(13 ) Commitments and Contingencies Operating Leases as Lessee We lease business offices, have entered into site lease agreements and use satellite transponder and fiber capacity and certain equipment pursuant to operating lease arrangements. Many of our leases are for multiple years and contain renewal options. Rental costs under such arrangements amounted to $ 3 7.4 million, $ 3 6 . 3 million and $ 31 . 0 million for the years ended December 31, 2012 , 2011 and 2010 , respectively. Capital Leases as Lessee We entered into a long-term capital lease agreement in 1991 with the wife of GCI's President and CEO for property occupied by u s as further described in N ote 11 , Related Party Transactions . W e have a capital lease agreement for transponder capacity on Intelsat, Ltd.'s ( Intelsat ) Galaxy 18 spacecraft that successfully launched in 2008. The Intelsat Galaxy 18 C-band and Ku-Band transponders are being leased over an expected term of 14 years. At lease inception the present value of the lease payments, excluding telemetry, tracking and command services and back-up protection, was $98.6 million. A summary of future minimum lease payments follows (amounts in thousands) : Years ending December 31: Operating Capital 2013 $ 27,764 11,775 2014 23,809 11,784 2015 22,527 11,794 2016 19,600 11,804 2017 15,411 11,783 2018 and thereafter 64,944 54,948 Total minimum lease payments $ 174,055 113,888 Less amount representing interest 33,276 Less current maturity of obligations under capital leases 5,995 Long-term obligations under capital leases, excluding current maturity $ 74,617 The leases generally provide that we pay the taxes, insurance and maintenance expenses related to the leased assets. Several of our leases include renewal options, escalation clauses and immaterial amounts of contingent rent expense. We expect that in the normal course of business leases that expire will be renewed or replaced by leases on other properties. Operating Leases as Lessor and IRU Revenue We enter into lease or service arrangements