CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS
 3 Months Ended
Apr. 30, 2016
Cash, Cash Equivalents, and Short-term Investments [Abstract]  
Cash, Cash Equivalents and Short-term Investments
CASH, CASH EQUIVALENTS, AND SHORT-TERM INVESTMENTS

The following tables summarize our cash, cash equivalents, and short-term investments as of April 30, 2016 and January 31, 2016:
 
 
April 30, 2016
(in thousands) 
 
Cost Basis
 
Gross Unrealized Gains
 
Gross Unrealized Losses
 
Estimated Fair Value
Cash and cash equivalents:
 
 
 
 
 
 
 
 
Cash and bank time deposits
 
$
306,252

 
$
—

 
$
—

 
$
306,252

Money market funds
 
170

 
—

 
—

 
170

Commercial paper and corporate debt securities
 
17,483

 
—

 
—

 
17,483

Total cash and cash equivalents
 
$
323,905

 
$
—

 
$
—

 
$
323,905

 
 
 
 
 
 
 
 
 
Short-term investments:
 
 
 
 
 
 
 
 
Commercial paper and corporate debt securities (available-for-sale)
 
$
41,036

 
$
—

 
$
(5
)
 
$
41,031

Bank time deposits
 
7,056

 
—

 
—

 
7,056

Total short-term investments
 
$
48,092

 
$
—

 
$
(5
)
 
$
48,087

 
 
January 31, 2016
(in thousands)
 
Cost Basis
 
Gross Unrealized Gains
 
Gross Unrealized Losses
 
Estimated Fair Value
Cash and cash equivalents:
 
 
 
 
 
 
 
 
Cash and bank time deposits
 
$
334,938

 
$
—

 
$
—

 
$
334,938

Money market funds
 
12,137

 
—

 
—

 
12,137

Commercial paper and corporate debt securities
 
5,054

 
—

 
(24
)
 
5,030

Total cash and cash equivalents
 
$
352,129

 
$
—

 
$
(24
)
 
$
352,105

 
 
 
 
 
 
 
 
 
Short-term investments:
 
 
 
 
 
 
 
 
Commercial paper and corporate debt securities (available-for-sale)
 
$
53,018

 
$
—

 
$
(86
)
 
$
52,932

Bank time deposits
 
3,050

 
—

 
—

 
3,050

Total short-term investments
 
$
56,068

 
$
—

 
$
(86
)
 
$
55,982



Bank time deposits which are reported within short-term investments consist of deposits held outside of the U.S. with maturities of greater than 90 days, or without specified maturity dates which we intend to hold for periods in excess of 90 days. All other bank deposits are included within cash and cash equivalents.

As of April 30, 2016 and January 31, 2016, all of our available-for-sale investments had contractual maturities of less than one year. Gains and losses on sales of available-for-sale securities during the three months ended April 30, 2016 and 2015 were not significant.

During the three months ended April 30, 2016 and 2015, proceeds from maturities and sales of available-for-sale securities were $32.9 million and $5.5 million, respectively.

We believe that the investments we held at April 30, 2016 were not other-than-temporarily impaired. We held available-for-sale securities with aggregate fair values of $17.0 million which had insignificant unrealized losses at April 30, 2016. We do not intend to sell our available-for-sale securities and it is not more likely than not that we will be required to sell them before recovery at par, which may be at maturity.