Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Assump) (Details)

v3.3.0.814
Stock-Based Compensation (Assump) (Details) - $ / shares
3 Months Ended 9 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Summary of weighted average assumptions used to value options granted        
Grant date fair value of options (in dollars per share)   $ 16.80 $ 20.90 $ 16.81
Volatility (as a percent)   33.70% 37.20% 37.30%
Risk-free interest rate (as a percent)   2.00% 1.70% 1.90%
Dividend yield (as a percent) 0.00% 0.00% 0.00% 0.00%
Expected term   6 years 6 years 6 years