Quarterly report pursuant to Section 13 or 15(d)

Share Repurchase Program (Details)

v3.8.0.1
Share Repurchase Program (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended 16 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Jun. 30, 2017
Jul. 05, 2017
Feb. 24, 2017
Number of shares repurchased (in shares) 1,507,443 188,068 2,365,836 341,500      
Share repurchase cost $ 100,000 $ 6,415 $ 139,286 $ 11,377      
2016 Repurchase program              
Number of shares repurchased (in shares)         788,399    
Share repurchase cost         $ 26,600    
Average price per share (in dollars per share)         $ 33.72    
2017 Repurchase program | Maximum              
Share repurchase program, authorized amount             $ 200,000
2017 ASR Agreement              
Payment under ASR agreement           $ 100,000  
Initial number of shares delivered under ASR agreement (in shares)           1,500,000  
Initial percentage of shares delivered under ASR agreement           80.00%