Debt	12 Months Ended
Jan. 31, 2016
Debt Disclosure [Abstract]
Debt	Note 8. Debt In December 2010, we entered into a Loan and Security Agreement with Hercules Technology Growth Capital, Inc. (Hercules) with a maturity date of December 31, 2014, and amended such agreement in January 2011 (the Hercules 2010 Agreement). Under the Hercules 2010 Agreement, equipment loans of up to $3.0 million and a growth capital loan of up to $7.0 million were available for draw through October 31, 2011, at an interest rate equal to the greater of (a) the prime rate on the date of the draw as reported by the Wall Street Journal plus 5.25%, and (b) 8.50%. With respect to equipment loans, the Hercules 2010 Agreement has an end of term payment of 5% of the aggregate amount borrowed. In March 2011, we drew equipment loan borrowings of $1.6 million at an interest rate of 8.50%. Principal payments of $968,000 and $577,000 were made during the years ended January 31, 2014 and 2013, respectively. Also, in connection with the Hercules 2010 Agreement, we granted Hercules a security interest in all equipment financed under the Hercules 2010 Agreement and issued warrants to purchase 199,219 shares of our Series C redeemable convertible preferred stock. Separately, in March 2011, Hercules purchased 158,133 shares of our Series D redeemable convertible preferred stock at a purchase price of $3.1619 per share. In August 2011, we entered into a Loan and Security Agreement with Hercules with a maturity date of March 1, 2016, and amended such agreement in March 2012 (the Hercules 2011 Agreement). Under the Hercules 2011 Agreement, equipment loans of up to $10.0 million were available for draw through June 30, 2012, at an interest rate equal to the greater of (a) 7.5% plus the prime rate as reported in The Wall Street Journal minus 3.75%, and (b) 7.5%. In addition, there was an end of term payment of 2.5% of the aggregate amount borrowed. Under the Hercules 2011 Agreement, we drew equipment loan borrowings of $4.8 million, $4.8 million and $353,000 at an interest rate of 7.5% in September 2011, December 2011, and April 2012. Principal payments of $10.0 million were made during the year ended January 31, 2014. No principal payments were made during the year ended January 31, 2013. Also, in connection with the Hercules 2011 Agreement, we granted Hercules a security interest in all equipment financed under the agreement and issued warrants to purchase 62,255 shares of our Series D-1 redeemable convertible preferred stock. Separately, in September 2011, Hercules purchased 124,511 shares of our Series D-1 redeemable convertible preferred stock at a purchase price of $8.0314 per share. In March 2012, we entered into a Loan and Security Agreement with Hercules with a maturity date of July 1, 2016 and amended such agreement in June 2012 (the Hercules 2012 Agreement). Under this agreement, growth capital loans of up to $20.0 million were available for draw through June 30, 2012, at an interest rate equal to the greater of (a) 8.875% plus the prime rate as reported in The Wall Street Journal minus 3.75%, and (b) 8.875%. Under the Hercules 2012 Agreement, we had an end of term payment of 4.5% of the aggregate amount borrowed. In March 2012, May 2012, and June 2012, we drew loan borrowings of $5.0 million, $5.0 million and $10.0 million at an interest rate of 8.375%. Principal payment of $20.0 million was made during the year ended January 31, 2014. No principal payments were made during the year ended January 31, 2013. Also, in connection with the Hercules 2012 Agreement, we granted the lender a security interest in all equipment financed under the agreement and all of our patents, patent applications, copyrights, trademarks and trademark applications. Separately, in March 2012, Hercules purchased 220,751 shares of our Series D-2 redeemable convertible preferred stock at a purchase price of $9.0657 per share. The loan and security agreements with Hercules discussed above provided certain financial-related covenants, among others, relating to delivery of audited financial statements to Hercules. We received waivers from Hercules for not complying with the covenants and accordingly did not change the classification of the related Notes Payable to short term at January 31, 2013. We were not otherwise in default on the loan. In August 2013, we repaid the Hercules loans in conjunction with entering into a line of credit agreement discussed below. Accordingly, the related remaining unamortized debt issuance and end of term fees, along with the early pay off penalty, of $1.4 million was expensed immediately and was included in interest expense, net in the consolidated statement of operations. In conjunction with the Hercules loans, we incurred interest expense of $3.0 million and $1.9 million during the years ended January 31, 2014 and 2013, respectively. During the same periods we capitalized $200,000 and $585,000 of interest costs. Interest expense consists of offering costs, including the amortization of the