Mallinckrodt (MNKTQ) 10-K 26 Feb 19 2018 FY Annual report Financial data

Document And Entity Information

Document And Entity Information [Abstract] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 28, 2018	Feb. 22, 2019	Jun. 29, 2018
Document And Entity Information [Abstract]
Entity Common Stock, Shares Outstanding		83,505,008
Entity Registrant Name	Mallinckrodt plc
Share Price			$ 18.66
Entity Central Index Key	1,567,892
Trading Symbol	MNK
Current Fiscal Year End Date	--12-28
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 28, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Public Float			$ 1,542.3

Consolidated and Combined State

Consolidated and Combined Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 28, 2018		Sep. 28, 2018		Jun. 29, 2018		Mar. 30, 2018		Dec. 29, 2017		Sep. 29, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 30, 2016	Dec. 25, 2015		Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Net sales	$ 834.9		$ 799.9		$ 825.5		$ 755.3		$ 792.3		$ 793.9		$ 824.5		$ 810.9		$ 829.9	$ 811.2		$ 3,215.6	$ 3,221.6	$ 3,380.8
Cost of sales																	383.2	360	[1]	1,744.4	1,564.1	1,523.2
Gross profit	363.3	[2]	366.4	[2]	394	[2]	347.5	[2]	421	[2]	400.6	[2]	416.1	[2]	419.8	[2]	446.7	451.2	[1]	1,471.2	1,657.5	1,857.6
Selling, general and administrative expenses																	321.1	221.8	[1]	834.1	849.7	913.7
Research and development expenses																	66.1	61.3	[1]	361.1	276.9	261.2
Non-restructuring impairment charges																	214.3	0		3,893.1	63.7	16.9
Losses (gains) on divestiture																	0			0.8	(56.9)	0
Restructuring charges, net																	3.8	4.1		103	31.2	32.7
Non-restructuring impairment charges																	214.3			3,893.1	63.7	16.9
Losses (gains) on divestiture																				(0.8)	(56.9)
Operating (loss) income																	(158.6)	(164)	[1]	(3,720.9)	492.9	633.1
Interest expense																	(91.3)	(97.8)		(370.2)	(369.1)	(384.6)
Interest income																	0.5	0.2		8.2	4.6	1.3
Other income (expense), net																	(49.1)	0.1	[1]	30.9	(66.8)	(16.4)
(Loss) income from continuing operations before income taxes																	(298.5)	66.5		(4,052)	61.6	233.4
Income Tax Expense (Benefit)																	(121.7)	(37.3)		(430.1)	(1,709.6)	(255.6)
(Loss) income from continuing operations	(3,718.4)	[3]	114.2	[3]	3.2	[3]	(20.9)	[3]	1,607.4	[3]	64.3	[3]	70.6	[3]	28.9	[3]	(176.8)	103.8		(3,621.9)	1,771.2	489
Income from discontinued operations, net of tax expense of $1.4, $5.4, $43.5, and $15.3	0		(0.4)		12.4		2.9		1.3		(0.6)		(7.8)		370.3		23.6	107.3		14.9	363.2	154.7
Net (loss) income	$ (3,718.4)		$ 113.8		$ 15.6		$ (18)		$ 1,608.7		$ 63.7		$ 62.8		$ 399.2		$ (153.2)	$ 211.1		$ (3,607)	$ 2,134.4	$ 643.7
Basic earnings per share (Note 10):
(Loss) income from continuing operations	$ (44.64)	[4]	$ 1.37	[4]	$ 0.04	[4]	$ (0.24)	[4]	$ 17.43	[4]	$ 0.66	[4]	$ 0.72	[4]	$ 0.28	[4]	$ (1.67)	$ 0.90		$ (43.12)	$ 18.13	$ 4.42
Income from discontinued operations, net of income taxes																	0.22	0.93		0.18	3.72	1.40
Net (loss) income																	$ (1.45)	$ 1.83		$ (42.94)	$ 21.85	$ 5.82
Basic weighted-average shares outstanding																	105.7	115.4		84	97.7	110.6
Diluted earnings per share (Note 10):
(Loss) income from continuing operations	$ (44.64)	[4]	$ 1.34	[4]	$ 0.04	[4]	$ (0.24)	[4]	$ 17.40	[4]	$ 0.66	[4]	$ 0.72	[4]	$ 0.28	[4]	$ (1.67)	$ 0.89		$ (43.12)	$ 18.09	$ 4.39
Income from discontinued operations, net of income taxes																	0.22	0.92		0.18	3.71	1.39
Net (loss) income																	$ (1.45)	$ 1.82		$ (42.94)	$ 21.80	$ 5.77
Diluted weighted-average shares outstanding																	105.7	116.3		84	97.9	111.5
[1]	Financial data for this period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of Accounting Standards Update ("ASU") 2017-07. See Note 4 for further information on this ASU.
[2]	Financial data for each period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of ASU 2017-07. See Note 4 for further information.
[3]	(Loss) income from continuing operations for the quarter ended December 28, 2018 reflects impairment charges for goodwill and an IPR&D asset. See Note 13 for further information. Income from continuing operations for the quarter ended December 29, 2017 reflects one-time effects for the completion of the reorganization of the Company's legal entity ownership and the impact of the TCJA.
[4]	Quarterly and annual computations are prepared independently. Therefore, the sum of each quarter may not necessarily total the fiscal period amounts noted elsewhere within this Annual Report on Form 10-K.

Consolidated and Combined Sta_2

Consolidated and Combined Statements of Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Income Statement [Abstract]
Tax (benefit) expense on income (loss) from discontinued operations	$ 15.3	$ 1.4	$ 5.4	$ 43.5

Consolidated and Combined Sta_3

Consolidated and Combined Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended										12 Months Ended
	Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Net (loss) income	$ (3,718.4)	$ 113.8	$ 15.6	$ (18)	$ 1,608.7	$ 63.7	$ 62.8	$ 399.2	$ (153.2)	$ 211.1	$ (3,607)	$ 2,134.4	$ 643.7
Other comprehensive (loss) income, net of tax
Unrecognized gain on investments									0		0	1.5	0
Currency translation adjustments									(21.1)		(12.2)	11.3	(58.6)
Unrecognized gain on derivatives, net of tax expense of $0.2, $0.3, $0.2, and $-									0.2		0.7	1	0.5
Unrecognized gain (loss) on benefit plans, net of tax expense (benefit) of $0.5, $30.8, ($15.0), and ($19.3)									34		1.6	45.8	(28.4)
Total other comprehensive (loss) income, net of tax									13.1		(9.9)	59.6	(86.5)
Comprehensive (loss) income									$ (140.1)		$ (3,616.9)	$ 2,194	$ 557.2

Consolidated and Combined Sta_4

Consolidated and Combined Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Unrecognized loss on derivatives, tax	$ 0	$ (0.2)	$ (0.3)	$ (0.2)
Unrecognized gain (loss) on benefit plans, tax	$ 19.3	$ (0.5)	$ (30.8)	$ 15

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Current Assets:
Cash and cash equivalents	$ 348.9	$ 1,260.9
Accounts receivable, less allowance for doubtful accounts of $5.0 and $3.9	623.3	445.8
Inventories	322.3	340.4
Prepaid expenses and other current assets	132.7	84.1
Notes receivable	0	154
Total current assets	1,427.2	2,285.2
Property, plant and equipment, net	982	966.8
Goodwill	0	3,482.7
Intangible assets, net	8,282.8	8,375
Other assets	185.3	171.2
Total Assets	10,877.3	15,280.9
Current Liabilities:
Current maturities of long-term debt	22.4	313.7
Accounts payable	147.5	113.3
Accrued payroll and payroll-related costs	124	98.5
Interest Payable, Current	77.6	57
Taxes Payable, Current	25	15.8
Accrued and other current liabilities	547.2	452.1
Total current liabilities	943.7	1,050.4
Long-term debt	6,069.2	6,420.9
Pension and postretirement benefits	60.5	67.1
Environmental liabilities	59.7	73.2
Deferred income taxes	324.3	689
Other income tax liabilities	228	94.1
Other liabilities	304.6	364.2
Total Liabilities	7,990	8,758.9
Shareholders' Equity:
Preferred shares, $0.20 par value, 500,000,000 authorized; none issued or outstanding	0	0
Ordinary A shares, €1.00 par value, 40,000 authorized; none issued or outstanding	0	0
Ordinary shares, $0.20 par value, 500,000,000 authorized; 92,705,747 and 92,196,662 issued; 83,323,877 and 86,336,232 outstanding	18.5	18.4
Ordinary shares held in treasury at cost, 9,381,870 and 5,860,430	(1,617.4)	(1,564.7)
Additional paid-in capital	5,528.2	5,492.6
Retained (deficit) earnings	(1,017.7)	2,588.6
Accumulated other comprehensive loss	(24.3)	(12.9)
Total Shareholders' Equity	2,887.3	6,522
Total Liabilities and Shareholders' Equity	$ 10,877.3	$ 15,280.9

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical)	Dec. 28, 2018$ / sharesshares	Dec. 28, 2018€ / sharesshares	Dec. 29, 2017$ / sharesshares	Dec. 29, 2017€ / sharesshares
Preferred shares, par value (in usd per share) | $ / shares	$ 0.20		$ 0.20
Preferred shares, shares authorized (in shares)	500,000,000	500,000,000	500,000,000	500,000,000
Preferred shares, shares issued (in shares)	0	0	0	0
Preferred shares, shares outstanding (in shares)	0	0	0	0
Ordinary A shares, par value (in eur per share) | € / shares		€ 1		€ 1
Ordinary A shares, shares authorized (in shares)	40,000	40,000	40,000	40,000
Ordinary A shares, shares issued (in shares)	0	0	0	0
Ordinary A shares, shares outstanding (in shares)	0	0	0	0
Ordinary shares, par value (in usd per share) | $ / shares	$ 0.20		$ 0.20
Ordinary shares, shares authorized (in shares)	500,000,000	500,000,000	500,000,000	500,000,000
Ordinary shares, shares issued (in shares)	92,705,747	92,705,747	92,196,662	92,196,662
Ordinary shares, shares outstanding (in shares)	83,323,877	83,323,877	86,336,232	86,336,232
Ordinary shares held in treasury (in shares)	9,381,870	9,381,870	5,860,430	5,860,430

Consolidated and Combined Sta_5

Consolidated and Combined Statements of Cash Flows - USD ($)	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Restricted Cash and Investments, Current	$ 100,000	$ 0	$ 0	$ 100,000
Restricted Cash and Investments, Noncurrent	19,000,000	18,600,000	18,200,000	19,000,000
Cash and Cash Equivalents, Including Restricted Cash	361,100,000	367,500,000	1,279,100,000	299,600,000
Cash and cash equivalents	342,000,000	348,900,000	1,260,900,000	280,500,000
Cash Flows from Operating Activities:
Net (loss) income	(153,200,000)	(3,607,000,000)	2,134,400,000	643,700,000
Adjustments to reconcile net cash provided by operating activities:
Depreciation and amortization	203,200,000	852,100,000	808,300,000	834,500,000
Share-based compensation	11,000,000	34,600,000	59,200,000	42,900,000
Deferred income taxes	(204,300,000)	(541,500,000)	(1,744,100,000)	(432,900,000)
Non-cash impairment charges	214,300,000	3,893,100,000	63,700,000	16,900,000
Inventory provisions	8,500,000	37,900,000	34,100,000	29,200,000
Gain (Loss) on Disposition of Business	0	800,000	(418,100,000)	(95,300,000)
Other non-cash items	(9,200,000)	(50,900,000)	(21,400,000)	29,600,000
Changes in assets and liabilities, net of the effects of acquisitions:
Accounts receivable, net	(36,500,000)	(145,800,000)	(16,200,000)	31,200,000
Inventories	26,300,000	63,100,000	(23,600,000)	(17,300,000)
Accounts payable	5,400,000	24,600,000	(25,800,000)	(9,700,000)
Income taxes	600,000	99,000,000	(34,200,000)	93,900,000
Other	(109,100,000)	5,500,000	(89,000,000)	17,900,000
Net cash from operating activities	195,600,000	665,500,000	727,300,000	1,184,600,000
Cash Flows from Investing Activities:
Capital expenditures	(65,200,000)	(127,000,000)	(186,100,000)	(182,900,000)
Acquisitions, net of cash acquired	1,800,000	(699,900,000)	(76,300,000)	(245,400,000)
Proceeds from Divestiture of Businesses, Net of Cash Divested	0	313,000,000	576,900,000	266,700,000
Other	10,200,000	33,600,000	3,900,000	6,000,000
Net cash from investing activities	(77,200,000)	(480,300,000)	318,400,000	(155,600,000)
Cash Flows from Financing Activities:
Issuance of external debt	190,000,000	690,300,000	1,465,000,000	98,300,000
Repayment of external debt and capital lease obligation	(86,700,000)	(1,693,600,000)	(917,200,000)	(568,600,000)
Debt financing costs	0	(12,100,000)	(12,700,000)	(100,000)
Proceeds from exercise of share options	400,000	1,000,000	4,100,000	14,000,000
Repurchase of shares	(158,800,000)	(57,500,000)	(651,700,000)	(652,900,000)
Other	1,200,000	(23,100,000)	(17,700,000)	(53,000,000)
Net cash from financing activities	(53,900,000)	(1,095,000,000)	(130,200,000)	(1,162,300,000)
Effect of currency rate changes on cash	(3,000,000)	(1,800,000)	2,500,000	300,000
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	61,500,000	(911,600,000)	918,000,000	(133,000,000)
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	95,400,000	309,700,000	339,100,000	332,400,000
Cash paid for income taxes, net	$ 95,600,000	$ 12,400,000	$ 73,400,000	$ 165,400,000

Consolidated and Combined Sta_6

Consolidated and Combined Statement of Changes in Shareholders' Equity Statement - USD ($) $ in Millions	Total	Ordinary Shares	Treasury Shares	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income
Beginning balance, shares at Sep. 25, 2015		117,500,000	1,200,000
Beginning balance, value at Sep. 25, 2015	$ 5,311.2	$ 23.5	$ (109.7)	$ 5,357.6	$ 38.9	$ 0.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	643.7				643.7
Currency translation adjustments	(58.6)					(58.6)
Change in derivatives, net of tax	0.5					0.5
Minimum pension liability, net of tax	(28.4)					(28.4)
Unrecognized gain on investments	$ 0
Share options exercised, shares	413,830	400,000
Share options exercised, value	$ 14	$ 0.1		13.9
Vesting of restricted shares, shares		200,000
Vesting of restricted shares, value	0	$ 0		0
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	$ (1.7)			(1.7)
Treasury Stock, Shares, Acquired	9,800,000
Treasury Stock, Value, Acquired, Cost Method	$ (652.9)
Share-based compensation	42.9			42.9
Ending balance, shares at Sep. 30, 2016		118,100,000	11,000,000
Ending balance, value at Sep. 30, 2016	5,270.7	$ 23.6	$ (762.6)	5,412.7	682.6	(85.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(153.2)				(153.2)
Currency translation adjustments	(21.1)					(21.1)
Change in derivatives, net of tax	0.2					0.2
Minimum pension liability, net of tax	34					34
Unrecognized gain on investments	$ 0
Share options exercised, shares	16,382	100,000
Share options exercised, value	$ 0.4	$ 0		0.4
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	$ (0.1)			(0.1)
Treasury Stock, Shares, Acquired	2,500,000
Treasury Stock, Value, Acquired, Cost Method	$ (158.8)		158.8
Share-based compensation	11			11
Stock Issued During Period, Value, Treasury Stock Reissued	(1.2)		$ (1.6)		(0.4)
Ending balance, shares at Dec. 30, 2016		118,200,000	13,500,000
Ending balance, value at Dec. 30, 2016	4,984.3	$ 23.6	$ (919.8)	5,424	529	(72.5)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	(72.1)				(72.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	2,134.4
Currency translation adjustments	11.3					11.3
Change in derivatives, net of tax	1					1
Minimum pension liability, net of tax	45.8					(45.8)
Unrecognized gain on investments	1.5					1.5
Treasury Stock, Shares, Retired		(26,500,000)
Stock Repurchased and Retired During Period, Value	$ 0	$ (5.3)		(5.3)
Treasury Stock, Shares, Retired			(26,500,000)
Share options exercised, shares	113,605	100,000
Share options exercised, value	$ 4.1	$ 0		4.1
Vesting of restricted shares, shares		400,000
Vesting of restricted shares, value	(0.1)	$ (0.1)		0
Treasury Stock, Shares, Acquired			18,900,000
Treasury Stock, Value, Acquired, Cost Method	(651.7)		$ 651.7
Share-based compensation	59.2			59.2
Stock Issued During Period, Value, Treasury Stock Reissued	(4.1)		$ (6.8)		2.7
Ending balance, shares at Dec. 29, 2017		92,200,000	5,900,000
Ending balance, value at Dec. 29, 2017	6,522	$ 18.4	$ (1,564.7)	5,492.6	2,588.6	(12.9)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	1.1				2.6	(1.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(3,607)
Currency translation adjustments	(12.2)					(12.2)
Change in derivatives, net of tax	0.7					0.7
Minimum pension liability, net of tax	1.6					1.6
Unrecognized gain on investments	$ 0
Share options exercised, shares	39,949	0
Share options exercised, value	$ 1	$ 0		1
Vesting of restricted shares, shares		500,000	100,000
Vesting of restricted shares, value	2.2	$ (0.1)	$ 2.3	0
Treasury Stock, Shares, Acquired			3,600,000
Treasury Stock, Value, Acquired, Cost Method	(55.2)		$ 55.2
Share-based compensation	$ 34.6			34.6
Stock Issued During Period, Shares, Treasury Stock Reissued	(200,000)
Stock Issued During Period, Value, Treasury Stock Reissued	$ (2.9)		$ (4.8)		(1.9)
Ending balance, shares at Dec. 28, 2018		92,700,000	9,400,000
Ending balance, value at Dec. 28, 2018	$ 2,887.3	$ 18.5	$ (1,617.4)	$ 5,528.2	$ (1,017.7)	$ (24.3)

Background and Basis of Present

Background and Basis of Presentation (Notes)	12 Months Ended
	Dec. 28, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Background and Basis of Presentation	Background Mallinckrodt plc and its subsidiaries (collectively, "Mallinckrodt" or "the Company"), is a global business that develops, manufactures, markets and distributes specialty pharmaceutical products and therapies. As of December 28, 2018 , areas of focus include autoimmune and rare diseases in specialty areas like neurology, rheumatology, nephrology, pulmonology and ophthalmology; immunotherapy and neonatal respiratory critical care therapies; analgesics and gastrointestinal products. Our core strengths include the acquisition and management of highly regulated raw materials and specialized chemistry, formulation and manufacturing capabilities. Our business is operated in two reportable segments, which are further described below: • Specialty Brands includes innovative specialty pharmaceutical brands; and • Specialty Generics and Amitiza includes niche specialty generic drug products, active pharmaceutical ingredients ("API(s)") and Amitiza ® (lubiprostone) ("Amitiza"). In May 2015, the Board of Directors of Mallinckrodt plc approved the migration of the Company’s principal executive offices from Ireland to the United Kingdom. The Company remains incorporated in Ireland and continues to be subject to United States ("U.S.") Securities and Exchange Commission ("SEC") reporting requirements and the applicable corporate governance rules of the New York Stock Exchange. Basis of Presentation The consolidated financial statements have been prepared in U.S. dollars and in accordance with accounting principles generally accepted in the U.S. ("GAAP"). The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities, disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses. Actual results may differ from those estimates. The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and entities in which they own or control more than 50% of the voting shares, or have the ability to control through similar rights. All intercompany balances and transactions have been eliminated in consolidation and all normal recurring adjustments necessary for a fair presentation have been included in the results reported. The results of entities disposed of are included in the consolidated financial statements up to the date of disposal and, where appropriate, these operations have been reflected as discontinued operations. Divestitures of product lines not meeting the criteria for discontinued operations have been reflected in operating (loss) income. On December 6, 2018, the Company announced its plans to spin off a new company consisting of the Specialty Generics/API business and the Amitiza product to the Company's shareholders ("the Separation"). The Separation is expected to create two independent, appropriately capitalized, publicly traded companies – one focused on innovative specialty pharmaceutical brands, the other concentrated primarily in niche specialty generic products and API manufacturing – each positioned to optimize future success as they pursue independent growth strategies. The Company anticipates that the transaction will be in the form of a distribution of new publicly traded stock in the new company that is intended to be generally tax-free for U.S. federal income tax purposes to the Company's shareholders. Completion of the transaction is expected to be subject to certain conditions, including, among others, receipt of regulatory approvals, assurance as to the tax-free status of the spin-off of the business to the Company's shareholders, the effectiveness of a Form 10 registration statement to be filed with the SEC and final approval by the Company's Board of Directors. The Company currently expects completion of the transaction in the second half of 2019; however, there can be no assurance regarding the ultimate timing of the proposed transaction or that the transaction will be completed. Beginning in the first quarter through the third quarter of fiscal 2018, the historical financial results attributable to "the Specialty Generics Disposal Group" were reflected in the Company's interim condensed consolidated financial statements as discontinued operations. The Specialty Generics Disposal Group included (1) the Company's Specialty Generics business comprised of what was the Company's Specialty Generics segment in fiscal 2017, with the exception of BioVectra, Inc. - a wholly owned subsidiary of the Company that operates a contract manufacturing business in Canada ("BioVectra"); (2) certain of the Company's non-promoted brands business, which was previously reflected in the Company's Specialty Brands segment; and (3) the Company's ongoing, post-divestiture supply agreement with the acquirer of the contrast media and delivery systems ("CMDS") business, which was previously reflected in the Company's Other non-operating segment. As a result of the Separation announcement, the Specialty Generics Disposal Group no longer met the requirements to be classified as held-for-sale, and the historical financial results attributable to the Specialty Generics Disposal Group have been recast in the Company's consolidated financial statements as continuing operations. Prior year amounts have been recast to conform to current presentation. See further discussion in Note 23. Fiscal Year

Transition Period (Notes)

Transition Period (Notes)	12 Months Ended
	Dec. 28, 2018
Transition Period [Text Block]	2. Transition Period The Company is presenting audited financial statements for the three month period ended December 30, 2016. The following tables provide certain unaudited comparative financial information for the same period of the prior year. Consolidated Statements of Income Three Months Ended (unaudited) (1) Net sales $ 829.9 $ 811.2 Cost of sales 383.2 360.0 Gross profit 446.7 451.2 Selling, general and administrative expenses 321.1 221.8 Research and development expenses 66.1 61.3 Restructuring charges, net 3.8 4.1 Non-restructuring impairment charges 214.3 — Operating (loss) income (158.6 ) 164.0 Interest expense (91.3 ) (97.8 ) Interest income 0.5 0.2 Other (expense) income, net (49.1 ) 0.1 (Loss) income from continuing operations before income taxes (298.5 ) 66.5 Benefit from income taxes (121.7 ) (37.3 ) (Loss) income from continuing operations (176.8 ) 103.8 Income from discontinued operations 23.6 107.3 Net (loss) income $ (153.2 ) $ 211.1 Basic earnings per share (Note 10): (Loss) income from continuing operations $ (1.67 ) $ 0.90 Income from discontinued operations, net of income taxes 0.22 0.93 Net (loss) income $ (1.45 ) $ 1.83 Basic weighted-average shares outstanding 105.7 115.4 Diluted earnings per share (Note 10): (Loss) income from continuing operations $ (1.67 ) $ 0.89 Income from discontinued operations, net of income taxes 0.22 0.92 Net (loss) income $ (1.45 ) $ 1.82 Diluted weighted-average shares outstanding 105.7 116.3 (1) Financial data for this period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of Accounting Standards Update ("ASU") 2017-07. See Note 4 for further information on this ASU. Consolidated Statements of Cash Flows Three Months Ended December 30, 2016 (unaudited) December 25, 2015 Cash Flows From Operating Activities: Net (loss) income $ (153.2 ) $ 211.1 Adjustments to reconcile net cash provided by operating activities: Depreciation and amortization 203.2 206.0 Share-based compensation 11.0 8.5 Deferred income taxes (204.3 ) (108.9 ) Non-cash impairment charges 214.3 — Inventory provisions 8.5 1.2 Gain on disposal of discontinued operations — (97.0 ) Other non-cash items (9.2 ) 2.9 Changes in assets and liabilities, net of the effects of acquisitions: Accounts receivable, net 36.5 68.4 Inventories (26.3 ) (14.5 ) Accounts payable 5.4 (13.0 ) Income taxes 0.6 82.3 Other 109.1 (35.6 ) Net cash from operating activities 195.6 311.4 Cash Flows From Investing Activities: Capital expenditures (65.2 ) (49.0 ) Acquisitions and intangibles, net of cash acquired (1.8 ) — Proceeds from disposal of discontinued operations, net of cash — 263.7 Other (10.2 ) 0.7 Net cash from investing activities (77.2 ) 215.4 Cash Flows From Financing Activities: Issuance of external debt 190.0 62.0 Repayment of external debt and capital leases (86.7 ) (129.6 ) Debt financing costs — (0.1 ) Proceeds from exercise of share options 0.4 3.6 Repurchase of shares (158.8 ) (275.4 ) Other 1.2 (30.0 ) Net cash from financing activities (53.9 ) (369.5 ) Effect of currency rate changes on cash (3.0 ) (1.5 ) Net change in cash, cash equivalents and restricted cash 61.5 155.8 Cash, cash equivalents and restricted cash at beginning of period 299.6 432.6 Cash, cash equivalents and restricted cash at end of period $ 361.1 $ 588.4 Cash and cash equivalents at end of period $ 342.0 $ 521.9 Restricted cash included in prepaid expenses and other assets at end of period 0.1 47.5 Restricted cash included in other long-term assets at end of period 19.0 19.0 Cash, cash equivalents and restricted cash at end of period $ 361.1 $ 588.4

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 28, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Revenue Recognition Product Sales Revenue The Company sells its products through independent channels, including direct to retail pharmacies, end user customers and through distributors who resell the products to retail pharmacies, institutions and end user customers, while certain products are sold and distributed to hospitals. The Company also enters into arrangements with indirect customers, such as health care providers and payers, wholesalers, government agencies, institutions, managed care organizations and group purchasing organizations to establish contract pricing for certain products that provide for government-mandated and/or privately-negotiated rebates, sales incentives, chargebacks, distribution service agreements fees, fees for services and administration fees, and discounts with respect to the purchase of the Company's products. Reserve for Variable Considerations Product sales are recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established. These reserves result from estimated chargebacks, rebates, product returns and other sales deductions that are offered within contracts between the Company and its customers, health care providers and payers relating to the Company’s sales of its products. These reserves are based on the amounts earned or to be claimed on the related sales and are classified as reductions of accounts receivable (if the amount is payable to the customer) or a current liability (if the amount is payable to a party other than a customer). Where appropriate, these estimates take into consideration a range of possible outcomes which are probability-weighted for relevant factors such as the Company’s historical experience, estimated future trends, estimated customer inventory levels, current contracted sales terms with customers, level of utilization of the Company’s products and other competitive factors. Overall, these reserves reflect the Company’s best estimate of the amount of consideration to which it is entitled based on the terms of the contract. The amount of variable consideration which is included in the transaction price may be constrained (reduced), and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. The Company adjusts reserves for chargebacks, rebates, product returns and other sales deductions to reflect differences between estimated and actual experience. Such adjustments impact the amount of net sales recognized in the period of adjustment. Product sales are recognized when the customer obtains control of the Company's product. Control is transferred either at a point in time, generally upon delivery to the customer site, or in the case of certain of the Company's products, over the period in which the customer has access to the product and related services. Revenue recognized over time is based upon either consumption of the product or passage of time based upon the Company's determination of the measure that best aligns with how the obligation is satisfied. The Company's considerations of why such measures provide a faithful depiction of the transfer of its products are as follows: • For those contracts whereby revenue is recognized over time based upon consumption of the product, the Company either has: 1. the right to invoice the customer in an amount that directly corresponds with the value to the customer of the Company's performance to date, for which the practical expedient to recognize in proportion to the amount it has the right to invoice has been applied, or 2. the remaining goods and services to which the customer is entitled is diminished upon consumption. • For those contracts whereby revenue is recognized over time based upon the passage of time, the benefit that the customer receives from unlimited access to the Company's product does not vary, regardless of consumption. As a result, the Company's obligation diminishes with the passage of time; therefore, it was determined that ratable recognition of the transaction price over the contract period is the measure that best aligns with how the obligation is satisfied. Transaction price allocated to the remaining performance obligations The majority of the Company's contracts are less than one year; therefore, the related disclosure of the amount of transaction price allocated to the performance obligations that are unsatisfied at period end has been omitted. Cost to obtain a contract As the majority of the Company's contracts are short-term in nature, sales commissions are generally expensed when incurred as the amortization period would have been less than one year. These costs are recorded within selling, general and administrative expense ("SG&A") in the consolidated statements of income. For contracts that extend beyond one year, the incremental expense recognition matches the recognition of related revenue. Costs to fulfill a contract The Company capitalizes the costs associated with the devices used in the Company's portfolio of drug-device combination products, which are used in satisfaction of future performance obligations. Capital expenditures for these devices represent cash outflows for the Company's cost to produce the asset, which is classified in property, plant and equipment, net on the consolidated balance sheets and expensed to cost of sales over the useful life of the equipment. Product Royalty Revenues In relation to the Company's acquisition of Sucampo Pharmaceuticals, Inc. ("Sucampo") in fiscal 2018, as discussed further in Note 7, it acquired an arrangement under which the Company licenses certain rights to Amitiza to a third party in exchange for royalties on net sales of the product. The Company recognizes such royalty revenue as the related sales occur. Contract Balances Accounts receivable are recorded when the right to consideration becomes unconditional. Payments received from customers are typically based upon payment terms of 30 days. The Company does not maintain contract asset balances aside from the accounts receivable balance as presented on the consolidated balance sheets as costs to obtain a contract are expensed when incurred as the amortization period would have been less than one year. These costs are recorded within SG&A on the consolidated statements of income. Contract liabilities are recorded when cash payments are received in advance of the Company's performance, including amounts which are refundable. Taxes collected from customers relating to product sales and remitted to governmental authorities are accounted for on a net basis. Accordingly, such taxes are excluded from both net sales and expenses. For additional information, refer to Note 5. Shipping and Handling Costs Shipping costs, which are costs incurred to physically move product from the Company's premises to the customer's premises, are classified as SG&A. Handling costs, which are costs incurred to store, move and prepare product for shipment, are classified as cost of sales. Shipping costs included in SG&A expenses in continuing operations were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Shipping and handling costs $ 12.8 $ 13.9 $ 12.4 $ 3.4 Research and Development Internal research and development costs are expensed as incurred. Research and development ("R&D") expenses include salary and benefits, allocated overhead and occupancy costs, clinical trial and related clinical manufacturing costs, contract services, medical affairs and other costs. Upfront and milestone payments made to third parties under license arrangements are expensed as incurred up to the point of regulatory approval of the product. Milestone payments made to third parties upon or subsequent to regulatory approval are capitalized as an intangible asset and amortized to cost of sales over the estimated useful life of the related product. Currency Translation For the Company's non-U.S. subsidiaries that transact in a functional currency other than U.S. dollars, assets and liabilities are translated into U.S. dollars using fiscal year-end exchange rates. Revenues and expenses are translated at the average exchange rates in effect during the related month. The net effect of these translation adjustments is shown in the consolidated financial statements as a component of accumulated other comprehensive loss. For subsidiaries operating in highly inflationary environments or where the functional currency is different from the local currency, non-monetary assets and liabilities are translated at the rate of exchange in effect on the date the assets and liabilities were acquired or assumed, while monetary assets and liabilities are translated at fiscal year-end exchange rates. The Company also entered into derivative instruments to mitigate the exposure of movements in certain of these foreign currency transactions. The Company recognized the following during the respective periods: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 Foreign currency (losses), gains $ (3.1 ) $ 2.5 $ (3.6 ) $ 9.0 Derivative hedge gains (losses) 2.7 (4.1 ) 0.2 (8.9 ) Cash and Cash Equivalents The Company classifies cash on hand and deposits in banks, including commercial paper, money market accounts and other investments it may hold from time to time, with an original maturity to the Company of three months or less, as cash and cash equivalents. Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable are presented net of an allowance for doubtful accounts. The allowance for doubtful accounts reflects an estimate of losses inherent in the Company's accounts receivable portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other available evidence. Accounts receivable are written off when management determines they are uncollectible. Trade accounts receivable are also presented net of reserves related to chargebacks and rebates payable to customers for whom the Company has trade accounts receivable and the right of offset exists. Inventories Inventories are recorded at the lower of cost or net realizable value, primarily using the first-in, first-out convention. The Company reduces the carrying value of inventories for those items that are potentially excess, obsolete or slow-moving based on changes in customer demand, technology developments or other economic factors. Property, Plant and Equipment Property, plant and equipment are stated at cost. Major renewals and improvements are capitalized, while routine maintenance and repairs are expensed as incurred. Depreciation for property, plant and equipment assets, other than land and construction in process, is generally based upon the following estimated useful lives, using the straight-line method: Buildings 10 to 45 years Leasehold improvements 1 to 20 years Capitalized software 1 to 10 years Machinery and equipment 1 to 20 years The Company capitalizes certain computer software and development costs incurred in connection with developing or obtaining software for internal use. Upon retirement or other disposal of property, plant and equipment, the cost and related amount of accumulated depreciation are eliminated from the asset and accumulated depreciation accounts, respectively. The difference, if any, between the net asset value and the proceeds is included in net income. The Company assesses the recoverability of assets or asset groups using undiscounted cash flows whenever events or circumstances indicate that the carrying value of an asset or asset group may not be recoverable. If an asset or asset group is found to be impaired, the amount recognized for impairment is equal to the difference between the carrying value of the asset or asset group and its fair value. Acquisitions Amounts paid for acquisitions are allocated to the tangible assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. The Company then allocates the purchase price in excess of net tangible assets acquired to identifiable intangible assets, including purchased R&D. The fair value of identifiable intangible assets is based on detailed valuations. The Company allocates any excess purchase price over the fair value of the net tangible and intangible assets acquired to goodwill. The Company's purchased R&D represents the estimated fair value as of the acquisition date of in-process projects that have not reached technological feasibility. The primary basis for determining technological feasibility of these projects is obtaining regulatory approval. The fair value of in-process research and development ("IPR&D") is determined using the discounted cash flow method. In determining the fair value of IPR&D, the Company considers, among other factors, appraisals, the stage of completion of the projects, the technological feasibility of the projects, whether the projects have an alternative future use and the estimated residual cash flows that could be generated from the various projects and technologies over their respective projected economic lives. The discount rate used includes a rate of return which accounts for the time value of money, as well as risk factors that reflect the economic risk that the cash flows projected may not be realized. The fair value attributable to IPR&D projects at the time of acquisition is capitalized as an indefinite-lived intangible asset and tested annually for impairment until the project is completed or abandoned. Upon completion of the project, the indefinite-lived intangible asset is then accounted for as a finite-lived intangible asset and amortized on a straight-line basis over its estimated useful life. If the project is abandoned, the indefinite-lived intangible asset is charged to expense. Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price of an acquired entity over the amounts assigned to assets and liabilities assumed in a business combination. The Company tests goodwill for impairment on the first day of the fourth quarter of each fiscal year, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The impairment test is comprised of comparing the carrying value of a reporting unit to its estimated fair value. The Company estimates the fair value of a reporting unit through internal analyses and valuation, utilizing an income approach (a level three measurement technique) based on the present value of future cash flows. The fair value of the Company's reporting units is reconciled to its share price and market capitalization as a corroborative step. If the carrying value of a reporting unit exceeds its fair value, the Company will recognize the excess of the carrying value over the fair value as a goodwill impairment loss. Intangible assets acquired in a business combination are recorded at fair value, while intangible assets acquired in other transactions are recorded at cost. Intangible assets with finite useful lives are subsequently amortized, generally using the straight-line method, over the following estimated useful lives of the assets, except for customer relationships which are amortized over the estimated pattern of benefit from these relationships: Completed technology 5 to 25 years License agreements 7 to 30 years Trademarks 13 to 30 years Customer relationships 12 years Amortization expense related to completed technology and certain other intangible assets is included in cost of sales, while amortization expense related to intangible assets that contribute to the Company's ability to sell, market and distribute products is included in SG&A. When a triggering event occurs, the Company evaluates potential impairment of finite-lived intangible assets by first comparing undiscounted cash flows associated with the asset, or the asset group they are part of, to its carrying value. If the carrying value is greater than the undiscounted cash flows, the amount of potential impairment is measured by comparing the fair value of the assets, or the asset group they are part of, with their carrying value. The fair value of the intangible asset, or the asset group they are part of, is estimated using an income approach. If the fair value is less than the carrying value of the intangible asset, or the asset group they are part of, the amount recognized for impairment is equal to the difference between the carrying value of the asset and the fair value of the asset. The Company assesses the remaining useful life and the recoverability of finite-lived intangible assets whenever events or circumstances indicate that the carrying value of an asset may not be recoverable. The Company annually tests the indefinite-lived intangible assets for impairment, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable by either a qualitative or income approach. The Company will compare the fair value of the assets with their carrying value and record an impairment when the carrying value exceeds the fair value. Contingencies The Company is subject to various patent infringement claims, product liability matters, government investigations, environmental matters, employee disputes, contractual disputes and other commercial disputes, and other legal proceedings in the ordinary course of business as further discussed in Note 20. The Company records accruals for contingencies when it is probable that a liability has been incurred and the amount can be reasonably estimated. The Company discounts environmental liabilities using a risk-free rate of return when the obligation is fixed or reasonably determinable. The impact of the discount in the consolidated balance sheets was not material in any period presented. Legal fees, other than those pertaining to environmental and asbestos matters, are expensed as incurred. Insurance recoveries related to potential claims are recognized up to the amount of the recorded liability when coverage is confirmed and the estimated recoveries are probable of payment. Assets and liabilities are not netted for financial statement presentation. Share-Based Compensation The Company recognizes the cost of employee services received in exchange for awards of equity instruments based on the grant-date fair value of those awards. That cost is recognized over the period during which an employee is required to provide service in exchange for the award, the requisite service period (generally the vesting period). Restructuring The Company recognizes charges associated with board approved restructuring programs designed to transform its business and improve its cost structure. Restructuring charges can include severance costs, infrastructure charges, distributor contract cancellations and other items. The Company accrues for costs when they are probable and reasonably estimable. Income Taxes Deferred tax assets and liabilities are recognized for the expected future tax consequences of events that have been reflected in the consolidated financial statements. Deferred tax assets and liabilities are determined based on the differences between the book and tax bases of assets and liabilities and operating loss carryforwards, using tax rates expected to be in effect for the years in which the differences are expected to reverse. A valuation allowance is provided to reduce net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. Deferred tax liabilities are also recorded for deferred tax obligations related to installment sale arrangements. The deferral of tax payments to the U.S. Internal Revenue Service ("IRS") are subject to interest, which is accrued and included within interest expense. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. The tax benefit of any tax position that meets the more-likely-than-not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the uncertainty. To the extent a full benefit is not expected to be realized on the uncertain tax position, an income tax liability is established. Interest and penalties on income tax obligations, associated with uncertain tax positions, are included in the provision for income taxes.

