10. Commitments and Contingencies Lease Commitments The Company leases office space under non-cancelable lease agreements expiring at various dates through 2033. Office space leases are subject to escalation based on certain costs incurred by the landlord. Minimum rental commitments as of June 30, 2017 under such operating leases were as follows (in thousands): 2017 $ 2,304 2018 4,349 2019 9,258 2020 10,545 2021 10,109 2022 and thereafter 108,081 $ 144,646 Rental expense was $2.5 million and $2.1 million for the six months ended June 30, 2017 and 2016, respectively, and is included in occupancy expense in the Consolidated Statements of Operations. Rental expense has been recorded based on the total minimum lease payments after giving effect to rent abatement and concessions, which are being amortized on a straight-line basis over the life of the lease. The Company is contingently obligated for standby letters of credit amounting to $1.0 million that were issued to landlords for office space. During 2016, the Company entered into non-cancelable lease agreements for approximately 108,000 square feet of office space with commencement dates on or after December 1, 2016 that expire through December 31, 2033. The aggregate minimum rental commitment remaining under such leases is $126.8 million. The Company has assigned a lease agreement on a leased property to a third party and is contingently liable should the assignee default on future lease obligations through the November 2020 lease termination date. The aggregate amount of the future lease obligation under this arrangement is $0.9 million as of June 30, 2017. Legal In the normal course of business, the Company and its subsidiaries included in the consolidated financial statements may be involved in various lawsuits, proceedings and regulatory examinations. The Company assesses its liabilities and contingencies in connection with outstanding legal proceedings, if any, utilizing the latest information available. For matters where it is probable that the Company will