10. Commitments and Contingencies The Company leases office space and equipment under non-cancelable lease agreements expiring at various dates through 2022. Office space leases are subject to escalation based on certain costs incurred by the landlord. Minimum rental commitments as of June 30, 2011 under such operating and capital leases were as follows: Operating Capital Leases Leases (In thousands) Remainder of 2011 $ 893 $ 168 2012 1,810 335 2013 1,794 322 2014 1,761 42 2015 2,022   2016 2,035   Thereafter 10,192   Minimum lease payments 20,507 867 Less amount representing interest   78 $ 20,507 $ 789 Rental expense was $1.2 million and $1.5 million for the six months ended June 30, 2011 and 2010, respectively, and is included in occupancy expenses 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, and sublease income. In 2008, the Company assigned the lease agreement on a leased property to a third party. The Company is contingently liable should the assignee default on future lease obligations through the November 2015 lease termination date. The aggregate amount of future lease obligations under this arrangement was $1.6 million as of June 30, 2011. The Company is contingently obligated for standby letters of credit that were issued to landlords for office space. The Company uses a U.S. government obligation as collateral for these standby letters of credit. This collateral is included with prepaid expenses and other assets in the Consolidated Statements of Financial Condition and had a fair market value and amortized cost of $3.5 million as of June 30, 2011 and December 31, 2010. The Company, through two regulated subsidiaries, executes certain bond transactions between and among institutional investor and broker-dealer clients on a riskless principal basis by serving as counterparty to both the buyer and