Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plan - Fair Value Assumptions (Details)

v3.6.0.2
Stock Incentive Plan - Fair Value Assumptions (Details) - Stock Options - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Fair value significant assumptions:      
Expected dividend yield $ 0 $ 0 $ 0
Risk-free interest rate, minimum 1.16% 1.53% 1.93%
Risk-free interest rate, maximum 1.77% 2.01% 2.01%
Expected volatility, minimum 46.00% 44.00% 50.00%
Expected volatility, maximum 49.00% 49.00% 52.00%
Expected life     6 years 6 months
Minimum      
Fair value significant assumptions:      
Expected life 6 years 6 months 5 years  
Maximum      
Fair value significant assumptions:      
Expected life 10 years 6 years 6 months