Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 26, 2014	Dec. 27, 2013	Sep. 26, 2014	Aug. 14, 2014
Income Taxes [Line Items]
(Benefit) provision for income taxes	$ (9.3)	$ 16.6
Income from continuing operations before income taxes	82.8	63.0
Effective tax rate	(11.20%)	26.30%
Intangible asset amortization	125.5	8.8
Increase in prepaid taxes	54.3
Decrease in current deferred tax assets	18.8
Unrecognized tax benefits	83.9		82.0
Unrecognized tax benefits, net increase	(1.9)
Unrecognized tax benefits, additions related to prior period tax positions	0.3
Unrecognized tax benefits, additions related to current year tax positions	3.3
Unrecognized tax benefits, decrease related to settlements	0.9
Unrecognized tax benefits, lapse of statute of limitations	0.8
Unrecognized tax benefits, which if favorably settled would benefit the effective tax rate	83.9
Interest accrued on unrecognized tax benefits	44.3		45.1
Unrecognized tax benefits that would impact effective tax rate, upper bound of change	29.1
Income tax penalties and interest accrued that would impact effective tax rate, upper bound of change	17.0
Questcor Pharmaceuticals, Inc.
Income Taxes [Line Items]
Intangible asset amortization	75.4
Increase in deferred tax liability, net due to installment sale note receivable	1,515.9
Increase in deferred tax charge, due to installment sale	25.3
Increase in prepaid taxes, due to installment sale	1.9
Acquired deferred tax liabilities, net	1,914.5		1,900.7	1,914.5
Tax receivable associated with the Questcor Acquisition			60.0
Cash tax refund	20.0
H. P. Acthar Gel | Questcor Pharmaceuticals, Inc.
Income Taxes [Line Items]
Decrease in deferred tax liability, net due to Acthar intangible asset	$ (1,488.7)