Common Stock Repurchase Plan	9 Months Ended
Sep. 30, 2013
Common Stock Share Repurchase Plan [Abstract]
Common Stock Repurchase Plan	Common Stock Repurchase Plans On January 3, 2013, the Corporation announced that its board of directors approved a share repurchase program pursuant to which the Corporation was authorized to repurchase up to eight million shares, or approximately 4.0% of its outstanding shares, through June 30, 2013. On June 18, 2013, the Corporation announced that its board of directors had extended the timeframe for this stock repurchase program to September 30, 2013. During the three and nine months ended September 30, 2013, approximately 1.6 million and 8.0 million shares, respectively, were repurchased, completing this repurchase program. On October 22, 2013, the Corporation announced that its board of directors approved a share repurchase program pursuant to which the Corporation is authorized to repurchase up to 4.0 million shares, or approximately 2.1% of its outstanding shares, through March 31, 2014. Repurchased shares will be added to treasury stock, at cost, and will be used for general corporate purposes. As permitted by securities laws and other legal requirements, and subject to market conditions and other factors, purchases may be made from time to time in the open market at prevailing prices. The program may be discontinued at any time.

Common Stock Repurchase Plans

On January 3, 2013, the Corporation announced that its board of directors approved a share repurchase program pursuant to which the Corporation was authorized to repurchase up to eight million shares, or approximately 4.0% of its outstanding shares, through June 30, 2013. On June 18, 2013, the Corporation announced that its board of directors had extended the timeframe for this stock repurchase program to September 30, 2013. During the three and nine months ended September 30, 2013, approximately 1.6 million and 8.0 million shares, respectively, were repurchased, completing this repurchase program.

On October 22, 2013, the Corporation announced that its board of directors approved a share repurchase program pursuant to which the Corporation is authorized to repurchase up to 4.0 million shares, or approximately 2.1% of its outstanding shares, through March 31, 2014.

Repurchased shares will be added to treasury stock, at cost, and will be used for general corporate purposes. As permitted by securities laws and other legal requirements, and subject to market conditions and other factors, purchases may be made from time to time in the open market at prevailing prices. The program may be discontinued at any time.