Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation Plans and Awards - Stock-based compensation expense narrative (Details)

v3.6.0.2
Stock-based Compensation Plans and Awards - Stock-based compensation expense narrative (Details)
$ in Millions
12 Months Ended
Dec. 31, 2016
USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Capitalized cost related to internal use software and website development costs $ 7.5
General and administrative  
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]  
Accelerated awards in connection with executive severance $ 8.7