Condensed Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2018		Jul. 01, 2017	Jun. 30, 2018		Jul. 01, 2017
Income Statement [Abstract]
Net sales	$ 1,186.4	[1]	$ 1,237.9	$ 2,403.4	[1]	$ 2,431.9
Cost of sales	715.4		733.3	1,439.7		1,463.0
Gross profit	471.0		504.6	963.7		968.9
Operating expenses
Distribution	23.8		21.6	48.5		42.7
Research and development	91.9		42.6	130.3		82.3
Selling	155.2		155.6	316.5		310.6
Administration	96.8		98.2	204.5		203.6
Impairment charges	1.7		27.4	1.7		39.6
Restructuring charges	3.7		12.1	5.2		50.8
Other operating expense (income)	3.2		(1.7)	6.1		(38.0)
Total operating expenses	376.3		355.8	712.8		691.6
Operating income	94.7		148.8	250.9		277.3
Change in financial assets	(0.6)		38.7	9.0		21.6
Interest expense, net	32.1		45.1	63.5		98.4
Other expense, net	7.9		6.1	12.1		2.5
Loss on extinguishment of debt	0.0		135.2	0.5		135.2
Income (loss) before income taxes	55.3		(76.3)	165.8		19.6
Income tax expense (benefit)	19.1		(6.7)	48.8		17.6
Net income (loss)	$ 36.2		$ (69.6)	$ 117.0		$ 2.0
Earnings (loss) per share
Basic (in dollars per share)	$ 0.26		$ (0.49)	$ 0.84		$ 0.01
Diluted (in dollars per share)	$ 0.26		$ (0.49)	$ 0.84		$ 0.01
Weighted-average shares outstanding
Basic (in shares)	138.1		143.3	139.5		143.3
Diluted (in shares)	138.7		143.3	140.0		143.6
Dividends declared per share (in dollars per share)	$ 0.19		$ 0.16	$ 0.38		$ 0.32

[1] The net sales by geography is derived from the location of the entity that sells to a third party.