initial fair value of the redeemable convertible preferred stock warrants issued in connection with obtaining the loan, and amortization of end of term payments, commitment and legal and facility fees, as appropriate, over the related term of the loan using the effective interest rate method, as well as the expenses incurred when we repaid the Hercules loans in August 2013, as discussed above. Line of Credit In August 2013, we entered into a two-year $100.0 million secured revolving credit facility (August 2013 Facility). The August 2013 Facility is denominated in U.S. dollars and, depending on certain conditions, each borrowing is subject to a floating interest rate equal to the London Interbank Offer Rate (LIBOR) plus 3.0% or the Alternate Base Rate (ABR) plus 2.0%. In addition, there is a commitment fee of 0.5% on outstanding unused commitment amount. At closing, we drew $34.0 million at 3.4% (six month LIBOR plus 3.0%) which we used to repay the outstanding Hercules loans and the related early payoff and end of term fees, as well as for other general corporate purposes. In July 2014, we drew an additional $12.0 million under the credit facility at 3.3% (six month LIBOR plus 3.0%). In September 2014, we paid down $6.0 million and amended the credit facility to reduce our borrowing capacity from $100.0 million to $75.0 million and extend the facility through August 2016. Concurrently and in conjunction with the execution of our new headquarters lease in September 2014, letters of credit in the aggregate amount of $25.0 million were issued under the credit facility. These letters of credit reduce our total borrowing capacity under the credit facility and are subject to interest at 3.25% per annum. As of January 31, 2015, the outstanding borrowings under the credit facility were $40.0 million, and our remaining borrowing capacity under the credit facility was $10.0 million. In March 2015, we amended the August 2013 Facility to reduce our borrowing capacity to $60.0 million as of April 2015, and to increase certain limitations on the amount of capital asset and real estate related obligations we may incur. In connection with this amendment, the letters of credit under the August 2013 Facility were cancelled, and a new letter of credit in the amount of $25.0 million was issued by a party not affiliated with the August 2013 Facility, which was secured by a certificate of deposit in the same amount. Borrowings under the August 2013 Facility were collateralized by substantially all of our assets. The August 2013 Facility also contained various covenants, including covenants related to the delivery of financial and other information, the maintenance of quarterly financial covenants, material adverse effects, as well as limitations on dispositions, mergers or consolidations and other corporate activities. In December 2015, we paid in full all amounts outstanding under the August 2013 Facility, including the outstanding principal balance of $40.0 million, and terminated the August 2013 Facility and all related loan documents and collateral documents, in conjunction with entering into a new revolving credit facility with a different lender (December 2015 Facility). The December 2015 Facility provides for a revolving loan facility in the amount of up to $40.0 million maturing in December 2017. The December 2015 Facility is denominated in U.S. dollars and, depending on certain conditions, each borrowing is subject to a floating interest rate equal to either the prime rate plus a spread of 0.25% to 2.75% or a reserve adjusted LIBOR rate (based on one, three or six-month interest periods) plus a spread of 1.25% to 3.75%. Although no minimum deposit is required for the December 2015 Facility, we are eligible for the lowest interest rate if we maintain at least $40 million in deposits with the lender. In addition, there is an annual fee of 0.2% on the total commitment amount. At closing, we drew $40.0 million at 1.82% (six month LIBOR plus 1.25%) which we used repay the outstanding principal balance under the August 2013 Facility. Borrowings under the December 2015 Facility are collateralized by substantially all of our assets in the United States. It also contains various covenants, including covenants related to the delivery of financial and other information, the maintenance of quarterly financial covenants, as well as customary limitations on dispositions, mergers or consolidations and other corporate activities. As of January 31, 2016, we were in compliance with all financial covenants. In connection with the above credit facilities, we incurred interest expense, net of capitalized interest costs, of $1.9 million, $2.5 million and $946,000 during the years ended January 31, 2016, 2015 and 2014, respectively. During the same periods, we capitalized $400,000, $311,000 and $84,000 of interest costs. Interest expense also includes amortization of issuance costs, unused commitment fees and fees on letters of credit which are recognized over the related term of the borrowing.

