Quarterly report pursuant to Section 13 or 15(d)

Stock-based Compensation Plans and Awards - Schedule of assumptions used for determining the per-share fair value (Details)

v3.4.0.3
Stock-based Compensation Plans and Awards - Schedule of assumptions used for determining the per-share fair value (Details) - Employee stock - Black Scholes Options Pricing Model
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Assumptions used to calculate per-share fair value of award    
Expected life (in years) 6 months 6 months
Expected volatility 41.00% 42.00%
Expected dividend yield 0.00% 0.00%
Minimum    
Assumptions used to calculate per-share fair value of award    
Risk-free interest rate 0.24% 0.05%
Maximum    
Assumptions used to calculate per-share fair value of award    
Risk-free interest rate 0.41% 0.07%