Fair value on recurring and non-recurring basis (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jul. 02, 2016		Apr. 02, 2016	Jul. 02, 2016		Jun. 27, 2015	Dec. 31, 2015	Sep. 15, 2015	Mar. 28, 2015	Dec. 27, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, assets, level 1, level 2, level 3 Transfers, Amount				$ 0		$ 0
Goodwill, Impairment Loss				163,300,000
Liabilities:
Contingent consideration								$ 0
Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Assets:
Investment securities	$ 40,000,000			40,000,000			$ 14,900,000
Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Assets:
Foreign currency forward contracts	4,300,000			4,300,000			4,800,000
Funds associated with Israeli post employment benefits	16,300,000			16,300,000			17,200,000
Total assets at fair value	20,600,000			20,600,000			22,000,000
Liabilities:
Interest rate swap agreements	0			0			300,000
Foreign currency forward contracts	2,800,000			2,800,000			3,900,000
Total liabilities at fair value	2,800,000			2,800,000			4,200,000
Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Liabilities:
Contingent consideration							17,900,000
Fair value, measurements, non-recurring [Member] | Fair value, inputs, level 3 [Member]
Assets:
Goodwill	1,792,600,000	[1]		1,792,600,000	[1]		0
Indefinite-lived intangible assets	1,082,000,000	[2]		1,082,000,000	[2]		1,031,800,000
Assets held for sale, net	70,100,000			70,100,000			37,500,000
Total assets at fair value	2,944,700,000			2,944,700,000			1,069,300,000
BCH [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill, Gross	1,955,900,000			1,955,900,000
Goodwill, Impairment Loss	(30,300,000)		$ 193,600,000	163,300,000
Contingent Consideration Classified as Equity [Member] | Fair value, measurements, recurring [Member] | Fair value, inputs, level 3 [Member]
Liabilities:
Contingent consideration	$ 44,900,000		$ 48,000,000	$ 44,900,000		$ 0	$ 17,900,000		$ 12,400,000	$ 12,400,000

[1] (1)Goodwill with a carrying amount of $1,955.9 million was written down to its implied fair value of $1,792.6 million, resulting in total impairment charges of $163.3 million for the six months ended July 2, 2016, which are included in Impairment charges (credits) on the Condensed Consolidated Statements of Operations. The implied fair value is as of April 2, 2016, the date of the goodwill impairment test.

[2] (2)Intangible assets estimated fair value at July 2, 2016 is as of April 2, 2016, the date the impairment was taken.