XML 89 R58.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-based Compensation (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Stock-based Compensation      
Shares available for grant 2,000    
Restricted Stock Units      
No. of Stock Units      
Nonvested restricted stock units, beginning of period 782    
Granted (in units) 221    
Vested (in units) (274)    
Forfeited (in units) (39)    
Nonvested restricted stock units, end of period 690 782  
Weighted Average Grant Date Fair Value      
Nonvested restricted stock units, beginning of period $ 19.84    
Granted (in dollars per share) 37.04    
Vested (in dollars per share) 19.50    
Forfeited (in dollars per share) 22.48    
Nonvested restricted stock units, end of period $ 25.34 $ 19.84  
Stock-based Compensation      
Vesting period 3 years    
Unrecognized compensation cost $ 11.1    
Weighted average period over which unrecognized compensation cost is expected to be recognized 2 years    
Selling, General and Administrative Expenses      
Stock-based Compensation      
Share-based compensation costs recognized $ 7.0 $ 4.7 $ 0.0