XML 43 R44.htm IDEA: XBRL DOCUMENT v3.19.3
Net Income Per Share of Class A and Class B Common Stock (Earnings Per Share Reconciliation) (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Weighted average common shares outstanding - basic (in shares) 23.2 24.2 23.2 24.7
Weighted average common shares outstanding - diluted (in shares) 23.4 24.3 23.3 24.8
Net income per common share - basic (in dollars per share) $ 3.67 $ 3.85 $ 8.77 $ 8.34
Net income per common share - diluted (in dollars per share) $ 3.64 $ 3.84 $ 8.72 $ 8.31
Class A common stock        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Net income applicable to common stockholders - basic $ 83.0 $ 89.3 $ 198.2 $ 197.5
Reallocation of net income due to conversion of Class B to Class A common shares outstanding 0.2 0.3 0.6 0.8
Conversion of Class B common shares into Class A common shares 2.0 3.5 4.7 7.5
Net income applicable to common stockholders - diluted $ 85.2 $ 93.1 $ 203.5 $ 205.8
Weighted average common shares outstanding - basic (in shares) 22.6 23.2 22.6 23.7
Conversion of Class B common shares into Class A common shares (in shares) 0.6 1.0 0.6 1.0
Effect of dilutive stock options on weighted average common shares (in shares) 0.2 0.1 0.1 0.1
Weighted average common shares outstanding - diluted (in shares) 23.4 24.3 23.3 24.8
Net income per common share - basic (in dollars per share) $ 3.67 $ 3.85 $ 8.77 $ 8.34
Net income per common share - diluted (in dollars per share) $ 3.64 $ 3.84 $ 8.72 $ 8.31
Class B common stock        
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]        
Net income applicable to common stockholders - basic $ 2.2 $ 3.8 $ 5.3 $ 8.3
Reallocation of net income due to conversion of Class B to Class A common shares outstanding 0.0 0.0 0.0 0.0
Conversion of Class B common shares into Class A common shares 0.0 0.0 0.0 0.0
Net income applicable to common stockholders - diluted $ 2.2 $ 3.8 $ 5.3 $ 8.3
Weighted average common shares outstanding - basic (in shares) 0.6 1.0 0.6 1.0
Conversion of Class B common shares into Class A common shares (in shares) 0.0 0.0 0.0 0.0
Effect of dilutive stock options on weighted average common shares (in shares) 0.0 0.0 0.0 0.0
Weighted average common shares outstanding - diluted (in shares) 0.6 1.0 0.6 1.0
Net income per common share - basic (in dollars per share) $ 3.67 $ 3.85 $ 8.77 $ 8.34
Net income per common share - diluted (in dollars per share) $ 3.64 $ 3.84 $ 8.72 $ 8.31