Recently Issued Accounting Stan

Recently Issued Accounting Standards	12 Months Ended
	Dec. 28, 2018
Recently Issued Accounting Pronouncements [Abstract]
Recently Issued Accounting Standards	4. Recently Issued Accounting Standards Adopted In August 2018, the SEC adopted the final rule under SEC Release No. 33-10532, Disclosure Update and Simplification, amending certain disclosure requirements that were redundant, duplicative, overlapping, outdated or superseded. In addition, the amendments expanded the disclosure requirements on the analysis of stockholders' equity for interim financial statements. Under the amendments, an analysis of changes in each caption of stockholders' equity presented in the balance sheet must be provided in a note or separate statement. The analysis should present a reconciliation of the beginning balance to the ending balance of each period for which a statement of comprehensive income is required to be filed. This final rule was effective for all filings made on or after November 5, 2018. The Company has complied with all relevant disclosure requirements, with the exception of the expanded interim disclosure requirements for changes in shareholders' equity, which is required in the first interim reporting period after the effective date. The interim analysis of changes in shareholders' equity will be effective for the Company's quarterly reporting in the year ending December 27, 2019. The Financial Accounting Standards Board ("FASB") issued ASU 2018-05, "Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 (SEC Update)" in March 2018. This update adds SEC paragraphs pursuant to the SEC's Staff Accounting Bulletin ("SAB") 118, which provides guidance on accounting for the tax effects of the Tax Cuts and Jobs Act ("TCJA" or "U.S. Tax Reform") that was enacted in December 2017. SAB 118 provides a measurement period that should not extend beyond one year from the TCJA enactment date for companies to complete the accounting for the tax effects of the TCJA. The Company adopted this standard in fiscal 2018. See Note 9 for additional details of the Company's assessment of impact of this adoption. The FASB issued ASU 2017-09, "Compensation - Stock Compensation: Scope of Modification Accounting," in May 2017. Under the new guidance, the effects of a modification should be accounted for unless all of the following are met: (1) the fair value or calculated intrinsic value of the modified award is the same as the fair value of the original award immediately before the original award is modified; (2) the vesting conditions of the modified award are the same as the vesting conditions of the original award immediately before the original award is modified; and (3) the classification of the modified award as an equity instrument or a liability instrument is the same as the classification of the original award immediately before the original award is modified. The Company adopted this standard in fiscal 2018 and will apply this standard to prospective modifications. The adoption of this standard did not result in any material changes to the consolidated financial statements. The FASB issued ASU 2017-07, "Compensation - Retirement Benefits: Improving the Presentation of Net Periodic Pension Cost and Net Periodic Post Retirement Benefit Cost," in March 2017. This update requires that the service cost component be disaggregated from the other components of net benefit cost. Service cost should be reported in the same line item or items as other compensation costs arising from services rendered by pertinent employees during the period. The other components of net benefit cost should be presented in the income statement separately from the service cost component and outside a subtotal of income from operations, if one is presented. The Company adopted this guidance in fiscal 2018 which required retroactive application resulting in the reclassification of the following: Fiscal Year Ended Three Months Ended December 29, September 30, December 30, Cost of sales $ 1.2 $ 2.6 $ 0.9 Selling, general and administrative expenses 71.2 11.6 47.2 Research and development expenses 0.4 1.0 0.1 Restructuring charges, net — 0.6 — Other income (expense), net $ 72.8 $ 15.8 $ 48.2 The adoption of this standard did not result in any material changes to the consolidated financial statements. The FASB issued ASU 2017-01, "Business Combinations (Topic 805): Clarifying the Definition of a Business," in January 2017. This update provides a screen to determine whether or not a set of assets is a business. The screen requires that when substantially all of the fair value of the gross assets acquired (or disposed of) is concentrated in a single identifiable asset or a group of similar identifiable assets, the set of assets is not a business. If the screen is not met, the amendments in this update (1) require that to be considered a business, a set of assets must include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create output and (2) remove the evaluation of whether a market participant could replace missing elements. The Company adopted this standard in fiscal 2018, which did not have a material impact to the consolidated financial statements. The FASB issued ASU 2016-16, "Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory," in October 2016. This update simplifies the practice in how income tax consequences of an intra-entity transfer of an asset other than inventory should be recognized. Upon adoption, the entity must recognize such income tax consequences when the intra-entity transfer occurs rather than waiting until such time as the asset has been sold to an outside party. The Company early adopted this standard in fiscal 2017, which resulted in a $75.0 million decrease to beginning retained earnings with an offsetting decrease of $67.2 million to other assets and a $7.8 million decrease to prepaid expenses on the consolidated balance sheet. The prior periods were not restated. The FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” in August 2016 and ASU 2016-18 "Statement of Cash Flows (Topic 230): Restricted Cash," in November 2016. These updates provide guidance for nine targeted clarifications with respect to how cash receipts and cash payments are classified in the statements of cash flows, with the objective of reducing diversity in practice. The Company early adopted these standards in fiscal 2017 and revised the prior year statement of cash flow. The adoption of ASU 2016-18, regarding presentation of restricted cash, increased the net cash used in investing activities during fiscal 2016 by $47.3 million . The adoption of ASU 2016-15, regarding the other targeted clarifications, did not result in any material changes to the consolidated financial statements. The FASB issued ASU 2016-09, "Stock Compensation," in March 2016. This update simplifies several aspects of the accounting for share-based payment award transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification of certain tax effects within the statement of cash flows. Upon adoption, the entity must recognize the incremental income tax expense or benefit related to share option exercises and restricted share unit vesting in the statement of income, whereas these tax effects are presently recognized directly in shareholders' equity. In addition, the incremental tax benefit associated with these events will be classified as a cash inflow from operating activity as compared with a financing activity, as required under current guidance. The Company adopted this guidance in fiscal 2017, which resulted in a $2.9 million increase to beginning retained earnings to recognize net operating loss carryforwards, net of a valuation allowance, attributable to excess tax benefits on stock compensation that had not been previously recognized in additional paid-in capital. The FASB issued ASU 2016-01, "Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities," in January 2016. This update addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Under the new guidance, equity investments, other than equity method investments, are to be measured at fair value with changes in fair value recognized through net income. The Company adopted this guidance in fiscal 2018, resulting in a $1.5 million increase to beginning retained earnings with an offsetting decrease to other accumulated comprehensive loss relating to the unrealized gain on its investment in Mesoblast Limited ("Mesoblast"). The adoption of this standard did not result in any material changes to the consolidated financial statements. The FASB issued ASU 2014-09, "Revenue from Contracts with Customers," in May 2014. The issuance of ASU 2014-09 and International Financial Reporting Standards ("IFRS") 15, "Revenue from Contracts with Customers," completes the joint effort by the FASB and the International Accounting Standards Board to clarify the principles for recognizing revenue and develop a common revenue standard for GAAP and IFRS. Under the new guidance, an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services, applying the following steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract(s); (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract(s); and (5) recognize revenue when (or as) the entity satisfies a performance obligation. The FASB subsequently issued additional ASUs to clarify the guidance of ASU 2014-09. The ASUs issued include ASU 2016-08, "Revenue from Contracts with Customers;" ASU 2016-10 "Revenue from Contracts with Customers, Identifying Performance Obligations and Licensing;" and ASU 2016-12 "Narrow-Scope Improvements and Practical Expedients." The Company adopted ASU 2014-09 and its related amendments (collectively known as “ASC 606”) effective on December 30, 2017 using the modified retrospective transition approach. The adoption of ASC 606 represents a change in accounting principle that more closely aligns revenue recognition with the delivery of the Company's products and will provide financial statement readers with enhanced disclosures, which have been included in Note 5. The cumulative effect of applying the new standard to contracts not completed at December 30, 2017 was recorded as a $1.1 million increase, net of tax, to beginning retained earnings. The prior periods were not restated. The adoption of this standard did not result in any material changes to the consolidated financial statements. Not Yet Adopted The FASB issued ASU 2018-15, "Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract," in August 2018. This update aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The amendments in this update also require the entity (customer) to expense the capitalized implementation costs of a hosting arrangement that is a service contract over the term of the hosting arrangement. Upon adoption, the update will be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. This standard is effective for the Company in the first quarter of fiscal 2020; however, early adoption is permitted. The Company intends to adopt this standard in the first quarter of 2019 and does not believe the standard will have a material impact on the consolidated financial statements. The FASB issued ASU 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income," in February 2018. This update allows a reclassification from accumulated other comprehensive income ("AOCI") to retained earnings for the tax effects resulting from TCJA that are stranded in AOCI. This standard is effective for the Company in the first quarter of fiscal 2019. The Company has assessed the impact of this standard and determined the standard will not result in any material changes to the consolidated financial statements. The FASB issued ASU 2017-12, "Derivatives and Hedging: Targeted Improvements to Accounting for Hedging Activities," in August 2017. This update simplifies the application of hedge accounting and enhances the economics of the entity’s risk management activities in its financial statements. The update amends the guidance on designation and measurement for qualifying hedging relationships requiring the application of a modified retrospective approach on the date of adoption. This standard is effective for the Company in the first quarter of fiscal 2019. The Company has assessed the impact of this standard and determined the standard will not result in any material changes to the consolidated financial statements. The FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments," in June 2016. This update calls for financial assets to be measured at their net amount to be collected, or net of credit losses. Credit losses are to be measured on a probability weighted approach comprised of historical loss experience, current economic conditions, and reasonable and supportable forecasts. This standard is effective for the Company in the first quarter of fiscal 2020. The Company is assessing the impact of this guidance on the consolidated financial statements. The FASB issued ASU 2016-02, "Leases," in February 2016. This update was issued to increase transparency and comparability among organizations by recognizing all lease transactions (with terms in excess of 12 months) on the balance sheet as a lease liability and a right-of-use asset (as defined). This standard is effective for the Company in the first quarter of fiscal 2019. The FASB subsequently issued additional ASUs to clarify the guidance of ASU 2016-02. The ASUs issued include ASU 2018-01 "Leases: Land Easement Practical Expedient for Transition to Topic 842;" ASU 2018-10 "Codification Improvements to Topic 842, Leases;" ASU 2018-11 "Leases (Topic 842: Targeted Improvements; and ASU 2018-20 "Leases (Topic 842): Narrow-Scope Improvements for Lessors." The Company has identified its population of lease agreements and embedded leases. The Company expects to elect the package of practical expedients, the lessor expedient, and the modified transition approach expedient. Although the Company is in process of finalizing the impact on its consolidated financial statements, it anticipates that the most significant change will be related to the Company recording additional assets and corresponding liabilities on the consolidated balance sheet for operating leases of approximately $85.0 million

Revenue from Contracts with Cus

Revenue from Contracts with Customers (Notes)	12 Months Ended
	Dec. 28, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	5. Revenue from Contracts with Customers Product Sales Revenue See Note 22 for presentation of the Company’s net sales by product family. Reserves for variable consideration The following table reflects activity in the Company’s sales reserve accounts: Rebates and Chargebacks Product Returns Other Sales Deductions Total Balance as of December 29, 2017 $ 327.4 $ 34.5 $ 14.7 $ 376.6 Provisions 2,281.3 39.3 66.9 2,387.5 Payments or credits (2,254.4 ) (39.8 ) (64.5 ) (2,358.7 ) Balance as of December 28, 2018 $ 354.3 $ 34.0 $ 17.1 $ 405.4 Product sales transferred to customers at a point in time and over time accounted for 82.9% and 17.1% of net sales, respectively, for fiscal 2018 . Transaction price allocated to the remaining performance obligations The following table includes estimated revenue from contracts extending greater than one year for certain of the Company’s hospital products that are expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied at December 28, 2018 : Fiscal 2019 $ 145.0 Fiscal 2020 127.3 Fiscal 2021 32.6 Thereafter 3.2 Co sts to fulfill a contract As of December 28, 2018 , the total net book value of the devices used in the Company’s portfolio of drug-device combination products, which are used in satisfying future performance obligations, was $28.4 million and are classified in property, plant and equipment, net, on the consolidated balance sheet. The associated depreciation expense recognized during fiscal 2018 was $7.4 million . Product Royalty Revenues In relation to the Company’s acquisition of Sucampo on February 13, 2018, as discussed in further detail in Note 7, it acquired an arrangement under which the Company licenses certain rights to Amitiza to a third party in exchange for royalties on net sales of the product. The Company recognizes such royalty revenue as the related sales occur. The associated royalty revenue recognized during fiscal 2018 was $81.3 million . Contract Liabilities The following table reflects the balance of the Company's contract liabilities at the end of the respective periods: December 28, December 29, Accrued and other current liabilities $ 20.4 $ 14.0 Other liabilities 15.1 6.6 Contract liabilities $ 35.5 $ 20.6 Revenue recognized during fiscal 2018 from amounts included in contract liabilities at the beginning of the period was approximately $12.5 million

Discontinued Operations and Div

Discontinued Operations and Divestitures	12 Months Ended
	Dec. 28, 2018
Discontinued Operations [Abstract]
Discontinued Operations and Divestitures	6. Discontinued Operations and Divestitures Discontinued Operations The below businesses met the discontinued operations criteria and, accordingly, were included in discontinued operations for all periods presented. Nuclear Imaging: On January 27, 2017, the Company completed the sale of its Nuclear Imaging business to IBA Molecular ("IBAM") for approximately $690.0 million before tax impacts, including up-front considerations of approximately $574.0 million , up to $77.0 million of contingent considerations and the assumption of certain liabilities. The Company recorded a pre-tax gain on the sale of the business of $362.8 million during fiscal 2017, which excluded any potential proceeds from the contingent consideration. During fiscal 2018, the Company received a total of $15.0 million in contingent consideration related to the sale of the Nuclear Imaging business, consisting of a $6.0 million cash payment and the issuance of $9.0 million par value non-voting preferred equity certificates. The preferred equity certificates accrue interest at a rate of 10.0% per annum and are redeemable on the retirement date of July 27, 2025, or earlier if elected by the issuer, for cash at a price equal to the par value and any accrued but unpaid interest. The Company recorded a tax expense of $1.4 million associated with the $6.0 million contingent consideration cash payment. The $9.0 million in preferred equity certificates is presented as a non-cash investing activity on the consolidated statements of cash flows. The $13.6 million of contingent consideration received, net of tax, was recorded as income from discontinued operations. The following table summarizes the financial results of the Nuclear Imaging business for respective periods as presented in the consolidated statements of income: Fiscal Year Ended Three Months Ended Major line items constituting income from discontinued operations December 29, 2017 September 30, 2016 December 30, 2016 Net sales $ 31.6 $ 418.6 $ 99.4 Cost of sales 15.6 216.6 44.7 Selling, general and administrative 7.8 83.7 16.4 Restructuring charges, net — 2.3 — Other (0.2 ) 5.7 0.2 Income from discontinued operations 8.4 110.3 38.1 Gain on disposal of discontinued operations 362.8 — — Income from discontinued operations, before income taxes 371.2 110.3 38.1 Income tax expense 5.2 49.0 15.3 Income from discontinued operations, net of tax $ 366.0 $ 61.3 $ 22.8 The following table summarizes significant cash and non-cash transactions of the Nuclear Imaging business that are included within the consolidated statements of cash flows for the respective periods: Fiscal Year Ended Three Months Ended December 29, 2017 September 30, 2016 December 30, 2016 Depreciation $ — $ 20.9 $ — Capital expenditures 0.3 9.7 2.0 CMDS: On November 27, 2015, the Company completed the sale of the CMDS business to Guerbet S.A. ("Guerbet") for cash consideration of approximately $270.0 million . Subsequent to the sale of the CMDS business, the Company continues to supply certain products under a supply agreement with Guerbet. The following table summarizes the financial results of the CMDS business for fiscal 2016 as presented in the consolidated statement of income: Fiscal Year Ended Major line items constituting (loss) income from discontinued operations September 30, 2016 Net sales $ 61.0 Cost of sales 46.9 Selling, general and administrative 20.3 Other 1.2 Loss from discontinued operations (7.4 ) Gain on disposal of discontinued operations 95.3 Income from discontinued operations, before income taxes 87.9 Income tax benefit (2.5 ) Income from discontinued operations net of tax $ 90.4 The Company incurred $1.6 million of capital expenditures related to the CMDS business that are included within the consolidated statement of cash flows for fiscal 2016. Mallinckrodt Baker: During fiscal 2010, the Specialty Chemicals business (formerly known as "Mallinckrodt Baker") was sold because its products and customer base were not aligned with the Company's long-term strategic objectives. During fiscal 2018 and 2017, the Company recorded a loss, net of tax of $0.3 million and $0.6 million , respectively. During fiscal 2016 and the three months ended December 30, 2016, the Company recorded a gain, net of tax, of $3.0 million and $0.6 million , respectively. The gains and losses were primarily related to the indemnification obligations to the purchaser, which are discussed in Note 19. Divestitures PreveLeak/Recothrom: On March 16, 2018, the Company completed the sale of a portion of its Hemostasis business, inclusive of its PreveLeak™ Surgical Sealant ("PreveLeak") and RECOTHROM ® Thrombin topical (Recombinant) ("Recothrom") products to Baxter International Inc. ("Baxter") for approximately $185.0 million , with a base payment of $153.0 million , inclusive of existing inventory and subject to a closing inventory adjustment, with the remainder in potential future milestones. Baxter assumed other expenses, including contingent liabilities associated with PreveLeak. During fiscal 2018, the Company recorded a pre-tax loss on the sale of $0.8 million , which excluded any potential proceeds from the potential future milestones and reflected a post-sale closing inventory adjustment of $13.7 million . The financial results of the PreveLeak and Recothrom operations are presented within continuing operations as this divestiture did not meet the criteria for discontinued operations classification. As part of the divestiture and calculation of the loss, the Company wrote off intangible assets of $49.9 million and goodwill of $51.5 million during the first quarter of fiscal 2018, from the Specialty Brands segment, ascribed to the PreveLeak and Recothrom operations. The remaining items included in the gain calculation are primarily attributable to inventory transferred, contingent consideration transferred and transaction costs incurred by the Company. Intrathecal Therapy: On March 17, 2017, the Company completed its sale of its Intrathecal Therapy business to Piramal Enterprises Limited's subsidiary in the U.K., Piramal Critical Care ("Piramal"), for approximately $203.0 million , including fixed consideration of $171.0 million and contingent consideration of up to $32.0 million . The $171.0 million of fixed consideration consisted of $17.0 million received at closing and a $154.0 million note receivable due one year from the transaction closing date. The Company recorded a pre-tax gain on the sale of the business of $56.6 million during fiscal 2017, which excluded any potential proceeds from the contingent consideration and reflects a post-sale working capital adjustment. In fiscal 2018, the Company received $154.0 million from Piramal for the settlement of the aforementioned note receivable. The financial results of the Intrathecal Therapy business are presented within continuing operations as this divestiture did not meet the criteria for discontinued operations classification. During fiscal 2017, as part of the divestiture and calculation of the gain, the Company wrote off intangible assets of $48.7 million and goodwill of $49.8 million , from the Specialty Brands segment, ascribed to the Intrathecal Therapy business. The Company is committed to reimburse up to $7.3 million of product development expenses incurred by Piramal, of which $3.1 million and $6.5 million

Acquisitions and License Agreem

Acquisitions and License Agreements	12 Months Ended
	Dec. 28, 2018
Business Combinations [Abstract]
Acquisitions and License Agreements	7. Acquisitions and License Agreements Business Acquisitions Sucampo Pharmaceuticals, Inc. In February 2018, the Company acquired Sucampo through the acquisition of all the outstanding common stock of Sucampo. Consideration for the transaction consisted of approximately $1.2 billion , including the assumption of Sucampo's third-party debt ("the Sucampo Acquisition"). The acquisition was funded through the issuance of a $600.0 million aggregate principal amount of senior secured term loan, a $900.0 million borrowing under the Company's revolving credit facility, as discussed further in Note 14, and cash on hand. Sucampo's primary commercialized product was Amitiza, a leading global product in the branded constipation market. Through this acquisition, the Company acquired VTS-270, a Phase 3 development product for Niemann-Pick Type C, a complicated, ultra-rare neurodegenerative disease that typically presents in childhood and is ultimately fatal. Also acquired was an option to exercise a collaborative agreement with Cancer Prevention Pharmaceuticals ("CPP") associated with the development of CPP-1X/sulindac, a Phase 3 development product for Familial Adenomatous Polyposis ("FAP"). Refer to the License Agreements section below for further information on the CPP agreement. Upon completion of the Sucampo Acquisition, Sucampo’s 3.25% convertible senior notes due 2021 ("the Sucampo Notes") became eligible to receive increased consideration in conjunction with a make-whole fundamental change, such that each $1,000 principal face amount of Sucampo Notes could be converted into $1,221 cash. As of December 28, 2018 , the issued convertible debt of $300.0 million had been converted and paid in full by the Company. Ocera Therapeutics, Inc. In December 2017, the Company acquired Ocera Therapeutics, Inc. ("Ocera") for upfront consideration of approximately $42.4 million , of which $1.9 million of the consideration was paid subsequent to December 29, 2017, and contingent consideration up to $75.0 million based on the successful completion of certain development and sales milestones ("the Ocera Acquisition"). Through this acquisition, the Company acquired Ocera’s primary development product MNK-6105/6106, an ammonia scavenger, which is being studied for treatment of hepatic encephalopathy, a neuropsychiatric syndrome associated with hyperammonemia, a complication of acute or chronic liver disease. The Ocera Acquisition was funded with cash on hand. InfaCare Pharmaceutical Corporation On September 25, 2017, the Company acquired InfaCare Pharmaceutical Corporation ("InfaCare") in a transaction valued at approximately $80.4 million , with additional payments of up to $345.0 million dependent on regulatory and sales milestones ("the InfaCare Acquisition"). Consideration for the transaction consisted of approximately $37.2 million in cash paid to the prior shareholders of InfaCare and the assumption of approximately $43.2 million of debt and other liabilities, which was repaid in conjunction with the InfaCare Acquisition. Through this acquisition, the Company acquired InfaCare's development product stannsoporfin, a heme oxygenase inhibitor, which is under investigation for its potential to reduce the production of bilirubin, the elevation of which can contribute to serious consequences in infants. The InfaCare Acquisition was funded with cash on hand. See further discussion related to the stannsoporfin developmental product in Notes 13 and 21. Stratatech Corporation In August 2016, the Company acquired Stratatech Corporation ("Stratatech") for upfront consideration of $76.0 million , and contingent milestone payments, which are primarily regulatory, and royalty obligations that could result in up to $121.0 million of additional consideration ("the Stratatech Acquisition"). Through this acquisition, the Company acquired Stratatech's development products including StrataGraft ® regenerative skin tissue ("StrataGraft") and a technology platform for genetically enhanced skin tissues. The Stratatech Acquisition was funded through cash on hand. Hemostasis Products In February 2016, the Company acquired three commercial stage topical hemostasis drugs from The Medicines Company ("the Hemostasis Acquisition") - Recothrom, PreveLeak, and RAPLIXA TM (Fibrin Sealant (Human)) ("Raplixa") - for upfront consideration of $173.5 million , inclusive of existing inventory, and contingent sales-based milestone payments that could result in up to $395.0 million of additional consideration. The Hemostasis Acquisition was funded through cash on hand. As the Company shifted its focus to the critical care, autoimmune and rare disease spaces, the Company sold the Recothrom and PreveLeak assets and discontinued marketing of Raplixa. See further discussion in Notes 6, 13, and 21. Fair Value Allocation The following amounts represent the allocation of the fair value of the identifiable assets acquired and liabilities assumed for the respective acquisitions: Sucampo Ocera (1) InfaCare (2) Stratatech Hemostasis (3) Acquisition Date February 2018 December 2017 September 2017 August 2016 February 2016 Cash $ 149.6 $ 1.0 $ 1.3 $ 0.2 $ 3.3 Accounts receivable 35.7 — — 1.3 — Inventory 153.2 — — — 94.6 Intangible assets 919.5 64.5 113.5 99.8 132.7 Goodwill (non-tax deductible) (4) 248.6 18.0 11.4 55.1 3.3 Other assets, current and non-current 25.8 0.4 0.1 1.9 7.9 Total assets acquired 1,532.4 83.9 126.3 158.3 241.8 Current liabilities 109.4 12.0 14.5 4.3 3.6 Other liabilities (non-current) 33.3 — — — 10.6 Deferred tax liabilities, net (non-current) 175.8 16.7 8.7 22.1 2.1 Contingent consideration (non-current) — 12.8 35.0 54.9 52.0 Debt 366.3 — 30.0 1.0 — Total liabilities assumed 684.8 41.5 88.2 82.3 68.3 Net assets acquired $ 847.6 $ 42.4 $ 38.1 $ 76.0 $ 173.5 (1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million was paid in fiscal 2017 and 2018, respectively. (2) During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million fair value adjustment. Refer to Note 21 for further information. (3) During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information. (4) Refer to Note 13 for further information relating to the full goodwill impairment recorded in fiscal 2018. The following reconciles the total consideration to net assets acquired: Sucampo Ocera (1) InfaCare Stratatech Hemostasis Total consideration, net of cash $ 698.0 $ 63.4 $ 71.8 $ 130.7 $ 222.2 Plus: cash assumed in acquisition 149.6 1.0 1.3 0.2 3.3 Total consideration 847.6 64.4 73.1 130.9 225.5 Less: non-cash contingent consideration — (22.0 ) (35.0 ) (54.9 ) (52.0 ) Net assets acquired $ 847.6 $ 42.4 $ 38.1 $ 76.0 $ 173.5 (1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date. Intangible assets acquired consist of the following: Acquisition Intangible Asset Acquired Amount Amortization Period Discount Rate Segment Sucampo Completed technology - Amitiza $ 634.0 9 years 14.0 % Specialty Generics and Amitiza Sucampo Completed technology - Other 11.0 8 years 14.0 % Specialty Generics and Amitiza Sucampo In-process research and development - VTS-270 274.5 Non-Amortizable 15.0 % Specialty Brands Ocera In-process research and development - MNK-6105/6106 64.5 Non-Amortizable 15.5 % Specialty Brands InfaCare In-process research and development - stannsoporfin 113.5 Non-Amortizable 13.5 % Specialty Brands Stratatech In-process research and development - StrataGraft 99.8 Non-Amortizable 16.5 % Specialty Brands Hemostasis Completed technology - Raplixa (1) 73.0 15 years 17.0 % Specialty Brands Hemostasis Completed technology - Recothrom (2) 42.7 13 years 16.0 % Specialty Brands Hemostasis Completed technology - PreveLeak (2) 17.0 13 years 17.0 % Specialty Brands (1) During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to the Raplixa intangible asset. Refer to Note 13 for further information. (2) During fiscal 2018, the Company sold the Recothrom and PreveLeak assets to Baxter. Refer to Note 6 for further information. The fair value of the intangible assets was determined using the income approach. The fair value of the IPR&D, completed technology and trademark was determined using the income approach, which is a valuation technique that provides an estimate of fair value of the assets based on the market participant expectations of cash flows the asset would generate. The discount rates were developed after assigning a probability of success to achieving the projected cash flows based on the current stage of development, inherent uncertainty in the Food and Drug Administration ("FDA") approval process and risks associated with commercialization of a new product. Based on the Company's preliminary estimate, the excess of purchase price over net tangible and intangible assets acquired resulted in goodwill, which represents future product development, the assembled workforce, and the tax status of the transaction. The goodwill is not deductible for U.S. income tax purposes. Financial Results The amount of net sales and operating losses included in the Company's fiscal 2018 consolidated statement of income related to the Sucampo Acquisition were $190.5 million and $369.1 million , respectively. Included within Sucampo's results was $62.9 million of amortization associated with intangibles recognized from this acquisition and $118.8 million of expense associated with fair value adjustments of acquired inventory. During fiscal 2018, 2017 and 2016 and the three months ended December 30, 2016, the Company in total recognized $120.8 million , $10.1 million , $24.3 million and $3.6 million , respectively, of expense associated with fair value adjustments of acquired inventory. This expense was included within cost of sales. Acquisition-Related Costs - Acquisition-related costs incurred for each of the acquisitions discussed above were as follows: Fiscal Year Ended Three Months Ended Acquisition-related costs December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Sucampo $ 5.2 $ 4.2 $ — $ — Ocera 0.5 0.9 — — InfaCare — 1.2 — — Stratatech — — 3.7 — Hemostasis — — 2.7 0.1 Other 0.1 0.1 0.5 — Total acquisition-related costs $ 5.8 $ 6.4 $ 6.9 $ 0.1 License Agreements CPP In April 2018, the Company exercised the option under its collaborative agreement with CPP to negotiate terms of an exclusive license to commercialize CPP-1X/sulindac in North America. In addition, the Company provided CPP with a $10.0 million upfront R&D payment for expenses related to the FAP pivotal trial incurred during the "Negotiation Period," or the period from the exercise date through the execution of such license agreement. CPP shall return to the Company any portion of the R&D payment that is not utilized during the Negotiation Period. Of the $10.0 million upfront payment, $7.3 million was utilized during fiscal 2018 and recorded as R&D expense within the consolidated statements of income. The remaining $2.7 million was included in prepaid expenses and other current assets on the consolidated balance sheet as of December 28, 2018. In August 2018, the license agreement with CPP was executed and the Company paid $5.0 million upfront with cash on hand and gained exclusive rights to develop and commercialize the product in North America, if approved. The agreement includes additional payments of up to $185.0 million dependent on developmental, regulatory and sales milestones, subject to reduction up to $15.0 million related to amounts provided by the Company in advance of entering into this agreement, and provides for both parties' reimbursement of R&D expenses from future profits. Following the commercialization of the product, CPP and the Company will share profits in accordance with the agreement. The Company will manage the development of the product in North America. Xenon Gas for Inhalation In October 2017, the Company entered into a licensing agreement for development and commercialization of NeuroproteXeon Inc.'s ("NeuroproteXeon" and "the Xenon Licensing Agreement") investigational, pharmaceutical-grade xenon gas for inhalation therapy being evaluated to improve survival and functional outcomes for patients resuscitated after a cardiac arrest. If approved, xenon gas for inhalation will expand the Company's portfolio of hospital drug-device combination products providing therapies for critically ill patients. The Company paid $10.0 million upfront with cash on hand to reimburse NeuroproteXeon for certain product development costs, and gained exclusive rights to commercialize the therapy, if approved, in the U.S., Canada, Japan and Australia. The Xenon Licensing Agreement includes additional payments of up to $25.0 million dependent on developmental, regulatory and sales milestones. In addition, NeuroproteXeon will receive tiered royalties on applicable worldwide net sales and a transfer price for commercial product supply. NeuroproteXeon will continue to be responsible for the cost of development and will manage the development of the product in collaboration with the Company. During fiscal 2018, the Company paid a milestone payment of $5.0 million related to the first patient enrolled in a Phase 3 trial. The initial $10.0 million upfront cash payment and the $5.0 million milestone payment were both recorded within R&D expense during fiscal 2017 and fiscal 2018, respectively. Of the remaining $20.0 million additional payments, certain payments may be expensed as R&D, cost of sales, or capitalized as an intangible asset dependent upon the successful completion of certain milestone events. Mesoblast In January 2017, $21.5 million of consideration was remitted to Mesoblast in exchange for equity shares and rights to a nine month exclusivity period related to any potential commercial and development agreements the Company may enter into for Mesoblast's therapy products used to treat acute graft versus host disease and/or chronic lower back pain. As a result of this transaction the Company recorded an available for sale investment of $19.7 million included within prepaid and other current assets and an intangible asset of $1.8 million in the consolidated balance sheet as of March 31, 2017. This intangible asset was fully amortized as of December 29, 2017 as the nine month exclusivity period had ended. During fiscal 2018, all of the Company's shares were sold for gross proceeds of $25.5 million resulting in a $3.4 million gain being recognized within other income (expense), net within the consolidated statement of income. Ofirmev As part of the acquisition of Cadence Pharmaceuticals, Inc. ("Cadence" or "Cadence Acquisition") in March 2014, the Company acquired the exclusive development and commercialization rights to Ofirmev ® in the U.S. and Canada, as well as the rights to the patents and technology, which were originally in-licensed by Cadence from Bristol-Myers Squibb Company ("BMS") in March 2006. BMS sublicensed these rights to Cadence under a license agreement with SCR Pharmatop S.A. ("Pharmatop"), and the Company has the right to grant sublicenses to third parties. Under this license agreement, the Company made the final milestone payment of $15.0 million in fiscal 2018. In addition, the Company is obligated to pay royalties on sales of the product. During fiscal 2018, 2017 , 2016 and the three months ended December 30, 2016, the Company paid royalties of $76.9 million , $53.9 million , $46.3 million and $14.7 million , respectively, which were recorded within cost of sales on the consolidated statements of income. Assertio Therapeutics, Inc. (formerly known as Depomed, Inc.) In 2009, the Company licensed worldwide rights to utilize Assertio Therapeutics, Inc. (formerly known as Depomed, Inc.) Acuform gastric retentive drug delivery technology for the exclusive development of four products. Under this license agreement, the Company may be obligated to pay up to $64.0 million in development milestone payments. Through fiscal 2018 , approximately $22.0 million of these payments have been made by the Company, and as of December 28, 2018, the Company has no remaining obligations under this arrangement. During fiscal 2014, upon approval by the FDA for XARTEMIS™ XR (oxycodone HCl and acetaminophen) extended release tablets CII ("Xartemis"), the Company made a milestone payment of $10.0 million , which was capitalized as an intangible asset. During the three months ended December 30, 2016, the Company elected to discontinue this product and recorded a $7.3 million non-restructuring impairment charge associated with the Xartemis intangible asset. Advanced Accelerator Applications In 2007, the Company's Nuclear Imaging business entered into a license agreement with BioSynthema, Inc. ("BioSynthema"), which was subsequently amended in 2010 when Advanced Accelerator Applications ("AAA") acquired BioSythema. Pursuant to the amended agreement, upon the first commercial sale of Lutathera ® ("Lutathera"), AAA is to provide the Company with a royalty based on net sales of the product through January 1, 2020. In early 2018, the FDA approved Lutathera for treatment of gastroenteropancreatic neuroendocrine tumors and commercial sales commenced. During fiscal 2018, in relation to this agreement, the Company recognized royalty income of $15.5 million

