Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Dec. 27, 2019	Sep. 26, 2014
Income Taxes [Line Items]
Income tax benefit	$ (18.9)	$ (204.7)
Increase (decrease) tax benefit	185.8
Increase (Decrease) Tax Benefit, Intercompany Financing Reorganization	192.8
(Loss) income from continuing operations before income taxes	$ (75.6)	$ (49.5)
Effective tax rate	25.00%	413.50%
Current Income Tax Expense (Benefit)	$ (22.4)	$ 38.5
Deferred Income Tax Expense (Benefit)	3.5	$ (243.2)
Income Taxes Paid, Net	12.7		$ 30.7
Operating Loss Carryforwards	765.1
Unrecognized tax benefits	418.9		398.6
Unrecognized tax benefits, net increase	20.3
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	25.1
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	4.8
Unrecognized tax benefits, which if favorably settled would benefit the effective tax rate	416.6
Interest accrued on unrecognized tax benefits	34.5		$ 32.9
Unrecognized tax benefits that would impact effective tax rate, upper bound of change	95.5
Income tax penalties and interest accrued that would impact effective tax rate, upper bound of change	22.3
Increase (Decrease) Tax Expense (Benefit), Change in Operating Income	6.0
Increase (Decrease), Tax Expense (Benefit), Gain on Debt Repurchases	1.7
Increase (Decrease), Tax Expense (Benefit), Restructuring	1.4
Increase (Decrease), Tax Expense (Benefit), CARES Act	(11.5)
Increase (Decrease), Tax Expense (Benefit), Separation Costs	1.2
Discontinued Operations [Member]
Income Taxes [Line Items]
Unrecognized tax benefits, which if favorably settled would benefit the effective tax rate	20.0
CARES Act [Member]
Income Taxes [Line Items]
Proceeds from Income Tax Refunds	91.5
Income tax benefit	$ (11.5)
Internal Revenue Service (IRS) [Member] | Cadence Pharmaceuticals, Inc. [Member]
Income Taxes [Line Items]
Proposed Adjustment to Taxable Income				$ 871.0