Stock Repurchase Program

6 Months Ended

Jun. 30, 2018

Equity [Abstract]

Stock Repurchase Programs

Stock Repurchase Program

On September 11, 2017, the board of directors approved the repurchase of an additional $125 million for our share repurchase program commencing September 11, 2017 and expiring on December 31, 2018. The board of directors had previously authorized $150 million under the program in November 2015. Under this publicly announced program, we repurchased 959,786 and 748,448 shares for an aggregate purchase price of $28.3 and $34.5 million during the six months ended June 30, 2018 and 2017, respectively. As of June 30, 2018, $81.1 million remained authorized for repurchases under this program.

Our employees have the option to surrender shares of common stock to satisfy their tax withholding obligations that arise on the vesting of RSUs, the exercise price of certain stock options, and any tax withholding obligations incurred from exercise of stock options. Employees surrendered 25,768 and 146,302 shares at an aggregate value of $0.7 and $6.8 million during the six months ended June 30, 2018 and 2017, respectively.