Cash and Cash Equivalents, Investments and Funds Held for Customers

We consider highly liquid investments with maturities of three months or less at the date of purchase to be cash equivalents. Cash equivalents consist primarily of AAA-rated money market funds in all periods presented. Investments at July 31, 2015 consisted of available-for-sale investment-grade debt securities that we carried at fair value. Funds held for customers consist of cash and cash equivalents and investment grade available-for-sale debt securities in all periods presented. Except for direct obligations of the United States government, securities issued by agencies of the United States government, and money market funds, we diversify our investments in debt securities by limiting our holdings with any individual issuer.

The following table summarizes our cash and cash equivalents, investments, and funds held for customers by balance sheet classification at the dates indicated.



	January 31, 2016				July 31, 2015
(In millions)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Classification on balance sheets:
Cash and cash equivalents	$	334	$	334	$	808	$	808
Investments	—		—		890		889
Funds held for customers	373		373		337		337
Long-term investments	28		28		27		27
Total cash and cash equivalents, investments, and funds held for customers	$	735	$	735	$	2,062	$	2,061

The following table summarizes our cash and cash equivalents, investments, and funds held for customers by investment category at the dates indicated.



	January 31, 2016				July 31, 2015
(In millions)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Type of issue:
Total cash and cash equivalents	$	532	$	532	$	970	$	970
Available-for-sale debt securities:
Municipal bonds	6		6		507		506
Corporate notes	169		169		546		546
U.S. agency securities	—		—		12		12
Municipal auction rate securities	15		15		15		15
Total available-for-sale debt securities	190		190		1,080		1,079
Other long-term investments	13		13		12		12
Total cash and cash equivalents, investments, and funds held for customers	$	735	$	735	$	2,062	$	2,061

We use the specific identification method to compute gains and losses on investments. We include realized gains and losses on our available-for-sale debt securities in interest and other income, net in our statements of operations. Gross realized gains and losses on our available-for-sale debt securities for the three and six months ended January 31, 2016 and January 31, 2015 were not significant.

We accumulate unrealized gains and losses on our available-for-sale debt securities, net of tax, in accumulated other comprehensive income or loss in the stockholders’ equity section of our balance sheets. Gross unrealized gains and losses on our available-for-sale debt securities at January 31, 2016 and July 31, 2015 were not significant.

We periodically review our investment portfolios to determine if any investment is other-than-temporarily impaired due to changes in credit risk or other potential valuation concerns. We believe that the investments we held at January 31, 2016 were not other-than-temporarily impaired. Unrealized losses on available-for-sale debt securities at January 31, 2016 were not significant and were due to changes in interest rates, including market credit spreads, and not due to increased credit risks associated with specific securities. We do not intend to sell these investments. In addition, it is more likely than not that we will not be required to sell them before recovery at par, which may be at maturity.

The following table summarizes our available-for-sale debt securities classified by the stated maturity date of the security at the dates indicated.



	January 31, 2016				July 31, 2015
(In millions)	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due within one year	$	89	$	89	$	434	$	435
Due within two years	41		41		443		442
Due within three years	45		45		156		156
Due after three years	15		15		47		46
Total available-for-sale debt securities	$	190	$	190	$	1,080	$	1,079

Available-for-sale debt securities due after three years in the table above include our municipal auction rate securities. See Note 2, “Fair Value Measurements,” for more information. All of the remaining securities in that category had interest reset dates or mandatory call dates within three years of the dates indicated in the table.