Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Class A Common Stock	Class B Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Total
Balance at the beginning of the period at Dec. 31, 2019	$ 2.8	$ 0.6	$ 591.5	$ 513.9	$ (130.8)	$ 978.0
Balance (in shares) at Dec. 31, 2019	27,586,416	6,279,290
Increase (Decrease) in Stockholders' Equity
Net income				32.0		32.0
Other comprehensive income					(17.4)	(17.4)
Comprehensive income						14.6
Shares of Class B common stock converted to Class A common stock (in shares)	50,000	(50,000)
Stock-based compensation			3.6			3.6
Stock repurchase				(14.7)		(14.7)
Stock repurchase (in shares)	(174,707)
Net change in restricted stock units			2.0	(7.7)		(5.7)
Net change in restricted and performance stock units (in shares)	83,048
Common stock dividends				(8.0)		(8.0)
Balance at the end of the period at Mar. 29, 2020	$ 2.8	$ 0.6	597.1	515.5	(148.2)	967.8
Balance (in shares) at Mar. 29, 2020	27,544,757	6,229,290
Increase (Decrease) in Stockholders' Equity
Change in accounting principle						560.1
Balance at the beginning of the period at Dec. 31, 2020	$ 2.8	$ 0.6	606.3	560.1	(100.0)	1,069.8
Balance (in shares) at Dec. 31, 2020	27,478,512	6,144,290
Increase (Decrease) in Stockholders' Equity
Net income				41.7		41.7
Other comprehensive income					(14.2)	(14.2)
Comprehensive income						27.5
Shares of Class B common stock converted to Class A common stock (in shares)	20,000	(20,000)
Stock-based compensation			2.9			2.9
Stock repurchase				(3.8)		(3.8)
Stock repurchase (in shares)	(31,153)
Net change in restricted stock units			1.8	(9.2)		(7.4)
Net change in restricted and performance stock units (in shares)	117,723
Common stock dividends				(7.8)		(7.8)
Balance at the end of the period at Mar. 28, 2021	$ 2.8	$ 0.6	$ 611.0	$ 581.0	$ (114.2)	1,081.2
Balance (in shares) at Mar. 28, 2021	27,585,082	6,124,290
Increase (Decrease) in Stockholders' Equity
Change in accounting principle						$ 581.0