Fair value on recurring and non-recurring basis (Details) - USD ($)	3 Months Ended		6 Months Ended
	Apr. 02, 2016		Dec. 31, 2015	Sep. 15, 2015	Jun. 27, 2015	Nov. 08, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes	$ 5,937,100,000		$ 4,698,300,000			$ 2,300,000,000
Fair value, assets, level 1, level 2, level 3 Transfers, Amount	0		0
Liabilities:
Contingent consideration				$ 0
Goodwill, Impairment Loss	193,600,000		0
Fair value, measurements, recurring [Member] | Fair value, inputs, level 1 [Member]
Assets:
Investment securities	38,600,000		14,900,000
Fair value, measurements, recurring [Member] | Fair value, inputs, level 2 [Member]
Assets:
Foreign currency forward contracts	9,400,000		4,800,000
Funds associated with Israeli post employment benefits	17,600,000		17,200,000
Assets, Fair Value Disclosure	27,000,000		22,000,000
Liabilities:
Interest rate swap agreements	0		300,000
Foreign currency forward contracts	3,400,000		3,900,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	3,400,000		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:
Assets, Fair Value Disclosure	2,843,600,000		1,069,300,000
Goodwill, Fair Value Disclosure	1,761,600,000	[1]	0
Indefinite-lived intangible assets	1,082,000,000		1,031,800,000
Assets held-for-sale, long lived, fair value disclosure	0		37,500,000
Public bonds and private placement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes	5,100,000,000		3,900,000,000
Public bonds and private placement [Member] | Fair value, inputs, level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, fair value disclosure	5,100,000,000				$ 3,800,000,000
Retail bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	837,100,000		798,300,000
Debt instrument, unamortized premium	76,500,000		82,500,000
Retail bonds [Member] | Fair value, inputs, level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, fair value disclosure	905,500,000		$ 859,800,000
BCH [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill	1,955,200,000
Liabilities:
Goodwill, Impairment Loss	$ 193,600,000

[1] Goodwill with a carrying amount of $1,955.2 million was written down to its implied fair value of $1,761.6 million, resulting in an impairment charge of $193.6 million, which was included in Impairment charges on the Condensed Consolidated Statements of Operations for the three months ended April 2, 2016.