Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock Capital Stock, Class A common stock	Common Stock Capital Stock, Class B common stock	Treasury Stock Treasury Stock, Class A common stock	Treasury Stock Treasury Stock, Class B common stock	Paid-in Capital	Earnings Invested in the Business	Accumulated Other Comprehensive Income
Beginning balance at Jan. 01, 2017		$ 36.6	$ 3.5	$ (38.4)	$ (0.6)	$ 28.6	$ 923.6	$ 58.7
Increase (Decrease) in Stockholders' Equity
Issuance of stock awards				0.9	0.0	2.9
Net earnings	$ 12.2						12.2
Dividends							(2.9)
Other comprehensive income, net of tax	24.6							24.6
Ending balance at Apr. 02, 2017	1,049.7	36.6	3.5	(37.5)	(0.6)	31.5	932.9	83.3
Increase (Decrease) in Stockholders' Equity
Cumulative effect adjustment | Accounting Standards Update 2016-01							0.0	0.0
Cumulative effect adjustment | Accounting Standards Update 2014-09							0.0
Beginning balance at Dec. 31, 2017	1,151.5	36.6	3.5	(34.6)	(0.6)	32.2	983.6	130.8
Increase (Decrease) in Stockholders' Equity
Issuance of stock awards				7.3	0.0	(11.1)
Net earnings	29.1						29.1
Dividends							(2.9)
Other comprehensive income, net of tax	14.0							14.0
Ending balance at Apr. 01, 2018	$ 1,191.3	$ 36.6	$ 3.5	$ (27.3)	$ (0.6)	$ 21.1	1,153.2	4.8
Increase (Decrease) in Stockholders' Equity
Cumulative effect adjustment | Accounting Standards Update 2016-01							140.0	$ (140.0)
Cumulative effect adjustment | Accounting Standards Update 2014-09							$ 3.4