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 $51.5 million , $43.8 million and $46.5 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Capital Leases as Lessee We entered into a long-term capital lease agreement in 1991 with the wife of GCIs President and CEO for property occupied by us as further described in Note 11 of this Form 10-K. We have a capital lease agreement for transponder capacity on Intelsat, Ltd.s (Intelsat) Galaxy 18 spacecraft. 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 2016 $ 45,585 13,454 2017 35,642 13,433 2018 28,822 13,440 2019 23,611 13,450 2020 20,134 13,459 2021 and thereafter 50,933 19,752 Total minimum lease payments $ 204,727 86,988 Less amount representing interest 18,629 Less current maturity of obligations under capital leases 8,708 Long-term obligations under capital leases, excluding current maturity $ 59,651 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. Guaranteed Service Levels Certain customers have guaranteed levels of service with varying terms. In the event we are unable to provide the minimum ser