Earnings per Share and Stock Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2024	Sep. 24, 2023	Sep. 29, 2024	Sep. 24, 2023	Jul. 31, 2023	Feb. 06, 2019
Net (loss) income
Net income	$ 69.1	$ 65.8	$ 223.6	$ 206.4
Shares
Shares (in shares)	33,500,000	33,400,000	33,500,000	33,400,000
Per Share Amount
Net income (in dollars per share)	$ 2.07	$ 1.97	$ 6.68	$ 6.17
Dilutive securities, principally common stock options
Common stock equivalents (in shares)		100,000		100,000
Common stock equivalents (in dollars per share)	$ (0.01)	$ (0.01)	$ (0.01)	$ (0.02)
Net (loss) income
Net income	$ 69.1	$ 65.8	$ 223.6	$ 206.4
Weighted average number of shares:
Shares (in shares)	33,500,000	33,500,000	33,500,000	33,500,000
Securities not included in the computation of diluted EPS
Net income (in dollars per share)	$ 2.06	$ 1.96	$ 6.67	$ 6.15
Dilutive securities, principally common stock options
Options to purchase shares of Class A common stock, anti-dilutive	0	0	0	0
Shares repurchased
Number of shares repurchased	25,885	22,013	65,897	68,569
Cost of shares repurchased	$ 4.9	$ 4.0	$ 13.0	$ 11.7
Class A
Shares repurchased
Value of shares of the entity's Class A common stock authorized to be repurchased					$ 150.0	$ 150.0
2019 stock repurchase program | Class A
Shares repurchased
Value of shares of the entity's Class A common stock authorized to be repurchased	150.0		150.0
2023 repurchase program | Class A
Shares repurchased
Remaining authorized repurchase amount	$ 149.0		$ 149.0