Common Stock	9 Months Ended
Sep. 30, 2017
Stockholders' Equity Note [Abstract]
Common Stock	Common Stock As of September 30, 2017 and December 31, 2016, there were 58,806,509 and 59,946,984 shares of our common stock outstanding, respectively. During the three months ended September 30, 2017 and 2016, we issued 19,679 and 47,050 shares of common stock, respectively, primarily upon: (a) the purchase of common stock pursuant to our employee stock purchase plan and (b) the satisfaction of required conditions under certain of our share-based compensation plans. During the nine months ended September 30, 2017 and 2016, we issued 213,060 and 353,116 shares of common stock, respectively, primarily upon: (a) the satisfaction of required conditions under certain of our share-based compensation plans, (b) the purchase of common stock pursuant to our employee stock purchase plan and (c) the exercise of stock options. On September 26, 2011, our Board of Directors authorized us to repurchase up to $100.0 million of our outstanding common stock. On December 5, 2013, October 23, 2014 and October 28, 2015, our Board of Directors authorized us to repurchase up to an additional $100.0 million, $250.0 million and $200.0 million of our outstanding common stock, respectively. During 2017, we have repurchased approximately 1.4 million shares of our common stock for approximately $88.6 million. Since the inception of the repurchase programs through September 30, 2017, we have repurchased approximately 12.8 million shares of our common stock for approximately $573.0 million. As of September 30, 2017, there remained authorization for us to repurchase approximately $77.0 million of our shares. Subsequent to September 30, 2017, our Board of Directors authorized us to repurchase up to an additional $100.0 million of our outstanding common stock. The repurchase programs have no expiration date and do not obligate the Company to acquire any particular amount of common stock and may be suspended, recommenced or discontinued at any time or from time to time without prior notice. We may repurchase our shares from time to time to the extent permitted by securities laws and other legal requirements, including provisions in our 2016 Credit Agreement placing limitations on such repurchases. The repurchase programs have been and will be funded from our operations.

Common Stock

As of September 30, 2017 and December 31, 2016, there were 58,806,509 and 59,946,984 shares of our common stock outstanding, respectively.

During the three months ended September 30, 2017 and 2016, we issued 19,679 and 47,050 shares of common stock, respectively, primarily upon: (a) the purchase of common stock pursuant to our employee stock purchase plan and (b) the satisfaction of required conditions under certain of our share-based compensation plans. During the nine months ended September 30, 2017 and 2016, we issued 213,060 and 353,116 shares of common stock, respectively, primarily upon: (a) the satisfaction of required conditions under certain of our share-based compensation plans, (b) the purchase of common stock pursuant to our employee stock purchase plan and (c) the exercise of stock options.

On September 26, 2011, our Board of Directors authorized us to repurchase up to $100.0 million of our outstanding common stock. On December 5, 2013, October 23, 2014 and October 28, 2015, our Board of Directors authorized us to repurchase up to an additional $100.0 million, $250.0 million and $200.0 million of our outstanding common stock, respectively. During 2017, we have repurchased approximately 1.4 million shares of our common stock for approximately $88.6 million. Since the inception of the repurchase programs through September 30, 2017, we have repurchased approximately 12.8 million shares of our common stock for approximately $573.0 million. As of September 30, 2017, there remained authorization for us to repurchase approximately $77.0 million of our shares. Subsequent to September 30, 2017, our Board of Directors authorized us to repurchase up to an additional $100.0 million of our outstanding common stock. The repurchase programs have no expiration date and do not obligate the Company to acquire any particular amount of common stock and may be suspended, recommenced or discontinued at any time or from time to time without prior notice. We may repurchase our shares from time to time to the extent permitted by securities laws and other legal requirements, including provisions in our 2016 Credit Agreement placing limitations on such repurchases. The repurchase programs have been and will be funded from our operations.