Commitments and Contingencies Leases The Company leases various office facilities under non-cancelable leases, which expire on various dates through April 2022. Future minimum lease payments under all operating leases at March 31, 2018 are as follows: Year Ending March 31, 2019 $ 9,858 2020 8,316 2021 6,558 2022 4,449 2023 and thereafter 3,746 $ 32,927 Rent expenses were $12,215 , $10,377 , and $9,856 for the years ended March 31, 2018 , 2017 and 2016 , respectively. Rent expense is calculated by amortizing total rental payments (net of any rental abatements, allowances and other rental concessions), on a straight-line basis, over the lease term. Accordingly, rent expense charged to operations differs from rent paid resulting in the Company recording deferred rent. Purchase Commitments The Company, in the normal course of business, enters into various purchase commitments for goods or services. Total non-cancellable purchase commitments as of March 31, 2018 are approximately $20,164 for fiscal 2019 , $5,841 for fiscal 2020 , $1,025 for fiscal 2021 and $299 for fiscal 2022 , totaling $27,329 for all periods through fiscal 2022 . These purchase commitments relate primarily to marketing and IT services. The Company has certain software royalty commitments associated with the shipment and licensing of certain products. Royalty expense is generally based on a fixed cost per unit shipped or a fixed fee for unlimited units shipped over a designated period. Royalty expense, included in cost of software and products revenues, was $4,462 in fiscal 2018 , $2,646 in fiscal 2017 and $1,933 in fiscal 2016 . Warranties and Indemnifications The Company offers a 90 -day limited product warranty for its software. To date, costs related to this product warranty have not been material. The Company provides certain provisions within its software licensing agreements to indemnify its customers from any claim, suit or proceeding arising from alleged or actual intellectual property infringement. These provisions continue in perpetuity,