Income Taxes (Details) € in Millions			1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Nov. 04, 2020 USD ($)	Aug. 15, 2017 USD ($)	May 31, 2020 USD ($)	Sep. 26, 2020 USD ($)	Sep. 28, 2019	Sep. 26, 2020 USD ($)	Sep. 28, 2019	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Aug. 22, 2019 USD ($)	Apr. 26, 2019 USD ($)	Nov. 29, 2018 EUR (€)
Income Tax Contingency [Line Items]
Effective income tax rate reconciliation, percent				(21.10%)	5.20%	78.90%	19.60%
Income tax examination, debts subject to limit of deductibility of interest expense												$ 7,500,000,000
Interest rate cap on debts for U.S. Federal tax purposes, as percent of Applicable Federal Rate			130.00%
Income tax examination, reduction in blended interest rate due to cap for U.S. Federal tax purposes			4.00%
IRS notice of proposed audit adjustment to reduce deductible interest expense for fiscal years 2014 and 2015			$ 480,000,000.0
Income tax examination, estimated increase to tax expense from audit adjustment to fiscal years 2014 and 2015, excluding interest and penalties			170,000,000.0
Income tax examination, estimate of additional tax expense for the period from June 28, 2015 through December 31, 2019, excluding interest and penalties			$ 200,000,000.0
Income tax examination, penalties and interest expense		$ 163,600,000						$ 24,700,000	$ 40,200,000	$ 61,500,000	$ 37,200,000
Cumulative deferred charge related to tax litigation				$ 101,800,000		$ 101,800,000
Income tax overpayments applied to succeeding years				$ 29,700,000		$ 29,700,000
Royalty conceded on all omeprazole sales as a percent of refund claims (percent)						24.00%
IRS notice of proposed adjustment amount from 2011,2012 and 2013 audit of Athena, including penalty													$ 843,000,000.0
IRS notice of proposed adjustment, penalty (percent)													40.00%
Revenue Commissioners, Ireland
Income Tax Contingency [Line Items]
Unsettled audit assessment from income tax examination | €														€ 1,636
Subsequent Event | Revenue Commissioners, Ireland
Income Tax Contingency [Line Items]
Period available to file appeal against the judgment of the High Court	28 days
Payment required before final determination of the judicial review case and appeal pending before the Tax Appeals Commission	$ 0