Restructuring and Related Charg

Restructuring and Related Charges	12 Months Ended
	Dec. 28, 2018
Restructuring and Related Activities [Abstract]
Restructuring and Related Charges	8. Restructuring and Related Charges During fiscal 2013, the Company launched a restructuring program designed to improve its cost structure ("the 2013 Mallinckrodt Program"). The 2013 Mallinckrodt Program included actions across the Specialty Brands, Specialty Generics and former Global Medical Imaging segments, as well as within corporate functions. The Company expected to incur charges of $100.0 million to $125.0 million under this program as the specific actions required to execute on these initiatives were identified and approved. As of December 28, 2018, the 2013 Mallinckrodt Program is complete. In July 2016, the Company's Board of Directors approved a $100.0 million to $125.0 million restructuring program ("the 2016 Mallinckrodt Program") designed to further improve its cost structure, as the Company continues to transform its business. The 2016 Mallinckrodt Program included actions across the Specialty Brands and Specialty Generics and Amitiza segments, as well as within corporate functions. As of December 28, 2018, the 2016 Mallinckrodt Program is substantially complete. In February 2018, the Company's Board of Directors approved a $100.0 million to $125.0 million restructuring program ("the 2018 Mallinckrodt Program") that is of similar design as the 2016 Mallinckrodt Program. The utilization of the 2018 Mallinckrodt Program commenced upon substantial completion of the 2016 Mallinckrodt Program. There is no specified time period associated with the 2018 Mallinckrodt Program. In addition to the 2018, 2016 and the 2013 Mallinckrodt Programs, the Company has taken restructuring actions to generate synergies from its acquisitions. Net restructuring and related charges by segment from continuing operations are as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Specialty Brands $ 52.2 $ 25.4 $ 23.3 $ 2.6 Specialty Generics and Amitiza 29.0 7.7 3.4 0.8 Corporate 27.0 3.3 10.9 1.9 Restructuring and related charges, net 108.2 36.4 37.6 5.3 Less: accelerated depreciation (5.2 ) (5.2 ) (4.9 ) (1.5 ) Restructuring charges, net $ 103.0 $ 31.2 $ 32.7 $ 3.8 Charges in other income (expense) (1) $ — $ — $ 0.6 $ — (1) Charges incurred under restructuring programs related to pension that were reclassified to other income (expense), net due to the adoption of ASU 2017-07. Net restructuring and related charges by program from continuing operations are comprised of the following: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 2018 Mallinckrodt Program $ 5.2 $ — $ — $ — 2016 Mallinckrodt Program 71.6 36.2 8.3 5.2 2013 Mallinckrodt Program — (0.7 ) 25.6 — Acquisition programs 31.4 0.9 3.7 0.1 Total programs 108.2 36.4 37.6 5.3 Less: non-cash charges, including accelerated depreciation and impairments (5.2 ) (5.2 ) (4.9 ) (1.5 ) Total charges expected to be settled in cash $ 103.0 $ 31.2 $ 32.7 $ 3.8 Charges in other income (expense) (1) $ — $ — $ 0.6 $ — (1) Charges incurred under restructuring programs related to pension that were reclassified to other income (expense) due to the adoption of ASU 2017-07. The following table summarizes cash activity for restructuring reserves, substantially all of which related to contract termination costs, employee severance and benefits and exiting of certain facilities: 2018 Mallinckrodt Program 2016 Mallinckrodt Program 2013 Mallinckrodt Program Acquisition Programs Total Balance at September 25, 2015 $ — $ — $ 8.0 $ 10.0 $ 18.0 Charges from continuing operations — 6.4 24.0 5.0 35.4 Charges from discontinued operations — — 2.5 — 2.5 Changes in estimate from continuing operations — — (1.4 ) (1.3 ) (2.7 ) Changes in estimate from discontinued operations — — (0.3 ) — (0.3 ) Cash payments — (0.2 ) (20.3 ) (13.2 ) (33.7 ) Reclassifications (1) — — (0.7 ) — (0.7 ) Balance at September 30, 2016 — 6.2 11.8 0.5 18.5 Charges from continuing operations — 3.7 — 0.1 3.8 Cash payments — (0.4 ) (6.7 ) (0.4 ) (7.5 ) Balance at December 30, 2016 — 9.5 5.1 0.2 14.8 Charges from continuing operations — 35.8 — 0.9 36.7 Changes in estimate from continuing operations — (4.8 ) (0.7 ) — (5.5 ) Cash payments — (26.1 ) (4.4 ) (0.3 ) (30.8 ) Reclassifications — 0.3 — — 0.3 Balance at December 29, 2017 — 14.7 — 0.8 15.5 Charges from continuing operations 2.2 76.9 — 29.9 109.0 Changes in estimate from continuing operations — (5.3 ) — (0.7 ) (6.0 ) Cash payments — (23.4 ) — (22.2 ) (45.6 ) Reclassifications — (1.9 ) — — (1.9 ) Balance at December 28, 2018 $ 2.2 $ 61.0 $ — $ 7.8 $ 71.0 (1) Represents the reclassification of pension and other postretirement benefits from restructuring reserves to pension and postretirement obligations. Net restructuring and related charges, including associated asset impairments, incurred cumulative to date related to the 2018, 2016 and 2013 Mallinckrodt Programs are as follows: 2018 Mallinckrodt Program 2016 Mallinckrodt Program 2013 Mallinckrodt Program Specialty Brands $ 3.0 $ 81.7 $ 18.8 Specialty Generics and Amitiza — 14.6 18.3 Discontinued Operations — — 69.9 Corporate 2.2 25.9 17.7 $ 5.2 $ 122.2 $ 124.7 In fiscal 2018, the Company discontinued the marketing of Raplixa after an evaluation of strategic options and incurred restructuring expenses of $51.1 million under the 2016 Mallinckrodt Program, consisting primarily of contract termination costs related to the production of Raplixa. Amounts paid in the future may differ from the amount currently recorded.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 28, 2018
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the TCJA. The TCJA reduces the U.S. federal corporate statutory rate from 35% to 21%, requires companies to pay a one-time transition tax on certain undistributed earnings of foreign subsidiaries of U.S. entities and creates new taxes on certain foreign sourced earnings. As of December 28, 2018, the Company has completed its accounting for all of the tax effects of the TCJA. During fiscal 2017 the Company recorded a deferred tax benefit of $444.8 million for the provisional estimate of the remeasurement of its net U.S. deferred tax liabilities for the reduction in the U.S. federal corporate statutory tax rate to 21%. The provisional estimate was affected by other analyses related to the TCJA, including, but not limited to, having a U.S. tax return year that straddles the effective date of the statutory rate change and that is different than the Company's financial statement year. During fiscal 2018, on the basis of additional analysis related to certain tax calculations, the Company recognized an additional deferred tax benefit of $8.5 million , impacting the effective tax rate by 0.2% . The one-time transition tax under the TCJA is based upon the amount of post-1986 cumulative undistributed earnings of certain of the Company's subsidiaries which was deferred from U.S. income tax under previous U.S. law. During fiscal 2017, the Company estimated this item would not result in any current or future tax. During fiscal 2018, no adjustments to the one-time transition tax have been made. TCJA subjects a U.S. shareholder to current tax on global intangible low-taxed income (“GILTI”) earned by certain foreign subsidiaries. The FASB Staff Question & Answer Topic 740 No. 5, Accounting for Global Intangible Low-Taxed Income , states that an entity can make an accounting policy election to either recognize deferred taxes for temporary differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI in the year the tax is incurred. The Company has elected to recognize the tax on GILTI as a period expense in the period the tax is incurred. The U.K. and non-U.K. components of (loss) income from continuing operations before income taxes were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 U.K. $ (233.7 ) $ (165.9 ) $ (275.3 ) $ (97.4 ) Non-U.K. (3,818.3 ) 227.5 508.7 (201.1 ) Total $ (4,052.0 ) $ 61.6 $ 233.4 $ (298.5 ) Significant components of income taxes related to continuing operations are as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Current: U.K. $ (0.2 ) $ 0.4 $ 0.3 $ — Non-U.K. 113.0 37.7 120.5 82.0 Current income tax provision 112.8 38.1 120.8 82.0 Deferred: U.K. 1.4 0.6 0.7 (0.5 ) Non-U.K. (544.3 ) (1,748.3 ) (377.1 ) (203.2 ) Deferred income tax benefit (542.9 ) (1,747.7 ) (376.4 ) (203.7 ) Total $ (430.1 ) $ (1,709.6 ) $ (255.6 ) $ (121.7 ) The fiscal 2018 U.K. current income tax provision reflects a tax benefit of $8.5 million from utilization of net operating loss carryforwards. The fiscal 2018 non-U.K. current income tax provision reflects a tax benefit of $13.7 million from utilization of net operating loss carryforwards. The fiscal 2017 U.K. current income tax provision reflects a tax benefit of $14.3 million from utilization of net operating loss carryforwards. The fiscal 2017 non-U.K. current income tax provision reflects a tax benefit of $57.2 million from utilization of net operating loss carryforwards and $5.6 million of U.S. credits. In addition, the non-U.K. current income tax provision includes a tax benefit of $27.2 million related to carryback claims filed in fiscal 2017. The U.S. credit utilization is comprised of credit carryforwards and credits generated during fiscal 2017. The fiscal 2016 U.K. current income tax provision reflects a tax benefit of $1.0 million from utilization of net operating loss carryforwards. The fiscal 2016 non-U.K. current income tax provision reflects a tax benefit of $29.2 million from utilization of net operating loss carryforwards and $9.5 million of U.S. credits. The non-U.K. net operating loss utilization is comprised of $17.9 million of net operating losses acquired in conjunction with the Hemostasis Acquisition and the remainder of the utilization relates to net operating loss carryforwards. The U.S. credit utilization is comprised of credit carryforwards and credits generated during fiscal 2016. The three months ended December 30, 2016 non-U.K. current income tax provision reflects a tax benefit of $0.3 million from utilization of net operating loss carryforwards and $2.0 million of U.S. credits. The U.S. credit utilization is comprised of credit carryforwards and credits generated during the three months ended December 30, 2016. During fiscal years 2018, 2017, and 2016 net cash payments for income taxes was $12.4 million , $73.4 million and $165.4 million , respectively. During the three months ended December 30, 2016 net cash payments for income taxes was $95.6 million . The Company has a provincial tax holiday in Canada that expires on April 1, 2027. The tax holiday reduced non-U.K. tax expense by $1.0 million , $1.8 million and $1.0 million for the fiscal years 2018, 2017 and 2016, respectively. Due to an operating loss, there is no benefit from the tax holiday for the three months ended December 30, 2016. The reconciliation between U.K. income taxes at the statutory rate and the Company's provision for income taxes on continuing operations is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 (Benefit) provision for income taxes at U.K. statutory income tax rate (1) $ (770.1 ) $ 11.7 $ 46.6 $ (59.7 ) Adjustments to reconcile to income tax provision: Rate difference between U.K. and non-U.K. jurisdictions (2) (4) (235.7 ) (219.9 ) (249.3 ) (123.0 ) Valuation allowances, nonrecurring — (3.7 ) 2.1 — Adjustments to accrued income tax liabilities and uncertain tax positions 60.1 5.1 (14.9 ) 0.9 Interest and penalties on accrued income tax liabilities and uncertain tax positions 13.1 0.2 (16.4 ) (0.1 ) Investment in partnership — — — (12.7 ) Credits, principally research and orphan drug (3) (25.9 ) (13.8 ) (33.7 ) (0.7 ) Impairments non deductible 788.7 — — 75.3 Permanently nondeductible and nontaxable items 7.2 6.4 7.9 1.6 Pension plan settlement, release of tax effects lodged in other comprehensive income — (2.4 ) — — Divestitures (7) (2.7 ) 18.2 — — U.S. Tax Reform (5) (8.5 ) (456.9 ) — — Legal Entity Reorganization (6) (256.0 ) (1,054.8 ) — — Other (0.3 ) 0.3 2.1 (3.3 ) Benefit for income taxes $ (430.1 ) $ (1,709.6 ) $ (255.6 ) $ (121.7 ) (1) The statutory tax rate reflects the U.K. statutory tax rate of 19% for fiscal 2018 and 2017 and 20% for fiscal 2016 and the three months ended December 30, 2016. (2) Includes the impact of certain recurring valuation allowances for U.K. and non-U.K. jurisdictions. (3) During fiscal 2018, the research and orphan drug credits increased in conjunction with the Company's increased investment in qualified research. During fiscal 2016, the Company realized a tax benefit of $27.4 million resulting from a U.K. tax credit on a dividend between affiliates. (4) During the three months ended December 30, 2016, the rate difference between U.K. and non-U.K. jurisdictions was favorably impacted by a benefit of $16.1 million on a $102.0 million settlement with the Federal Trade Commission and a benefit of $34.5 million on a $207.0 million goodwill impairment in the Specialty Generics reporting unit. (5) For fiscal 2018, the Company completed its analysis of the TCJA and recognized an additional tax benefit. Other line items, to the extent U.S. related, are reflected at the current U.S. statutory income tax rate of 21%. For fiscal 2017, the benefit reflects the redetermination of the Company’s end of year net deferred tax liabilities as a result of the new U.S. statutory income tax rate of 21%. Other line items, to the extent U.S. related, are reflected at the former U.S. statutory income tax rate of 35%. (6) Associated unrecognized tax benefit netted within this line. (7) During fiscal 2018, the Company completed the sale of a portion of its Hemostasis business. During fiscal 2017, the Company completed the sale of the Intrathecal Therapy Business. The rate difference between U.K. and non-U.K. jurisdictions changed from $219.9 million of tax benefit to $235.7 million of tax benefit for fiscal 2017 to fiscal 2018, respectively. The $15.8 million increase in the tax benefit included a $90.3 million increase attributable to the non-restructuring impairment charges in fiscal 2018, a $22.2 million increase attributable to the divestiture of the Intrathecal Therapy business in fiscal 2017 and of the PreveLeak and Recothrom assets in fiscal 2018; partially offset by decreases of $80.2 million to the tax benefit attributable to the impact of U.S. Tax Reform, an $11.8 million decrease related to recent acquisitions, and a $4.7 million decrease attributable to changes in operating income and fiscal 2017 one-time items that did not recur in fiscal 2018. The rate difference between U.K. and non-U.K. jurisdictions changed from $249.3 million of tax benefit to $219.9 million of tax benefit for fiscal 2016 to fiscal 2017, respectively. The $29.4 million decrease in the tax benefit included $37.6 million of decreases primarily attributed to the divestiture of the Intrathecal Therapy business and the planned divestiture of the PreveLeak and Recothrom assets and fiscal 2016 one-time items that did not recur in fiscal 2017, and $15.2 million of decreases to the tax benefit associated with the impact of U.S. Tax Reform on a U.S. tax return year that straddles the effective date of the statutory rate change; partially offset by increases of $23.4 million to the tax benefit attributed to changes in operating income and termination and settlement of the Company's funded U.S. pension plan in fiscal 2017. During fiscal 2018, the Company initiated a reorganization of its intercompany financing and associated legal entity ownership in response to the changing global tax environment. As a result, the Company recognized current income tax expense of $25.5 million and a deferred income tax benefit of $281.5 million with a corresponding reduction to net deferred tax liabilities. The reduction in net deferred tax liabilities is comprised of a $310.6 million decrease in interest-bearing deferred tax obligations, a $58.9 million increase in deferred tax liabilities associated with its investment in partnership, a $58.9 million decrease in deferred tax liabilities predominately associated with intangible assets, a $39.7 million increase related to a change in valuation allowances, a $9.3 million decrease in various other net deferred tax liabilities and a $1.3 million decrease associated with generation of tax loss and credit carryforwards. The following table summarizes the activity related to the Company's unrecognized tax benefits, excluding interest: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Balance at beginning of period $ 182.5 $ 118.7 $ 89.2 $ 114.8 Additions related to current year tax positions 19.6 79.9 63.8 5.0 Additions related to prior period tax positions 125.1 0.3 10.8 — Reductions related to prior period tax positions (32.7 ) (13.6 ) (37.8 ) (1.1 ) Reductions related to disposition transactions — — (6.6 ) — Settlements (2.0 ) — (2.6 ) — Lapse of statute of limitations (4.8 ) (2.8 ) (2.0 ) — Balance at end of period $ 287.7 $ 182.5 $ 114.8 $ 118.7 Unrecognized tax benefits, excluding interest, are reported in the following consolidated balance sheet captions in the amounts shown: December 28, 2018 December 29, 2017 Accrued and other current liabilities $ 1.0 $ 1.5 Other income tax liabilities 189.9 82.6 Deferred income taxes (non-current liability) 96.8 98.4 $ 287.7 $ 182.5 Included within total unrecognized tax benefits at December 28, 2018 , December 29, 2017, September 30, 2016 and December 30, 2016, were $275.8 million , $180.8 million , $113.1 million and $116.9 million respectively, of unrecognized tax benefits, which if favorably settled would benefit the effective tax rate. The remaining unrecognized tax benefits for each period would be offset by the write-off of related deferred and other tax assets, if recognized. During fiscal 2018 , the Company recorded $33.2 million of additional interest and penalties through tax provision and acquisition accounting and decreased accrued interest by $3.2 million related to prior period reductions, settlements and lapse of statute of limitations. During fiscal 2017 , 2016 and the three months ended December 30, 2016, the Company had net interest and penalties activity of zero , an increase of $1.9 million and a decrease of $0.2 million , respectively. The total amount of accrued interest and penalties related to uncertain tax positions was $37.1 million , $7.1 million , $7.4 million and $7.1 million , respectively. It is reasonably possible that within the next twelve months, as a result of the resolution of various U.K. and non-U.K. examinations and appeals and the expiration of various statutes of limitation, that the unrecognized tax benefits could decrease by up to $136.9 million . Interest and penalties could decrease by up to $32.8 million . Income taxes payable, including uncertain tax positions and related interest accruals, is reported in the following consolidated balance sheet captions in the amounts shown: December 28, 2018 December 29, 2017 Income taxes payable $ 25.0 $ 15.8 Other income tax liabilities 228.0 94.1 $ 253.0 $ 109.9 Tax receivables and payments associated with deferred intercompany transactions are included in the following consolidated balance sheet captions in the amounts shown: December 28, 2018 December 29, 2017 Other assets $ 3.0 $ — Prepaid expenses and other current assets 16.2 6.1 $ 19.2 $ 6.1 Certain of the Company’s subsidiaries continue to be subject to examination by the IRS for tax years as early as 2014 . As of December 28, 2018, the primary unresolved issue relates to transfer pricing, which could have a significant impact to the consolidated financial statements if not resolved favorably. The Company believes its allowances for income tax contingencies are adequate. The Company has not received a proposed assessment for the unresolved issues and does not expect a final resolution of these issues in the next 12 months. In addition, the earliest open years for state tax jurisdictions are 2009 and a number of tax periods from 2013 to present are subject to examination by tax authorities in various jurisdictions, including Ireland, Luxembourg, Switzerland and the U.K. Deferred income taxes result from temporary differences between the amount of assets and liabilities recognized for financial reporting and tax purposes. The components of the net deferred tax (liability) asset at the end of each fiscal year were as follows: December 28, 2018 December 29, 2017 Deferred tax assets: Accrued liabilities and reserves $ 56.3 $ 62.7 Tax loss and credit carryforwards 1,987.8 1,734.5 Intangible assets 757.7 575.1 Other 204.6 113.3 3,006.4 2,485.6 Deferred tax liabilities: Intangible assets (264.7 ) (181.0 ) Interest-bearing deferred tax obligations (227.5 ) (553.5 ) Investment in partnership (170.2 ) (108.8 ) Other (42.9 ) (47.0 ) (705.3 ) (890.3 ) Net deferred tax asset before valuation allowances 2,301.1 1,595.3 Valuation allowances (2,604.9 ) (2,267.9 ) Net deferred tax liability $ (303.8 ) $ (672.6 ) The deferred tax asset valuation allowances of $2,604.9 million and $2,267.9 million at December 28, 2018 and December 29, 2017, respectively, relate primarily to the uncertainty of the utilization of certain deferred tax assets, driven by U.K. and non-U.K. net operating losses, credits and intangible assets. The Company believes that it will generate sufficient future taxable income to realize the tax benefits related to the remaining net deferred tax assets. Deferred taxes are reported in the following consolidated balance sheet captions in the amounts shown: December 28, 2018 December 29, 2017 Other assets $ 20.5 $ 16.4 Deferred income taxes (non-current liability) (324.3 ) (689.0 ) Net deferred tax liability $ (303.8 ) $ (672.6 ) Non-current deferred tax liability decreased from $689.0 million at December 29, 2017 to $324.3 million at December 28, 2018 , primarily due to $281.5 million of decreases associated with the deferred tax benefit recognized from the reorganization of the Company's intercompany financing and associated legal entity ownership, $135.9 million of decreases predominately related to the generation of net operating losses and other operational activity, $49.1 million of decreases related to impairments, $28.9 million of decreases associated with the amortization of intangibles, $23.6 million of decreases associated with inventory step up amortization, $8.5 million of decreases associated with the impact of U.S. Tax Reform and $6.5 million of decreases related to reductions of deferred tax assets associated with legal settlements. These decreases are partially offset by $169.3 million of increases related to recent acquisitions. The sale of a portion of the Hemostasis business, inclusive of the PreveLeak and Recothrom products, was completed on March 16, 2018. This divestiture resulted in a net deferred tax liability decrease of $2.7 million . A significant component of this decrease includes a decrease of $2.7 million of deferred tax liability associated with inventories. In addition, there was a decrease of $1.5 million associated with other deferred tax assets, a decrease of $2.7 million of deferred tax assets associated with tax loss and credit carryforwards, and a decrease of $4.2 million of deferred tax assets associated with intangible assets, all of which were offset by a reduction in valuation allowance of $8.4 million . The Sucampo Acquisition resulted in a net deferred tax liability increase of $175.8 million . Significant components of this increase include $179.3 million of deferred tax liabilities associated with intangible assets and a $25.7 million deferred tax liability associated with inventories. The increase in deferred tax liabilities is partially offset by $25.1 million of deferred tax assets associated with tax loss and credit carryforwards, and various other net deferred tax assets of $4.1 million . The Company refined its acquisition accounting estimate associated with the measurement of its acquired Ocera net deferred tax liabilities in fiscal 2018, resulting in a decrease to the acquired net deferred tax liabilities from $23.2 million to $16.7 million prior to recording the impact from the TCJA. As of December 28, 2018 , the Company had approximately $1,817.8 million of net operating loss carryforwards in certain non-U.K. jurisdictions measured at the applicable statutory rates, of which $1,484.4 million have no expiration and the remaining $333.4 million will expire in future years through 2039 . The Company had $108.2 million of U.K. net operating loss carryforwards measured at the applicable statutory rates at December 28, 2018 , which have no expiration date. As of December 28, 2018 , the Company also had $61.8 million of tax credits available to reduce future income taxes payable, primarily in jurisdictions within the U.S., of which $4.6 million have no expiration and the remainder will expire in future years through 2039 . As of December 28, 2018, the Company’s financial reporting basis in international subsidiaries that may be subject to tax was in excess of its corresponding tax basis by $41.6 million . Such excess amount is considered to be indefinitely reinvested and it is not practicable to determine the cumulative amount of tax liability that would arise if this indefinitely reinvested amount were realized due to a variety of factors including the complexity of the Company’s legal entity structure as well as the timing, extent, and nature of any hypothetical realization. The net increase, as compared to the period ending December 29, 2017, was attributable to the finalization of the impacts of the TCJA as well as income and losses attributed to current year activity. The Company has recorded a deferred tax liability of $9.1 million

Earnings (Loss) per Share

Earnings (Loss) per Share	12 Months Ended
	Dec. 28, 2018
Earnings (Loss) per Share [Abstract]
Earnings (Loss) per Share	10. (Loss) Earnings per Share Basic (loss) earnings per share is computed by dividing net (loss) income by the number of weighted-average shares outstanding during the period. Diluted (loss) earnings per share was computed using the weighted-average shares outstanding and, if dilutive, potential ordinary shares outstanding during the period. Potential ordinary shares represent the incremental ordinary shares issuable for restricted share units and share option exercises. The Company calculated the dilutive effect of outstanding restricted share units and share options on (loss) earnings per share by application of the treasury stock method. Dilutive securities, including participating securities, are not included in the computation of loss per share when the Company reports a net loss from continuing operations as the impact would be anti-dilutive. Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 (Loss) earnings per share numerator: (Loss) income from continuing operations attributable to common shareholders $ (3,621.9 ) $ 1,771.2 $ 489.0 $ (176.8 ) Income from discontinued operations 14.9 363.2 154.7 23.6 Net (loss) income attributable to common shareholders $ (3,607.0 ) $ 2,134.4 $ 643.7 $ (153.2 ) (Loss) earnings per share denominator: Weighted-average shares outstanding - basic 84.0 97.7 110.6 105.7 Impact of dilutive securities — 0.2 0.9 — Weighted-average shares outstanding - diluted 84.0 97.9 111.5 105.7 Basic (loss) earnings per share attributable to common shareholders: (Loss) income from continuing operations $ (43.12 ) $ 18.13 $ 4.42 $ (1.67 ) Income from discontinued operations 0.18 3.72 1.40 0.22 Net (loss) income attributable to common shareholders $ (42.94 ) $ 21.85 $ 5.82 $ (1.45 ) Diluted (loss) earnings per share attributable to common shareholders: (Loss) income from continuing operations $ (43.12 ) $ 18.09 $ 4.39 $ (1.67 ) Income from discontinued operations 0.18 3.71 1.39 0.22 Net (loss) income attributable to common shareholders $ (42.94 ) $ 21.80 $ 5.77 $ (1.45 ) The computation of diluted earnings per share for fiscal 2018 , 2017 , 2016 and the three months ended December 30, 2016, excludes approximately 3.3 million , 4.2 million , 1.7 million and 2.4 million

Inventories

Inventories	12 Months Ended
	Dec. 28, 2018
Inventory, Net [Abstract]
Inventories	11. Inventories Inventories are comprised of the following at the end of each period: December 28, December 29, Raw materials and supplies $ 69.2 $ 70.0 Work in process 167.6 167.1 Finished goods 85.5 103.3 Inventories $ 322.3 $ 340.4

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 28, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	12. Property, Plant and Equipment The gross carrying amount and accumulated depreciation of property, plant and equipment at the end of each period was as follows: December 28, 2018 December 29, 2017 Land $ 43.9 $ 44.0 Buildings 379.5 355.5 Capitalized software 130.8 109.0 Machinery and equipment 1,137.3 1,123.8 Construction in process 244.7 209.7 1,936.2 1,842.0 Less: accumulated depreciation (954.2 ) (875.2 ) Property, plant and equipment, net $ 982.0 $ 966.8 Depreciation expense for continuing operations was as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Depreciation expense $ 111.9 $ 113.8 $ 113.3 $ 27.5

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 28, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	13. Goodwill and Intangible Assets The changes in the carrying amount of goodwill by segment were as follows: December 28, 2018 December 29, 2017 Gross Carrying amount Accumulated Impairment Gross Carrying amount Accumulated Impairment Specialty Brands $ 3,672.8 $ (3,672.8 ) $ 3,482.7 $ — Specialty Generics 207.0 (207.0 ) 207.0 (207.0 ) Total $ 3,879.8 ($3,879.8 ) $ 3,689.7 $ (207.0 ) During the fiscal year ended December 28, 2018, the gross carrying value of goodwill in the Specialty Brands segment increased by $190.1 million . The increase was primarily attributable to the Sucampo Acquisition, which yielded $248.6 million of goodwill, partially offset by $51.5 million of goodwill ascribed to the sale of a portion of the Company's Hemostasis business, inclusive of the PreveLeak and Recothrom products. The remaining change in goodwill was related to purchase accounting adjustments during the twelve month measurement period for previous acquisitions. Goodwill Impairment Analysis Fiscal Year ended December 28, 2018 The Company performed its annual goodwill impairment analysis for the Specialty Brands reporting unit as of the first day of the fourth quarter. The Company’s 2018 annual assessment first considered its internally developed future cash flows, which reflect the Company's overall strategy, future growth and value proposition. There continues to be a disparity between the Company's anticipated future performance and present uncertainty reflected in its market capitalization, driven by a sustained decrease in its share price. The Company continues to believe that its share price has been adversely affected primarily by uncertainties regarding patient withdrawal issues impacting net sales of H.P. Acthar ® Gel ("H.P. Acthar Gel"), ongoing Inomax ® ("Inomax") patent litigation and the perceived value of its various pipeline products. Given the passage of time since first experiencing a substantial decline in its share price during the three months ended December 29, 2017 and the fact that the aforementioned uncertainties are not expected to be resolved in the near-term, the Company's annual goodwill impairment analysis resulted in the recognition of a full goodwill impairment of $3,672.8 million . For purposes of the 2018 goodwill impairment assessment for the Specialty Brands reporting unit, the Company made various assumptions regarding estimated future cash flows, discount rate and other factors in determining the respective fair value of the reporting unit using the income approach. The projections of future cash flows were discounted based on a weighted average cost of capital of 12.5% that was determined from relevant market comparisons, adjusted upward for specific reporting unit risks. A terminal value growth rate was applied to the terminal year cash flows, representing the Company's estimate of stable cash flows. The fair value of the Specialty Brands reporting unit represents the sum of the discounted cash flows from the discrete period and the terminal year cash flows. The Three Months Ended December 30, 2016 The Specialty Generics reporting unit has experienced customer consolidation and increased competition that have and are expected to result in further downward pressure to net sales and operating income in this reporting unit. During the three months ended December 30, 2016, the FDA approved new products that were expected to compete with the Company's methylphenidate HCl extended-release tablets USP (CII) ("Methylphenidate ER") products and at that time one competitor had launched their Methylphenidate ER products. Additional products expected to compete with the Company's Methylphenidate ER products were launched during fiscal 2017. All of these products have a class AB rating compared with the class BX rating on the Company's Methylphenidate ER products. The Company determined that these events represented a triggering event and the Company performed an assessment of the goodwill associated with the Specialty Generics reporting unit as of December 30, 2016. The Company's projections in the Specialty Generics reporting unit included long-term net sales and operating income at lower than historical levels primarily attributable to customer consolidation and increased competition, including the competition effects on Methylphenidate ER. The Company utilized a weighted average cost of capital of 9.5% which reflects the Company's risk premium associated with the projected cash flows. These assumptions resulted in a fair value of the Specialty Generics reporting unit that was less than its net book value. As this impairment analysis was performed prior to the Company's adoption of ASU 2017-04 in fiscal 2017, the Company performed step two of the goodwill impairment test and recognized a $207.0 million goodwill impairment in the Specialty Generics segment. Intangible Assets The gross carrying amount and accumulated amortization of intangible assets at the end of each period were as follows: December 28, 2018 December 29, 2017 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortizable: Completed technology $ 10,467.9 $ 2,980.6 $ 9,882.8 $ 2,260.8 License agreements 120.1 70.1 177.1 121.1 Trademarks 81.9 18.1 82.1 14.5 Customer relationships 27.5 14.1 29.5 12.2 Other — — 8.6 8.6 Total $ 10,697.4 $ 3,082.9 $ 10,180.1 $ 2,417.2 Non-Amortizable: Trademarks $ 35.0 $ 35.0 In-process research and development 633.3 577.1 Total $ 668.3 $ 612.1 The Company recorded impairment charges totaling $220.3 million , $63.7 million , $16.9 million , and $7.3 million during fiscal 2018, 2017, 2016 and the three months ended December 30, 2016, respectively. The fiscal 2018 and 2017 impairment charges primarily related to the MNK-1411 and Raplixa intangible assets respectively, and were a result of lower than previously anticipated pricing assumptions and commercial opportunities, respectively, for the products. The fiscal 2016 impairment charge primarily related to IPR&D assets acquired as part of the CNS Therapeutics acquisition in fiscal 2013, and resulted from delays in anticipated FDA approval, higher than expected development costs and lower than previously anticipated commercial opportunities. The impairment charge recorded during the three months ended December 30, 2016 related to the impairment of licenses associated with the Xartemis product upon the Company's election to discontinue the product. The valuation method used to approximate fair value in each of these periods was based on the estimated discounted cash flows for the respective asset. Stannsoporfin On May 3, 2018, in a joint meeting, the FDA's Gastrointestinal Drugs Advisory Committee and Pediatric Advisory Committee (the "Advisory Committee") recommended that the risk benefit profile of the Company's stannsoporfin IPR&D product does not support approval for the treatment of newborns ≥35 weeks of gestational age with indicators of hemolysis who are at risk of developing hyperbilirubinemia (severe jaundice). On August 9, 2018, the Company received a complete response letter from the FDA related to its new drug application ("NDA") for stannsoporfin. In the letter, the FDA provided guidance regarding areas of further evaluation for resubmitting the stannsoporfin NDA for the treatment of newborns ≥35 weeks of gestational age with indicators of hemolysis who are at risk of developing hyperbilirubinemia. While the timing of the development program has shifted outward, the Company continues to have conversations with the FDA to determine the best path forward. The Company will continue to assess the impact of any changes to planned revenue or earnings on the fair value of the associated IPR&D asset of $113.5 million included within intangible assets, net on the consolidated balance sheet as of December 28, 2018. Refer to Note 21 for the associated impact on the Company's contingent consideration liability related to stannsoporfin. VTS-270 VTS-270 is the Company’s development product to treat Niemann-Pick Type C, a complicated, ultra-rare neurodegenerative disease that typically presents in childhood and is ultimately fatal. The results of the Company’s recently completed registration trial for the product did not show a statistically significant separation from placebo. Neither the VTS-270 nor the placebo arm showed disease progression as would be expected for a neurodegenerative condition over 52 weeks of observation. The Company is in the process of evaluating this portion of the study in order to ensure the data was properly captured and of the highest quality. The FDA indicated to the Company at a Type A meeting in August 2018 that their view on the potential approvability will be based on the totality of data, not a single study or endpoint. Accordingly, the Company’s review of the data from the Phase 2b/3 trial, including the longer term open label portion, continues to proceed and is being assessed in combination with several other available data sources. The Company expects that a better understanding of the potential benefit of VTS-270 will emerge as it carefully considers the totality of data available and continues to work with the primary investigators and the FDA to determine the best path forward. The Company will continue to assess the impact of any changes to planned revenue or earnings on the fair value of the associated IPR&D asset of $274.5 million included within intangible assets, net, on the consolidated balance sheet as of December 28, 2018. Finite-lived intangible asset amortization expense within continuing operations is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Amortization expense $ 740.2 $ 694.5 $ 700.1 $ 175.7 The estimated aggregate amortization expense on intangible assets owned by the Company is expected to be as follows: Fiscal 2019 $ 748.4 Fiscal 2020 748.0 Fiscal 2021 747.8 Fiscal 2022 620.8 Fiscal 2023 584.8

