Income Taxes (Details) - USD ($)	3 Months Ended			9 Months Ended
	Jun. 26, 2015	Dec. 26, 2014	Jun. 27, 2014	Jun. 26, 2015	Jun. 27, 2014	Apr. 16, 2015	Sep. 26, 2014
Income Taxes [Line Items]
Income tax expense (benefit)	$ 3,300,000		$ (2,400,000)	$ (40,200,000)	$ (6,100,000)
Income (loss) from continuing operations before income taxes	$ 60,800,000		$ (26,700,000)	$ 185,900,000	$ 27,700,000
Effective tax rate	5.40%		9.00%	(21.60%)	(22.00%)
Increase (Decrease) In Effective Tax Rate, Amount	$ 3.6			$ 0.4
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Amount	13.4			20.9
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount	1.2			0.2
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	34.5			49.1
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	22.3			28.0
Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount	30.8			49.4
Discontinued Operation, Tax Effect of Discontinued Operation				22,500,000
Deferred Tax Assets, Valuation Allowance	8,200,000			8,200,000
Unrecognized tax benefits	90,600,000			90,600,000			$ 82,000,000
Unrecognized tax benefits, net increase				8,600,000
Unrecognized tax benefits, additions related to prior period tax positions				10,700,000
Unrecognized tax benefits, additions related to current year tax positions				6,000,000
Unrecognized tax benefits, decrease related to settlements				6,600,000
Unrecognized tax benefits, lapse of statute of limitations				1,500,000
Unrecognized tax benefits, which if favorably settled would benefit the effective tax rate	88,900,000			88,900,000
Interest accrued on unrecognized tax benefits	41,500,000			41,500,000			$ 45,100,000
Unrecognized tax benefits that would impact effective tax rate, upper bound of change	16,200,000			16,200,000
Income tax penalties and interest accrued that would impact effective tax rate, upper bound of change	10,100,000			10,100,000
Increase (Decrease) in Income Taxes Payable	(3,300,000)			(8,300,000)
Tax Adjustments, Settlements, and Unusual Provisions	3,300,000			6,300,000
Deferred Tax Liabilities, Undistributed Foreign Earnings	800,000			800,000
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries	404,400,000			404,400,000
Undistributed Earnings of Foreign Subsidiaries	16,100,000			16,100,000
Ikaria, Inc.
Income Taxes [Line Items]
Increase (Decrease), Deferred Tax Liability, Net, Noncurrent				620,000,000
Deferred Tax Liabilities, Net						$ 643,300,000
Deferred Tax Liabilities, Property, Plant and Equipment	17,600,000			17,600,000
Deferred Tax Assets, Tax Credit Carryforwards	21,700,000			21,700,000
Deferred Tax Assets, Other	13,100,000			13,100,000
Deferred Tax Assets, Operating Loss Carryforwards	$ 4,900,000			$ 4,900,000
Questcor Pharmaceuticals, Inc.
Income Taxes [Line Items]
Increase in deferred tax liability, net due to installment sale note receivable		$ 1,488,700,000
Increase in deferred tax charge, due to installment sale		25,300,000
Increase in prepaid taxes, due to installment sale		1,900,000
Questcor and Cadence Pharmaceuticals
Income Taxes [Line Items]
Increase in deferred tax liability, net due to installment sale note receivable		$ 1,515,900,000