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Stockholders' Equity - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended
Apr. 10, 2018
Jan. 02, 2018
Mar. 31, 2018
Mar. 31, 2017
Share-based Compensation [Abstract]        
Non-employee director options elected (in shares)   21,185    
Non-employee director option exercise (strike) price (in dollars per share)   $ 55.00    
Options vesting and exercisable period, maximum     8 years  
Options termination period     9 years  
Total stock-based compensation expense     $ 1.4 $ 1.2
Total unrecognized stock-based compensation expense     $ 17.3  
Weighted average period over which total unrecognized stock-based compensation expense will be recognized     4 years 5 months 15 days  
Subsequent Event        
Subsequent Event [Line Items]        
Dividend declared (in dollars per share) $ 0.37