Share Repurchase Program

9 Months Ended

Sep. 30, 2012

Share Repurchase Program [Abstract]

Share Repurchase Program Disclosure [Text Block]

Share Repurchase Program

In September 2010, the board of directors approved a share repurchase program that authorizes the repurchase of up to $100 million in shares of our outstanding common stock. In December 2011, the board approved an increase to the 2010 share repurchase program. The board approval authorized the company to repurchase up to an additional $200 million in shares of our outstanding common stock with a revised expiration date of December 31, 2013. We may repurchase shares from time to time at prevailing market prices on the open market or in private transactions at our discretion. As of September 30, 2012, we had repurchased a total of 3,964,411 shares for $231,553,933 under this authorization.