Consolidated Statements Shareholders' Equity - USD ($) $ in Millions	Total	Class A Common Shares	Class B Common Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance at Dec. 31, 2022	$ 2,837.2			$ 0.0	$ 1,584.4	$ 1,257.8	$ (5.0)	$ 0.0
Increase (Decrease) in Stockholders' Equity
Net income	98.0			0.0	0.0	98.0	0.0	0.0
Other comprehensive (loss) income	0.8			0.0	0.0	0.0	0.8	0.0
Share-based compensation expense	5.1			0.0	5.1	0.0	0.0	0.0
Dividends declared per share		$ 0.09	$ 0.09
Dividends declared	(16.4)			0.0	0.0	(16.4)	0.0	0.0
Share issuances	0.1			0.0	0.1	0.0	0.0	0.0
Exercise of employee stock options	0.1			0.0	0.1	0.0	0.0	0.0
Shares withheld for employee taxes	(6.1)			0.0	(6.1)	0.0	0.0	0.0
Balance at Mar. 31, 2023	2,918.8			0.0	1,583.6	1,339.4	(4.2)	0.0
Balance at Dec. 31, 2022	2,837.2			0.0	1,584.4	1,257.8	(5.0)	0.0
Increase (Decrease) in Stockholders' Equity
Net income	211.1
Balance at Sep. 30, 2023	2,957.1			0.0	1,592.8	1,420.3	(5.0)	(51.0)
Balance at Mar. 31, 2023	2,918.8			0.0	1,583.6	1,339.4	(4.2)	0.0
Increase (Decrease) in Stockholders' Equity
Net income	77.5			0.0	0.0	77.5	0.0	0.0
Other comprehensive (loss) income	(0.1)			0.0	0.0	0.0	(0.1)	0.0
Share-based compensation expense	4.4			0.0	4.4	0.0	0.0	0.0
Dividends declared per share		0.09	0.09
Dividends declared	(16.1)			0.0	0.0	(16.1)	0.0	0.0
Repurchases of common stock	(36.1)			0.0	0.0	0.0	0.0	(36.1)
Balance at Jun. 30, 2023	2,948.4			0.0	1,588.0	1,400.8	(4.3)	(36.1)
Increase (Decrease) in Stockholders' Equity
Net income	35.6			0.0	0.0	35.6	0.0	0.0
Other comprehensive (loss) income	(0.7)			0.0	0.0	0.0	(0.7)	0.0
Share-based compensation expense	4.8			0.0	4.8	0.0	0.0	0.0
Dividends declared per share		0.09	0.09
Dividends declared	(16.1)			0.0	0.0	(16.1)	0.0	0.0
Repurchases of common stock	(14.9)			0.0	0.0	0.0	0.0	(14.9)
Balance at Sep. 30, 2023	2,957.1			0.0	1,592.8	1,420.3	(5.0)	(51.0)
Balance at Dec. 31, 2023	2,956.8			0.0	1,595.2	1,431.9	(3.4)	(66.9)
Increase (Decrease) in Stockholders' Equity
Net income	18.5			0.0	0.0	18.5	0.0	0.0
Other comprehensive (loss) income	(0.2)			0.0	0.0	0.0	(0.2)	0.0
Share-based compensation expense	1.5			0.0	1.5	0.0	0.0	0.0
Dividends declared per share		0.095	0.095
Dividends declared	(16.7)			0.0	0.0	(16.7)	0.0	0.0
Repurchases of common stock	(13.0)			0.0	0.0	0.0	0.0	(13.0)
Exercise of employee stock options	1.5			0.0	1.5	0.0	0.0	0.0
Shares withheld for employee taxes	(6.4)			0.0	(6.4)	0.0	0.0	0.0
Balance at Mar. 31, 2024	2,942.0			0.0	1,591.8	1,433.7	(3.6)	(79.9)
Balance at Dec. 31, 2023	2,956.8			0.0	1,595.2	1,431.9	(3.4)	(66.9)
Increase (Decrease) in Stockholders' Equity
Net income	84.4
Balance at Sep. 30, 2024	2,967.2			0.0	1,600.5	1,466.0	(2.9)	(96.4)
Balance at Mar. 31, 2024	2,942.0			0.0	1,591.8	1,433.7	(3.6)	(79.9)
Increase (Decrease) in Stockholders' Equity
Net income	35.3			0.0	0.0	35.3	0.0	0.0
Other comprehensive (loss) income	(0.3)			0.0	0.0	0.0	(0.3)	0.0
Share-based compensation expense	4.3			0.0	4.3	0.0	0.0	0.0
Dividends declared per share		0.095	0.095
Dividends declared	(16.9)			0.0	0.0	(16.9)	0.0	0.0
Repurchases of common stock	(12.8)			0.0	0.0	0.0	0.0	(12.8)
Balance at Jun. 30, 2024	2,951.6			0.0	1,596.1	1,452.1	(3.9)	(92.7)
Increase (Decrease) in Stockholders' Equity
Net income	30.6			0.0	0.0	30.6	0.0	0.0
Other comprehensive (loss) income	1.0			0.0	0.0	0.0	1.0	0.0
Share-based compensation expense	4.4			0.0	4.4	0.0	0.0	0.0
Dividends declared per share		$ 0.095	$ 0.095
Dividends declared	(16.7)			0.0	0.0	(16.7)	0.0	0.0
Repurchases of common stock	(3.7)			0.0	0.0	0.0	0.0	(3.7)
Balance at Sep. 30, 2024	$ 2,967.2			$ 0.0	$ 1,600.5	$ 1,466.0	$ (2.9)	$ (96.4)