18. Share Repurchase Program

Effective January 1, 2014, our Board of Directors authorized the repurchase of up to 120 million shares of our common stock by December 31, 2017, replacing our previous repurchase program. As of June 30, 2014, we repurchased a total of $10.8 billion of our common stock since the commencement of our repurchase programs in 2007. The table below represents shares repurchased in the first and second quarters of 2013 under our previous repurchase program, and shares repurchased in the first and second quarters of 2014 under the new program.

Management's assessments of market conditions and other pertinent factors guide the timing and volume of all repurchases. We expect to fund any share repurchases under this program through cash generated from operations, the sale or lease of various operating and non-operating properties, debt issuances, and cash on hand. Repurchased shares are recorded in treasury stock at cost, which includes any applicable commissions and fees.