Annual report pursuant to Section 13 and 15(d)

Share Repurchase Program (Details)

v3.10.0.1
Share Repurchase Program (Details) - USD ($)
$ / shares in Units, $ in Thousands
 2 Months Ended 12 Months Ended 18 Months Ended 20 Months Ended 22 Months Ended
Dec. 31, 2018
Dec. 31, 2018
Dec. 31, 2017
Feb. 28, 2017
Dec. 31, 2018
Dec. 31, 2018
Dec. 31, 2018
Nov. 07, 2018
Jul. 05, 2017
Feb. 24, 2017
Number of shares repurchased (in shares)   1,063,528 2,365,836              
Share repurchase cost   $ 65,025 $ 139,286 $ 26,600            
Average price per share (in dollars per share)       $ 33.72            
2016 Repurchase program                    
Number of shares repurchased (in shares)       788,399            
2017 Repurchase program                    
Number of shares repurchased (in shares)             996,566      
Share repurchase cost             $ 50,000      
Average price per share (in dollars per share)             $ 50.17      
2017 ASR Agreement                    
Number of shares repurchased (in shares)   13,657       1,521,100        
Share repurchase cost         $ 100,000          
Average price per share (in dollars per share)           $ 65.74        
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%  
2018 ASR Agreement                    
Share repurchase cost $ 50,000                  
Initial number of shares delivered under ASR agreement (in shares)               796,925    
Initial percentage of shares delivered under ASR agreement               85.00%    
Initial value of shares delivered under ASR agreement               $ 50,000    
Maximum | 2017 Repurchase program                    
Share repurchase program, authorized amount                   $ 200,000