Debt

Debt	12 Months Ended
	Dec. 28, 2018
Debt Disclosure [Abstract]
Debt	14. Debt Debt was comprised of the following at the end of each period: December 28, 2018 December 29, 2017 Principal Unamortized Discount and Debt Issuance Costs Principal Unamortized Discount and Debt Issuance Costs Current maturities of long-term debt: 3.50% notes due April 2018 $ — $ — $ 300.0 $ 0.2 Term loan due September 2024 16.4 0.2 14.0 0.3 Term loan due February 2025 6.0 0.1 — — Other 0.3 — 0.2 — Total current debt 22.7 0.3 314.2 0.5 Long-term debt: 4.875% notes due April 2020 700.0 3.2 700.0 5.7 Variable-rate receivable securitization due July 2020 250.0 0.4 200.0 0.7 9.50% debentures due May 2022 10.4 — 10.4 — 5.75% notes due August 2022 835.2 7.0 884.0 9.5 8.00% debentures due March 2023 4.4 — 4.4 — 4.75% notes due April 2023 500.2 3.5 526.5 4.5 5.625% notes due October 2023 731.4 8.0 738.0 9.7 Term loan due September 2024 1,597.4 19.8 1,837.2 26.7 Term loan due February 2025 591.0 10.7 — — 5.50% notes due April 2025 692.1 7.7 692.1 9.0 Other 1.9 — — — Revolving credit facility 220.0 4.5 900.0 5.9 Total long-term debt 6,134.0 64.8 6,492.6 71.7 Total debt $ 6,156.7 $ 65.1 $ 6,806.8 $ 72.2 Mallinckrodt International Finance S.A. ("MIFSA") is a wholly-owned subsidiary of the Company. MIFSA functions as a holding company, established to own, directly or indirectly, substantially all of the operating subsidiaries of the Company, as well as to issue debt securities and to perform treasury operations. In April 2013, MIFSA issued a $600.0 million aggregate principal amount of 4.75% senior unsecured notes due April 2023 ("the 2013 Notes"). Mallinckrodt plc has fully and unconditionally guaranteed the 2013 Notes on an unsecured and unsubordinated basis. The 2013 Notes are subject to an indenture which contains covenants limiting the ability of MIFSA, its restricted subsidiaries (as defined in the 2013 Notes) and Mallinckrodt plc, as guarantor, to incur certain liens or enter into sale and lease-back transactions. It also restricts Mallinckrodt plc and MIFSA's ability to merge or consolidate with any other person or sell or convey all or substantially all of their assets to any one person. MIFSA may redeem all of the 2013 Notes at any time, and some of the 2013 Notes from time to time, at a redemption price equal to the principal amount of the 2013 Notes redeemed plus a make-whole premium. The Company pays interest on the 2013 Notes semiannually in arrears on April 15 th and October 15 th of each year, which commenced on October 15, 2013. In April 2018, the Company's $300.0 million aggregate principal amount of 3.50% senior unsecured notes, which were issued in tandem with the 2013 Notes with similar terms, matured and were repaid with cash on hand. In August 2014, MIFSA and Mallinckrodt CB LLC ("MCB") ("the Issuers") issued $900.0 million aggregate principal amount of 5.75% senior unsecured notes due August 2022 ("the 2022 Notes”). The 2022 Notes are guaranteed by Mallinckrodt plc and each of its subsidiaries that guarantee the obligations under the 2017 Facilities (as defined below). The 2022 Notes are subject to an indenture that contains certain customary covenants and events of default (subject in certain cases to customary grace and cure periods). The occurrence of an event of default under the indenture could result in the acceleration of the 2022 Notes and could cause a cross-default that could result in the acceleration of other indebtedness of Mallinckrodt plc and its subsidiaries. The Issuers may redeem some or all of the 2022 Notes on or after August 1, 2017 at specified redemption prices. The Issuers are obligated to offer to repurchase the 2022 Notes at a price of (a) 101% of their principal amount plus accrued and unpaid interest, if any, as a result of certain change of control events and (b) 100% of their principal amount plus accrued and unpaid interest of net proceeds from certain asset sales. These obligations are subject to certain qualifications and exceptions. The Company pays interest on the 2022 Notes semiannually in arrears on February 1 st and August 1 st of each year, which commenced on February 1, 2015. In April 2015, in connection with the Company's acquisition of Ikaria, Inc. ("Ikaria"), MIFSA and MCB issued $700.0 million aggregate principal amount of 4.875% senior unsecured notes due April 2020 ("the 2020 Notes") and $700.0 million aggregate principal amount of 5.50% senior unsecured notes due April 2025 ("the 2025 Notes", and together with the 2020 Notes, the "Ikaria Notes"). The Ikaria Notes are guaranteed by Mallinckrodt plc and each of its subsidiaries that guarantee the obligations under the 2017 Facilities (as defined below), which following the acquisition of Ikaria includes Compound Holdings II, Inc. (or its successors) and its U.S. subsidiaries. The Ikaria Notes are subject to an indenture that contains certain customary covenants and events of default (subject in certain cases to customary grace and cure periods). The occurrence of an event of default under the indenture could result in the acceleration of the Ikaria Notes and could cause a cross-default that could result in the acceleration of other indebtedness of the Company. The Issuers may redeem some or all of the (i) 2020 Notes prior to April 15, 2017 and (ii) 2025 Notes prior to April 15, 2020, in each case, by paying a “make-whole” premium. The Issuers may redeem some or all of the (i) 2020 Notes on or after April 15, 2017 and (ii) 2025 Notes on or after April 15, 2020, in each case, at specified redemption prices. The Issuers are obligated to offer to repurchase the Ikaria Notes (a) at a price of 101% of their respective principal amount plus accrued and unpaid interest, if any, as a result of certain change of control events and (b) at a price of 100% of their respective principal amount plus accrued and unpaid interest of net proceeds from certain asset sales. These obligations are subject to certain qualifications and exceptions. The Company pays interest on the Ikaria Notes semiannually on April 15 th and October 15 th of each year, which commenced on October 15, 2015. In September 2015, in connection with the Company's acquisition of Therakos, Inc. ("Therakos"), MIFSA and MCB issued $750.0 million aggregate principal amount of 5.625% senior unsecured notes due October 2023 (the “2023 Notes”). The 2023 Notes are guaranteed by Mallinckrodt plc and each of its subsidiaries under the 2017 Facilities (as defined below), which following the acquisition of Therakos, includes TGG Medical Solutions, Inc. (or its successors) and its U.S. subsidiaries. The 2023 Notes are subject to an indenture that contains certain customary covenants and events of default (subject in certain cases to customary grace and cure periods). The occurrence of an event of default under the indenture could result in the acceleration of the 2023 Notes and could cause a cross-default that could result in the acceleration of other indebtedness of the Company. As of October 15, 2018, issuers may call some or all of the 2023 Notes at specified redemption prices. The issuers may also redeem all, but not less than all, of the 2023 Notes at any time at a price of 100% of their principal amount, plus accrued and unpaid interest, if any, in the event the issuers become obligated to pay additional amounts as a result of changes affecting certain withholding tax laws applicable to payments on the 2023 Notes. The Issuers are obligated to offer to repurchase the 2023 Notes (a) at a price of 101% of their principal amount plus accrued and unpaid interest, if any, as a result of certain change of control events and (b) at a price of 100% of their principal amount plus accrued and unpaid interest of net proceeds from certain asset sales. These obligations are subject to certain qualifications and exceptions. The Company pays interest on the 2023 Notes semiannually on April 15 th and October 15 th of each year, which commenced on April 15, 2016. In February 2017, MIFSA and MCB refinanced the March 2014 and August 2014 term loans, both of which were due March 2021 ("the Existing Term Loans"). The Company accounted for the term loan refinancing as a debt modification, which resulted in a $10.0 million charge included within the other expense line in the consolidated statement of income. The refinanced term loan had an initial aggregate principal amount of $1,865.0 million , is due September 2024 and bears interest at London Interbank Offered Rate ("LIBOR") plus 2.75% ("the 2017 Term Loan"). The 2017 Term Loan requires quarterly principal amortization payments in an amount equal to 0.25% of the original principal balance of the 2017 Term Loan, and may be reduced by making optional prepayments. The quarterly principal amortization is payable on the last day of each calendar quarter, which commenced on June 30, 2017, with the remaining balance due September 2024. In January 2018, the Company made a $225.0 million prepayment on the 2017 Term Loan. In making this payment, the Company satisfied certain obligations included within external debt agreements to reinvest proceeds from the sale of assets and businesses within the year of the respective transaction or use the proceeds to pay down debt. In conjunction with the term loan refinancing, MIFSA and MCB entered into a $900.0 million revolving credit facility that matures on February 28, 2022 ("the 2017 Revolving Credit Facility"). The 2017 Revolving Credit Facility bears interest at LIBOR plus 2.25% and contains a $50.0 million letter of credit provision, of which none had been issued as of December 28, 2018. Unused commitments on the 2017 Revolving Credit Facility are subject to an annual commitment fee, which was 0.275% as of December 28, 2018 , and the fee applied to outstanding letters of credit is based on the interest rate applied to borrowings. The 2017 Revolving Credit Facility added certain wholly-owned subsidiaries of the Company as borrowers, in addition to MIFSA and MCB. The 2017 Term Loan and 2017 Revolving Credit Facility (collectively "the 2017 Facilities") are fully and unconditionally guaranteed by Mallinckrodt plc, certain of its direct or indirect wholly-owned U.S. subsidiaries and each of its direct or indirect wholly-owned subsidiaries that owns directly or indirectly any wholly-owned U.S. subsidiaries and certain of its other subsidiaries (collectively, "the Guarantors"). The 2017 Facilities are secured by a security interest in certain assets of MIFSA, MCB and the Guarantors. The 2017 Facilities contain customary affirmative and negative covenants, which include, among other things, restrictions on the Company's ability to declare or pay dividends, create liens, incur additional indebtedness, enter into sale and lease-back transactions, make investments, dispose of assets and merge or consolidate with any other person. On July 28, 2017, Mallinckrodt Securitization S.à r.l. ("Mallinckrodt Securitization"), a wholly-owned special purpose subsidiary of the Company, entered into a $250.0 million accounts receivable securitization facility ("the Receivable Securitization") with a three year term. Mallinckrodt Securitization may, from time to time, obtain up to $250.0 million in third-party borrowings secured by certain receivables. Loans under the Receivable Securitization bear interest (including facility fees) at a rate equal to one month LIBOR rate plus a margin of 0.90% . Unused commitments on the Receivables Securitization are subject to an annual commitment fee of 0.40% . The Receivable Securitization agreements contain customary representations, warranties, and affirmative and negative covenants. The size of the securitization facility may be increased to $300.0 million upon approval of the third-party lenders. In February 2018, in connection with the Sucampo Acquisition, MIFSA and MCB issued a $600.0 million senior secured term loan due February 2025. The variable-rate loan bears an interest rate of LIBOR plus 3.00% basis points and was issued with a discount of 0.25% . The incremental term loan requires quarterly principal amortization payments in an amount equal to 0.25% of the original principal balance of the incremental term loan, and may be reduced by making optional prepayments. The quarterly principal amortization is payable on the last day of each calendar quarter, which commenced on June 30, 2018. As of December 28, 2018 , the applicable interest rate and outstanding borrowings on the Company's variable-rate debt instruments were as follows: Applicable interest rate Outstanding borrowings Term loan due September 2024 5.14 % $ 1,613.8 Term loan due February 2025 5.62 % 597.0 Variable-rate receivable securitization 3.22 % 250.0 Revolving credit facility 4.64 % 220.0 The aggregate amounts of debt maturing during the next five fiscal years are as follows: Fiscal 2019 $ 22.7 Fiscal 2020 972.7 Fiscal 2021 28.2 Fiscal 2022 1,088.2 Fiscal 2023 1,258.6

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 28, 2018
Retirement Benefits [Abstract]
Retirement Plans	15. Retirement Plans Pension Plan Termination On March 31, 2016, the Company terminated six of its previously frozen U.S. pension plans. During fiscal 2017, approximately $212.9 million of obligations and corresponding pension assets were transferred to a third party for settlement of the terminated pension plans through the purchase of annuity contracts. As a result of the settlement, the Company made a $62.3 million cash contribution to the terminated plans and recognized a $70.5 million charge included within other income (expense) during fiscal 2017. During fiscal 2018, the Company received a refund of $3.4 million of the initial cash contribution, recorded as other income (expense), net within the consolidated statement of income. Defined Benefit Plans The Company sponsors a number of defined benefit retirement plans covering certain of its U.S. employees and non-U.S. employees. As of December 28, 2018 , U.S. plans represented 36% of the Company's remaining projected benefit obligation. The Company generally does not provide postretirement benefits other than retirement plan benefits for its employees; however, certain of the Company's U.S. employees participate in postretirement benefit plans that provide medical benefits. These plans are unfunded. The net periodic benefit cost (credit) for the Company's pension and postretirement benefit plans was as follows: Pension Benefits Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, Service cost $ 0.2 $ 1.4 $ 1.8 $ 0.8 Interest cost 0.6 2.3 13.2 2.0 Expected return on plan assets — (1.3 ) (16.7 ) (2.3 ) Amortization of net actuarial loss 0.5 2.7 11.3 3.5 Amortization of prior service cost 0.1 0.2 — 0.1 Loss on plan settlements 0.1 71.1 8.1 45.0 Curtailment gain — (1.0 ) — — Net periodic benefit cost $ 1.5 $ 75.4 $ 17.7 $ 49.1 Postretirement Benefits Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, Service cost $ — $ — $ 0.1 $ 0.1 Interest cost 1.5 1.7 2.0 0.4 Amortization of net actuarial loss 0.1 — — — Amortization of prior service credit (2.1 ) (2.0 ) (2.1 ) (0.5 ) Gain on plan settlements (0.7 ) (0.9 ) — — Net periodic benefit credit $ (1.2 ) $ (1.2 ) $ — $ — The following table represents the changes in benefit obligations, plan assets and the net amounts recognized on the consolidated balance sheets for pension and postretirement benefit plans at the end of each period: Pension Benefits Postretirement Benefits December 28, December 29, December 28, December 29, Change in benefit obligations: Projected benefit obligations at beginning of year $ 27.8 $ 257.4 $ 45.6 $ 47.5 Service cost 0.2 1.4 — — Interest cost 0.6 2.3 1.5 1.7 Actuarial loss (gain) 0.7 (9.0 ) (3.9 ) 0.2 Benefits and administrative expenses paid (1.6 ) (9.4 ) (2.7 ) (2.9 ) Plan settlements (0.8 ) (217.0 ) (0.7 ) (0.9 ) Currency translation (0.8 ) 2.1 — — Projected benefit obligations at end of year 26.1 27.8 39.8 45.6 Change in plan assets: Fair value of plan assets at beginning of year — 161.0 — — Actual return on plan assets — 0.3 — — Employer contributions 2.4 68.0 2.7 2.9 Benefits and administrative expenses paid (1.6 ) (9.4 ) (2.7 ) (2.9 ) Plan settlements (0.8 ) (217.0 ) — — Net transfer out — (2.9 ) — — Fair value of plan assets at end of year — — — — Funded status at end of year $ (26.1 ) $ (27.8 ) $ (39.8 ) $ (45.6 ) Pension Benefits Postretirement Benefits December 28, December 29, December 28, December 29, Amounts recognized on the consolidated balance sheet: Current liabilities $ (2.0 ) $ (2.4 ) $ (3.4 ) $ (3.9 ) Non-current liabilities (24.1 ) (25.4 ) (36.4 ) (41.7 ) Net amount recognized on the consolidated balance sheet $ (26.1 ) $ (27.8 ) $ (39.8 ) $ (45.6 ) Amounts recognized in accumulated other comprehensive loss consist of: Net actuarial (loss) gain $ (8.4 ) $ (8.6 ) $ 0.9 $ (3.0 ) Prior service (cost) credit (0.4 ) (0.5 ) 8.1 10.2 Net amount recognized in accumulated other comprehensive loss $ (8.8 ) $ (9.1 ) $ 9.0 $ 7.2 The estimated amounts that will be amortized from accumulated other comprehensive loss into net periodic benefit cost (credit) in fiscal 2019 are as follows: Pension Benefits Postretirement Benefits Amortization of net actuarial loss $ 0.5 $ — Amortization of prior service cost (credit) 0.1 (2.1 ) December 28, December 29, Pension plans with accumulated benefit obligations in excess of plan assets: Accumulated benefit obligation $ 25.6 $ 27.3 The accumulated benefit obligation for pension plans with projected benefit obligations in excess of plan assets do not significantly differ from the amounts in the table above since all of the Company's U.S. pension plans are frozen. Actuarial Assumptions Weighted-average assumptions used each period to determine net periodic benefit cost for the Company's pension plans are as follows: U.S. Plans Non-U.S. Plans Fiscal Year Ended Three Months Ended Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Discount rate 3.3 % 3.0 % 3.9 % 2.2 % 1.9 % 1.8 % 2.0 % 1.3 % Expected return on plan assets — % 3.5 % 5.8 % 3.5 % — % — % 2.0 % — % Rate of compensation increase — % — % — % — % 2.5 % 2.5 % — % — % Weighted-average assumptions used each period to determine benefit obligations for the Company's pension plans are as follows: U.S. Plans Non-U.S. Plans Fiscal Year Ended Three Months Ended Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Discount rate 4.0 % 3.3 % 2.3 % 3.0 % 2.0 % 1.9 % 1.3 % 1.8 % Rate of compensation increase — % — % — % — % 2.5 % 2.5 % — % 0.3 % For the Company's unfunded U.S. plans, the discount rate is based on the market rate for a broad population of AA-rated (Moody's or S&P) corporate bonds over $250.0 million . For the Company's U.S. plans that were funded in prior periods, the discount rate was based on the estimated final settlement discount rates based on quotes received from a group of well-rated insurance carriers who are active in the single premium group annuity marketplace. The group of insurance carriers are rated A or better by AM best. Prior to the settlement of the funded U.S. plans in fiscal 2017, the Company determined the expected return on pension plan assets, through its considerations of the relative weighting of plan assets by class and individual asset class performance expectations as provided by external advisors in reaching conclusions on appropriate assumptions. The investment strategy for the pension plans was to obtain a long-term return on plan assets that was consistent with the level of investment risk that was considered appropriate. Investment risks and returns were reviewed regularly against benchmarks to ensure objectives were being met. The weighted-average discount rate used to determine net periodic benefit cost and obligations for the Company's postretirement benefit plans are as follows: Fiscal Year Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Net periodic benefit cost 3.4 % 3.7 % 4.0 % 3.2 % Benefit obligations 4.1 % 3.4 % 3.2 % 3.8 % Healthcare cost trend assumptions for postretirement benefit plans are as follows: December 28, December 29, Healthcare cost trend rate assumed for next fiscal year 6.3 % 6.9 % Rate to which the cost trend rate is assumed to decline 4.5 % 4.5 % Fiscal year the ultimate trend rate is achieved 2038 2038 A one-percentage-point change in assumed healthcare cost trend rates would have the following effects: One-Percentage-Point Increase One-Percentage-Point Decrease Effect on total of service and interest cost $ — $ — Effect on postretirement benefit obligation 0.2 (0.2 ) Contributions The Company's funding policy is to make contributions in accordance with the laws and customs of the various countries in which the Company operates, as well as to make discretionary voluntary contributions from time to time. In fiscal 2018 and 2017, the Company made $2.4 million and $68.0 million in contributions, respectively, to the Company's pension plans. The fiscal 2017 contribution included additional payments to settle the terminated plans. Expected Future Benefit Payments Benefit payments expected to be paid, reflecting future expected service as appropriate, are as follows: Pension Benefits Postretirement Benefits Fiscal 2019 $ 2.0 $ 3.5 Fiscal 2020 1.7 3.4 Fiscal 2021 1.7 3.2 Fiscal 2022 1.6 3.1 Fiscal 2023 1.6 3.0 Fiscal 2024 - 2028 7.4 13.4 Defined Contribution Retirement Plans The Company maintains one active tax-qualified 401(k) retirement plan and one active non-qualified deferred compensation plan in the U.S. The 401(k) retirement plan provides for an automatic Company contribution of three percent of an eligible employee's pay, with an additional Company matching contribution generally equal to 50% of each employee's elective contribution to the plan up to six percent of the employee's eligible pay. The deferred compensation plan permits eligible employees to defer a portion of their compensation. Total defined contribution expense related to continuing operations was $25.3 million , $25.2 million , $25.3 million and $4.2 million for fiscal 2018 , 2017 , 2016 and the three months ended December 30, 2016, respectively. Rabbi Trusts and Other Investments The Company maintains several rabbi trusts, the assets of which are used to pay retirement benefits. The rabbi trust assets are subject to the claims of the Company's creditors in the event of the Company's insolvency. Plan participants are general creditors of the Company with respect to these benefits. The trusts primarily hold life insurance policies and debt and equity securities, the value of which is included in other assets on the consolidated balance sheets. Note 21 provides additional information regarding the debt and equity securities. The carrying value of the 118 life insurance contracts held by these trusts was $58.4 million and $58.1 million at December 28, 2018 and December 29, 2017 , respectively. These contracts had a total death benefit of $142.9 million and $145.8 million at December 28, 2018 and December 29, 2017 , respectively. However, there are outstanding loans against the policies amounting to $43.8 million and $44.5 million at December 28, 2018 and December 29, 2017 , respectively. The Company has insurance contracts which serve as collateral for certain of the Company's non-U.S. pension plan benefits, which totaled $8.0 million and $8.8 million at December 28, 2018 and December 29, 2017

Equity Equity

Equity Equity	12 Months Ended
	Dec. 28, 2018
Equity [Abstract]
Stockholders' Equity Note Disclosure	16. Equity Preferred Shares Mallinckrodt is authorized to issue 500,000,000 preferred shares, par value of $0.20 per share, none of which were issued or outstanding at December 28, 2018 . Rights as to dividends, return of capital, redemption, conversion, voting and otherwise with respect to these shares may be determined by Mallinckrodt's Board of Directors on or before the time of issuance. In the event of the liquidation of the Company, the holders of any preferred shares then outstanding would, if issued on such terms that they carry a preferential distribution entitlement on liquidation, be entitled to payment to them of the amount for which the preferred shares were subscribed and any unpaid dividends prior to any payment to the ordinary shareholders. Share Repurchases From time to time, the Company's Board of Directors have authorized share repurchase programs. The details of such programs are as follows: March 2017 Repurchase Program March 2016 November 2015 Repurchase Program January 2015 Repurchase Program Number of Shares Amount Number of Shares Amount Number of Shares Amount Number of Shares Amount Authorized repurchase amount $ 1,000.0 $ 350.0 $ 500.0 $ 300.0 Repurchases: Fiscal 2015 — — — — — — 823,592 75.0 Fiscal 2016 — — — — 6,510,824 425.6 3,199,279 225.0 Three months ended December 30, 2016 — — 1,501,676 84.0 1,063,337 74.4 — — Fiscal 2017 13,490,448 380.6 5,366,741 266.0 — — — — Fiscal 2018 3,610,968 55.2 — — — — — — Remaining amount available $ 564.2 $ — $ — $ — The March 2017 Program has no time limit or expiration date, and the Company currently expects to fully utilize the program. The Company also repurchases shares from certain employees in order to satisfy employee tax withholding requirements in connection with the vesting of restricted shares. In addition, the Company repurchases shares to settle certain option exercises. The Company spent zero , $5.1 million , $2.3 million and $0.4 million to acquire shares in connection with equity-based awards in fiscal 2018, 2017, 2016 and the three months ended December 30, 2016, respectively. Treasury Shares During December 2017, the Company canceled approximately 26.5 million treasury shares. Irish law requires a company's treasury share value to represent less than 10% of Company capital. The cancellation of treasury shares had a net zero impact on shareholders' equity as $5.3 million

Share Plans

Share Plans	12 Months Ended
	Dec. 28, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Plans	17. Share Plans Total share-based compensation cost from continuing operations was $34.6 million , $58.5 million , $41.4 million and $10.6 million for fiscal 2018 , 2017 , 2016 and the three months ended December 30, 2016, respectively. These amounts are generally included within SG&A expenses in the consolidated statements of income. The Company recognized a related tax benefit associated with this expense of zero , $11.0 million , $13.1 million and $3.6 million in fiscal 2018 , 2017 , 2016 and the three months ended December 30, 2016, respectively. During fiscal 2017, the $11.0 million tax benefit was comprised of $16.0 million associated with amortization and net stock exercises, partially offset by $5.0 million associated with U.S. Tax Reform re-measurement. Stock Compensation Plans The Company has adopted and amended its Mallinckrodt Pharmaceuticals Stock and Incentive Plan over the years which provides for the award of share options, share appreciation rights, annual performance bonuses, long-term performance awards, restricted units, restricted shares, deferred share units, promissory shares and other share-based awards (collectively, "Awards"). The maximum number of common shares to be issued as Awards, subject to adjustment as provided under the terms of the respective plans are as follows: Maximum Number of Common Shares to be Issued as Awards (in millions) 2013 Plan 5.7 2015 Plan 17.8 2018 Plan 26.8 As of December 28, 2018 , all equity awards held by the Company's employees were converted from equity awards issued by Questcor Pharmaceuticals, Inc. ("Questcor"), acquired during fiscal 2014, or granted under the aforementioned plans. Share options. Share options are granted to purchase the Company's ordinary shares at prices that are equal to the fair market value of the shares on the date the share option is granted. Share options generally vest in equal annual installments over a period of four years and expire ten years after the date of grant. The grant-date fair value of share options, adjusted for estimated forfeitures, is recognized as expense on a straight-line basis over the requisite service period, which is generally the vesting period. Forfeitures are estimated based on historical experience. Share option activity and information is as follows: Share Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at September 25, 2015 2,786,443 $ 52.76 Granted 1,248,828 72.44 Exercised (413,830 ) 32.76 Expired/Forfeited (199,585 ) 72.65 Outstanding at September 30, 2016 3,421,856 61.17 Granted 3,742 60.01 Exercised (16,382 ) 36.42 Expired/Forfeited (22,522 ) 70.82 Outstanding at December 30, 2016 3,386,694 61.24 Granted 1,719,532 51.57 Exercised (113,605 ) 47.74 Expired/Forfeited (348,637 ) 68.08 Outstanding at December 29, 2017 4,643,984 57.78 Granted 3,159,521 13.92 Exercised (39,949 ) 32.00 Expired/Forfeited (756,505 ) 52.63 Outstanding at December 28, 2018 7,007,051 38.74 4.8 $ 6.5 Vested and non-vested expected to vest as of December 28, 2018 6,114,782 39.94 7.6 $ 5.5 Exercisable at December 28, 2018 2,414,968 55.24 4.9 0.1 As of December 28, 2018 , there was $29.6 million of total unrecognized compensation cost related to non-vested share option awards, which is expected to be recognized over a weighted-average period of 2.4 years. The grant-date fair value of share options has been estimated using the Black-Scholes pricing model. Use of a valuation model requires management to make certain assumptions with respect to selected model inputs. The expected volatility assumption is based on the historical and implied volatility of the Company's peer group with similar business models. The expected life assumption is based on the contractual and vesting term of the share option, employee exercise patterns and employee post-vesting termination behavior. The expected annual dividend per share is based on the Company's current intentions regarding payment of cash dividends. The risk-free interest rate is based on U.S. Treasury zero-coupon issues with a remaining term equal to the expected life assumed at the date of grant. The weighted-average assumptions used in the Black-Scholes pricing model for shares granted in fiscal 2018 , 2017 , 2016 and the three months ended December 30, 2016, along with the weighted-average grant-date fair value, were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Expected share price volatility 38 % 36 % 31 % 35 % Risk-free interest rate 2.64 % 2.00 % 1.74 % 1.23 % Expected annual dividend per share — % — % — % — % Expected life of options (in years) 5.3 5.3 5.3 5.3 Fair value per option $ 5.32 $ 18.36 $ 22.82 $ 20.04 In fiscal 2018 , 2017 , 2016 and the three months ended December 30, 2016, the total intrinsic value of options exercised was $0.2 million , $1.4 million , $15.3 million and $0.3 million , respectively, and the related tax benefit was $0.1 million , $0.5 million , $5.7 million and $0.1 million , respectively. Restricted share units. Recipients of restricted share units ("RSUs") have no voting rights and receive dividend equivalent units which vest upon the vesting of the related shares. RSUs generally vest in equal annual installments over a period of four years. Restrictions on RSUs lapse upon normal retirement, death or disability of the employee. The grant-date fair value of RSUs, adjusted for estimated forfeitures, is recognized as expense on a straight-line basis over the service period. The fair market value of RSUs granted is determined based on the market value of the Company's shares on the date of grant for periods after the Company's separation from Covidien plc ("Covidien") in fiscal 2013. RSU activity is as follows: Shares Weighted-Average Non-vested at September 25, 2015 572,494 $ 73.45 Granted 615,074 70.10 Vested (193,849 ) 69.27 Expired/Forfeited (99,260 ) 79.95 Non-vested at September 30, 2016 894,459 70.40 Granted 36,731 69.08 Exercised (30,919 ) 47.54 Expired/Forfeited (16,809 ) 49.62 Non-vested at December 30, 2016 883,462 71.03 Granted 655,282 50.74 Exercised (263,189 ) 69.14 Expired/Forfeited (169,789 ) 68.57 Non-vested at December 29, 2017 1,105,766 60.08 Granted 1,222,568 14.58 Exercised (433,354 ) 57.93 Expired/Forfeited (209,879 ) 44.38 Non-vested at December 28, 2018 1,685,101 29.54 The total fair value of Mallinckrodt RSU awards granted during fiscal 2018 was $17.8 million . The total vest date fair value of Mallinckrodt RSUs vested during fiscal 2018 was $25.1 million . As of December 28, 2018 , there was $29.6 million of total unrecognized compensation cost related to non-vested restricted share units granted. The cost is expected to be recognized over a weighted-average period of 2.2 years . Performance share units. Similar to recipients of RSUs, recipients of performance share units ("PSUs") have no voting rights and receive dividend equivalent units. The grant-date fair value of PSUs, adjusted for estimated forfeitures, is generally recognized as expense on a straight-line basis from the grant-date through the end of the performance period. The vesting of PSUs and related dividend equivalent units is generally based on various performance metrics and relative total shareholder return (total shareholder return for the Company as compared to total shareholder return of the PSU peer group), measured over a three year performance period. The PSU peer group is comprised of various healthcare companies which attempts to replicate the Company’s mix of businesses. Depending on Mallinckrodt's relative performance during the performance period, a recipient of the award is entitled to receive a number of ordinary shares equal to a percentage, ranging from 0% to 200% , of the award granted. PSU activity is as follows (1) : Shares Weighted-Average Non-vested at September 25, 2015 130,974 $ 96.05 Granted 145,192 83.00 Forfeited (9,521 ) 96.30 Non-vested at September 30, 2016 266,645 88.59 Forfeited (997 ) 154.42 Non-vested at December 30, 2016 265,648 88.51 Granted 348,963 51.73 Forfeited (48,606 ) 107.00 Vested (61,554 ) 62.65 Non-vested at December 29, 2017 504,451 64.44 Granted 770,714 13.80 Forfeited (89,614 ) 59.18 Vested (24,022 ) 98.27 Non-vested at December 28, 2018 1,161,529 28.61 (1) The number of shares disclosed within this table are at the target number of 100%. The Company generally uses the Monte Carlo model to estimate the probability of satisfying the performance criteria and the resulting fair value of PSU awards. The assumptions used in the Monte Carlo model for PSUs granted during each year were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Expected stock price volatility 57 % 48 % 41 % 48 % Peer group stock price volatility 39 % 40 % 36 % 40 % Correlation of returns 2 % 17 % 24 % 17 % The weighted-average grant-date fair value per share of PSUs granted was $13.80 in fiscal 2018 . As of December 28, 2018 , there was $12.6 million of unrecognized compensation cost related to PSUs, which is expected to be recognized over a weighted-average period of 1.9 years. Restricted stock awards. Recipients of restricted stock awards ("RSAs") pertain solely to converted awards from Questcor, which were converted at identical terms to their original award. The converted RSAs maintain voting rights and a non-forfeitable right to receive dividends. RSAs were subject to accelerated vesting as prescribed by the terms of the original award based on a change in control, and all of which have vested as of December 28, 2018. Restrictions on RSAs lapse upon normal retirement, death or disability of the employee. The grant-date fair value of RSAs, adjusted for estimated forfeitures, was recognized as expense on a straight-line basis over the service period. The weighted average grant-date fair value per share was $70.88 . Shares Non-vested at September 25, 2015 34,562 Vested (9,760 ) Forfeited (7,936 ) Non-vested at September 30, 2016 16,866 Vested (1,087 ) Forfeited (911 ) Non-vested at December 30, 2016 14,868 Vested (7,970 ) Forfeited (2,223 ) Non-vested at December 29, 2017 4,675 Vested (3,970 ) Forfeited (705 ) Non-vested at December 28, 2018 — The total vest date fair value of Mallinckrodt restricted share awards vested during fiscal 2018 was $0.2 million . Employee Stock Purchase Plans Effective March 16, 2016, upon approval by the shareholders of Mallinckrodt, the Company adopted a new qualified Mallinckrodt Employee Stock Purchase Plan ("ESPP"). Substantially all full-time employees of the Company's U.S. subsidiaries and employees of certain qualified non-U.S. subsidiaries are eligible to participate in the ESPP. Eligible employees authorize payroll deductions to be made to purchase shares at 15% below the market price at the beginning or end of an offering period. Employees are eligible to authorize withholdings such that purchases of shares may amount to $25,000 of fair market value for each calendar year as prescribed by the Internal Revenue Code Section 423. Mallinckrodt has elected to deliver shares under the period by utilizing treasury stock accumulated by the Company. Prior to the first offering period of the ESPP (July 1, 2016), the Company maintained a non-qualified employee stock purchase plan ("the Old ESPP"). Substantially all full-time employees of the Company's U.S. subsidiaries and employees of certain qualified non-U.S. subsidiaries were eligible to participate in the Old ESPP. Eligible employees authorized payroll deductions to be made for the purchase of shares. The Company matched a portion of the employee contribution by contributing an additional 15% ( 25% in fiscal 2015) of the employee's payroll deduction up to a $25,000

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 28, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income	18. Accumulated Other Comprehensive Loss The components of accumulated other comprehensive loss are as follows: Currency Translation Unrecognized Loss on Derivatives Unrecognized (Loss) Gain on Benefit Plans Unrecognized Gain on Equity Securities (1) Accumulated Other Comprehensive Loss (1) Balance at December 30, 2016 $ (19.5 ) $ (5.7 ) $ (47.3 ) $ — $ (72.5 ) Other comprehensive income, net 16.0 — 5.2 1.5 22.7 Reclassification from other comprehensive (loss) income (4.7 ) 1.0 40.6 (1.5 ) 35.4 Balance at December 29, 2017 (8.2 ) (4.7 ) (1.5 ) — (14.4 ) Other comprehensive (loss) income, net (12.2 ) — 3.1 — (9.1 ) Reclassification from other comprehensive income (loss) — 0.7 (1.5 ) — (0.8 ) Balance at December 28, 2018 $ (20.4 ) $ (4.0 ) $ 0.1 $ — $ (24.3 ) (1) Upon adoption of ASU 2016-01, a reclassification of $1.5 million relating to the unrealized gain on investment resulted in an increase to beginning retained earnings with an offsetting decrease to accumulated other comprehensive loss. See Note 4 for additional details. The following summarizes reclassifications from accumulated other comprehensive loss: Amount Reclassified From Accumulated Other Comprehensive Loss December 28, 2018 December 29, 2017 Line Item in the Consolidated Currency translation $ — $ (4.7 ) Amortization of unrealized loss on derivatives 0.9 1.3 Interest expense Income tax provision (0.2 ) (0.3 ) Provision for income taxes Net of income taxes 0.7 1.0 Amortization of pension and post-retirement benefit plans: Net actuarial loss 0.6 2.7 (1) Prior service credit (2.0 ) (1.9 ) (1) Disposal of discontinued operations — (3.1 ) Plan settlements (0.6 ) 70.2 (1) Total before tax (2.0 ) 67.9 Income tax effect 0.5 (27.3 ) Provision for income taxes Net of income taxes (1.5 ) 40.6 Recognized gain on equity securities (2) — (1.5 ) Total reclassifications for the period $ (0.8 ) $ 35.4 (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 15 for additional details. (2) Upon adoption of ASU 2016-01, a reclassification of $1.5 million	[1]
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 15 for additional details.

