Guarantees:

12 Months Ended

Dec. 31, 2012

Guarantees:

Guarantees:

12. Guarantees:

    As of December 31, 2012 and 2011, we had guarantees for rental payments due under the terms of the Rocky Mountain lease transactions and replacement credit enhancement. We estimate that the current maximum aggregate amount of exposure we would have if we were required to purchase the equity interests of the remaining owner trust under the Rocky Mountain lease transactions is approximately $25,000,000. See Note 4 for discussion of Rocky Mountain lease transactions.