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 (Loss)
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				3.8	0.0	1.4
Net earnings	$ 53.9						53.9
Dividends							(8.7)
Other comprehensive income (loss), net of tax	64.6							64.6
Ending balance at Oct. 01, 2017	1,127.0	36.6	3.5	(34.6)	(0.6)	30.0	968.8	123.3
Beginning balance at Jul. 02, 2017		36.6	3.5	(37.0)	(0.6)	31.1	948.7	91.1
Increase (Decrease) in Stockholders' Equity
Issuance of stock awards				2.4	0.0	(1.1)
Net earnings	23.0						23.0
Dividends							(2.9)
Other comprehensive income (loss), net of tax	32.2							32.2
Ending balance at Oct. 01, 2017	1,127.0	36.6	3.5	(34.6)	(0.6)	30.0	968.8	123.3
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				7.9	0.0	(7.2)
Net earnings	46.8						46.8
Dividends							(8.8)
Other comprehensive income (loss), net of tax	(7.8)							(7.8)
Ending balance at Sep. 30, 2018	1,185.8	36.6	3.5	(26.7)	(0.6)	25.0	1,165.0	(17.0)
Beginning balance at Jul. 01, 2018		36.6	3.5	(26.8)	(0.6)	23.4	1,134.8	(10.0)
Increase (Decrease) in Stockholders' Equity
Issuance of stock awards				0.1	0.0	1.6
Net earnings	33.1						33.1
Dividends							(2.9)
Other comprehensive income (loss), net of tax	(7.0)							(7.0)
Ending balance at Sep. 30, 2018	$ 1,185.8	$ 36.6	$ 3.5	$ (26.7)	$ (0.6)	$ 25.0	1,165.0	(17.0)
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