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

3 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

Three Months Ended March 31,	2020				2019
(in millions, except per share data)	Class A		Class B		Class A		Class B
Net income applicable to common stockholders - basic	$	45.0	$	1.2	$	54.4	$	2.0
Reallocation of net income due to conversion of Class B to Class A common shares outstanding	0.2		—		0.3		—
Conversion of Class B common shares into Class A common shares	1.0		—		1.7		—
Net income applicable to common stockholders - diluted	$	46.2	$	1.2	$	56.4	$	2.0
Weighted average common shares outstanding – basic	22.7		0.6		22.3		0.8
Conversion of Class B common shares into Class A common shares	0.6		—		0.8		—
Effect of employee stock purchases and restricted stock units on weighted average common shares	0.2		—		0.1		—
Weighted average common shares outstanding – diluted	23.5		0.6		23.2		0.8
Net income per common share - basic	$	1.99	$	1.99	$	2.43	$	2.43
Net income per common share - diluted	$	1.97	$	1.97	$	2.42	$	2.42