724

Available-for-sale securities, continuous unrealized loss position, fair value

As of December 31, 2018, the fair values and gross unrealized losses of available-for-sale investments in an unrealized loss position aggregated by type and length of time that the securities have been in a continuous loss position were as follows (in millions):

	Less than 12 months					12 months or more
Types of securities as of December 31, 2018	Fair values		Unrealized losses			Fair values		Unrealized losses
U.S. Treasury notes	$	1,219	$	(21	)	$	1,444	$	(26	)
Other government-related debt securities:
U.S.	—		—			110		(2		)
Foreign and other	631		(31		)	240		(10		)
Corporate debt securities:
Financial	1,968		(59		)	718		(22		)
Industrial	1,898		(81		)	529		(18		)
Other	529		(20		)	28		(1		)
Residential-mortgage-backed securities	576		(14		)	840		(22		)
Other mortgage- and asset-backed securities	17		—			451		(14		)
Total	$	6,838	$	(226	)	$	4,360	$	(115	)