Earnings per Share and Stock Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018	Feb. 06, 2019	Jul. 27, 2015
Net (loss) income
Net income	$ 31.0	$ 28.2
Shares
Shares (in shares)	34,200,000	34,300,000
Per Share Amount
Net income (in dollars per share)	$ 0.91	$ 0.82
Dilutive securities, principally common stock options
Common stock equivalents (in shares)		100,000
Net (loss) income
Net income	$ 31.0	$ 28.2
Weighted average number of shares:
Shares (in shares)	34,200,000	34,400,000
Securities not included in the computation of diluted EPS
Net income (in dollars per share)	$ 0.91	$ 0.82
Dilutive securities, principally common stock options
Options to purchase shares of Class A common stock, anti-dilutive	0	0
Shares repurchased
Number of shares repurchased	74,409	80,055
Cost of shares repurchased	$ 5.6	$ 6.2
Class A
Shares repurchased
Value of shares of the entity's Class A common stock authorized to be repurchased			$ 150.0	$ 100.0
July 27, 2015 | Class A
Shares repurchased
Remaining authorized repurchase amount	$ 6.2