Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Assump) (Details)

v3.7.0.1
Stock-Based Compensation (Assump) (Details) - $ / shares
3 Months Ended
Mar. 31, 2017
Mar. 31, 2016
Summary of weighted average assumptions used to value options granted    
Grant date fair value of options (in dollars per share) $ 14.51 $ 20.51
Volatility (as a percent) 43.80% 42.10%
Risk-free interest rate (as a percent) 2.10% 1.40%
Expected term (in years) 6 years 3 months 18 days 6 years 7 months 6 days