Note 8. Debt

In December 2010, we entered into a Loan and Security Agreement with Hercules Technology Growth Capital, Inc. (Hercules) with a maturity date of December 31, 2014, and amended such agreement in January 2011 (the Hercules 2010 Agreement). Under the Hercules 2010 Agreement, equipment loans of up to $3.0 million and a growth capital loan of up to $7.0 million were available for draw through October 31, 2011, at an interest rate equal to the greater of (a) the prime rate on the date of the draw as reported by the Wall Street Journal plus 5.25%, and (b) 8.50%. With respect to equipment loans, the Hercules 2010 Agreement has an end of term payment of 5% of the aggregate amount borrowed. In March 2011, we drew equipment loan borrowings of $1.6 million at an interest rate of 8.50%. Principal payments of $968,000 and $577,000 were made during the years ended January 31, 2014 and 2013, respectively. Also, in connection with the Hercules 2010 Agreement, we granted Hercules a security interest in all equipment financed under the Hercules 2010 Agreement and issued warrants to purchase 199,219 shares of our Series C redeemable convertible preferred stock. Separately, in March 2011, Hercules purchased 158,133 shares of our Series D redeemable convertible preferred stock at a purchase price of $3.1619 per share.

In August 2011, we entered into a Loan and Security Agreement with Hercules with a maturity date of March 1, 2016, and amended such agreement in March 2012 (the Hercules 2011 Agreement). Under the Hercules 2011 Agreement, equipment loans of up to $10.0 million were available for draw through June 30, 2012, at an interest rate equal to the greater of (a) 7.5% plus the prime rate as reported in The Wall Street Journal minus 3.75%, and (b) 7.5%. In addition, there was an end of term payment of 2.5% of the aggregate amount borrowed. Under the Hercules 2011 Agreement, we drew equipment loan borrowings of $4.8 million, $4.8 million and $353,000 at an interest rate of 7.5% in September 2011, December 2011, and April 2012. Principal payments of $10.0 million were made during the year ended January 31, 2014. No principal payments were made during the year ended January 31, 2013. Also, in connection with the Hercules 2011 Agreement, we granted Hercules a security interest in all equipment financed under the agreement and issued warrants to purchase 62,255 shares of our Series D-1 redeemable convertible preferred stock. Separately, in September 2011, Hercules purchased 124,511 shares of our Series D-1 redeemable convertible preferred stock at a purchase price of $8.0314 per share.

In March 2012, we entered into a Loan and Security Agreement with Hercules with a maturity date of July 1, 2016 and amended such agreement in June 2012 (the Hercules 2012 Agreement). Under this agreement, growth capital loans of up to $20.0 million were available for draw through June 30, 2012, at an interest rate equal to the greater of (a) 8.875% plus the prime rate as reported in The Wall Street Journal minus 3.75%, and (b) 8.875%. Under the Hercules 2012 Agreement, we had an end of term payment of 4.5% of the aggregate amount borrowed. In March 2012, May 2012, and June 2012, we drew loan borrowings of $5.0 million, $5.0 million and $10.0 million at an interest rate of 8.375%. Principal payment of $20.0 million was made during the year ended January 31, 2014. No principal payments were made during the year ended January 31, 2013. Also, in connection with the Hercules 2012 Agreement, we granted the lender a security interest in all equipment financed under the agreement and all of our patents, patent applications, copyrights, trademarks and trademark applications. Separately, in March 2012, Hercules purchased 220,751 shares of our Series D-2 redeemable convertible preferred stock at a purchase price of $9.0657 per share.

The loan and security agreements with Hercules discussed above provided certain financial-related covenants, among others, relating to delivery of audited financial statements to Hercules. We received waivers from Hercules for not complying with the covenants and accordingly did not change the classification of the related Notes Payable to short term at January 31, 2013. We were not otherwise in default on the loan.

In August 2013, we repaid the Hercules loans in conjunction with entering into a line of credit agreement discussed below. Accordingly, the related remaining unamortized debt issuance and end of term fees, along with the early pay off penalty, of $1.4 million was expensed immediately and was included in interest expense, net in the consolidated statement of operations.

