Commitments and Contingencies: Leases We lease certain real and personal property under non-cancelable operating leases. Several of the lease agreements contain rent escalation clauses (including index-based escalations), rent holidays, capital improvement funding or other lease concessions. We recognize our minimum rental expense on a straight-line basis. We amortize this expense over the term of the lease beginning with the date of initial possession, which is the date we enter the leased space and begin to make improvements in preparation for its intended use. The approximate minimum commitments under all non-cancelable leases outstanding as of December 31, 2012 were as follows (in millions): Operating Leases Capital Leases 2013 $ 52.8 $ 1.1 2014 36.1 1.0 2015 26.0 0.7 2016 17.9 0.1 2017 12.9   Thereafter 18.1 14.6 Total minimum lease payments (1) $ 163.8 17.5 Less amount representing interest 0.8 Present value of minimum payments $ 16.7 (1) Approximately $25.9 million of operating lease commitments relate to discontinued operations. No capital lease obligations relate to discontinued operations. On June 22, 2006, we entered into an agreement with a financial institution to lease our corporate headquarters in Richardson, Texas for a term of seven years (the  Lake Park Lease ). The leased property consists of an office building of approximately 192,000 square feet, land and related improvements. During the term, the Lake Park Lease requires us to pay base rent in quarterly installments, payable in arrears. At the end of the term, we must do one of the following: (i) purchase the property for approximately $41.2 million ; (ii) make a final payment under the lease equal to approximately 82% of the lease balance and return the property to the financial institution in good condition; (iii) arrange for the sale of the leased property to a third party; or (iv) renew the lease under mutually agreeable terms. If we elect to sell the property to a third party and the sales proceeds are less than the lease balance, we mu