XML 152 R136.htm IDEA: XBRL DOCUMENT v3.20.4
Stock Based Compensation (Summary Of Company's Outstanding Restricted Stock Units) (Details) - Long-Term Equity Incentive Plan - Restricted Stock Units - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Restricted Stock Units      
Shares outstanding, Beginning Balance (in shares) 749,954    
Grants (in shares) 340,879    
Vests (in shares) (320,354)    
Forfeitures (in shares) (46,753)    
Shares outstanding, Ending Balance (in shares) 723,726 749,954  
Weighted-Average Grant-Date Fair Value      
Weighted-average grant-date fair value, shares outstanding, beginning balance (in dollars per share) $ 95.69    
Grants, weight-average grant-date fair value (in dollars per share) 96.33 $ 102.86 $ 93.20
Vests, weighted-average grant-date fair value (in dollars per share) 96.10    
Forfeitures, weighted-average grant-date fair value (in dollars per share) 97.90    
Weighted-average grant-date fair value, shares outstanding, ending balance (in dollars per share) $ 95.67 $ 95.69  
Shares vested but deferred (shares) 63,755    
Vested but deferred, weighted-average grant-date fair value (in dollars per share) $ 76.95    
Fair value of shares vested during the period (in dollars per share) $ 32.3 $ 38.4 $ 25.3