Annual report pursuant to Section 13 and 15(d)

Share-Based Compensation - Expense (Details)

v3.8.0.1
Share-Based Compensation - Expense (Details) - USD ($)
$ in Thousands, shares in Millions
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Share-Based Compensation      
Share-based compensation expense $ 9,889 $ 7,669 $ 4,651
Income tax benefit realized from award vestings $ 2,882 $ 588  
2015 Plan      
Share-Based Compensation      
Number of shares authorized 4.0    
Number of shares available 2.7