In conjunction with the Hercules loans, we incurred interest expense of $3.0 million and $1.9 million during the years ended January 31, 2014 and 2013, respectively. During the same periods we capitalized $200,000 and $585,000 of interest costs. Interest expense consists of offering costs, including the amortization of the initial fair value of the redeemable convertible preferred stock warrants issued in connection with obtaining the loan, and amortization of end of term payments, commitment and legal and facility fees, as appropriate, over the related term of the loan using the effective interest rate method, as well as the expenses incurred when we repaid the Hercules loans in August 2013, as discussed above.

Line of Credit

In August 2013, we entered into a two-year $100.0 million secured revolving credit facility (August 2013 Facility). The August 2013 Facility is denominated in U.S. dollars and, depending on certain conditions, each borrowing is subject to a floating interest rate equal to the London Interbank Offer Rate (LIBOR) plus 3.0% or the Alternate Base Rate (ABR) plus 2.0%. In addition, there is a commitment fee of 0.5% on outstanding unused commitment amount. At closing, we drew $34.0 million at 3.4% (six month LIBOR plus 3.0%) which we used to repay the outstanding Hercules loans and the related early payoff and end of term fees, as well as for other general corporate purposes. In July 2014, we drew an additional $12.0 million under the credit facility at 3.3% (six month LIBOR plus 3.0%). In September 2014, we paid down $6.0 million and amended the credit facility to reduce our borrowing capacity from $100.0 million to $75.0 million and extend the facility through August 2016. Concurrently and in conjunction with the execution of our new headquarters lease in September 2014, letters of credit in the aggregate amount of $25.0 million were issued under the credit facility. These letters of credit reduce our total borrowing capacity under the credit facility and are subject to interest at 3.25% per annum. As of January 31, 2015, the outstanding borrowings under the credit facility were $40.0 million, and our remaining borrowing capacity under the credit facility was $10.0 million.

In March 2015, we amended the August 2013 Facility to reduce our borrowing capacity to $60.0 million as of April 2015, and to increase certain limitations on the amount of capital asset and real estate related obligations we may incur. In connection with this amendment, the letters of credit under the August 2013 Facility were cancelled, and a new letter of credit in the amount of $25.0 million was issued by a party not affiliated with the August 2013 Facility, which was secured by a certificate of deposit in the same amount.

Borrowings under the August 2013 Facility were collateralized by substantially all of our assets. The August 2013 Facility also contained various covenants, including covenants related to the delivery of financial and other information, the maintenance of quarterly financial covenants, material adverse effects, as well as limitations on dispositions, mergers or consolidations and other corporate activities.

In December 2015, we paid in full all amounts outstanding under the August 2013 Facility, including the outstanding principal balance of $40.0 million, and terminated the August 2013 Facility and all related loan documents and collateral documents, in conjunction with entering into a new revolving credit facility with a different lender (December 2015 Facility). The December 2015 Facility provides for a revolving loan facility in the amount of up to $40.0 million maturing in December 2017.

The December 2015 Facility is denominated in U.S. dollars and, depending on certain conditions, each borrowing is subject to a floating interest rate equal to either the prime rate plus a spread of 0.25% to 2.75% or a reserve adjusted LIBOR rate (based on one, three or six-month interest periods) plus a spread of 1.25% to 3.75%. Although no minimum deposit is required for the December 2015 Facility, we are eligible for the lowest interest rate if we maintain at least $40 million in deposits with the lender. In addition, there is an annual fee of 0.2% on the total commitment amount. At closing, we drew $40.0 million at 1.82% (six month LIBOR plus 1.25%) which we used repay the outstanding principal balance under the August 2013 Facility. Borrowings under the December 2015 Facility are collateralized by substantially all of our assets in the United States. It also contains various covenants, including covenants related to the delivery of financial and other information, the maintenance of quarterly financial covenants, as well as customary limitations on dispositions, mergers or consolidations and other corporate activities. As of January 31, 2016, we were in compliance with all financial covenants.

In connection with the above credit facilities, we incurred interest expense, net of capitalized interest costs, of $1.9 million, $2.5 million and $946,000 during the years ended January 31, 2016, 2015 and 2014, respectively. During the same periods, we capitalized $400,000, $311,000 and $84,000 of interest costs. Interest expense also includes amortization of issuance costs, unused commitment fees and fees on letters of credit which are recognized over the related term of the borrowing.