Investments

Available-for-sale investments

The amortized cost, gross unrealized gains, gross unrealized losses and fair values of available-for-sale investments by type of security were as follows (in millions):



Types of securities as of September 30, 2018	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair values
U.S. Treasury notes	$	2,710	$	—	$	(84	)	$	2,626
U.S. Treasury bills	5,376		—		—			5,376
Other government-related debt securities:
U.S.	112		—		(3		)	109
Foreign and other	1,048		1		(41		)	1,008
Corporate debt securities:
Financial	2,786		—		(89		)	2,697
Industrial	2,654		4		(80		)	2,578
Other	594		—		(21		)	573
Residential-mortgage-backed securities	1,524		—		(62		)	1,462
Other mortgage- and asset-backed securities	490		—		(17		)	473
Money market mutual funds	8,955		—		—			8,955
Other short-term interest-bearing securities	3,561		—		—			3,561
Total available-for-sale investments	$	29,810	$	5	$	(397	)	$	29,418



Types of securities as of December 31, 2017	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair values
U.S. Treasury notes	$	8,313	$	1	$	(72	)	$	8,242
Other government-related debt securities:
U.S.	225		—		(2		)	223
Foreign and other	2,415		18		(11		)	2,422
Corporate debt securities:
Financial	10,089		17		(34		)	10,072
Industrial	9,688		34		(52		)	9,670
Other	1,393		3		(6		)	1,390
Residential-mortgage-backed securities	2,198		—		(30		)	2,168
Other mortgage- and asset-backed securities	2,312		—		(15		)	2,297
Money market mutual funds	3,245		—		—			3,245
Other short-term interest-bearing securities	1,440		—		—			1,440
Total interest-bearing securities	41,318		73		(222		)	41,169
Equity securities	135		14		—			149
Total available-for-sale investments	$	41,453	$	87	$	(222	)	$	41,318

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



Condensed Consolidated Balance Sheets locations	September 30, 2018		December 31, 2017
Cash and cash equivalents	$	11,453	$	3,291
Marketable securities	17,965		37,878
Other assets	—		149
Total available-for-sale investments	$	29,418	$	41,318

Cash and cash equivalents in the above table excludes bank account cash of $503 million and $509 million as of September 30, 2018 and December 31, 2017, respectively. Other assets as of December 31, 2017, consisted of equity securities, which are no longer classified as available-for-sale.

As a result of the adoption of the new accounting standard related to the classification and measurement of financial instruments on January 1, 2018, equity investments (except for investments accounted for under the equity method of accounting) are now measured at fair value, with changes in fair value recognized in earnings. These investments were previously measured at fair value, with changes in fair value recognized in AOCI. Accordingly, these securities are no longer classified as available-for-sale and their presentation is not comparable to the presentation as of December 31, 2017. See Equity securities, discussed below, and Note 1, Summary of significant accounting policies.

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



Contractual maturities	September 30, 2018		December 31, 2017
Maturing in one year or less	$	17,943	$	6,733
Maturing after one year through three years	2,947		12,820
Maturing after three years through five years	5,585		13,836
Maturing after five years through ten years	1,008		3,263
Maturing after ten years	—		52
Mortgage- and asset-backed securities	1,935		4,465
Total interest-bearing securities	$	29,418	$	41,169

For the three months ended September 30, 2018 and 2017, realized gains on interest-bearing securities were $5 million and $26 million, respectively, and realized losses on interest-bearing securities were $108 million and $12 million, respectively. For the nine months ended September 30, 2018 and 2017, realized gains on interest-bearing securities were $27 million and $91 million, respectively, and realized losses on interest-bearing securities were $379 million and $183 million, respectively. Realized gains and losses on interest-bearing securities are recorded in Interest and other income, net, in the Condensed Consolidated Statements of Income. The cost of securities sold is based on the specific-identification method.

