Annual report pursuant to Section 13 and 15(d)

Capital Stock, Stock Plans and Stock-based Compensation - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details)

v3.8.0.1
Capital Stock, Stock Plans and Stock-based Compensation - Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions (Details) - $ / shares
 12 Months Ended
Oct. 19, 2017
Jul. 27, 2017
Jan. 13, 2017
Jul. 28, 2016
May 15, 2016
Dec. 31, 2017
Risk -free interest rate           2.30%
Dividend yield          
Expected option life           6 years 7 months 6 days
Employee Stock Option Granted [Member]            
Weighted-average fair value per shares $ 1.75 $ 1.88     $ 2.00  
Risk -free interest rate [1] 1.98% 1.98%     1.27%  
Expected volatility of stock [2] 54.64% 53.15%     53.12%  
Dividend yield      
Expected option life [3] 5 years 6 years     6 years  
Outside Director Stock Options Granted [Member]            
Weighted-average fair value per shares   $ 2.48 $ 2.63 $ 3.00    
Risk -free interest rate [1]   2.32% 2.40% 1.52%    
Expected volatility of stock [2]   57.21% 56.32% 55.99%    
Dividend yield      
Expected option life [3]   10 years 10 years 10 years    
[1] The risk-free interest rate is based on the U.S. Treasury yield in effect at the grant date over the expected term of the option.
[2] The expected volatility is based on historical volatility from our traded Common Stock over the expected term of the option.
[3] The expected option life is based on historical exercises and post-vesting data.