Commitments and Contingencies There has been no material change in the Companys contractual obligations and commitments other than in the ordinary course of business since the Companys fiscal year ended July 31, 2015 . See the Annual Report on Form 10-K for the fiscal year ended July 31, 2015 for additional information regarding the Companys contractual obligations. Leases The Company leases certain facilities and equipment under operating leases. On December 5, 2011, the Company entered into a seven -year lease for a facility to serve as its corporate headquarters, located in Foster City, California, for approximately 97,674 square feet of space which commenced on August 1, 2012. In connection with this lease, the Company opened an unsecured letter of credit with Silicon Valley Bank for $1.2 million . On July 1, 2015 , the unsecured letter of credit was reduced to $0.4 million in accordance with the lease agreement. Lease expense for all worldwide facilities and equipment, which is being recognized on a straight-line basis over terms of the various leases, was $1.4 million and $ 2.8 million for the three and six months ended January 31, 2016 , respectively, and was $1.6 million and $3.2 million for the three and six months ended January 31, 2015 , respectively. Letters of Credit The Company had two outstanding letters of credit required to secure contractual commitments and prepayments as of January 31, 2016 and July 31, 2015 , respectively. In addition to the unsecured letter of credit for the building lease, the Company had an unsecured letter of credit agreement related to a customer arrangement for Polish Zloty 10.0 million (approximately $2.5 million as of January 31, 2016 ) to secure contractual commitments and prepayments. No amounts were outstanding under the Companys unsecured letters of credit as of January 31, 2016 or July 31, 2015 . Legal Proceedings From time to time, the Company is involved in various legal proceedings and receives claims, arising from the normal course of business activities.