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 September 30, 2018	Fair values		Unrealized losses			Fair values		Unrealized losses
U.S. Treasury notes	$	1,795	$	(58	)	$	831	$	(26	)
Other government-related debt securities:
U.S.	43		(1		)	66		(2		)
Foreign and other	855		(38		)	74		(3		)
Corporate debt securities:
Financial	2,262		(74		)	397		(15		)
Industrial	1,970		(68		)	318		(12		)
Other	533		(21		)	13		—
Residential-mortgage-backed securities	673		(27		)	782		(35		)
Other mortgage- and asset-backed securities	135		(4		)	337		(13		)
Total	$	8,266	$	(291	)	$	2,818	$	(106	)



	Less than 12 months					12 months or more
Types of securities as of December 31, 2017	Fair values		Unrealized losses			Fair values		Unrealized losses
U.S. Treasury notes	$	7,728	$	(70	)	$	195	$	(2	)
Other government-related debt securities:
U.S.	188		(1		)	34		(1		)
Foreign and other	1,163		(9		)	115		(2		)
Corporate debt securities:
Financial	5,928		(28		)	462		(6		)
Industrial	5,760		(43		)	612		(9		)
Other	868		(4		)	117		(2		)
Residential-mortgage-backed securities	1,838		(24		)	276		(6		)
Other mortgage- and asset-backed securities	1,777		(12		)	250		(3		)
Total	$	25,250	$	(191	)	$	2,061	$	(31	)

The primary objective of our investment portfolio is to enhance overall returns in an efficient manner while maintaining safety of principal, prudent levels of liquidity and acceptable levels of risk. Our investment policy limits interest-bearing security investments to certain types of debt and money market instruments issued by institutions with primarily investment-grade credit ratings, and it places restrictions on maturities and concentration by asset class and issuer.

We review our available-for-sale investments for other-than-temporary declines in fair value below our cost basis each quarter and whenever events or changes in circumstances indicate that the cost basis of an asset may not be recoverable. The evaluation is based on a number of factors, including the length of time and the extent to which the fair value has been below our cost basis and adverse conditions related specifically to the security, including any changes to the credit rating of the security, and the intent to sell or whether we will more likely than not be required to sell the security before recovery of its amortized cost basis. Our assessment of whether a security is other-than-temporarily impaired could change in the future based on new developments or changes in assumptions related to that particular security. As of September 30, 2018, unrealized losses on available-for-sale investments were due primarily to higher interest rates on that date than at the time the securities were purchased. As of September 30, 2018 and December 31, 2017, we believe the cost bases for our available-for-sale investments were recoverable in all material respects.

Equity securities

We held investments in equity securities with readily determinable fair values of $217 million and $149 million as of September 30, 2018 and December 31, 2017, respectively, which are included in Other assets in the Condensed Consolidated Balance Sheets. As a result of the adoption of the new accounting standard related to the classification and measurement of financial instruments on January 1, 2018, equity investments (except for investments accounted for under the equity method of accounting) are now measured at fair value, with changes in fair value recognized in earnings. These investments were previously measured at fair value, with changes in fair value recognized in AOCI. Accordingly, these securities are no longer classified as available-for-sale and their presentation is not comparable to the presentation as of December 31, 2017. See Available-for-sale investments, discussed above, and Note 1, Summary of significant accounting policies. Gains and losses recognized on equity securities, including gains and losses recognized on sales, were not material for the three and nine months ended September 30, 2018 and 2017.

Limited partnership investments

We held limited partnership investments of $292 million and $213 million as of September 30, 2018 and December 31, 2017, respectively, which are included in Other assets in the Condensed Consolidated Balance Sheets. These investments are measured by using the net asset values of the underlying investments as a practical expedient. These investments are typically redeemable only through distributions upon liquidation of the underlying assets. As of September 30, 2018, unfunded additional commitments to be made during the next several years for these investments were not material. Gains and losses recognized on our limited partnership investments were not material.