Guarantees

Guarantees	12 Months Ended
	Dec. 28, 2018
Guarantees [Abstract]
Guarantees	19. Guarantees In disposing of assets or businesses, the Company has from time to time provided representations, warranties and indemnities to cover various risks and liabilities, including unknown damage to the assets, environmental risks involved in the sale of real estate, liability to investigate and remediate environmental contamination at waste disposal sites and manufacturing facilities, and unidentified tax liabilities related to periods prior to disposition. The Company assesses the probability of potential liabilities related to such representations, warranties and indemnities and adjusts potential liabilities as a result of changes in facts and circumstances. The Company believes, given the information currently available, that the ultimate resolution will not have a material adverse effect on its financial condition, results of operations and cash flows. In connection with the sale of the Specialty Chemical business (formerly known as Mallinckrodt Baker) in fiscal 2010, the Company agreed to indemnify the purchaser with respect to various matters, including certain environmental, health, safety, tax and other matters. The indemnification obligations relating to certain environmental, health and safety matters have a term of 17 years from the sale, while some of the other indemnification obligations have an indefinite term. The amount of the liability relating to all of these indemnification obligations included in other liabilities on the Company's consolidated balance sheets at December 28, 2018 and December 29, 2017 was $14.6 million and $14.9 million , of which $11.8 million and $12.1 million , respectively, related to environmental, health and safety matters. The value of the environmental, health and safety indemnity was measured based on the probability-weighted present value of the costs expected to be incurred to address environmental, health and safety claims made under the indemnity. The aggregate fair value of these indemnification obligations did not differ significantly from their aggregate carrying value at December 28, 2018 and December 29, 2017 . As of December 28, 2018 , the maximum future payments the Company could be required to make under these indemnification obligations was $70.2 million . The Company was required to pay $30.0 million into an escrow account as collateral to the purchaser, of which $18.6 million and $18.3 million remained in other assets on the consolidated balance sheets at December 28, 2018 and December 29, 2017 , respectively. The Company has recorded liabilities for known indemnification obligations included as part of environmental liabilities, which are discussed in Note 20. In addition, the Company is liable for product performance; however the Company believes, given the information currently available, that their ultimate resolution will not have a material adverse effect on its financial condition, results of operations and cash flows. As of December 28, 2018 , the Company had various other letters of credit and guarantee and surety bonds totaling $38.7 million .

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 28, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	20. Commitments and Contingencies The Company has purchase obligations related to commitments to purchase certain goods and services. At December 28, 2018 , such obligations were as follows: Fiscal 2019 $ 110.3 Fiscal 2020 43.5 Fiscal 2021 2.2 Fiscal 2022 2.1 Fiscal 2023 1.7 The Company is subject to various legal proceedings and claims, including patent infringement claims, product liability matters, personal injury, environmental matters, employment disputes, contractual disputes and other commercial disputes, including those described below. The Company believes that these legal proceedings and claims likely will be resolved over an extended period of time. Although it is not feasible to predict the outcome of these matters, the Company believes, unless indicated below, given the information currently available, that their ultimate resolution will not have a material adverse effect on its financial condition, results of operations and cash flows. Governmental Proceedings Opioid Related Matters Since 2017, multiple U.S. states, counties, other governmental persons or entities and private plaintiffs have filed lawsuits against certain Mallinckrodt entities, as well as various other manufacturers, distributors, pharmacies, pharmacy benefit managers, individual doctors and/or others, asserting claims relating to defendants’ alleged sales, marketing, distribution, reimbursement, prescribing, dispensing and/or other practices with respect to prescription opioid medications, including certain of the Company's products. As of February 26, 2019, the cases of which the Company is aware include, but are not limited to, approximately 1,487 cases filed by counties, cities, Native American tribes and/or other government-related persons or entities; approximately 104 cases filed by hospitals, health systems, unions, health and welfare funds or other third-party payers; approximately 15 cases filed by individuals and 6 cases filed by the Attorneys General for New Mexico, Kentucky, Rhode Island. Georgia, Florida, and Alaska. Certain of the lawsuits have been filed as putative class actions. Many of the lawsuits have been coordinated in a federal multi-district litigation (“MDL”) pending in the U.S. District Court for the Northern District of Ohio. The MDL court has issued a series of case management orders permitting motion practice addressing threshold legal issues in certain cases, allowing discovery and setting a trial date in October 2019 for two cases originally filed in the Northern District of Ohio. Other lawsuits remain pending in various state courts. In some jurisdictions, such as Connecticut, Illinois, New York, Pennsylvania and Texas, certain state court cases have been coordinated for pretrial proceedings before a single court within their respective state court systems. State cases are generally at the pleading and/or discovery stage. The lawsuits assert a variety of claims, including, but not limited to, public nuisance, negligence, civil conspiracy, fraud, violations of the Racketeer Influenced and Corrupt Organizations Act (“RICO”) or similar state laws, violations of state Controlled Substances Acts or state False Claims Acts, product liability, consumer fraud, unfair or deceptive trade practices, false advertising, insurance fraud, unjust enrichment and other common law and statutory claims arising from defendants’ manufacturing, distribution, marketing and promotion of opioids and seek restitution, damages, injunctive and other relief and attorneys’ fees and costs. The claims generally are based on alleged misrepresentations and/or omissions in connection with the sale and marketing of prescription opioid medications and/or an alleged failure to take adequate steps to prevent abuse and diversion. The Company intends to vigorously defend itself against these lawsuits and similar lawsuits that may be brought by others. Since these lawsuits are in early stages, the Company is unable to predict outcomes or estimate a range of reasonably possible losses. In addition to the lawsuits described above, certain Mallinckrodt entities have received subpoenas and civil investigative demands ("CID(s)") for information concerning the sale, marketing and/or distribution of prescription opioid medications, including from U.S. Department of Justice ("DOJ") and the Attorneys General for Missouri, New Hampshire, Kentucky, Washington, Alaska, South Carolina, Puerto Rico and New York. Our Company has been contacted by the coalition of State Attorneys General investigating the role manufacturers and distributors may have had in contributing to the increased use of opioids in the U.S. On January 27, 2018, the Company received a grand jury subpoena from the U.S. Attorneys’ Office (“USAO”) for the Southern District of Florida for documents related to the distribution, marketing and sale of generic oxymorphone products. The Company is in the process of responding to these subpoenas, CIDs and any informal requests for documents. On August 2, 2018, Energy and Commerce Committee leaders in the U.S. House of Representatives sent a letter to one of Mallinckrodt's subsidiaries requesting information about that subsidiary’s efforts to monitor opioid sales for suspicious orders. The subsidiary has responded to this letter. Similar subpoenas and investigations may be brought by others or the foregoing matters may be expanded or result in litigation. Since these investigations are in early stages, we are unable to predict outcomes or estimate a range of reasonably possible losses. New York State Opioid Stewardship Act . On October 24, 2018, the Company filed suit in the United States District Court for the Southern District of New York against the State of New York, asking the court to declare New York State’s Opioid Stewardship Act (“OSA”) unconstitutional and to enjoin its enforcement. On December 19, 2018, the court declared the OSA unconstitutional and granted the Company’s motion for preliminary injunctive relief. On January 17, 2019, the State of New York appealed the Court’s decision. The Company intends to vigorously assert its position in this matter. DEA Investigation. In November 2011 and October 2012, the Company received subpoenas from the U.S. Drug Enforcement Administration ("DEA") requesting production of documents relating to its suspicious order monitoring program for controlled substances. The USAO for the Eastern District of Michigan investigated the possibility that the Company failed to report suspicious orders of controlled substances during the period 2006-2011 in violation of the Controlled Substances Act and its related regulations. The USAO for the Northern District of New York and Office of Chief Counsel for the U.S. DEA investigated the possibility that the Company failed to maintain appropriate records and security measures with respect to manufacturing of certain controlled substances at its Hobart facility during the period 2012-2013. In July 2017, the Company entered into a final settlement with the DEA and the USAOs for Eastern District of Michigan and the Northern District of New York to settle these investigations. As part of the agreement, the Company paid $35.0 million to resolve all potential claims and agreed, as part of a Memorandum of Agreement (“MOA”), to utilize all available transaction information to identify suspicious orders of any Mallinckrodt controlled substance product and to report to the DEA when it concludes that chargeback data or other information indicates that a downstream registrant poses a risk of diversion, among other things. The MOA remains in effect until July 10, 2020. Other Matters U.S. House Committee Investigation. In January 2019, the Company along with 11 other pharmaceutical companies, received a letter from the U.S. House Committee on Oversight and Reform requesting information relating to the Company's pricing strategy for H.P. Acthar Gel and related matters. The Company is cooperating with the Committee investigation. Florida Civil Investigative Demand. In February 2019, the Company received a CID from the U.S. Attorney’s Office for the Middle District of Florida. The demand relates to documents related to alleged payments to healthcare providers in Florida and whether those payments violated the Anti-Kickback Statute. The Company is in the process of responding to this demand for documents and intends to cooperate with the investigation. Boston Civil Investigative Demand. In January 2019, the Company received a CID from the U.S. Attorney’s Office for the District of Massachusetts for documents related to the Company’s participation in the Medicaid Drug Rebate Program. The Company is in the process of responding to this demand for documents, and intends to cooperate with the investigation. Generic Pricing Subpoena. In March 2018, the Company received a grand jury subpoena issued by the U.S. District Court for the Eastern District of Pennsylvania pursuant to which the Antitrust Division of the DOJ is seeking documents regarding generic products and pricing, communications with generic competitors and other related matters. The Company is in the process of responding to this subpoena, and the Company intends to cooperate fully in the investigation. Boston Subpoena. In December 2016, the Company received a subpoena from the USAO for the District of Massachusetts for documents related to the Company’s provision of financial and other support to patients, including through charitable foundations, and related matters. The Company is in the process of responding to this subpoena, and the Company intends to cooperate fully in the investigation. Texas Pricing Investigation. In November 2014, the Company received a CID from the Civil Medicaid Fraud Division of the Texas Attorney General's Office. According to the CID, the Attorney General's office is investigating the possibility of false reporting of information by the Company regarding the prices of certain of its drugs used by Texas Medicaid to establish reimbursement rates for pharmacies that dispensed the Company's drugs to Texas Medicaid recipients. The Company responded to these requests. In December 2018, the Company entered into a final settlement with the Texas Attorney General's Office to resolve all potential claims in the investigation and recorded a corresponding expense, which is included in SG&A in the consolidated statement of income. MNK 2011 Inc. (formerly known as Mallinckrodt Inc.) v. U.S. Food and Drug Administration and United States of America. In November 2014, the FDA reclassified the Company's Methylphenidate ER in the Orange Book: Approved Drug Products with Therapeutic Equivalence ("the Orange Book"). In November 2014, the Company filed a Complaint in the U.S. District Court for the District of Maryland Greenbelt Division against the FDA and the United States (the "MD Complaint") for judicial review of the FDA’s reclassification. In July 2015, the court granted the FDA's motion to dismiss with respect to three of the five counts in the MD Complaint and granted summary judgment in favor of the FDA with respect to the two remaining counts (the “MD Order”). On October 18, 2016, the FDA initiated proceedings, proposing to withdraw approval of the Company's Abbreviated New Drug Applications ("ANDA") for Methylphenidate ER. On October 21, 2016, the United States Court of Appeals for the Fourth Circuit issued an order placing the Company’s appeal of the MD Order in abeyance pending the outcome of the withdrawal proceedings. The parties exchanged documents and in April 2018, the Company filed its submission in support of its position in the withdrawal proceedings. A potential outcome of the withdrawal proceedings is that the Company's Methylphenidate ER products may lose their FDA approval and have to be withdrawn from the market. FTC Investigation. In June 2014, Questcor received a subpoena and CID from the Federal Trade Commission ("FTC") seeking documentary materials and information regarding the FTC's investigation into whether Questcor's acquisition of certain rights to develop, market, manufacture, distribute, sell and commercialize MNK-1411 (the product formerly described as Synacthen Depot ® ) from Novartis AG and Novartis Pharma AG (collectively, "Novartis") violates antitrust laws. Subsequently, California, Maryland, Texas, Washington, New York and Alaska (collectively, "the Investigating States") commenced similar investigations focused on whether the transaction violates state antitrust laws. On January 17, 2017, the FTC, all Investigating States (except California) ("the Settling States") and the Company entered into an agreement to resolve this matter for a one-time cash payment of $102.0 million and an agreement to license MNK-1411 to a third party designated by the FTC for possible development in Infantile Spasms ("IS") and Nephrotic Syndrome ("NS") in the U.S. To facilitate that settlement, a complaint was filed on January 18, 2017, in the U.S. District Court for the District of Columbia. The settlement was approved by the court on January 30, 2017. On July 16, 2017, the Company announced the completion of the U.S. license of both the Synacthen trademark and certain intellectual property associated with MNK-1411 to West Pharmaceuticals to develop and pursue possible FDA approval of the product in IS and NS. The Company retains the right to develop MNK-1411 for all other indications in the U.S. and retains rights to the Synacthen trademark outside the U.S. Therakos Subpoena. In March 2014, the USAO for the Eastern District of Pennsylvania requested the production of documents related to an investigation of the U.S. promotion of Therakos’ drug/device system UVADEX/UVAR XTS and UVADEX/CELLEX (collectively, the "Therakos System"), for indications not approved by the FDA, including treatment of patients with graft versus host disease ("GvHD") and solid organ transplant patients, including pediatric patients. The investigation also includes Therakos’ efforts to secure FDA approval for additional uses of, and alleged quality issues relating to, UVADEX/UVAR. In August 2015, the USAO for the Eastern District of Pennsylvania sent Therakos a subsequent request for documents related to the investigation and has since made certain related requests. The Company responded to these requests, and continues to cooperate fully in the investigation. Questcor Subpoena. In September 2012, Questcor received a subpoena from the USAO for the Eastern District of Pennsylvania for information relating to its promotional practices related to H.P. Acthar Gel. Questcor was also informed by the USAO for the Eastern District of Pennsylvania that the USAO for the Southern District of New York and the SEC were participating in the investigation to review Questcor's promotional practices and related matters related to H.P. Acthar Gel. On March 9, 2015, the Company received a "No Action" letter from the SEC regarding its review of the Company's promotional practices related to H.P. Acthar Gel. The Company intends to cooperate fully in the investigation. Patent Litigation Amitiza Patent Litigation: Sun Pharmaceutical Industries, Ltd. and Sun Pharmaceutical Industries, Inc. In October 2018, Sucampo AG, Sucampo Pharmaceuticals, Inc. and Sucampo Pharma LLC, all subsidiaries of the Company, and Takeda Pharmaceutical Company Limited, Takeda Pharmaceuticals USA, Inc., and Takeda Pharmaceuticals America, Inc. (collectively "Takeda," the exclusive licensee under the patents in litigation) filed suit in the U.S. District Court for the District of New Jersey against Sun Pharmaceutical Industries, Ltd. and Sun Pharmaceutical Industries, Inc. (collectively “Sun”) alleging that Sun infringed U.S. Patent Nos. 7,795,312, 8,026,393, 8,097,653, 8,338,639, 8,389,542, 8,748,481 and 8,779,187 following receipt of a September 2018 notice from Sun concerning its submission of an ANDA containing a Paragraph IV patent certification with the FDA for a generic version of Amitiza. The Company intends to vigorously enforce its intellectual property rights relating to Amitiza. Amitiza Patent Litigation: Teva Pharmaceuticals USA, Inc. In September 2017, Sucampo AG and Sucampo Pharmaceuticals, Inc., both subsidiaries of the Company, and Takeda filed suit in the U.S. District Court for the District of New Jersey against Teva Pharmaceuticals USA, Inc. ("Teva") alleging that Teva infringed U.S. Patent Nos. 6,414,016, 6,982,283, 7,795,312, 8,026,393, 8,071,613, 8,097,653, 8,338,639, 8,389,542 and 8,748,481 following receipt of an August 2017 notice from Teva concerning its submission of an ANDA containing a Paragraph IV patent certification with the FDA for a generic version of Amitiza. On June 28, 2018, the parties entered into a settlement agreement under which Teva was granted the non-exclusive right to market a competing lubiprostone product in the U.S. under its ANDA on or after January 1, 2023, or earlier under certain circumstances. Amitiza Patent Litigation: Amneal Pharmaceuticals, LLC. In April 2017, Sucampo AG and Sucampo Pharmaceuticals, Inc., both subsidiaries of the Company, and Takeda filed suit in the U.S. District Court for the District of New Jersey against Amneal Pharmaceuticals, LLC ("Amneal") alleging that Amneal infringed U.S. Patent Nos. 6,982,283, 8,026,393, 8,097,653, 8,338,639 and 8,389,542 following receipt of a March 2017 notice from Amneal concerning its submission of an ANDA containing a Paragraph IV patent certification with the FDA for a generic version of Amitiza. On June 28, 2018, the parties entered into a settlement agreement under which Amneal was granted the non-exclusive right to market a competing lubiprostone product in the U.S. under its ANDA on or after January 1, 2023, or earlier under certain circumstances. Amitiza Patent Litigation: Par and DRL. Settlement and License Agreements were entered into with Anchen Pharmaceuticals, Inc., Par Pharmaceutical, Inc. and Par Pharmaceutical Companies, Inc. (collectively "Par") and Dr. Reddy's Laboratories, Inc. and Dr. Reddy's Laboratories, Ltd. (collectively "DRL") to settle Paragraph IV patent litigation with each of Par and DRL. Under the terms of the Par settlement dated September 30, 2014, Par was granted a non-exclusive license and right to market a competing generic of Amitiza on or after January 1, 2021, or earlier under certain circumstances. Under the terms of the DRL settlement dated September 14, 2016, DRL was granted a non-exclusive license and right to market a competing generic of Amitiza on or after January 1, 2023, or earlier under certain circumstances. Inomax Patent Litigation: Praxair Distribution, Inc. and Praxair, Inc. (collectively “Praxair”). In February 2015, INO Therapeutics LLC and Ikaria, Inc., both subsidiaries of the Company, filed suit in the U.S. District Court for the District of Delaware against Praxair following receipt of a January 2015 notice from Praxair concerning its submission of an ANDA containing a Paragraph IV patent certification with the FDA for a generic version of Inomax. In July 2016, the Company filed a second suit against Praxair in the U.S. District Court for the District of Delaware following receipt of a Paragraph IV notice concerning three additional patents recently added to the FDA Orange Book that was submitted by Praxair regarding its ANDA for a generic version of Inomax. The infringement claims in the second suit have been added to the original suit. In September 2016, the Company filed a third suit against Praxair in the U.S. District Court for the District of Delaware following receipt of a Paragraph IV notice concerning a fourth patent recently added to the FDA Orange Book that was submitted by Praxair regarding its ANDA for a generic version of Inomax. The Company intends to vigorously enforce its intellectual property rights relating to Inomax in the Praxair litigation to prevent the marketing of infringing generic products prior to the expiration of the patents covering Inomax. Trial of the suit filed in February 2015 was held in March 2017 and a decision was rendered September 5, 2017 that ruled five patents invalid and six patents not infringed. The Company has appealed the decision to the Court of Appeals for the Federal Circuit. The oral arguments in the appeal occurred on February 6, 2019. Praxair received FDA approval of their ANDA for their Noxivent nitric oxide and clearance of their 510(k) for their NOxBOXi device on October 2, 2018. An adverse outcome in the appeal of the Praxair litigation decision (or a decision by Praxair to launch at-risk prior to the appellate decision) could result in the launch of a competitive nitric oxide product before the expiration of the last of the listed patents on May 3, 2036 (November 3, 2036 including pediatric exclusivity), which could adversely affect the Company's ability to successfully maximize the value of Inomax and have an adverse effect on its financial condition, results of operations and cash flows. Inomax Patents: IPR Proceedings. In February 2015 and March 2015, the U.S. Patent and Trademark Office ("USPTO") issued Notices of Filing Dates Accorded to Petitions for IPR petitions filed by Praxair Distribution, Inc. concerning ten patents covering Inomax (i.e., five patents expiring in 2029 and five patents expiring in 2031). In July 2015 the USPTO Patent Trial and Appeal Board ("PTAB") issued rulings denying the institution of four of the five IPR petitions challenging the five patents expiring in 2029. The PTAB also issued a ruling in July 2015 that instituted the IPR proceeding in the fifth of this group of patents and the PTAB ruled in July 2016 that one claim of this patent survived review and is valid while the remaining claims were unpatentable. The Company believed the claim held valid by the PTAB describes and encompasses a manner in which Inomax is distributed in conjunction with its approved labeling and that Praxair infringes that claim. Praxair filed an appeal and Mallinckrodt filed a cross-appeal of this decision to the Court of Appeals for the Federal Circuit. Oral argument of that appeal occurred in January 2018. The Federal Circuit decision was issued May 16, 2018 and held all claims unpatentable (invalid). In September 2015 the USPTO PTAB issued rulings that instituted the IPR proceedings in each of the second set of five patents that expire in 2031. In September 2016 the PTAB ruled that all claims in the five patents expiring in 2031 are patentable. Ofirmev Patent Litigation: Aurobindo Pharma U.S.A., Inc. In December 2017, Mallinckrodt Hospital Products Inc. and Mallinckrodt IP Unlimited Company, both subsidiaries of the Company, and New Pharmatop LP, the current owner of the two U.S. patents licensed exclusively by the Company, filed suit in the U.S. District Court for the District of Delaware against Aurobindo Pharma U.S.A., Inc. (“Aurobindo”) alleging that Aurobindo infringed U.S. Patent No. 6,992,218 ("the ‘218 patent"), U.S. Patent No. 9,399,012 ("the ‘012 patent") and U.S. Patent No. 9,610,265 ("the ‘265 patent") following receipt of a November 2017 notice from Aurobindo concerning its submission of an ANDA, containing a Paragraph IV patent certification with the FDA for a competing version of Ofirmev. On May 7, 2018 the parties entered into a settlement agreement under which Aurobindo was granted the non-exclusive right to market a competing intravenous acetaminophen product in the U.S. under its ANDA on or after December 6, 2020, or earlier under certain circumstances. Ofirmev Patent Litigation: B. Braun Medical Inc. In April 2017, Mallinckrodt Hospital Products Inc. and Mallinckrodt IP, both subsidiaries of the Company, and Pharmatop, the then owner of the two U.S. patents licensed exclusively by the Company, filed suit in the U.S. District Court for the District of Delaware against B. Braun Medical Inc. ("B. Braun") alleging that B. Braun infringed the '218 patent and the '012 patent following receipt of a February 2017 notice from B. Braun concerning its submission of a NDA, containing a Paragraph IV patent certification with the FDA for a competing version of Ofirmev. On October 3, 2018, the parties entered into a settlement agreement under which B. Braun was granted the non-exclusive right to market a competing intravenous acetaminophen product in the U.S. under its ANDA on or after December 6, 2020, or earlier under certain circumstances. Ofirmev Patent Litigation: InnoPharma Licensing LLC and InnoPharma, Inc. In September 2014, Cadence and Mallinckrodt IP, both subsidiaries of the Company, and Pharmatop, the then owner of the two U.S. patents licensed exclusively by the Company, filed suit in the U.S. District Court for the District of Delaware against InnoPharma Licensing LLC and InnoPharma, Inc. (both are subsidiaries of Pfizer and collectively "InnoPharma") alleging that InnoPharma infringed U.S. Patent Nos. 6,028,222 ("the '222 patent") and 6,992,218 ("the '218 patent"). Separately, on December 1, 2016 Mallinckrodt IP Filed suit in the U.S. District Court for the District of Delaware against InnoPharma alleging that InnoPharma infringed the '012 patent. On May 4, 2017 the parties entered into settlement agreements on both suits under which InnoPharma was granted the non-exclusive right to market a competing intravenous acetaminophen product in the U.S. under its NDA on or after December 6, 2020, or earlier under certain circumstances. Ofirmev Patent Litigation: Agila Specialties Private Limited, Inc. (now Mylan Laboratories Ltd.) and Agila Specialties Inc. (a Mylan Inc. Group), (collectively "Agila"). In December 2014, Cadence and Mallinckrodt IP, both subsidiaries of the Company, and Pharmatop filed suit in the U.S. District Court for the District of Delaware against Agila alleging that Agila infringed the '222 and the '218 patents. Separately, on December 1, 2016 Mallinckrodt IP filed suit in the U.S. District Court for the District of Delaware against Agila alleging that Agila infringed the '012 patent. On December 31, 2016, the parties entered into settlement agreements on both suits under which Agila was granted the non-exclusive right to market a competing intravenous acetaminophen product in the U.S. under its NDA on or after December 6, 2020, or earlier under certain circumstances. The Company has successfully asserted the '222 and '218 patents and maintained their validity in both litigation and proceedings at the USPTO. The Company will continue to vigorously enforce its intellectual property rights relating to Ofirmev to prevent the marketing of infringing generic or competing products prior to December 6, 2020, which, if unsuccessful, could adversely affect the Company's ability to successfully maximize the value of Ofirmev and have an adverse effect on its financial condition, results of operations and cash flows. Jazz Pharmaceuticals, Inc. and Jazz Pharmaceuticals Ireland v. Mallinckrodt PLC, Mallinckrodt Inc. and Mallinckrodt LLC. In January 2018, Jazz Pharmaceuticals, Inc. and Jazz Pharmaceuticals Ireland (collectively, "Jazz") filed suit in the U.S. District Court for the District of New Jersey against the Company alleging that the Company infringed U.S. Patent Nos. 7,668,730, 7,765,106, 7,765,107, 7,895,059, 8,457,988, 8,589,182, 8,731,963, 8,772,306, 9,050,302, and 9,486,426 following receipt of a November 2017 notice from the Company concerning its submission of an ANDA, containing a Paragraph IV patent certification with the FDA for a competing version of Xyrem. On June 4, 2018, the parties entered into a settlement agreement under which the Company was granted the non-exclusive right to market a competing sodium oxybate product in the U.S. under its ANDA on or after December 31, 2025, or earlier under certain circumstances. Shire Development LLC, Shire LLC and Shire US, Inc. v. SpecGx LLC. In May 2018, Shire Development LLC, Shire LLC and Shire US, Inc. (collectively “Shire”) filed suit in the U.S. District Court for the District of Delaware against the Company alleging that the Company infringed U.S. Patent Nos. 6,913,768, 8,846,100, and 9,173,857 following receipt of an April 2018 notice from the Company concerning its submission of an ANDA, containing a Paragraph IV patent certification with the FDA for a competing version of Mydayis. On January 28, 2018, the parties entered into a settlement agreement under which the Company was granted the non-exclusive right to market a competing generic version of Mydayis in the U.S. under its ANDA on or after May 10, 2023 (or November 10, 2023 if any pediatric exclusivity is granted by the FDA with respect to the Mydayis product), or earlier under certain circumstances. Commercial and Securities Litigation Grifols. On March 13, 2018, Grifols initiated arbitration against the Company, alleging breach of a Manufacturing and Supply Agreement entered into between the Company's predecessor-in-interest, Cadence Pharmaceuticals Inc., and Grifols. The Company intends to vigorously defend itself in this matter. Putative Class Action Litigation (MSP) . On October 30, 2017, a putative class action lawsuit was filed against the Company and United BioSource Corporation ("UBC") in the U.S. District Court for the Central District of California. The case is captioned MSP Recovery Claims, Series II LLC, et al. v. Mallinckrodt ARD, Inc., et al. The complaint purports to be brought on behalf of two classes: all Medicare Advantage Organizations and related entities in the U.S. who purchased or provided reimbursement for H.P. Acthar Gel pursuant to (i) Medicare Part C contracts (Class 1) and (ii) Medicare Part D contracts (Class 2) since January 1, 2011, with certain exclusions. The complaint alleges that the Company engaged in anticompetitive, unfair, and deceptive acts to artificially raise and maintain the price of H.P. Acthar Gel. To this end, the complaint alleges that the Company unlawfully maintained a monopoly in a purported ACTH product market by acquiring the U.S. rights to Synacthen Depot and reaching anti-competitive agreements with the other defendants by selling H.P. Acthar Gel through an exclusive distribution network. The complaint purports to allege claims under federal and state antitrust laws and state unfair competition and unfair trade practice laws. Pursuant to a motion filed by defendants, this case has been transferred to the U.S. District Court for the Northern District of Illinois. The Company intends to vigorously defend itself in this matter. Putative Class Action Litigation (Rockford) . On April 6, 2017, a putative class action lawsuit was filed against the Company and UBC in the U.S. District Court for the Northern District of Illinois. The case is captioned City of Rockford v. Mallinckrodt ARD, Inc., et al. The complaint was subsequently amended, most recently on December 8, 2017, to include an additional named plaintiff and additional defendants. As amended, the complaint purports to be brought on behalf of all self-funded entities in the U.S. and its Territories, excluding any Medicare Advantage Organizations, related entities and certain others, that paid for H.P. Acthar Gel from August 2007 to the present. The lawsuit alleges that the Company engaged in anticompetitive, unfair, and deceptive acts to artificially raise and maintain the price of H.P. Acthar Gel. To this end, the suit alleges that the Company unlawfully maintained a monopoly in a purported ACTH product market by acquiring the U.S. rights to Synacthen Depot; conspired with UBC and violated anti-racketeering laws by selling H.P. Acthar Gel through an exclusive distributor; and committed fraud on consumers by failing to correctly identify H.P. Acthar Gel's active ingredient on package inserts. The Company intends to vigorously defend itself in this matter. Local 542. On May 25, 2018, the International Union of Operating Engineers Local 542 filed a complaint against the Company and other defendants alleging improper pricing and distribution of H.P. Acthar Gel, in violation of Pennsylvania's Unfair Trade Practices and Consumer Protection Law, aiding and abetting, unjust enrichment and negligent misrepresentation. Plaintiff filed an amended complaint on August 27, 2018. The Company intends to vigorously defend itself in this matter. Employee Stock Purchase Plan Securities Litigation. On July 20, 2017, a purported purchaser of Mallinckrodt stock through Mallinckrodt's ESPPs, filed a derivative lawsuit in the Federal District Court in the Eastern District of Missouri, captioned Solomon v. Mallinckrodt plc, et al. , against the Company, its Chief Executive Officer Mark C. Trudeau ("CEO"), its former Chief Financ

