Table of Contents

The following table summarizes gross gains and gross losses realized on sales of available-for-sale marketable securities (in millions):

The following table summarizes the maturities of our cash equivalent and marketable fixed-income securities as of December 31, 2012 (in millions):

Actual maturities may differ from the contractual maturities because borrowers may have certain prepayment conditions.

Note 3—PROPERTY AND EQUIPMENT

Property and equipment, at cost, consisted of the following (in millions):

In December 2012, we acquired our corporate headquarters for $1.2 billion consisting of land and 11 buildings that were previously accounted for as financing leases. The acquired building assets will be depreciated over their estimated useful lives of 40 years. We also acquired three city blocks of land for the expansion of our corporate headquarters for approximately $210 million.

Depreciation expense on property and equipment was $1.7 billion, $1.0 billion, and $552 million, which includes amortization of property and equipment acquired under capital lease obligations of $510 million, $335 million, and $164 million for 2012, 2011, and 2010. Gross assets remaining under capital leases were $2.3 billion and $1.6 billion at December 31, 2012 and 2011. Accumulated depreciation associated with capital leases was $1.1 billion and $603 million at December 31, 2012 and 2011. Cash paid for interest on capital leases was $51 million, $44 million, and $26 million for 2012, 2011, and 2010.

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