Earnings per Share and Stock Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 25, 2023	Jun. 30, 2024	Jun. 25, 2023	Jul. 31, 2023	Feb. 06, 2019
Net (loss) income
Net income	$ 82.0	$ 75.9	$ 154.5	$ 140.6
Shares
Shares (in shares)	33,500,000	33,500,000	33,500,000	33,400,000
Per Share Amount
Net income (in dollars per share)	$ 2.44	$ 2.27	$ 4.61	$ 4.21
Dilutive securities, principally common stock options
Common stock equivalents (in shares)		100,000		100,000
Common stock equivalents (in dollars per share)		$ (0.01)		$ (0.02)
Net (loss) income
Net income	$ 82.0	$ 75.9	$ 154.5	$ 140.6
Weighted average number of shares:
Shares (in shares)	33,500,000	33,600,000	33,500,000	33,500,000
Securities not included in the computation of diluted EPS
Net income (in dollars per share)	$ 2.44	$ 2.26	$ 4.61	$ 4.19
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	20,262	24,083	40,012	46,556
Cost of shares repurchased	$ 4.1	$ 4.0	$ 8.1	$ 7.7
Class A
Shares repurchased
Value of shares of the entity's Class A common stock authorized to be repurchased					$ 150.0	$ 150.0
February 6, 2019 | Class A
Shares repurchased
Remaining authorized repurchase amount	$ 3.9		$ 3.9