Discontinued operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016	Dec. 31, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 760.8	$ 641.8	$ 760.8	$ 641.8	$ 622.3	$ 417.8
Net sales	1,237.9	1,340.5	2,431.9	2,687.8
Income (Loss) from Continuing Operations before Income Taxes, Domestic	(76.3)	(812.2)	19.6	(1,302.4)
Income tax expense (benefit)	(6.7)	$ (277.9)	17.6	$ (238.9)
Accounts receivable, net of allowance for doubtful accounts of $5.3 million and $6.3 million, respectively	1,065.9		1,065.9		1,176.0
Inventories	818.1		818.1		795.0
Prepaid expenses and other current assets	176.5		176.5		212.0
Property, plant and equipment, net	876.9		876.9		870.1
Financial asset	0.0		0.0		2,350.0
Other intangible assets, net	3,373.4		3,373.4		3,396.8
Other non-current assets	435.9		435.9		211.9
Accounts payable	$ 480.8		$ 480.8		$ 471.7