XML 29 R53.htm IDEA: XBRL DOCUMENT v3.19.3
Stock-Based Compensation - Restricted Stock Award and RSU Activity (Details) - USD ($)
$ / shares in Units, $ in Millions
9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Restricted stock awards    
Restricted stock, Shares Subject to Restriction    
Outstanding at the beginning of the period (in shares) 24,633  
Vested (in shares) (24,633)  
Restricted stock, Weighted Average Grant Date Fair Value    
Outstanding at the beginning of the period (in dollars per share) $ 19.82  
Vested (in dollars per share) $ 19.82  
Additional share-based compensation disclosures    
Total fair value of shares vested $ 1.0 $ 1.1
Restricted stock units    
Restricted stock, Shares Subject to Restriction    
Outstanding at the beginning of the period (in shares) 806,249  
Granted (in shares) 346,462  
Vested (in shares) (213,286)  
Forfeited (in shares) (32,482)  
Outstanding at the end of the period (in shares) 906,943  
Restricted stock, Weighted Average Grant Date Fair Value    
Outstanding at the beginning of the period (in dollars per share) $ 29.88  
Granted (in dollars per share) 40.66  
Vested (in dollars per share) 31.14  
Forfeited (in dollars per share) 29.20  
Outstanding at the end of the period (in dollars per share) $ 33.73  
Additional share-based compensation disclosures    
Total fair value of shares vested $ 6.6 $ 3.7
Unrecognized pre-tax stock-based compensation expense $ 24.9  
Weighted average remaining service period 3 years