Shareholders' Equity	9 Months Ended
Sep. 30, 2018
Equity [Abstract]
Shareholders' Equity	Shareholders’ Equity In September 2018, we declared a cash dividend on our common stock of $0.70 per share, which was paid in October 2018. During both first and second quarters of 2018, we declared a cash dividend on our common stock of $0.60 per share, which was paid in April 2018 and July 2018, respectively. During the first quarter of 2018, we also paid a cash dividend on our common stock of $0.60 per share, which was declared during the fourth quarter of 2017. During the third quarter of 2017, we declared a cash dividend on our common stock of $0.60 per share, which was paid in October 2017. During both first and second quarters of 2017, we declared a cash dividend on our common stock of $0.48 per share which, was paid in April 2017 and July 2017, respectively. During the first quarter of 2017, we also paid a cash dividend on our common stock of $0.48 per share, which was declared during the fourth quarter of 2016. In May 2018, our board of directors authorized a 24-month common stock repurchase program for up to $1.0 billion. The timing and number of shares to be repurchased will depend on a variety of factors, including price and market conditions. Repurchases under the program may be made at management's discretion from time to time on the open market or through privately negotiated transactions. During the second and third quarters of 2018, we repurchased 1.3 million and 1.5 million shares of our common stock under this program, respectively, for a total of $137.5 million and $162.5 million, respectively, in open market transactions that were recorded within Treasury stock in our consolidated balance sheets. As of September 30, 2018, we have approximately $700.0 million that remains available for future stock repurchase transactions under our Board authorized program. In April 2017, our board of directors authorized a 12-month common stock repurchase program for up to $500.0 million that was completed in February 2018. During the first quarter of 2018, we repurchased 2.1 million shares of our common stock for a total of $275.0 million in open market transactions that were recorded within Treasury stock in our consolidated balance sheet. Our repurchases under this program, including the 1.8 million shares repurchased for $225.0 million during 2017, totaled $500.0 million.

Shareholders’ Equity

In September 2018, we declared a cash dividend on our common stock of $0.70 per share, which was paid in October 2018. During both first and second quarters of 2018, we declared a cash dividend on our common stock of $0.60 per share, which was paid in April 2018 and July 2018, respectively. During the first quarter of 2018, we also paid a cash dividend on our common stock of $0.60 per share, which was declared during the fourth quarter of 2017.

During the third quarter of 2017, we declared a cash dividend on our common stock of $0.60 per share, which was paid in October 2017. During both first and second quarters of 2017, we declared a cash dividend on our common stock of $0.48 per share which, was paid in April 2017 and July 2017, respectively. During the first quarter of 2017, we also paid a cash dividend on our common stock of $0.48 per share, which was declared during the fourth quarter of 2016.

In May 2018, our board of directors authorized a 24-month common stock repurchase program for up to $1.0 billion. The timing and number of shares to be repurchased will depend on a variety of factors, including price and market conditions. Repurchases under the program may be made at management's discretion from time to time on the open market or through privately negotiated transactions. During the second and third quarters of 2018, we repurchased 1.3 million and 1.5 million shares of our common stock under this program, respectively, for a total of $137.5 million and $162.5 million, respectively, in open market transactions that were recorded within Treasury stock in our consolidated balance sheets. As of September 30, 2018, we have approximately $700.0 million that remains available for future stock repurchase transactions under our Board authorized program.

In April 2017, our board of directors authorized a 12-month common stock repurchase program for up to $500.0 million that was completed in February 2018. During the first quarter of 2018, we repurchased 2.1 million shares of our common stock for a total of $275.0 million in open market transactions that were recorded within Treasury stock in our consolidated balance sheet. Our repurchases under this program, including the 1.8 million shares repurchased for $225.0 million during 2017, totaled $500.0 million.