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	12 Months Ended
	Dec. 28, 2018
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurements	21. Financial Instruments and Fair Value Measurements Fair value is defined as the exit price that would be received from the sale of an asset or paid to transfer a liability, using assumptions that market participants would use in pricing an asset or liability. The fair value guidance establishes a three-level fair value hierarchy, which maximizes the use of observable inputs and minimizes the use of unobservable inputs used in measuring fair value. The levels within the hierarchy are as follows: Level 1— observable inputs such as quoted prices in active markets for identical assets or liabilities; Level 2— significant other observable inputs that are observable either directly or indirectly; and Level 3— significant unobservable inputs in which there is little or no market data, which requires the Company to develop its own assumptions. The following tables provide a summary of the significant assets and liabilities that are measured at fair value on a recurring basis at the end of each period: December 28, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Assets: Debt and equity securities held in rabbi trusts $ 33.1 $ 22.4 $ 10.7 $ — Equity securities — — — — $ 33.1 $ 22.4 $ 10.7 $ — Liabilities: Deferred compensation liabilities $ 38.5 $ — $ 38.5 $ — Contingent consideration and acquired contingent liabilities 151.4 — — 151.4 $ 189.9 $ — $ 38.5 $ 151.4 December 29, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 35.4 $ 24.0 $ 11.4 $ — Equity securities 22.7 22.7 — — $ 58.1 $ 46.7 $ 11.4 $ — Liabilities: Deferred compensation liabilities $ 42.7 $ — $ 42.7 $ — Contingent consideration and acquired contingent liabilities 246.4 — — 246.4 $ 289.1 $ — $ 42.7 $ 246.4 Debt and equity securities held in rabbi trusts. Debt securities held in the rabbi trusts primarily consist of U.S. government and agency securities and corporate bonds. When quoted prices are available in an active market, the investments are classified as level 1. When quoted market prices for a security are not available in an active market, they are classified as level 2. Equity securities held in the rabbi trusts primarily consist of U.S. common stocks, which are valued using quoted market prices reported on nationally recognized securities exchanges. Equity securities . Equity securities consisted of shares in Mesoblast, for which quoted prices are available in an active market; therefore, the investment was classified as level 1 and is valued based on quoted market prices reported on a nationally recognized securities exchange. During fiscal 2018 , the Company sold all its shares for gross proceeds of $25.5 million resulting in a $3.4 million gain being recognized within other income (expense), net within the consolidated statement of income. Deferred compensation liabilities. The Company maintains a non-qualified deferred compensation plan in the U.S., which permits eligible employees of the Company to defer a portion of their compensation. A recordkeeping account is set up for each participant and the participant chooses from a variety of funds for the deemed investment of their accounts. The recordkeeping accounts generally correspond to the funds offered in the Company's U.S. tax-qualified defined contribution retirement plan and the account balance fluctuates with the investment returns on those funds. Goodwill. The Company performs an annual goodwill impairment assessment using an income approach based on the present value of future cash flows. See further discussion in Notes 3 and 13 to the consolidated financial statements. Contingent consideration and acquired contingent liabilities. As of December 28, 2018, the Company maintains various contingent consideration and acquired contingent liabilities associated with the acquisitions of Questcor, Stratatech, and Ocera. In August 2014, the Company recorded acquired contingent liabilities of $195.4 million from the acquisition of Questcor. The contingent liabilities relate to Questcor's contingent obligations associated with their acquisition of an exclusive, perpetual and irrevocable license to develop, market, manufacture, distribute, sell and commercialize MNK-1411 ("Synacthen") from Novartis and their acquisition of BioVectra. The fair value of these contingent consideration obligations at December 28, 2018 and December 29, 2017 were $76.2 million and $111.8 million , respectively. Under the terms of the license agreement with Novartis, the Company made a $25.0 million payment in fiscal 2018, and is obligated to make annual payments of $25.0 million subsequent to fiscal 2018 until such time that the Company obtains FDA approval of Synacthen and makes a $25.0 million payment upon obtaining FDA approval of Synacthen. If FDA approval is obtained, the Company will pay an annual royalty to Novartis based on a percentage of net sales in the U.S. market. As of December 28, 2018 , the total remaining payments under the license agreement shall not exceed $115.0 million . The terms of the license agreement allow the Company to terminate the license agreement upon the occurrence of certain events following the fiscal 2020 payment. The Company measured the fair value of the contingent payments based on a probability-weighted present value of the consideration expected to be transferred using a discount rate of 4.7% . As part of the Stratatech Acquisition, the Company provided contingent consideration to the prior shareholders of Stratatech, primarily in the form of regulatory filing and approval milestones associated with the deep partial thickness and full thickness indications associated with StrataGraft. The Company assesses the likelihood of and timing of making such payments. The fair value of the contingent payments was measured based on the net present value of a probability-weighted assessment. The Company determined the fair value of the contingent consideration associated with the Stratatech Acquisition to be $53.7 million and $53.5 million at December 28, 2018 and December 29, 2017 , respectively. As part of the Ocera Acquisition, the Company provided contingent consideration to the prior shareholders of Ocera in the form of both patient enrollment clinical study milestones for intravenous ("IV") and oral formulations of MNK-6105 and MNK-6106, which represent the IV and oral formulations, respectively, and sales-based milestones associated with MNK-6105 and MNK-6106. The Company determined the fair value of the contingent consideration based on an option pricing model to be $21.5 million and $22.0 million as of December 28, 2018 and December 29, 2017, respectively. Prior to December 28, 2018, the Company maintained various contingent consideration and acquired contingent liabilities associated with the Hemostasis Acquisition and InfaCare Acquisition. As part of the Hemostasis Acquisition, the Company provided contingent consideration to The Medicines Company in the form of sales based milestones associated with Raplixa and PreveLeak, and acquired contingent liabilities associated with The Medicines Company's prior acquisitions of the aforementioned products. The Company determined the fair value of the contingent consideration and acquired contingent liabilities based on an option pricing model to be $7.0 million and $17.1 million , respectively, at December 29, 2017, respectively. During fiscal 2017, the contingent consideration liability associated with Raplixa was reduced to zero, reflective of lower than previously anticipated commercial opportunities for the product, resulting in a $54.6 million fair value adjustment during fiscal 2017. The Company paid $12.0 million related to the FDA approval milestone of PreveLeak during the three months ended March 30, 2018. On March 16, 2018, the Company sold a portion of the Hemostasis business, inclusive of the Recothrom and PreveLeak products to Baxter and the remaining contingent consideration liability balance of $12.1 million was transferred upon sale. As part of the InfaCare Acquisition, the Company provided contingent consideration to the prior shareholders of InfaCare in the form of both regulatory approval milestones for full-term and pre-term neonates for stannsoporfin and sales-based milestones associated with stannsoporfin. Due to recent developments and discussions with the FDA, as discussed in further detail in Note 13, the timing of the development program is expected to shift outward. During fiscal 2018, the Company recognized a $35.0 million fair value adjustment due to this shift in timing and its impact on the achievement of milestones per the purchase agreement. The fair value of the contingent consideration based on an option pricing model was determined to be zero and $35.0 million as of December 28, 2018 and December 29, 2017, respectively. Of the total fair value of the contingent consideration of $151.4 million , $34.1 million was classified as current and $117.3 million was classified as non-current in the consolidated balance sheet as of December 28, 2018 . The following table summarizes the fiscal 2018 activity for contingent consideration: Balance at December 29, 2017 $ 246.4 Disposal of business (12.1 ) Payments (37.0 ) Accretion expense 4.3 Fair value adjustment (50.2 ) Balance at December 28, 2018 $ 151.4 Financial Instruments Not Measured at Fair Value The following methods and assumptions were used by the Company in estimating fair values for financial instruments not measured at fair value as of December 28, 2018 and December 29, 2017 : • The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and the majority of other current assets and liabilities approximate fair value because of their short-term nature. The Company classifies cash on hand and deposits in banks, including commercial paper, money market accounts and other investments it may hold from time to time, with an original maturity to the Company of three months or less, as cash and cash equivalents (level 1). The fair value of restricted cash is equivalent to its carrying value of $18.6 million and $18.3 million as of December 28, 2018 and December 29, 2017 , respectively (level 1), substantially all of which is included in other assets on the consolidated balance sheets. • The Company received a portion of consideration for the sale of the Intrathecal business in the form of a note receivable. The fair value of the note receivable was equivalent to its carrying value of $154.0 million as of December 29, 2017 (level 1). During fiscal 2018, the Company received $154.0 million from Piramal for settlement of the aforementioned note receivable. • The Company received a portion of consideration as part of contingent earn-out payments related to the sale of the Nuclear Imaging business in the form of preferred equity certificates during fiscal 2018. These securities are classified as held-to-maturity and are carried at amortized cost, which approximates fair value, of $9.0 million at December 28, 2018 (level 3). These securities are included in other assets on the consolidated balance sheet. • The Company's life insurance contracts are carried at cash surrender value, which is based on the present value of future cash flows under the terms of the contracts (level 3). Significant assumptions used in determining the cash surrender value include the amount and timing of future cash flows, interest rates and mortality charges. The fair value of these contracts approximates the carrying value of $66.4 million and $67.0 million at December 28, 2018 and December 29, 2017 , respectively. These contracts are included in other assets on the consolidated balance sheets. • The carrying values of the Company's revolving credit facility and variable-rate receivable securitization approximate the fair values due to the short-term nature of these instruments, and is therefore classified as level 1. The Company's 3.50% , 4.75% , 4.875% , 5.50% , 5.625% and 5.75% notes are classified as level 1, as quoted prices are available in an active market for these notes. Since the quoted market prices for the Company's term loans and 8.00% and 9.50% debentures are not available in an active market, they are classified as level 2 for purposes of developing an estimate of fair value. The fair value of the "other" loan is based on the present value of future cash flows under the terms of the agreement with future cash flows and interest rates as significant assumptions, and therefore classified as level 3. The following table presents the carrying values and estimated fair values of the Company's long-term debt, excluding capital leases, as of the end of each period: December 28, 2018 December 29, 2017 Carrying Value Fair Value Carrying Value Fair Value Level 1: 3.50% notes due April 2018 $ — $ — $ 300.0 $ 299.1 4.875% notes due April 2020 700.0 676.6 700.0 675.2 Variable-rate receivable securitization due July 2020 250.0 250.0 200.0 200.0 5.75% notes due August 2022 835.2 713.6 884.0 804.8 4.75% notes due April 2023 500.2 336.7 526.5 412.4 5.625% notes due October 2023 731.4 557.0 738.0 628.8 5.50% notes due April 2025 692.1 479.1 692.1 564.5 Revolving credit facility 220.0 220.0 900.0 900.0 Level 2: 9.50% debentures due May 2022 10.4 9.7 10.4 10.9 8.00% debentures due March 2023 4.4 3.8 4.4 4.4 Term loan due September 2024 1,613.8 1,472.4 1,851.2 1,848.7 Term loan due February 2025 597.0 548.0 — — Level 3: Other 2.2 2.2 — — Total Debt $ 6,156.7 $ 5,269.1 $ 6,806.6 $ 6,348.8 Concentration of Credit and Other Risks Financial instruments that potentially subject the Company to concentrations of credit risk primarily consist of accounts receivable. The Company generally does not require collateral from customers. A portion of the Company's accounts receivable outside the U.S. includes sales to government-owned or supported healthcare systems in several countries, which are subject to payment delays. Payment is dependent upon the financial stability and creditworthiness of those countries' national economies. The following table shows net sales attributable to distributors that accounted for 10% or more of the Company's total net sales: Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, CuraScript, Inc. 35 % 40 % 38 % 43 % McKesson Corporation * * 12 % 10 % * Net sales to these distributors were less than 10% of total net sales during the respective periods presented above. The following table shows accounts receivable attributable to distributors that accounted for 10% or more of the Company's gross accounts receivable at the end of each period: December 28, December 29, AmerisourceBergen Corporation 26 % 15 % McKesson Corporation 22 % 26 % CuraScript, Inc. 13 % 14 % Cardinal Health, Inc. * 11 % * Gross accounts receivables from these distributors were less than 10% of total gross accounts receivable during the respective periods presented above. The following table shows net sales attributable to products that accounted for 10% or more of the Company's total net sales: Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, H.P. Acthar Gel 35 % 37 % 34 % 39 % Inomax 17 % 16 % 14 % 14 %

Segment and Geographical Data

Segment and Geographical Data	12 Months Ended
	Dec. 28, 2018
Segment Reporting [Abstract]
Segment and Geographical Data	22. Segment and Geographical Data As a result of the planned Separation, the Company reassessed its segments based on the financial information viewed by the Chief Executive Officer, the Company's chief operating decision maker ("CODM"), for the purposes of making resource allocation decisions and assessing the performance of the business. The Company has identified two reportable segments that align with the operations of the two independent publicly traded companies anticipated post-separation: (1) Specialty Brands and (2) Specialty Generics and Amitiza, which are further described below: • Specialty Brands includes innovative specialty pharmaceutical brands; and • Specialty Generics and Amitiza includes niche specialty generic drugs products, APIs and Amitiza. Prior year amounts have been recast to conform to current presentation. Management measures and evaluates the Company's operating segments based on segment net sales and operating income. Management excludes corporate expenses from segment operating income. In addition, certain amounts that management considers to be non-recurring or non-operational are excluded from segment operating income because management evaluates the operating results of the segments excluding such items. These items include, but are not limited to, intangible asset amortization, net restructuring and related charges, non-restructuring impairments and separation costs. Although these amounts are excluded from segment operating income, as applicable, they are included in reported consolidated operating income and in the following reconciliations presented below. Management manages assets on a total company basis, not by operating segment. The CODM does not regularly review any asset information by operating segment and, accordingly, the Company does not report asset information by operating segment. Total assets were approximately $10.9 billion and $15.3 billion at December 28, 2018 and December 29, 2017 , respectively. Selected information by business segment is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Net sales: Specialty Brands $ 2,306.2 $ 2,352.0 $ 2,288.8 $ 600.1 Specialty Generics and Amitiza 909.4 869.6 1,092.0 229.8 Net sales $ 3,215.6 $ 3,221.6 $ 3,380.8 $ 829.9 Operating income: Specialty Brands $ 1,077.4 $ 1,146.3 $ 1,060.7 $ 295.2 Specialty Generics and Amitiza 105.0 266.4 444.7 64.6 Segment operating income 1,182.4 1,412.7 1,505.4 359.8 Unallocated amounts: Corporate and allocated expenses (1) (155.8 ) (125.2 ) (117.7 ) (123.1 ) Intangible asset amortization (740.2 ) (694.5 ) (700.1 ) (175.7 ) Restructuring and related charges, net (2) (108.2 ) (36.4 ) (37.6 ) (5.3 ) Non-restructuring impairments (3,893.1 ) (63.7 ) (16.9 ) (214.3 ) Separation costs (3) (6.0 ) — — — Operating income $ (3,720.9 ) $ 492.9 $ 633.1 $ (158.6 ) Depreciation and amortization (4) : Specialty Brands $ 696.0 $ 712.0 $ 715.7 $ 178.2 Specialty Generics and Amitiza 156.1 96.3 97.9 25.0 $ 852.1 $ 808.3 $ 813.6 $ 203.2 (1) Includes administration expenses and certain compensation, environmental and other costs not charged to the Company's operating segments. (2) Includes restructuring-related accelerated depreciation. (3) Represents costs incurred related to the separation of the Company’s Specialty Generics and Amitiza segment, which are included in selling, general and administrative expenses. (4) Depreciation for certain shared facilities is allocated based on occupancy percentage. Net sales by product family within the Company's segments are as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 H.P. Acthar Gel $ 1,110.1 $ 1,195.1 $ 1,160.4 $ 325.4 Inomax 542.7 505.2 474.3 118.3 Ofirmev 341.9 302.5 284.3 72.5 Therakos 231.2 214.9 207.6 47.4 BioVectra 53.1 54.7 49.5 7.4 Other (1) 27.2 79.6 112.7 29.1 Specialty Brands 2,306.2 2,352.0 2,288.8 600.1 Hydrocodone (API) and hydrocodone-containing tablets 65.9 85.3 146.5 23.2 Oxycodone (API) and oxycodone-containing tablets (1) 66.1 88.0 139.9 27.2 Acetaminophen (API) (1) 192.7 185.5 169.1 40.8 Amitiza (2) 183.8 — — — Other controlled substances (1) 343.8 412.0 543.9 117.4 Other (1), (3) 57.1 98.8 92.6 21.2 Specialty Generics and Amitiza 909.4 869.6 1,092.0 229.8 Net Sales $ 3,215.6 $ 3,221.6 $ 3,380.8 $ 829.9 (1) Prior year amounts have been reclassified to conform to current year presentation. (2) Amitiza net sales consist of both product and royalty net sales. Refer to Note 5 for further details on Amitiza's revenues. (3) Includes net sales from an ongoing, post-divestiture supply agreement with the acquirer of the CMDS business. Amounts for periods prior to the divestiture represent the reclassification of intercompany sales to third-party sales to conform with the expected presentation of the ongoing supply agreement. Selected information by geographic area excluding assets held-for-sale is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Net sales (1) : U.S. $ 2,834.5 $ 2,899.0 $ 3,095.4 $ 763.7 Europe, Middle East and Africa 256.8 242.3 211.8 52.8 Other 124.3 80.3 73.6 13.4 $ 3,215.6 $ 3,221.6 $ 3,380.8 $ 829.9 Fiscal Year Ended Long-lived assets (2) : December 28, 2018 December 29, 2017 U.S. $ 770.7 $ 788.5 Europe, Middle East and Africa (3) 146.7 127.0 Other 76.8 63.5 $ 994.2 $ 979.0 (1) Net sales are attributed to regions based on the location of the entity that records the transaction, none of which relate to the country of Ireland. (2) Long-lived assets are primarily composed of property, plant and equipment, net. (3) Includes long-lived assets located in Ireland of $145.2 million and $126.0 million as of December 28, 2018 and December 29, 2017

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 28, 2018
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	23. Selected Quarterly Financial Data (Unaudited) A summary of quarterly financial information for fiscal 2018 and 2017 is as follows: For the Quarter Ended (1) March 30, June 29, September 28, December 28, Net sales $ 755.3 $ 825.5 $ 799.9 $ 834.9 Gross profit (2) 347.5 394.0 366.4 363.3 (Loss) income from continuing operations (3) (20.9 ) 3.2 114.2 (3,718.4 ) Income (loss) from discontinued operations 2.9 12.4 (0.4 ) — Net (loss) income (18.0 ) 15.6 113.8 (3,718.4 ) Basic (loss) earnings per share from continuing operations (4) $ (0.24 ) $ 0.04 $ 1.37 $ (44.64 ) Diluted (loss) earnings per share from continuing operations (4) (0.24 ) 0.04 1.34 (44.64 ) For the Quarter Ended March 31, June 30, September 29, December 29, Net sales $ 810.9 $ 824.5 $ 793.9 $ 792.3 Gross profit (2) 419.8 416.1 400.6 421.0 Income from continuing operations (3) 28.9 70.6 64.3 1,607.4 Income (loss) from discontinued operations 370.3 (7.8 ) (0.6 ) 1.3 Net income 399.2 62.8 63.7 1,608.7 Basic earnings per share from continuing operations (4) $ 0.28 $ 0.72 $ 0.66 $ 17.43 Diluted earnings per share from continuing operations (4) 0.28 0.72 0.66 17.40 (1) The Specialty Generics Disposal Group was included within discontinued operations during the first three quarters of fiscal 2018, and has subsequently been recast to be included within continuing operations. In accordance with U.S. GAAP, depreciation and amortization are not recorded during the period in which a disposal group is classified as held-for-sale, thus the Company's financial results during the first three quarters of fiscal 2018 did not include $17.7 million and $6.8 million of depreciation and amortization expense, respectively, related to the Specialty Generics Disposal Group. During the fourth quarter of 2018, the Specialty Generics Disposal Group was reclassified to held and used and measured at its carrying amount before it was classified as held-for-sale, adjusted for depreciation and amortization expense that would have been recognized had the disposal group been continuously classified as held and used. The total adjustment of $24.5 million was reflected in loss from continuing operations during the fourth quarter of 2018, the period in which the held-for-sale criteria were no longer met. (2) Financial data for each period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of ASU 2017-07. See Note 4 for further information. (3) (Loss) income from continuing operations for the quarter ended December 28, 2018 reflects impairment charges for goodwill and an IPR&D asset. See Note 13 for further information. Income from continuing operations for the quarter ended December 29, 2017 reflects one-time effects for the completion of the reorganization of the Company's legal entity ownership and the impact of the TCJA. (4)

Condensed Consolidating and Com

Condensed Consolidating and Combining Financial Statements	12 Months Ended
	Dec. 28, 2018
Condensed Consolidating Financial Statements [Abstract]
Condensed Consolidating and Combining Financial Statements	24. Condensed Consolidating Financial Statements MIFSA is an indirectly 100%-owned subsidiary of Mallinckrodt plc established to own, directly or indirectly, substantially all of the operating subsidiaries of the Company, to issue debt securities and to perform treasury operations. MIFSA is the borrower under the 2013 Notes, which are fully and unconditionally guaranteed by Mallinckrodt plc. The following information provides the composition of the Company's comprehensive income, assets, liabilities, equity and cash flows by relevant group within the Company: Mallinckrodt plc as guarantor of the 2013 Notes, MIFSA as issuer of the 2013 Notes and the operating companies that represent assets of MIFSA. There are no subsidiary guarantees related to the 2013 Notes. Set forth below are the condensed consolidating balance sheets as of December 28, 2018 and December 29, 2017 and condensed consolidating statements of comprehensive income and cash flows for the fiscal three years ended December 28, 2018 and the three months ended December 30, 2016. Eliminations represent adjustments to eliminate investments in subsidiaries and intercompany balances and transactions between or among Mallinckrodt plc, MIFSA and the other subsidiaries. Condensed consolidating financial information for Mallinckrodt plc and MIFSA, on a standalone basis, has been presented using the equity method of accounting for subsidiaries. MALLINCKRODT PLC CONDENSED CONSOLIDATING BALANCE SHEET As of December 28, 2018 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Assets Current Assets: Cash and cash equivalents $ 0.4 $ 140.8 $ 207.7 $ — $ 348.9 Accounts receivable, net — — 623.3 — 623.3 Inventories — — 322.3 — 322.3 Prepaid expenses and other current assets 3.9 0.2 128.6 — 132.7 Notes receivable — — — — — Intercompany receivable 131.1 29.2 1,087.9 (1,248.2 ) — Total current assets 135.4 170.2 2,369.8 (1,248.2 ) 1,427.2 Property, plant and equipment, net — — 982.0 — 982.0 Goodwill — — — — — Intangible assets, net — — 8,282.8 — 8,282.8 Investment in subsidiaries 2,481.6 25,506.1 8,362.1 (36,349.8 ) — Intercompany loan receivable 497.7 — 12,343.0 (12,840.7 ) — Other assets — — 185.3 — 185.3 Total Assets $ 3,114.7 $ 25,676.3 $ 32,525.0 $ (50,438.7 ) $ 10,877.3 — Liabilities and Shareholders' Equity Current Liabilities: Current maturities of long-term debt $ — $ 22.1 $ 0.3 $ — $ 22.4 Accounts payable 0.1 — 147.4 — 147.5 Accrued payroll and payroll-related costs — — 124.0 — 124.0 Accrued interest — 48.7 28.9 — 77.6 Income taxes payable — — 25.0 — 25.0 Accrued and other current liabilities 0.6 0.4 546.2 — 547.2 Intercompany payable 226.7 827.8 193.7 (1,248.2 ) — Total current liabilities 227.4 899.0 1,065.5 (1,248.2 ) 943.7 Long-term debt — 3,566.9 2,502.3 — 6,069.2 Pension and postretirement benefits — — 60.5 — 60.5 Environmental liabilities — — 59.7 — 59.7 Deferred income taxes — — 324.3 — 324.3 Other income tax liabilities — — 228.0 — 228.0 Intercompany loans payable — 12,840.7 — (12,840.7 ) — Other liabilities — 7.6 297.0 — 304.6 Total liabilities 227.4 17,314.2 4,537.3 (14,088.9 ) 7,990.0 Shareholders' equity 2,887.3 8,362.1 27,987.7 (36,349.8 ) 2,887.3 Total Liabilities and Shareholders' Equity $ 3,114.7 $ 25,676.3 $ 32,525.0 $ (50,438.7 ) $ 10,877.3 MALLINCKRODT PLC CONDENSED CONSOLIDATING BALANCE SHEET As of December 29, 2017 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Assets Current Assets: Cash and cash equivalents $ 0.7 $ 908.8 $ 351.4 $ — $ 1,260.9 Accounts receivable, net — — 445.8 — 445.8 Inventories — — 340.4 — 340.4 Prepaid expenses and other current assets 1.0 0.2 82.9 — 84.1 Notes receivable — — 154.0 — 154.0 Intercompany receivable 70.0 173.4 831.4 (1,074.8 ) — Total current assets 71.7 1,082.4 2,205.9 (1,074.8 ) 2,285.2 Property, plant and equipment, net — — 966.8 — 966.8 Goodwill — — 3,482.7 — 3,482.7 Intangible assets, net — — 8,375.0 — 8,375.0 Investment in subsidiaries 6,551.6 23,217.8 12,356.2 (42,125.6 ) — Intercompany loan receivable 593.1 — 4,664.8 (5,257.9 ) — Other assets — — 171.2 — 171.2 Total Assets $ 7,216.4 $ 24,300.2 $ 32,222.6 $ (48,458.3 ) $ 15,280.9 Liabilities and Shareholders' Equity Current Liabilities: Current maturities of long-term debt $ — $ 313.5 $ 0.2 $ — $ 313.7 Accounts payable 0.1 — 113.2 — 113.3 Accrued payroll and payroll-related costs — — 98.5 — 98.5 Accrued interest — 53.0 4.0 — 57.0 Income taxes payable — — 15.8 15.8 Accrued and other current liabilities 0.8 0.4 450.9 — 452.1 Intercompany payable 693.5 104.6 276.7 (1,074.8 ) — Total current liabilities 694.4 471.5 959.3 (1,074.8 ) 1,050.4 Long-term debt — 6,206.8 214.1 — 6,420.9 Pension and postretirement benefits — — 67.1 — 67.1 Environmental liabilities — — 73.2 — 73.2 Deferred income taxes — — 689.0 — 689.0 Other income tax liabilities — — 94.1 — 94.1 Intercompany loans payable — 5,257.9 — (5,257.9 ) — Other liabilities — 7.8 356.4 — 364.2 Total liabilities 694.4 11,944.0 2,453.2 (6,332.7 ) 8,758.9 Shareholders' equity 6,522.0 12,356.2 29,769.4 (42,125.6 ) 6,522.0 Total Liabilities and Shareholders' Equity $ 7,216.4 $ 24,300.2 $ 32,222.6 $ (48,458.3 ) $ 15,280.9 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Fiscal year ended December 28, 2018 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 3,215.6 $ — $ 3,215.6 Cost of sales 2.0 — 1,742.4 — 1,744.4 Gross (loss) profit (2.0 ) — 1,473.2 — 1,471.2 Selling, general and administrative expenses 38.8 0.7 794.6 — 834.1 Research and development expenses 4.7 — 356.4 — 361.1 Restructuring charges, net — — 103.0 — 103.0 Non-restructuring impairment charges — — 3,893.1 — 3,893.1 Loss on divestiture — — 0.8 — 0.8 Operating loss (45.5 ) (0.7 ) (3,674.7 ) — (3,720.9 ) Interest expense (7.8 ) (460.8 ) (63.4 ) 161.8 (370.2 ) Interest income 9.5 2.5 158.0 (161.8 ) 8.2 Other income, net 9.9 8.7 12.3 — 30.9 Intercompany interest and fees (18.5 ) (0.1 ) 18.6 — — Equity in net income of subsidiaries (3,561.0 ) (2,726.0 ) (3,170.9 ) 9,457.9 — Loss from continuing operations before income taxes (3,613.4 ) (3,176.4 ) (6,720.1 ) 9,457.9 (4,052.0 ) Benefit from income taxes (6.4 ) (5.4 ) (418.3 ) — (430.1 ) Loss from continuing operations (3,607.0 ) (3,171.0 ) (6,301.8 ) 9,457.9 (3,621.9 ) Income from discontinued operations, net of income taxes — 0.1 14.8 — 14.9 Net loss (3,607.0 ) (3,170.9 ) (6,287.0 ) 9,457.9 (3,607.0 ) Other comprehensive loss, net of tax (9.9 ) (9.9 ) (20.5 ) 30.4 (9.9 ) Comprehensive loss $ (3,616.9 ) $ (3,180.8 ) $ (6,307.5 ) $ 9,488.3 $ (3,616.9 ) MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Fiscal year ended December 29, 2017 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 3,221.6 $ — $ 3,221.6 Cost of sales 2.6 — 1,561.5 — 1,564.1 Gross (loss) profit (2.6 ) — 1,660.1 — 1,657.5 Selling, general and administrative expenses 59.5 0.7 789.5 — 849.7 Research and development expenses 5.1 — 271.8 — 276.9 Restructuring charges, net — — 31.2 — 31.2 Non-restructuring impairments — — 63.7 — 63.7 Gains on divestiture — — (56.9 ) — (56.9 ) Operating (loss) income (67.2 ) (0.7 ) 560.8 — 492.9 Interest expense (13.8 ) (353.9 ) (74.2 ) 72.8 (369.1 ) Interest income 7.3 1.2 68.9 (72.8 ) 4.6 Other income (expense), net 20.3 (1.7 ) (85.4 ) — (66.8 ) Intercompany interest and fees (18.3 ) — 18.3 — — Equity in net income of subsidiaries 2,200.0 2,901.8 2,549.9 (7,651.7 ) — Income from continuing operations before income taxes 2,128.3 2,546.7 3,038.3 (7,651.7 ) 61.6 Benefit from income taxes (6.1 ) (5.3 ) (1,698.2 ) — (1,709.6 ) Income from continuing operations 2,134.4 2,552.0 4,736.5 (7,651.7 ) 1,771.2 (Loss) income from discontinued operations, net of income taxes — (2.1 ) 365.3 — 363.2 Net income 2,134.4 2,549.9 5,101.8 (7,651.7 ) 2,134.4 Other comprehensive income, net of tax 59.6 59.6 118.2 (177.8 ) 59.6 Comprehensive income $ 2,194.0 $ 2,609.5 $ 5,220.0 $ (7,829.5 ) $ 2,194.0 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Fiscal year ended September 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 3,380.8 $ — $ 3,380.8 Cost of sales — — 1,523.2 — 1,523.2 Gross profit — — 1,857.6 — 1,857.6 Selling, general and administrative expenses 51.3 0.8 861.6 — 913.7 Research and development expenses — — 261.2 — 261.2 Restructuring charges, net — — 32.7 — 32.7 Non-restructuring impairments — — 16.9 — 16.9 Operating (loss) income (51.3 ) (0.8 ) 685.2 — 633.1 Interest expense (230.3 ) (327.0 ) (82.4 ) 255.1 (384.6 ) Interest income — 0.5 255.9 (255.1 ) 1.3 Other income (expense), net 90.0 1.7 (108.1 ) — (16.4 ) Intercompany interest and fees (16.1 ) — 16.1 — — Equity in net income of subsidiaries 820.8 1,327.2 1,057.9 (3,205.9 ) — Income from continuing operations before income taxes 613.1 1,001.6 1,824.6 (3,205.9 ) 233.4 Benefit from income taxes (30.6 ) (18.1 ) (206.9 ) — (255.6 ) Income from continuing operations 643.7 1,019.7 2,031.5 (3,205.9 ) 489.0 Income from discontinued operations, net of income taxes — 38.2 116.5 — 154.7 Net income 643.7 1,057.9 2,148.0 (3,205.9 ) 643.7 Other comprehensive loss, net of tax (86.5 ) (86.5 ) (173.5 ) 260.0 (86.5 ) Comprehensive income $ 557.2 $ 971.4 $ 1,974.5 $ (2,945.9 ) $ 557.2 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Three months ended December 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 829.9 $ — $ 829.9 Cost of sales — — 383.2 — 383.2 Gross profit — — 446.7 — 446.7 Selling, general and administrative expenses 13.4 0.2 307.5 — 321.1 Research and development expenses — — 66.1 — 66.1 Restructuring charges, net — — 3.8 — 3.8 Non-restructuring impairments — — 214.3 — 214.3 Operating loss (13.4 ) (0.2 ) (145.0 ) — (158.6 ) Interest expense (2.9 ) (81.1 ) (17.9 ) 10.6 (91.3 ) Interest income — 0.1 11.0 (10.6 ) 0.5 Other income (expense), net 1.8 0.7 (51.6 ) — (49.1 ) Intercompany interest and fees (4.4 ) — 4.4 — — Equity in net income of subsidiaries (136.5 ) 35.2 (44.5 ) 145.8 — Loss from continuing operations before income taxes (155.4 ) (45.3 ) (243.6 ) 145.8 (298.5 ) Benefit from income taxes (2.2 ) (0.3 ) (119.2 ) — (121.7 ) Loss from continuing operations (153.2 ) (45.0 ) (124.4 ) 145.8 (176.8 ) Income from discontinued operations, net of income taxes — 0.4 23.2 — 23.6 Net loss (153.2 ) (44.6 ) (101.2 ) 145.8 (153.2 ) Other comprehensive income, net of tax 13.1 13.1 26.0 (39.1 ) 13.1 Comprehensive loss $ (140.1 ) $ (31.5 ) $ (75.2 ) $ 106.7 $ (140.1 ) MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Fiscal year ended December 28, 2018 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 438.9 $ 80.1 $ 1,702.5 $ (1,556.0 ) $ 665.5 Cash Flows From Investing Activities: Capital expenditures — — (127.0 ) — (127.0 ) Acquisitions, net of cash acquired — — (699.9 ) — (699.9 ) Proceeds from disposal of discontinued operations, net of cash — — 313.0 — 313.0 Intercompany loan investment (385.6 ) (90.1 ) (502.0 ) 977.7 — Investment in subsidiary — (220.0 ) — 220.0 — Proceeds from sale of subsidiary — — — — — Acquisition of subsidiary — — — — — Other — — 33.6 — 33.6 Net cash from investing activities (385.6 ) (310.1 ) (982.3 ) 1,197.7 (480.3 ) Cash Flows From Financing Activities: Issuance of external debt — 600.0 90.3 — 690.3 Repayment of external debt and capital leases — (1,289.4 ) (404.2 ) — (1,693.6 ) Debt financing costs — (12.1 ) — — (12.1 ) Proceeds from exercise of share options 1.0 — — — 1.0 Intercompany loan borrowings — 977.7 — (977.7 ) — Intercompany dividends — (814.2 ) (741.8 ) 1,556.0 — Capital contribution — — 220.0 (220.0 ) — Repurchase of shares (57.5 ) — — — (57.5 ) Other 2.9 — (26.0 ) — (23.1 ) Net cash from financing activities (53.6 ) (538.0 ) (861.7 ) 358.3 (1,095.0 ) Effect of currency rate changes on cash — — (1.8 ) — (1.8 ) Net decrease in cash, cash equivalents and restricted cash (0.3 ) (768.0 ) (143.3 ) — (911.6 ) Cash, cash equivalents and restricted cash at beginning of period 0.7 908.8 369.6 — 1,279.1 Cash, cash equivalents and restricted cash at end of period $ 0.4 $ 140.8 $ 226.3 $ — $ 367.5 Cash and cash equivalents at end of period $ 0.4 $ 140.8 $ 207.7 $ — $ 348.9 Restricted cash included in prepaid expenses and other assets at end of period — — — — — Restricted cash included in other long-term assets at end of period — — 18.6 — 18.6 Cash, cash equivalents and restricted cash at end of period $ 0.4 $ 140.8 $ 226.3 $ — $ 367.5 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Fiscal year ended December 29, 2017 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 1,233.2 $ 1,139.4 $ 2,274.9 $ (3,920.2 ) $ 727.3 Cash Flows From Investing Activities: Capital expenditures — — (186.1 ) — (186.1 ) Acquisitions, net of cash acquired — — (76.3 ) — (76.3 ) Proceeds from disposal of discontinued operations, net of cash — — 576.9 — 576.9 Intercompany loan investment (589.5 ) — (1,157.9 ) 1,747.4 — Investment in subsidiary — (1,475.3 ) — 1,475.3 — Other — — 3.9 — 3.9 Net cash from investing activities (589.5 ) (1,475.3 ) (839.5 ) — 3,222.7 318.4 Cash Flows From Financing Activities: Issuance of external debt — 1,400.0 65.0 — 1,465.0 Repayment of external debt and capital leases — (764.5 ) (152.7 ) — (917.2 ) Debt financing costs — (12.7 ) — — (12.7 ) Proceeds from exercise of share options 4.1 — — — 4.1 Intercompany loan borrowings — 1,747.4 — (1,747.4 ) — Intercompany dividends — (1,170.0 ) (2,750.2 ) 3,920.2 — Capital contribution — — 1,475.3 (1,475.3 ) — Repurchase of shares (651.7 ) — — — (651.7 ) Other 4.1 — (21.8 ) — (17.7 ) Net cash from financing activities (643.5 ) 1,200.2 — (1,384.4 ) 697.5 (130.2 ) Effect of currency rate changes on cash — — 2.5 — 2.5 Net increase in cash, cash equivalents and restricted cash 0.2 864.3 53.5 — 918.0 Cash, cash equivalents and restricted cash at beginning of period 0.5 44.5 316.1 — 361.1 Cash, cash equivalents and restricted cash at end of period $ 0.7 $ 908.8 $ 369.6 $ — $ 1,279.1 Cash and cash equivalents at end of period $ 0.7 $ 908.8 $ 351.4 $ — $ 1,260.9 Restricted cash included in prepaid expenses and other assets at end of period — — — — — Restricted cash included in other long-term assets at end of period — — 18.2 — 18.2 Cash, cash equivalents and restricted cash at end of period $ 0.7 $ 908.8 $ 369.6 $ — $ 1,279.1 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Fiscal year ended September 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 17.9 $ (47.4 ) $ 1,214.1 $ — $ 1,184.6 Cash Flows From Investing Activities: Capital expenditures — — (182.9 ) — (182.9 ) Acquisitions, net of cash acquired — — (245.4 ) — (245.4 ) Proceeds from disposal of discontinued operations, net of cash — 234.0 32.7 — 266.7 Intercompany loan investment — (175.2 ) (1,714.5 ) 1,889.7 — Investment in subsidiary — (861.2 ) — 861.2 — Proceeds from sale of subsidiary 3.4 — — (3.4 ) — Acquisition of subsidiary — — (3.4 ) 3.4 — Other — — 6.0 — 6.0 Net cash from investing activities 3.4 (802.4 ) (2,107.5 ) — 2,750.9 (155.6 ) Cash Flows From Financing Activities: Issuance of external debt — — 98.3 — 98.3 Repayment of external debt and capital leases — (549.2 ) (19.4 ) — (568.6 ) Debt financing costs — — (0.1 ) — (0.1 ) Proceeds from exercise of share options 14.0 — — — 14.0 Intercompany loan borrowings 617.8 1,271.9 — (1,889.7 ) — Capital contribution — — 861.2 (861.2 ) — Repurchase of shares (652.9 ) — — — (652.9 ) Other — — (53.0 ) — (53.0 ) Net cash from financing activities (21.1 ) 722.7 — 887.0 (2,750.9 ) (1,162.3 ) Effect of currency rate changes on cash — — 0.3 — 0.3 Net increase (decrease) in cash, cash equivalents and restricted cash 0.2 (127.1 ) (6.1 ) — (133.0 ) Cash, cash equivalents and restricted cash at beginning of period 0.1 152.1 280.4 — 432.6 Cash, cash equivalents and restricted cash at end of period $ 0.3 $ 25.0 $ 274.3 $ — $ 299.6 Cash and cash equivalents at end of period $ 0.3 $ 25.0 $ 255.2 $ — $ 280.5 Restricted cash included in prepaid expenses and other assets at end of period — — 0.1 — 0.1 Restricted cash included in other long-term assets at end of period — — 19.0 — 19.0 Cash, cash equivalents and restricted cash at end of period $ 0.3 $ 25.0 $ 274.3 $ — $ 299.6 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Three months ended December 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 17.4 $ (94.0 ) $ 272.2 $ — $ 195.6 Cash Flows From Investing Activities: Capital expenditures — — (65.2 ) — (65.2 ) Acquisitions, net of cash acquired — — (1.8 ) — (1.8 ) Intercompany loan investment — — (424.7 ) 424.7 — Subsidiary dividend proceeds — — — — — Investment in subsidiary — (260.0 ) — 260.0 — Other — — (10.2 ) — (10.2 ) Net cash from activities — (260.0 ) (501.9 ) — 684.7 (77.2 ) Cash Flows From Financing Activities: Issuance of external debt — 175.0 15.0 — 190.0 Repayment of external debt and capital leases — (86.2 ) (0.5 ) — (86.7 ) Debt financing costs — — — — — Proceeds from exercise of share options 0.4 — — — 0.4 Subsidiary dividend payment — — — — — Intercompany loan borrowings 140.0 284.7 — (424.7 ) — Capital contribution — — 260.0 (260.0 ) — Repurchase of shares (158.8 ) — — — (158.8 ) Other 1.2 — — — 1.2 Net cash from financing activities (17.2 ) 373.5 — 274.5 (684.7 ) (53.9 ) Effect of currency rate changes on cash — — (3.0 ) — (3.0 ) Net increase in cash, cash equivalents and restricted cash 0.2 19.5 41.8 — 61.5 Cash, cash equivalents and restricted cash at beginning of period 0.3 25.0 274.3 — 299.6 Cash, cash equivalents and restricted cash at end of period $ 0.5 $ 44.5 $ 316.1 $ — $ 361.1 Cash and cash equivalents at end of period $ 0.5 $ 44.5 $ 297.0 $ — $ 342.0 Restricted cash included in prepaid expenses and other assets at end of period — — 0.1 — 0.1 Restricted cash included in other long-term assets at end of period — — 19.0 — 19.0 Cash, cash equivalents and restricted cash at end of period $ 0.5 $ 44.5 $ 316.1 $ — $ 361.1

