Net Income Per Share of Class A and Class B Common Stock (Tables)

9 Months Ended

Sep. 30, 2020

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

Three Months Ended September 30,	2020				2019
(in millions, except per share data)	Class A		Class B		Class A		Class B
Net income applicable to common stockholders - basic	$	156.0	$	2.8	$	83.0	$	2.2
Reallocation of net income due to conversion of Class B to Class A common shares outstanding	0.2		—		0.2		—
Conversion of Class B common shares into Class A common shares	2.6		—		2.0		—
Net income applicable to common stockholders - diluted	$	158.8	$	2.8	$	85.2	$	2.2
Weighted average common shares outstanding – basic	22.5		0.4		22.6		0.6
Conversion of Class B common shares into Class A common shares	0.4		—		0.6		—
Effect of dilutive stock options on weighted average common shares	0.2		—		0.2		—
Weighted average common shares outstanding – diluted	23.1		0.4		23.4		0.6
Net income per common share - basic	$	6.95	$	6.95	$	3.67	$	3.67
Net income per common share - diluted	$	6.86	$	6.86	$	3.64	$	3.64

Nine Months Ended September 30,	2020				2019
(in millions, except per share data)	Class A		Class B		Class A		Class B
Net income applicable to common stockholders - basic	$	276.4	$	6.3	$	198.2	$	5.3
Reallocation of net income due to conversion of Class B to Class A common shares outstanding	0.5		—		0.6		—
Conversion of Class B common shares into Class A common shares	5.8		—		4.7		—
Net income applicable to common stockholders - diluted	$	282.7	$	6.3	$	203.5	$	5.3
Weighted average common shares outstanding – basic	22.5		0.5		22.6		0.6
Conversion of Class B common shares into Class A common shares	0.5		—		0.6		—
Effect of employee stock purchases and restricted stock units on weighted average common shares	0.2		—		0.1		—
Weighted average common shares outstanding – diluted	23.2		0.5		23.3		0.6
Net income per common share - basic	$	12.29	$	12.29	$	8.77	$	8.77
Net income per common share - diluted	$	12.18	$	12.18	$	8.72	$	8.72