XML 47 R37.htm IDEA: XBRL DOCUMENT v3.10.0.1
Share-Based Compensation - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 24, 2017
Sep. 30, 2018
Sep. 24, 2017
Dec. 31, 2017
Restricted Share Grants [Abstract]          
Granted (in shares)     217,590    
Forfeited (in shares)     14,754    
Unvested RSGs (in shares) 376,570   376,570   342,264
Weighted average grant date fair value of unvested RSGs (in dollars per share) $ 16.13   $ 16.13   $ 16.86
Aggregate intrinsic value of unvested RSGs $ 5,908   $ 5,908    
Share-based Compensation Costs [Abstract]          
Non-cash compensation expense 667 $ 769 2,499 $ 2,364  
Compensation cost not yet recognized related to non-vested awards $ 4,558   $ 4,558    
Compensation cost not yet recognized related to non-vested awards, weighted average recognition period     2 years