Subsequent Events (Notes)

Subsequent Events (Notes)	12 Months Ended
	Dec. 28, 2018
Subsequent Event [Line Items]
Subsequent Events [Text Block]	25. Subsequent Events Reorganization of Intercompany Financing and Legal Entity Ownership On January 26, 2019, the Company completed a reorganization of its intercompany financing and associated legal entity ownership in response to the changing global tax environment. The Company initiated the reorganization during the three months ended September 28, 2018 and continued the reorganization during the three months ended December 28, 2018. During the three months ending March 29, 2019, the Company expects to recognize a net income tax benefit of $125.0 million to $175.0 million which will serve to reduce its net deferred tax liabilities by a similar amount. The reduction to net deferred tax liabilities is expected to be comprised predominantly of the elimination of the December 28, 2018 balance of interest-bearing U.S. deferred tax liabilities of $227.5 million offset by a decrease to other deferred tax assets. The elimination of the interest-bearing deferred tax obligation will also eliminate the annual Internal Revenue Code section 453A interest expense. During fiscal 2018, the Company recognized current income tax expense of $25.5 million and a deferred income tax benefit of $281.5 million with a corresponding reduction to net deferred tax liabilities. See Note 9 for further details regarding the fiscal 2018 impact. Financing Activitie s On December 31, 2018, the Company made a $25.0 million voluntary prepayment on its outstanding term loan due September 2024 and $5.6 million of quarterly principal amortization payments on its outstanding term loans. On February 14, 2019, the Company made a $175.0 million voluntary prepayment on its outstanding term loan due February 2025. Subsequent to fiscal 2018 and up through the date of this filing, the Company repurchased fixed-rate debt that aggregated to a principal amount of $75.0 million . Commitments and Contingencies Certain litigation matters occurred in fiscal 2018

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts (Notes)	12 Months Ended
	Dec. 28, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	Financial Statement Schedules. The financial statement schedule is included below. All other schedules have been omitted because they are not applicable, not required or the information is included in the financial statements or notes thereto. Schedule II - Valuation and Qualifying Accounts (in millions) Description Balance at Beginning of Period Charged to Income Additions and Other Deductions Balance at End of Period Allowance for doubtful accounts: Fiscal year ended December 28, 2018 $ 3.9 $ 3.8 $ — $ (2.7 ) $ 5.0 Fiscal year ended December 29, 2017 4.0 0.6 — (0.7 ) 3.9 Three months ended December 30, 2016 4.0 0.1 — (0.1 ) 4.0 Fiscal year ended September 30, 2016 3.6 0.3 — 0.1 4.0 Sales reserve accounts: Fiscal year ended December 28, 2018 $ 376.6 $ 2,387.5 $ — $ (2,358.7 ) $ 405.4 Fiscal year ended December 29, 2017 391.3 2,008.5 — (2,023.2 ) 376.6 Three months ended December 30, 2016 378.0 515.3 — (502.0 ) 391.3 Fiscal year ended September 30, 2016 396.4 2,030.8 — (2,049.2 ) 378.0 Tax valuation allowance: Fiscal year ended December 28, 2018 $ 2,267.9 $ 332.8 $ 4.2 $ — $ 2,604.9 Fiscal year ended December 29, 2017 1,398.3 804.6 4.0 61.0 2,267.9 Three months ended December 30, 2016 564.9 833.4 — — 1,398.3 Fiscal year ended September 30, 2016 233.0 315.7 15.8 0.4 564.9

Background and Basis of Prese_2

Background and Basis of Presentation (Policies)	12 Months Ended
	Dec. 28, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	The consolidated financial statements have been prepared in U.S. dollars and in accordance with accounting principles generally accepted in the U.S. ("GAAP").
Use of Estimates	The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amount of assets and liabilities, disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses. Actual results may differ from those estimates.
Consolidation	The consolidated financial statements include the accounts of the Company, its wholly-owned subsidiaries and entities in which they own or control more than 50% of the voting shares, or have the ability to control through similar rights. All intercompany balances and transactions have been eliminated in consolidation and all normal recurring adjustments necessary for a fair presentation have been included in the results reported.
Fiscal Period	Fiscal YearThe Company reports its results based on a "52-53 week" year ending on the last Friday of December. Fiscal 2018 and 2017 each consisted of 52 weeks and fiscal 2016 consisted of 53 weeks. On May 17, 2016, the Board of Directors of the Company approved a change in the Company’s fiscal year end to the last Friday in December from the last Friday in September. The change in fiscal year became effective for the Company’s 2017 fiscal year, which began on December 31, 2016 and ended on December 29, 2017. As a result of the change in fiscal year end, the Company filed a Transition Report on Form 10-Q on February 7, 2017 covering the period from October 1, 2016 through December 30, 2016 ("the three months ended December 30, 2016") with the comparable period from September 26, 2015 through December 25, 2015. Fiscal 2016 covers the period from September 26, 2015 through September 30, 2016.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 28, 2018
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition Product Sales Revenue The Company sells its products through independent channels, including direct to retail pharmacies, end user customers and through distributors who resell the products to retail pharmacies, institutions and end user customers, while certain products are sold and distributed to hospitals. The Company also enters into arrangements with indirect customers, such as health care providers and payers, wholesalers, government agencies, institutions, managed care organizations and group purchasing organizations to establish contract pricing for certain products that provide for government-mandated and/or privately-negotiated rebates, sales incentives, chargebacks, distribution service agreements fees, fees for services and administration fees, and discounts with respect to the purchase of the Company's products. Reserve for Variable Considerations Product sales are recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established. These reserves result from estimated chargebacks, rebates, product returns and other sales deductions that are offered within contracts between the Company and its customers, health care providers and payers relating to the Company’s sales of its products. These reserves are based on the amounts earned or to be claimed on the related sales and are classified as reductions of accounts receivable (if the amount is payable to the customer) or a current liability (if the amount is payable to a party other than a customer). Where appropriate, these estimates take into consideration a range of possible outcomes which are probability-weighted for relevant factors such as the Company’s historical experience, estimated future trends, estimated customer inventory levels, current contracted sales terms with customers, level of utilization of the Company’s products and other competitive factors. Overall, these reserves reflect the Company’s best estimate of the amount of consideration to which it is entitled based on the terms of the contract. The amount of variable consideration which is included in the transaction price may be constrained (reduced), and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. The Company adjusts reserves for chargebacks, rebates, product returns and other sales deductions to reflect differences between estimated and actual experience. Such adjustments impact the amount of net sales recognized in the period of adjustment. Product sales are recognized when the customer obtains control of the Company's product. Control is transferred either at a point in time, generally upon delivery to the customer site, or in the case of certain of the Company's products, over the period in which the customer has access to the product and related services. Revenue recognized over time is based upon either consumption of the product or passage of time based upon the Company's determination of the measure that best aligns with how the obligation is satisfied. The Company's considerations of why such measures provide a faithful depiction of the transfer of its products are as follows: • For those contracts whereby revenue is recognized over time based upon consumption of the product, the Company either has: 1. the right to invoice the customer in an amount that directly corresponds with the value to the customer of the Company's performance to date, for which the practical expedient to recognize in proportion to the amount it has the right to invoice has been applied, or 2. the remaining goods and services to which the customer is entitled is diminished upon consumption. • For those contracts whereby revenue is recognized over time based upon the passage of time, the benefit that the customer receives from unlimited access to the Company's product does not vary, regardless of consumption. As a result, the Company's obligation diminishes with the passage of time; therefore, it was determined that ratable recognition of the transaction price over the contract period is the measure that best aligns with how the obligation is satisfied. Transaction price allocated to the remaining performance obligations The majority of the Company's contracts are less than one year; therefore, the related disclosure of the amount of transaction price allocated to the performance obligations that are unsatisfied at period end has been omitted. Cost to obtain a contract As the majority of the Company's contracts are short-term in nature, sales commissions are generally expensed when incurred as the amortization period would have been less than one year. These costs are recorded within selling, general and administrative expense ("SG&A") in the consolidated statements of income. For contracts that extend beyond one year, the incremental expense recognition matches the recognition of related revenue. Costs to fulfill a contract The Company capitalizes the costs associated with the devices used in the Company's portfolio of drug-device combination products, which are used in satisfaction of future performance obligations. Capital expenditures for these devices represent cash outflows for the Company's cost to produce the asset, which is classified in property, plant and equipment, net on the consolidated balance sheets and expensed to cost of sales over the useful life of the equipment. Product Royalty Revenues In relation to the Company's acquisition of Sucampo Pharmaceuticals, Inc. ("Sucampo") in fiscal 2018, as discussed further in Note 7, it acquired an arrangement under which the Company licenses certain rights to Amitiza to a third party in exchange for royalties on net sales of the product. The Company recognizes such royalty revenue as the related sales occur. Contract Balances Accounts receivable are recorded when the right to consideration becomes unconditional. Payments received from customers are typically based upon payment terms of 30 days. The Company does not maintain contract asset balances aside from the accounts receivable balance as presented on the consolidated balance sheets as costs to obtain a contract are expensed when incurred as the amortization period would have been less than one year. These costs are recorded within SG&A on the consolidated statements of income. Contract liabilities are recorded when cash payments are received in advance of the Company's performance, including amounts which are refundable.
Shipping and Handling Costs	Shipping and Handling CostsShipping costs, which are costs incurred to physically move product from the Company's premises to the customer's premises, are classified as SG&A. Handling costs, which are costs incurred to store, move and prepare product for shipment, are classified as cost of sales.
Research and Development	Research and Development Internal research and development costs are expensed as incurred. Research and development ("R&D") expenses include salary and benefits, allocated overhead and occupancy costs, clinical trial and related clinical manufacturing costs, contract services, medical affairs and other costs.
Currency Translation	Currency Translation For the Company's non-U.S. subsidiaries that transact in a functional currency other than U.S. dollars, assets and liabilities are translated into U.S. dollars using fiscal year-end exchange rates. Revenues and expenses are translated at the average exchange rates in effect during the related month. The net effect of these translation adjustments is shown in the consolidated financial statements as a component of accumulated other comprehensive loss. For subsidiaries operating in highly inflationary environments or where the functional currency is different from the local currency, non-monetary assets and liabilities are translated at the rate of exchange in effect on the date the assets and liabilities were acquired or assumed, while monetary assets and liabilities are translated at fiscal year-end exchange rates. The Company also entered into derivative instruments to mitigate the exposure of movements in certain of these foreign currency transactions. The Company recognized the following during the respective periods: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 Foreign currency (losses), gains $ (3.1 ) $ 2.5 $ (3.6 ) $ 9.0 Derivative hedge gains (losses) 2.7 (4.1 ) 0.2 (8.9 )
Cash and Cash Equivalents	Cash and Cash EquivalentsThe Company classifies cash on hand and deposits in banks, including commercial paper, money market accounts and other investments it may hold from time to time, with an original maturity to the Company of three months or less, as cash and cash equivalents.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable are presented net of an allowance for doubtful accounts. The allowance for doubtful accounts reflects an estimate of losses inherent in the Company's accounts receivable portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other available evidence. Accounts receivable are written off when management determines they are uncollectible. Trade accounts receivable are also presented net of reserves related to chargebacks and rebates payable to customers for whom the Company has trade accounts receivable and the right of offset exists.
Inventories	InventoriesInventories are recorded at the lower of cost or net realizable value, primarily using the first-in, first-out convention. The Company reduces the carrying value of inventories for those items that are potentially excess, obsolete or slow-moving based on changes in customer demand, technology developments or other economic factors.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost. Major renewals and improvements are capitalized, while routine maintenance and repairs are expensed as incurred. Depreciation for property, plant and equipment assets, other than land and construction in process, is generally based upon the following estimated useful lives, using the straight-line method: Buildings 10 to 45 years Leasehold improvements 1 to 20 years Capitalized software 1 to 10 years Machinery and equipment 1 to 20 years The Company capitalizes certain computer software and development costs incurred in connection with developing or obtaining software for internal use. Upon retirement or other disposal of property, plant and equipment, the cost and related amount of accumulated depreciation are eliminated from the asset and accumulated depreciation accounts, respectively. The difference, if any, between the net asset value and the proceeds is included in net income. The Company assesses the recoverability of assets or asset groups using undiscounted cash flows whenever events or circumstances indicate that the carrying value of an asset or asset group may not be recoverable. If an asset or asset group is found to be impaired, the amount recognized for impairment is equal to the difference between the carrying value of the asset or asset group and its fair value.
Acquisitions	Acquisitions Amounts paid for acquisitions are allocated to the tangible assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. The Company then allocates the purchase price in excess of net tangible assets acquired to identifiable intangible assets, including purchased R&D. The fair value of identifiable intangible assets is based on detailed valuations. The Company allocates any excess purchase price over the fair value of the net tangible and intangible assets acquired to goodwill. The Company's purchased R&D represents the estimated fair value as of the acquisition date of in-process projects that have not reached technological feasibility. The primary basis for determining technological feasibility of these projects is obtaining regulatory approval. The fair value of in-process research and development ("IPR&D") is determined using the discounted cash flow method. In determining the fair value of IPR&D, the Company considers, among other factors, appraisals, the stage of completion of the projects, the technological feasibility of the projects, whether the projects have an alternative future use and the estimated residual cash flows that could be generated from the various projects and technologies over their respective projected economic lives. The discount rate used includes a rate of return which accounts for the time value of money, as well as risk factors that reflect the economic risk that the cash flows projected may not be realized.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess of the purchase price of an acquired entity over the amounts assigned to assets and liabilities assumed in a business combination. The Company tests goodwill for impairment on the first day of the fourth quarter of each fiscal year, or whenever events or changes in circumstances indicate that the carrying value may not be recoverable. The impairment test is comprised of comparing the carrying value of a reporting unit to its estimated fair value. The Company estimates the fair value of a reporting unit through internal analyses and valuation, utilizing an income approach (a level three measurement technique) based on the present value of future cash flows. The fair value of the Company's reporting units is reconciled to its share price and market capitalization as a corroborative step. If the carrying value of a reporting unit exceeds its fair value, the Company will recognize the excess of the carrying value over the fair value as a goodwill impairment loss. Intangible assets acquired in a business combination are recorded at fair value, while intangible assets acquired in other transactions are recorded at cost. Intangible assets with finite useful lives are subsequently amortized, generally using the straight-line method, over the following estimated useful lives of the assets, except for customer relationships which are amortized over the estimated pattern of benefit from these relationships: Completed technology 5 to 25 years License agreements 7 to 30 years Trademarks 13 to 30 years Customer relationships 12 years Amortization expense related to completed technology and certain other intangible assets is included in cost of sales, while amortization expense related to intangible assets that contribute to the Company's ability to sell, market and distribute products is included in SG&A.
Contingencies	ContingenciesThe Company is subject to various patent infringement claims, product liability matters, government investigations, environmental matters, employee disputes, contractual disputes and other commercial disputes, and other legal proceedings in the ordinary course of business as further discussed in Note 20. The Company records accruals for contingencies when it is probable that a liability has been incurred and the amount can be reasonably estimated. The Company discounts environmental liabilities using a risk-free rate of return when the obligation is fixed or reasonably determinable. The impact of the discount in the consolidated balance sheets was not material in any period presented. Legal fees, other than those pertaining to environmental and asbestos matters, are expensed as incurred. Insurance recoveries related to potential claims are recognized up to the amount of the recorded liability when coverage is confirmed and the estimated recoveries are probable of payment. Assets and liabilities are not netted for financial statement presentation.
Share-Based Compensation	Share-Based CompensationThe Company recognizes the cost of employee services received in exchange for awards of equity instruments based on the grant-date fair value of those awards. That cost is recognized over the period during which an employee is required to provide service in exchange for the award, the requisite service period (generally the vesting period).
Restructuring	RestructuringThe Company recognizes charges associated with board approved restructuring programs designed to transform its business and improve its cost structure. Restructuring charges can include severance costs, infrastructure charges, distributor contract cancellations and other items. The Company accrues for costs when they are probable and reasonably estimable.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recognized for the expected future tax consequences of events that have been reflected in the consolidated financial statements. Deferred tax assets and liabilities are determined based on the differences between the book and tax bases of assets and liabilities and operating loss carryforwards, using tax rates expected to be in effect for the years in which the differences are expected to reverse. A valuation allowance is provided to reduce net deferred tax assets if, based upon the available evidence, it is more likely than not that some or all of the deferred tax assets will not be realized. Deferred tax liabilities are also recorded for deferred tax obligations related to installment sale arrangements. The deferral of tax payments to the U.S. Internal Revenue Service ("IRS") are subject to interest, which is accrued and included within interest expense. The Company determines whether it is more likely than not that a tax position will be sustained upon examination. The tax benefit of any tax position that meets the more-likely-than-not recognition threshold is calculated as the largest amount that is more than 50% likely of being realized upon resolution of the uncertainty. To the extent a full benefit is not expected to be realized on the uncertain tax position, an income tax liability is established. Interest and penalties on income tax obligations, associated with uncertain tax positions, are included in the provision for income taxes.

Earnings (Loss) per Share (Poli

Earnings (Loss) per Share (Policies)	12 Months Ended
	Dec. 28, 2018
Earnings (Loss) per Share [Abstract]
Earnings (Loss) Per Share Policy	Basic (loss) earnings per share is computed by dividing net (loss) income by the number of weighted-average shares outstanding during the period. Diluted (loss) earnings per share was computed using the weighted-average shares outstanding and, if dilutive, potential ordinary shares outstanding during the period. Potential ordinary shares represent the incremental ordinary shares issuable for restricted share units and share option exercises. The Company calculated the dilutive effect of outstanding restricted share units and share options on (loss) earnings per share by application of the treasury stock method.Dilutive securities, including participating securities, are not included in the computation of loss per share when the Company reports a net loss from continuing operations as the impact would be anti-dilutive.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 28, 2018
Accounting Policies [Abstract]
Schedule of Useful Lives for Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost. Major renewals and improvements are capitalized, while routine maintenance and repairs are expensed as incurred. Depreciation for property, plant and equipment assets, other than land and construction in process, is generally based upon the following estimated useful lives, using the straight-line method: Buildings 10 to 45 years Leasehold improvements 1 to 20 years Capitalized software 1 to 10 years Machinery and equipment 1 to 20 years The Company capitalizes certain computer software and development costs incurred in connection with developing or obtaining software for internal use. Upon retirement or other disposal of property, plant and equipment, the cost and related amount of accumulated depreciation are eliminated from the asset and accumulated depreciation accounts, respectively. The difference, if any, between the net asset value and the proceeds is included in net income. The Company assesses the recoverability of assets or asset groups using undiscounted cash flows whenever events or circumstances indicate that the carrying value of an asset or asset group may not be recoverable. If an asset or asset group is found to be impaired, the amount recognized for impairment is equal to the difference between the carrying value of the asset or asset group and its fair value.
Schedule of Useful Lives for Finite Lived Intangible Assets	Intangible assets with finite useful lives are subsequently amortized, generally using the straight-line method, over the following estimated useful lives of the assets, except for customer relationships which are amortized over the estimated pattern of benefit from these relationships: Completed technology 5 to 25 years License agreements 7 to 30 years Trademarks 13 to 30 years Customer relationships 12 years
Foreign Currency Transactions and Translations [Table Text Block]	The Company recognized the following during the respective periods: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 Foreign currency (losses), gains $ (3.1 ) $ 2.5 $ (3.6 ) $ 9.0 Derivative hedge gains (losses) 2.7 (4.1 ) 0.2 (8.9 )
Shipping and Handling Cost	Shipping costs included in SG&A expenses in continuing operations were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Shipping and handling costs $ 12.8 $ 13.9 $ 12.4 $ 3.4

Recently Issued Accounting St_2

Recently Issued Accounting Standards Recently Issued Accounting Standards (Tables)	12 Months Ended
	Dec. 28, 2018
Prior Period Reclassification Amounts [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]	The Company adopted this guidance in fiscal 2018 which required retroactive application resulting in the reclassification of the following: Fiscal Year Ended Three Months Ended December 29, September 30, December 30, Cost of sales $ 1.2 $ 2.6 $ 0.9 Selling, general and administrative expenses 71.2 11.6 47.2 Research and development expenses 0.4 1.0 0.1 Restructuring charges, net — 0.6 — Other income (expense), net $ 72.8 $ 15.8 $ 48.2

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 28, 2018
Revenue from Contract with Customer [Abstract]
Sales Reserves Rollforward [Table Text Block]	The following table reflects activity in the Company’s sales reserve accounts: Rebates and Chargebacks Product Returns Other Sales Deductions Total Balance as of December 29, 2017 $ 327.4 $ 34.5 $ 14.7 $ 376.6 Provisions 2,281.3 39.3 66.9 2,387.5 Payments or credits (2,254.4 ) (39.8 ) (64.5 ) (2,358.7 ) Balance as of December 28, 2018 $ 354.3 $ 34.0 $ 17.1 $ 405.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	Transaction price allocated to the remaining performance obligations The following table includes estimated revenue from contracts extending greater than one year for certain of the Company’s hospital products that are expected to be recognized in the future related to performance obligations that are unsatisfied or partially unsatisfied at December 28, 2018 : Fiscal 2019 $ 145.0 Fiscal 2020 127.3 Fiscal 2021 32.6 Thereafter 3.2
Contract with Customer, Asset and Liability [Table Text Block]	The following table reflects the balance of the Company's contract liabilities at the end of the respective periods: December 28, December 29, Accrued and other current liabilities $ 20.4 $ 14.0 Other liabilities 15.1 6.6 Contract liabilities $ 35.5 $ 20.6

Discontinued Operations and D_2

Discontinued Operations and Divestitures (Tables)	12 Months Ended
	Dec. 28, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Schedule of Income (Loss) from Discontinued Operations	The following table summarizes the financial results of the CMDS business for fiscal 2016 as presented in the consolidated statement of income: Fiscal Year Ended Major line items constituting (loss) income from discontinued operations September 30, 2016 Net sales $ 61.0 Cost of sales 46.9 Selling, general and administrative 20.3 Other 1.2 Loss from discontinued operations (7.4 ) Gain on disposal of discontinued operations 95.3 Income from discontinued operations, before income taxes 87.9 Income tax benefit (2.5 ) Income from discontinued operations net of tax $ 90.4 Fiscal Year Ended Three Months Ended Major line items constituting income from discontinued operations December 29, 2017 September 30, 2016 December 30, 2016 Net sales $ 31.6 $ 418.6 $ 99.4 Cost of sales 15.6 216.6 44.7 Selling, general and administrative 7.8 83.7 16.4 Restructuring charges, net — 2.3 — Other (0.2 ) 5.7 0.2 Income from discontinued operations 8.4 110.3 38.1 Gain on disposal of discontinued operations 362.8 — — Income from discontinued operations, before income taxes 371.2 110.3 38.1 Income tax expense 5.2 49.0 15.3 Income from discontinued operations, net of tax $ 366.0 $ 61.3 $ 22.8
Schedule of Assets and Liabilities Held-For-Sale
Schedule of Significant Cash and Non-Cash Transactions	The following table summarizes significant cash and non-cash transactions of the Nuclear Imaging business that are included within the consolidated statements of cash flows for the respective periods: Fiscal Year Ended Three Months Ended December 29, 2017 September 30, 2016 December 30, 2016 Depreciation $ — $ 20.9 $ — Capital expenditures 0.3 9.7 2.0

Acquisitions and License Agre_2

Acquisitions and License Agreements (Tables)	12 Months Ended
	Dec. 28, 2018
Business Combinations [Abstract]
Schedule of Fair Value of Identifiable Assets Acquired and Liabilities Assumed	The following amounts represent the allocation of the fair value of the identifiable assets acquired and liabilities assumed for the respective acquisitions: Sucampo Ocera (1) InfaCare (2) Stratatech Hemostasis (3) Acquisition Date February 2018 December 2017 September 2017 August 2016 February 2016 Cash $ 149.6 $ 1.0 $ 1.3 $ 0.2 $ 3.3 Accounts receivable 35.7 — — 1.3 — Inventory 153.2 — — — 94.6 Intangible assets 919.5 64.5 113.5 99.8 132.7 Goodwill (non-tax deductible) (4) 248.6 18.0 11.4 55.1 3.3 Other assets, current and non-current 25.8 0.4 0.1 1.9 7.9 Total assets acquired 1,532.4 83.9 126.3 158.3 241.8 Current liabilities 109.4 12.0 14.5 4.3 3.6 Other liabilities (non-current) 33.3 — — — 10.6 Deferred tax liabilities, net (non-current) 175.8 16.7 8.7 22.1 2.1 Contingent consideration (non-current) — 12.8 35.0 54.9 52.0 Debt 366.3 — 30.0 1.0 — Total liabilities assumed 684.8 41.5 88.2 82.3 68.3 Net assets acquired $ 847.6 $ 42.4 $ 38.1 $ 76.0 $ 173.5 (1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million was paid in fiscal 2017 and 2018, respectively. (2) During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million fair value adjustment. Refer to Note 21 for further information. (3) During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information. (4) Refer to Note 13 for further information relating to the full goodwill impairment recorded in fiscal 2018.	[1],[2]
Schedule of Reconciliation of Total Consideration	The following reconciles the total consideration to net assets acquired: Sucampo Ocera (1) InfaCare Stratatech Hemostasis Total consideration, net of cash $ 698.0 $ 63.4 $ 71.8 $ 130.7 $ 222.2 Plus: cash assumed in acquisition 149.6 1.0 1.3 0.2 3.3 Total consideration 847.6 64.4 73.1 130.9 225.5 Less: non-cash contingent consideration — (22.0 ) (35.0 ) (54.9 ) (52.0 ) Net assets acquired $ 847.6 $ 42.4 $ 38.1 $ 76.0 $ 173.5 (1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date.
Schedule of Acquisition Cost	Acquisition-Related Costs - Acquisition-related costs incurred for each of the acquisitions discussed above were as follows: Fiscal Year Ended Three Months Ended Acquisition-related costs December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Sucampo $ 5.2 $ 4.2 $ — $ — Ocera 0.5 0.9 — — InfaCare — 1.2 — — Stratatech — — 3.7 — Hemostasis — — 2.7 0.1 Other 0.1 0.1 0.5 — Total acquisition-related costs $ 5.8 $ 6.4 $ 6.9 $ 0.1
Schedule of Intangible Assets Acquired	Intangible assets acquired consist of the following: Acquisition Intangible Asset Acquired Amount Amortization Period Discount Rate Segment Sucampo Completed technology - Amitiza $ 634.0 9 years 14.0 % Specialty Generics and Amitiza Sucampo Completed technology - Other 11.0 8 years 14.0 % Specialty Generics and Amitiza Sucampo In-process research and development - VTS-270 274.5 Non-Amortizable 15.0 % Specialty Brands Ocera In-process research and development - MNK-6105/6106 64.5 Non-Amortizable 15.5 % Specialty Brands InfaCare In-process research and development - stannsoporfin 113.5 Non-Amortizable 13.5 % Specialty Brands Stratatech In-process research and development - StrataGraft 99.8 Non-Amortizable 16.5 % Specialty Brands Hemostasis Completed technology - Raplixa (1) 73.0 15 years 17.0 % Specialty Brands Hemostasis Completed technology - Recothrom (2) 42.7 13 years 16.0 % Specialty Brands Hemostasis Completed technology - PreveLeak (2) 17.0 13 years 17.0 % Specialty Brands (1) During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to the Raplixa intangible asset. Refer to Note 13 for further information. (2) During fiscal 2018, the Company sold the Recothrom and PreveLeak assets to Baxter. Refer to Note 6 for further information.	[3]
[1]	(1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million
[2]	During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million
[3]	(1)During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to the Raplixa intangible asset. Refer to Note 13 for further information.

Restructuring and Related Cha_2

Restructuring and Related Charges (Tables)	12 Months Ended
	Dec. 28, 2018
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Charges by Segment	Net restructuring and related charges by segment from continuing operations are as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Specialty Brands $ 52.2 $ 25.4 $ 23.3 $ 2.6 Specialty Generics and Amitiza 29.0 7.7 3.4 0.8 Corporate 27.0 3.3 10.9 1.9 Restructuring and related charges, net 108.2 36.4 37.6 5.3 Less: accelerated depreciation (5.2 ) (5.2 ) (4.9 ) (1.5 ) Restructuring charges, net $ 103.0 $ 31.2 $ 32.7 $ 3.8 Charges in other income (expense) (1) $ — $ — $ 0.6 $ —
Schedule of Net Restructuring and Related Charges	Net restructuring and related charges by program from continuing operations are comprised of the following: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 2018 Mallinckrodt Program $ 5.2 $ — $ — $ — 2016 Mallinckrodt Program 71.6 36.2 8.3 5.2 2013 Mallinckrodt Program — (0.7 ) 25.6 — Acquisition programs 31.4 0.9 3.7 0.1 Total programs 108.2 36.4 37.6 5.3 Less: non-cash charges, including accelerated depreciation and impairments (5.2 ) (5.2 ) (4.9 ) (1.5 ) Total charges expected to be settled in cash $ 103.0 $ 31.2 $ 32.7 $ 3.8 Charges in other income (expense) (1) $ — $ — $ 0.6 $ —
Schedule of Restructuring Reserves by Type of Cost	The following table summarizes cash activity for restructuring reserves, substantially all of which related to contract termination costs, employee severance and benefits and exiting of certain facilities: 2018 Mallinckrodt Program 2016 Mallinckrodt Program 2013 Mallinckrodt Program Acquisition Programs Total Balance at September 25, 2015 $ — $ — $ 8.0 $ 10.0 $ 18.0 Charges from continuing operations — 6.4 24.0 5.0 35.4 Charges from discontinued operations — — 2.5 — 2.5 Changes in estimate from continuing operations — — (1.4 ) (1.3 ) (2.7 ) Changes in estimate from discontinued operations — — (0.3 ) — (0.3 ) Cash payments — (0.2 ) (20.3 ) (13.2 ) (33.7 ) Reclassifications (1) — — (0.7 ) — (0.7 ) Balance at September 30, 2016 — 6.2 11.8 0.5 18.5 Charges from continuing operations — 3.7 — 0.1 3.8 Cash payments — (0.4 ) (6.7 ) (0.4 ) (7.5 ) Balance at December 30, 2016 — 9.5 5.1 0.2 14.8 Charges from continuing operations — 35.8 — 0.9 36.7 Changes in estimate from continuing operations — (4.8 ) (0.7 ) — (5.5 ) Cash payments — (26.1 ) (4.4 ) (0.3 ) (30.8 ) Reclassifications — 0.3 — — 0.3 Balance at December 29, 2017 — 14.7 — 0.8 15.5 Charges from continuing operations 2.2 76.9 — 29.9 109.0 Changes in estimate from continuing operations — (5.3 ) — (0.7 ) (6.0 ) Cash payments — (23.4 ) — (22.2 ) (45.6 ) Reclassifications — (1.9 ) — — (1.9 ) Balance at December 28, 2018 $ 2.2 $ 61.0 $ — $ 7.8 $ 71.0 (1)	[1]
Schedule of Restructuring Charges Incurred Cumulative to Date	Net restructuring and related charges, including associated asset impairments, incurred cumulative to date related to the 2018, 2016 and 2013 Mallinckrodt Programs are as follows: 2018 Mallinckrodt Program 2016 Mallinckrodt Program 2013 Mallinckrodt Program Specialty Brands $ 3.0 $ 81.7 $ 18.8 Specialty Generics and Amitiza — 14.6 18.3 Discontinued Operations — — 69.9 Corporate 2.2 25.9 17.7 $ 5.2 $ 122.2 $ 124.7
[1]	Represents the reclassification of pension and other postretirement benefits from restructuring reserves to pension and postretirement obligations.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 28, 2018
Income Tax Disclosure [Abstract]
Schedule of Components of Income from Continuing Operations before Income Taxes	The U.K. and non-U.K. components of (loss) income from continuing operations before income taxes were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 U.K. $ (233.7 ) $ (165.9 ) $ (275.3 ) $ (97.4 ) Non-U.K. (3,818.3 ) 227.5 508.7 (201.1 ) Total $ (4,052.0 ) $ 61.6 $ 233.4 $ (298.5 )
Schedule of Significant Components of Income Taxes Related to Continuing Operations	Significant components of income taxes related to continuing operations are as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Current: U.K. $ (0.2 ) $ 0.4 $ 0.3 $ — Non-U.K. 113.0 37.7 120.5 82.0 Current income tax provision 112.8 38.1 120.8 82.0 Deferred: U.K. 1.4 0.6 0.7 (0.5 ) Non-U.K. (544.3 ) (1,748.3 ) (377.1 ) (203.2 ) Deferred income tax benefit (542.9 ) (1,747.7 ) (376.4 ) (203.7 ) Total $ (430.1 ) $ (1,709.6 ) $ (255.6 ) $ (121.7 )
Schedule of Reconciliation of Income Taxes at Statutory Rate and Tax Provision	The reconciliation between U.K. income taxes at the statutory rate and the Company's provision for income taxes on continuing operations is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 (Benefit) provision for income taxes at U.K. statutory income tax rate (1) $ (770.1 ) $ 11.7 $ 46.6 $ (59.7 ) Adjustments to reconcile to income tax provision: Rate difference between U.K. and non-U.K. jurisdictions (2) (4) (235.7 ) (219.9 ) (249.3 ) (123.0 ) Valuation allowances, nonrecurring — (3.7 ) 2.1 — Adjustments to accrued income tax liabilities and uncertain tax positions 60.1 5.1 (14.9 ) 0.9 Interest and penalties on accrued income tax liabilities and uncertain tax positions 13.1 0.2 (16.4 ) (0.1 ) Investment in partnership — — — (12.7 ) Credits, principally research and orphan drug (3) (25.9 ) (13.8 ) (33.7 ) (0.7 ) Impairments non deductible 788.7 — — 75.3 Permanently nondeductible and nontaxable items 7.2 6.4 7.9 1.6 Pension plan settlement, release of tax effects lodged in other comprehensive income — (2.4 ) — — Divestitures (7) (2.7 ) 18.2 — — U.S. Tax Reform (5) (8.5 ) (456.9 ) — — Legal Entity Reorganization (6) (256.0 ) (1,054.8 ) — — Other (0.3 ) 0.3 2.1 (3.3 ) Benefit for income taxes $ (430.1 ) $ (1,709.6 ) $ (255.6 ) $ (121.7 ) (1) The statutory tax rate reflects the U.K. statutory tax rate of 19% for fiscal 2018 and 2017 and 20% for fiscal 2016 and the three months ended December 30, 2016. (2) Includes the impact of certain recurring valuation allowances for U.K. and non-U.K. jurisdictions. (3) During fiscal 2018, the research and orphan drug credits increased in conjunction with the Company's increased investment in qualified research. During fiscal 2016, the Company realized a tax benefit of $27.4 million resulting from a U.K. tax credit on a dividend between affiliates. (4) During the three months ended December 30, 2016, the rate difference between U.K. and non-U.K. jurisdictions was favorably impacted by a benefit of $16.1 million on a $102.0 million settlement with the Federal Trade Commission and a benefit of $34.5 million on a $207.0 million goodwill impairment in the Specialty Generics reporting unit. (5) For fiscal 2018, the Company completed its analysis of the TCJA and recognized an additional tax benefit. Other line items, to the extent U.S. related, are reflected at the current U.S. statutory income tax rate of 21%. For fiscal 2017, the benefit reflects the redetermination of the Company’s end of year net deferred tax liabilities as a result of the new U.S. statutory income tax rate of 21%. Other line items, to the extent U.S. related, are reflected at the former U.S. statutory income tax rate of 35%. (6) Associated unrecognized tax benefit netted within this line. (7)	[1],[2],[3],[4],[5]
Schedule of Unrecognized Tax Benefit Activity	The following table summarizes the activity related to the Company's unrecognized tax benefits, excluding interest: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Balance at beginning of period $ 182.5 $ 118.7 $ 89.2 $ 114.8 Additions related to current year tax positions 19.6 79.9 63.8 5.0 Additions related to prior period tax positions 125.1 0.3 10.8 — Reductions related to prior period tax positions (32.7 ) (13.6 ) (37.8 ) (1.1 ) Reductions related to disposition transactions — — (6.6 ) — Settlements (2.0 ) — (2.6 ) — Lapse of statute of limitations (4.8 ) (2.8 ) (2.0 ) — Balance at end of period $ 287.7 $ 182.5 $ 114.8 $ 118.7
Schedule of Unrecongized Tax Benefits Balance Sheet Location	Unrecognized tax benefits, excluding interest, are reported in the following consolidated balance sheet captions in the amounts shown: December 28, 2018 December 29, 2017 Accrued and other current liabilities $ 1.0 $ 1.5 Other income tax liabilities 189.9 82.6 Deferred income taxes (non-current liability) 96.8 98.4 $ 287.7 $ 182.5
Schedule of Income Taxes Payable	Income taxes payable, including uncertain tax positions and related interest accruals, is reported in the following consolidated balance sheet captions in the amounts shown: December 28, 2018 December 29, 2017 Income taxes payable $ 25.0 $ 15.8 Other income tax liabilities 228.0 94.1 $ 253.0 $ 109.9
Schedule of Income Tax Receivables and Other Assets	December 28, 2018 December 29, 2017 Other assets $ 3.0 $ — Prepaid expenses and other current assets 16.2 6.1 $ 19.2 $ 6.1
Schedule of Deferred Taxes Activity	The components of the net deferred tax (liability) asset at the end of each fiscal year were as follows: December 28, 2018 December 29, 2017 Deferred tax assets: Accrued liabilities and reserves $ 56.3 $ 62.7 Tax loss and credit carryforwards 1,987.8 1,734.5 Intangible assets 757.7 575.1 Other 204.6 113.3 3,006.4 2,485.6 Deferred tax liabilities: Intangible assets (264.7 ) (181.0 ) Interest-bearing deferred tax obligations (227.5 ) (553.5 ) Investment in partnership (170.2 ) (108.8 ) Other (42.9 ) (47.0 ) (705.3 ) (890.3 ) Net deferred tax asset before valuation allowances 2,301.1 1,595.3 Valuation allowances (2,604.9 ) (2,267.9 ) Net deferred tax liability $ (303.8 ) $ (672.6 )
Schedule of Deferred Taxes Balance Sheet Location	Deferred taxes are reported in the following consolidated balance sheet captions in the amounts shown: December 28, 2018 December 29, 2017 Other assets $ 20.5 $ 16.4 Deferred income taxes (non-current liability) (324.3 ) (689.0 ) Net deferred tax liability $ (303.8 ) $ (672.6 )
[1]	Associated unrecognized tax benefit netted within this line.
[2]	During the three months ended December 30, 2016, the rate difference between U.K. and non-U.K. jurisdictions was favorably impacted by a benefit of $16.1 million on a $102.0 million settlement with the Federal Trade Commission and a benefit of $34.5 million on a $207.0 million
[3]	For fiscal 2018, the Company completed its analysis of the TCJA and recognized an additional tax benefit. Other line items, to the extent U.S. related, are reflected at the current U.S. statutory income tax rate of 21%. For fiscal 2017, the benefit reflects the redetermination of the Company’s end of year net deferred tax liabilities as a result of the new U.S. statutory income tax rate of 21%. Other line items, to the extent U.S. related, are reflected at the former U.S. statutory income tax rate of 35%.
[4]	Includes the impact of certain recurring valuation allowances for U.K. and non-U.K. jurisdictions.
[5]	The statutory tax rate reflects the U.K. statutory tax rate of 19% for fiscal 2018 and 2017 and 20%

Earnings (Loss) per Share (Tabl

Earnings (Loss) per Share (Tables)	12 Months Ended
	Dec. 28, 2018
Earnings (Loss) per Share [Abstract]
Schedule of Earnings (Loss) per Share	Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 (Loss) earnings per share numerator: (Loss) income from continuing operations attributable to common shareholders $ (3,621.9 ) $ 1,771.2 $ 489.0 $ (176.8 ) Income from discontinued operations 14.9 363.2 154.7 23.6 Net (loss) income attributable to common shareholders $ (3,607.0 ) $ 2,134.4 $ 643.7 $ (153.2 ) (Loss) earnings per share denominator: Weighted-average shares outstanding - basic 84.0 97.7 110.6 105.7 Impact of dilutive securities — 0.2 0.9 — Weighted-average shares outstanding - diluted 84.0 97.9 111.5 105.7 Basic (loss) earnings per share attributable to common shareholders: (Loss) income from continuing operations $ (43.12 ) $ 18.13 $ 4.42 $ (1.67 ) Income from discontinued operations 0.18 3.72 1.40 0.22 Net (loss) income attributable to common shareholders $ (42.94 ) $ 21.85 $ 5.82 $ (1.45 ) Diluted (loss) earnings per share attributable to common shareholders: (Loss) income from continuing operations $ (43.12 ) $ 18.09 $ 4.39 $ (1.67 ) Income from discontinued operations 0.18 3.71 1.39 0.22 Net (loss) income attributable to common shareholders $ (42.94 ) $ 21.80 $ 5.77 $ (1.45 )

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 28, 2018
Inventory, Net [Abstract]
Schedule of Inventories	Inventories are comprised of the following at the end of each period: December 28, December 29, Raw materials and supplies $ 69.2 $ 70.0 Work in process 167.6 167.1 Finished goods 85.5 103.3 Inventories $ 322.3 $ 340.4

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 28, 2018
Property, Plant and Equipment [Line Items]
Depreciation of Property, Plant and Equipment	Depreciation expense for continuing operations was as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Depreciation expense $ 111.9 $ 113.8 $ 113.3 $ 27.5
Schedule of Property, Plant and Equipment	The gross carrying amount and accumulated depreciation of property, plant and equipment at the end of each period was as follows: December 28, 2018 December 29, 2017 Land $ 43.9 $ 44.0 Buildings 379.5 355.5 Capitalized software 130.8 109.0 Machinery and equipment 1,137.3 1,123.8 Construction in process 244.7 209.7 1,936.2 1,842.0 Less: accumulated depreciation (954.2 ) (875.2 ) Property, plant and equipment, net $ 982.0 $ 966.8

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 28, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-lived Intangible Assets Amortization Expense	Finite-lived intangible asset amortization expense within continuing operations is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Amortization expense $ 740.2 $ 694.5 $ 700.1 $ 175.7
Schedule of Goodwill	The changes in the carrying amount of goodwill by segment were as follows: December 28, 2018 December 29, 2017 Gross Carrying amount Accumulated Impairment Gross Carrying amount Accumulated Impairment Specialty Brands $ 3,672.8 $ (3,672.8 ) $ 3,482.7 $ — Specialty Generics 207.0 (207.0 ) 207.0 (207.0 ) Total $ 3,879.8 ($3,879.8 ) $ 3,689.7 $ (207.0 )
Schedule of Intangible Assets	The gross carrying amount and accumulated amortization of intangible assets at the end of each period were as follows: December 28, 2018 December 29, 2017 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortizable: Completed technology $ 10,467.9 $ 2,980.6 $ 9,882.8 $ 2,260.8 License agreements 120.1 70.1 177.1 121.1 Trademarks 81.9 18.1 82.1 14.5 Customer relationships 27.5 14.1 29.5 12.2 Other — — 8.6 8.6 Total $ 10,697.4 $ 3,082.9 $ 10,180.1 $ 2,417.2 Non-Amortizable: Trademarks $ 35.0 $ 35.0 In-process research and development 633.3 577.1 Total $ 668.3 $ 612.1
Schedule of Future Amortization Expense, Intangible Assets	The estimated aggregate amortization expense on intangible assets owned by the Company is expected to be as follows: Fiscal 2019 $ 748.4 Fiscal 2020 748.0 Fiscal 2021 747.8 Fiscal 2022 620.8 Fiscal 2023 584.8

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 28, 2018
Debt Instrument [Line Items]
Schedule of Long-term Debt Instruments [Table Text Block]	As of December 28, 2018 , the applicable interest rate and outstanding borrowings on the Company's variable-rate debt instruments were as follows: Applicable interest rate Outstanding borrowings Term loan due September 2024 5.14 % $ 1,613.8 Term loan due February 2025 5.62 % 597.0 Variable-rate receivable securitization 3.22 % 250.0 Revolving credit facility 4.64 % 220.0
Schedule of Long-term Debt including Capital Lease Obligation	Debt was comprised of the following at the end of each period: December 28, 2018 December 29, 2017 Principal Unamortized Discount and Debt Issuance Costs Principal Unamortized Discount and Debt Issuance Costs Current maturities of long-term debt: 3.50% notes due April 2018 $ — $ — $ 300.0 $ 0.2 Term loan due September 2024 16.4 0.2 14.0 0.3 Term loan due February 2025 6.0 0.1 — — Other 0.3 — 0.2 — Total current debt 22.7 0.3 314.2 0.5 Long-term debt: 4.875% notes due April 2020 700.0 3.2 700.0 5.7 Variable-rate receivable securitization due July 2020 250.0 0.4 200.0 0.7 9.50% debentures due May 2022 10.4 — 10.4 — 5.75% notes due August 2022 835.2 7.0 884.0 9.5 8.00% debentures due March 2023 4.4 — 4.4 — 4.75% notes due April 2023 500.2 3.5 526.5 4.5 5.625% notes due October 2023 731.4 8.0 738.0 9.7 Term loan due September 2024 1,597.4 19.8 1,837.2 26.7 Term loan due February 2025 591.0 10.7 — — 5.50% notes due April 2025 692.1 7.7 692.1 9.0 Other 1.9 — — — Revolving credit facility 220.0 4.5 900.0 5.9 Total long-term debt 6,134.0 64.8 6,492.6 71.7 Total debt $ 6,156.7 $ 65.1 $ 6,806.8 $ 72.2
Schedule of Maturities of Long-term Debt including Capital Lease Obligation	The aggregate amounts of debt maturing during the next five fiscal years are as follows: Fiscal 2019 $ 22.7 Fiscal 2020 972.7 Fiscal 2021 28.2 Fiscal 2022 1,088.2 Fiscal 2023 1,258.6

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 28, 2018
Retirement Benefits [Abstract]
Schedule of Net Periodic Benefit Cost	The net periodic benefit cost (credit) for the Company's pension and postretirement benefit plans was as follows: Pension Benefits Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, Service cost $ 0.2 $ 1.4 $ 1.8 $ 0.8 Interest cost 0.6 2.3 13.2 2.0 Expected return on plan assets — (1.3 ) (16.7 ) (2.3 ) Amortization of net actuarial loss 0.5 2.7 11.3 3.5 Amortization of prior service cost 0.1 0.2 — 0.1 Loss on plan settlements 0.1 71.1 8.1 45.0 Curtailment gain — (1.0 ) — — Net periodic benefit cost $ 1.5 $ 75.4 $ 17.7 $ 49.1 Postretirement Benefits Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, Service cost $ — $ — $ 0.1 $ 0.1 Interest cost 1.5 1.7 2.0 0.4 Amortization of net actuarial loss 0.1 — — — Amortization of prior service credit (2.1 ) (2.0 ) (2.1 ) (0.5 ) Gain on plan settlements (0.7 ) (0.9 ) — — Net periodic benefit credit $ (1.2 ) $ (1.2 ) $ — $ —
Schedule of Changes in Benefit Obligations, Plan Assets, and Funded Status of Plans	The following table represents the changes in benefit obligations, plan assets and the net amounts recognized on the consolidated balance sheets for pension and postretirement benefit plans at the end of each period: Pension Benefits Postretirement Benefits December 28, December 29, December 28, December 29, Change in benefit obligations: Projected benefit obligations at beginning of year $ 27.8 $ 257.4 $ 45.6 $ 47.5 Service cost 0.2 1.4 — — Interest cost 0.6 2.3 1.5 1.7 Actuarial loss (gain) 0.7 (9.0 ) (3.9 ) 0.2 Benefits and administrative expenses paid (1.6 ) (9.4 ) (2.7 ) (2.9 ) Plan settlements (0.8 ) (217.0 ) (0.7 ) (0.9 ) Currency translation (0.8 ) 2.1 — — Projected benefit obligations at end of year 26.1 27.8 39.8 45.6 Change in plan assets: Fair value of plan assets at beginning of year — 161.0 — — Actual return on plan assets — 0.3 — — Employer contributions 2.4 68.0 2.7 2.9 Benefits and administrative expenses paid (1.6 ) (9.4 ) (2.7 ) (2.9 ) Plan settlements (0.8 ) (217.0 ) — — Net transfer out — (2.9 ) — — Fair value of plan assets at end of year — — — — Funded status at end of year $ (26.1 ) $ (27.8 ) $ (39.8 ) $ (45.6 )
Schedule of Amounts Recognized in Balance Sheet	Pension Benefits Postretirement Benefits December 28, December 29, December 28, December 29, Amounts recognized on the consolidated balance sheet: Current liabilities $ (2.0 ) $ (2.4 ) $ (3.4 ) $ (3.9 ) Non-current liabilities (24.1 ) (25.4 ) (36.4 ) (41.7 ) Net amount recognized on the consolidated balance sheet $ (26.1 ) $ (27.8 ) $ (39.8 ) $ (45.6 ) Amounts recognized in accumulated other comprehensive loss consist of: Net actuarial (loss) gain $ (8.4 ) $ (8.6 ) $ 0.9 $ (3.0 ) Prior service (cost) credit (0.4 ) (0.5 ) 8.1 10.2 Net amount recognized in accumulated other comprehensive loss $ (8.8 ) $ (9.1 ) $ 9.0 $ 7.2
Schedule of Amounts to be Amortized from Accumulated Other Comprehensive Income	The estimated amounts that will be amortized from accumulated other comprehensive loss into net periodic benefit cost (credit) in fiscal 2019 are as follows: Pension Benefits Postretirement Benefits Amortization of net actuarial loss $ 0.5 $ — Amortization of prior service cost (credit) 0.1 (2.1 )
Schedule of Plans with Accumulated Benefit Obligations in Excess of Plan Assets	December 28, December 29, Pension plans with accumulated benefit obligations in excess of plan assets: Accumulated benefit obligation $ 25.6 $ 27.3
Schedule of Actuarial Assumptions	Weighted-average assumptions used each period to determine net periodic benefit cost for the Company's pension plans are as follows: U.S. Plans Non-U.S. Plans Fiscal Year Ended Three Months Ended Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Discount rate 3.3 % 3.0 % 3.9 % 2.2 % 1.9 % 1.8 % 2.0 % 1.3 % Expected return on plan assets — % 3.5 % 5.8 % 3.5 % — % — % 2.0 % — % Rate of compensation increase — % — % — % — % 2.5 % 2.5 % — % — % Weighted-average assumptions used each period to determine benefit obligations for the Company's pension plans are as follows: U.S. Plans Non-U.S. Plans Fiscal Year Ended Three Months Ended Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Discount rate 4.0 % 3.3 % 2.3 % 3.0 % 2.0 % 1.9 % 1.3 % 1.8 % Rate of compensation increase — % — % — % — % 2.5 % 2.5 % — % 0.3 % Fiscal Year Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Net periodic benefit cost 3.4 % 3.7 % 4.0 % 3.2 % Benefit obligations 4.1 % 3.4 % 3.2 % 3.8 %
Schedule of Healthcare Cost Trend Rates	Healthcare cost trend assumptions for postretirement benefit plans are as follows: December 28, December 29, Healthcare cost trend rate assumed for next fiscal year 6.3 % 6.9 % Rate to which the cost trend rate is assumed to decline 4.5 % 4.5 % Fiscal year the ultimate trend rate is achieved 2038 2038
Schedule of Effect of One-Percentage-Point Change in Assumed Healthcare Cost Trend Rates	A one-percentage-point change in assumed healthcare cost trend rates would have the following effects: One-Percentage-Point Increase One-Percentage-Point Decrease Effect on total of service and interest cost $ — $ — Effect on postretirement benefit obligation 0.2 (0.2 )
Schedule of Expected Benefit Payments	Benefit payments expected to be paid, reflecting future expected service as appropriate, are as follows: Pension Benefits Postretirement Benefits Fiscal 2019 $ 2.0 $ 3.5 Fiscal 2020 1.7 3.4 Fiscal 2021 1.7 3.2 Fiscal 2022 1.6 3.1 Fiscal 2023 1.6 3.0 Fiscal 2024 - 2028 7.4 13.4

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 28, 2018
Equity [Abstract]
Schedule of Share Repurchases under the Repurchase Plan	Share Repurchases From time to time, the Company's Board of Directors have authorized share repurchase programs. The details of such programs are as follows: March 2017 Repurchase Program March 2016 November 2015 Repurchase Program January 2015 Repurchase Program Number of Shares Amount Number of Shares Amount Number of Shares Amount Number of Shares Amount Authorized repurchase amount $ 1,000.0 $ 350.0 $ 500.0 $ 300.0 Repurchases: Fiscal 2015 — — — — — — 823,592 75.0 Fiscal 2016 — — — — 6,510,824 425.6 3,199,279 225.0 Three months ended December 30, 2016 — — 1,501,676 84.0 1,063,337 74.4 — — Fiscal 2017 13,490,448 380.6 5,366,741 266.0 — — — — Fiscal 2018 3,610,968 55.2 — — — — — — Remaining amount available $ 564.2 $ — $ — $ —

Share Plans (Tables)

Share Plans (Tables)	12 Months Ended
	Dec. 28, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity [Table Text Block]	The grant-date fair value of RSAs, adjusted for estimated forfeitures, was recognized as expense on a straight-line basis over the service period. The weighted average grant-date fair value per share was $70.88 . Shares Non-vested at September 25, 2015 34,562 Vested (9,760 ) Forfeited (7,936 ) Non-vested at September 30, 2016 16,866 Vested (1,087 ) Forfeited (911 ) Non-vested at December 30, 2016 14,868 Vested (7,970 ) Forfeited (2,223 ) Non-vested at December 29, 2017 4,675 Vested (3,970 ) Forfeited (705 ) Non-vested at December 28, 2018 —
Maximum Number of Common Shares to be Issued as Awards [Table Text Block]	The maximum number of common shares to be issued as Awards, subject to adjustment as provided under the terms of the respective plans are as follows: Maximum Number of Common Shares to be Issued as Awards (in millions) 2013 Plan 5.7 2015 Plan 17.8 2018 Plan 26.8
Schedule of the Valuation Assumptions Used in the Conversion	The weighted-average assumptions used in the Black-Scholes pricing model for shares granted in fiscal 2018 , 2017 , 2016 and the three months ended December 30, 2016, along with the weighted-average grant-date fair value, were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Expected share price volatility 38 % 36 % 31 % 35 % Risk-free interest rate 2.64 % 2.00 % 1.74 % 1.23 % Expected annual dividend per share — % — % — % — % Expected life of options (in years) 5.3 5.3 5.3 5.3 Fair value per option $ 5.32 $ 18.36 $ 22.82 $ 20.04
Schedule of Share Option Activity	Share option activity and information is as follows: Share Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term Aggregate Intrinsic Value Outstanding at September 25, 2015 2,786,443 $ 52.76 Granted 1,248,828 72.44 Exercised (413,830 ) 32.76 Expired/Forfeited (199,585 ) 72.65 Outstanding at September 30, 2016 3,421,856 61.17 Granted 3,742 60.01 Exercised (16,382 ) 36.42 Expired/Forfeited (22,522 ) 70.82 Outstanding at December 30, 2016 3,386,694 61.24 Granted 1,719,532 51.57 Exercised (113,605 ) 47.74 Expired/Forfeited (348,637 ) 68.08 Outstanding at December 29, 2017 4,643,984 57.78 Granted 3,159,521 13.92 Exercised (39,949 ) 32.00 Expired/Forfeited (756,505 ) 52.63 Outstanding at December 28, 2018 7,007,051 38.74 4.8 $ 6.5 Vested and non-vested expected to vest as of December 28, 2018 6,114,782 39.94 7.6 $ 5.5 Exercisable at December 28, 2018 2,414,968 55.24 4.9 0.1
Share-based Compensation, Performance Shares Award Outstanding Activity	PSU activity is as follows (1) : Shares Weighted-Average Non-vested at September 25, 2015 130,974 $ 96.05 Granted 145,192 83.00 Forfeited (9,521 ) 96.30 Non-vested at September 30, 2016 266,645 88.59 Forfeited (997 ) 154.42 Non-vested at December 30, 2016 265,648 88.51 Granted 348,963 51.73 Forfeited (48,606 ) 107.00 Vested (61,554 ) 62.65 Non-vested at December 29, 2017 504,451 64.44 Granted 770,714 13.80 Forfeited (89,614 ) 59.18 Vested (24,022 ) 98.27 Non-vested at December 28, 2018 1,161,529 28.61
Schedule of Share-based Payment Award, Performance Share Awards, Valuation Assumptions	The assumptions used in the Monte Carlo model for PSUs granted during each year were as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Expected stock price volatility 57 % 48 % 41 % 48 % Peer group stock price volatility 39 % 40 % 36 % 40 % Correlation of returns 2 % 17 % 24 % 17 %
Schedule of Restricted Share Unit Activity	RSU activity is as follows: Shares Weighted-Average Non-vested at September 25, 2015 572,494 $ 73.45 Granted 615,074 70.10 Vested (193,849 ) 69.27 Expired/Forfeited (99,260 ) 79.95 Non-vested at September 30, 2016 894,459 70.40 Granted 36,731 69.08 Exercised (30,919 ) 47.54 Expired/Forfeited (16,809 ) 49.62 Non-vested at December 30, 2016 883,462 71.03 Granted 655,282 50.74 Exercised (263,189 ) 69.14 Expired/Forfeited (169,789 ) 68.57 Non-vested at December 29, 2017 1,105,766 60.08 Granted 1,222,568 14.58 Exercised (433,354 ) 57.93 Expired/Forfeited (209,879 ) 44.38 Non-vested at December 28, 2018 1,685,101 29.54

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 28, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive loss are as follows: Currency Translation Unrecognized Loss on Derivatives Unrecognized (Loss) Gain on Benefit Plans Unrecognized Gain on Equity Securities (1) Accumulated Other Comprehensive Loss (1) Balance at December 30, 2016 $ (19.5 ) $ (5.7 ) $ (47.3 ) $ — $ (72.5 ) Other comprehensive income, net 16.0 — 5.2 1.5 22.7 Reclassification from other comprehensive (loss) income (4.7 ) 1.0 40.6 (1.5 ) 35.4 Balance at December 29, 2017 (8.2 ) (4.7 ) (1.5 ) — (14.4 ) Other comprehensive (loss) income, net (12.2 ) — 3.1 — (9.1 ) Reclassification from other comprehensive income (loss) — 0.7 (1.5 ) — (0.8 ) Balance at December 28, 2018 $ (20.4 ) $ (4.0 ) $ 0.1 $ — $ (24.3 )
Reclassification out of Accumulated Other Comprehensive Income	The following summarizes reclassifications from accumulated other comprehensive loss: Amount Reclassified From Accumulated Other Comprehensive Loss December 28, 2018 December 29, 2017 Line Item in the Consolidated Currency translation $ — $ (4.7 ) Amortization of unrealized loss on derivatives 0.9 1.3 Interest expense Income tax provision (0.2 ) (0.3 ) Provision for income taxes Net of income taxes 0.7 1.0 Amortization of pension and post-retirement benefit plans: Net actuarial loss 0.6 2.7 (1) Prior service credit (2.0 ) (1.9 ) (1) Disposal of discontinued operations — (3.1 ) Plan settlements (0.6 ) 70.2 (1) Total before tax (2.0 ) 67.9 Income tax effect 0.5 (27.3 ) Provision for income taxes Net of income taxes (1.5 ) 40.6 Recognized gain on equity securities (2) — (1.5 ) Total reclassifications for the period $ (0.8 ) $ 35.4 (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 15 for additional details. (2) Upon adoption of ASU 2016-01, a reclassification of $1.5 million relating to the unrealized gain on investment resulted in an increase to beginning retained earnings with an offsetting decrease to accumulated other comprehensive loss. See Note 4 for additional details.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 28, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of Purchase Obligations	At December 28, 2018 , such obligations were as follows: Fiscal 2019 $ 110.3 Fiscal 2020 43.5 Fiscal 2021 2.2 Fiscal 2022 2.1 Fiscal 2023 1.7
Schedule of Minimum Lease Payments for Non-cancelable Leases	The following is a schedule of minimum lease payments for non-cancelable leases as of December 28, 2018 : Operating Leases Fiscal 2019 $ 22.3 Fiscal 2020 16.4 Fiscal 2021 12.8 Fiscal 2022 10.6 Fiscal 2023 10.3 Thereafter 39.2 Total minimum lease payments $ 111.6

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurements (Tables)	12 Months Ended
	Dec. 28, 2018
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis	The following tables provide a summary of the significant assets and liabilities that are measured at fair value on a recurring basis at the end of each period: December 28, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Assets: Debt and equity securities held in rabbi trusts $ 33.1 $ 22.4 $ 10.7 $ — Equity securities — — — — $ 33.1 $ 22.4 $ 10.7 $ — Liabilities: Deferred compensation liabilities $ 38.5 $ — $ 38.5 $ — Contingent consideration and acquired contingent liabilities 151.4 — — 151.4 $ 189.9 $ — $ 38.5 $ 151.4 December 29, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets: Debt and equity securities held in rabbi trusts $ 35.4 $ 24.0 $ 11.4 $ — Equity securities 22.7 22.7 — — $ 58.1 $ 46.7 $ 11.4 $ — Liabilities: Deferred compensation liabilities $ 42.7 $ — $ 42.7 $ — Contingent consideration and acquired contingent liabilities 246.4 — — 246.4 $ 289.1 $ — $ 42.7 $ 246.4
Schedule of Reconciliation of Changes in Fair Value of Contingent Consideration	The following table summarizes the fiscal 2018 activity for contingent consideration: Balance at December 29, 2017 $ 246.4 Disposal of business (12.1 ) Payments (37.0 ) Accretion expense 4.3 Fair value adjustment (50.2 ) Balance at December 28, 2018 $ 151.4
Schedule of Carrying Amount and Fair Value of Long-term Debt	The following table presents the carrying values and estimated fair values of the Company's long-term debt, excluding capital leases, as of the end of each period: December 28, 2018 December 29, 2017 Carrying Value Fair Value Carrying Value Fair Value Level 1: 3.50% notes due April 2018 $ — $ — $ 300.0 $ 299.1 4.875% notes due April 2020 700.0 676.6 700.0 675.2 Variable-rate receivable securitization due July 2020 250.0 250.0 200.0 200.0 5.75% notes due August 2022 835.2 713.6 884.0 804.8 4.75% notes due April 2023 500.2 336.7 526.5 412.4 5.625% notes due October 2023 731.4 557.0 738.0 628.8 5.50% notes due April 2025 692.1 479.1 692.1 564.5 Revolving credit facility 220.0 220.0 900.0 900.0 Level 2: 9.50% debentures due May 2022 10.4 9.7 10.4 10.9 8.00% debentures due March 2023 4.4 3.8 4.4 4.4 Term loan due September 2024 1,613.8 1,472.4 1,851.2 1,848.7 Term loan due February 2025 597.0 548.0 — — Level 3: Other 2.2 2.2 — — Total Debt $ 6,156.7 $ 5,269.1 $ 6,806.6 $ 6,348.8
Schedules of Concentration of Risk	The following table shows net sales attributable to distributors that accounted for 10% or more of the Company's total net sales: Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, CuraScript, Inc. 35 % 40 % 38 % 43 % McKesson Corporation * * 12 % 10 % * Net sales to these distributors were less than 10% of total net sales during the respective periods presented above. The following table shows accounts receivable attributable to distributors that accounted for 10% or more of the Company's gross accounts receivable at the end of each period: December 28, December 29, AmerisourceBergen Corporation 26 % 15 % McKesson Corporation 22 % 26 % CuraScript, Inc. 13 % 14 % Cardinal Health, Inc. * 11 % * Gross accounts receivables from these distributors were less than 10% of total gross accounts receivable during the respective periods presented above. The following table shows net sales attributable to products that accounted for 10% or more of the Company's total net sales: Fiscal Year Ended Three Months Ended December 28, December 29, September 30, December 30, H.P. Acthar Gel 35 % 37 % 34 % 39 % Inomax 17 % 16 % 14 % 14 %

Segment and Geographical Data (

Segment and Geographical Data (Tables)	12 Months Ended
	Dec. 28, 2018
Segment Reporting [Abstract]
Schedule of Segment Reporting Information by Business Segment	Selected information by business segment is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Net sales: Specialty Brands $ 2,306.2 $ 2,352.0 $ 2,288.8 $ 600.1 Specialty Generics and Amitiza 909.4 869.6 1,092.0 229.8 Net sales $ 3,215.6 $ 3,221.6 $ 3,380.8 $ 829.9 Operating income: Specialty Brands $ 1,077.4 $ 1,146.3 $ 1,060.7 $ 295.2 Specialty Generics and Amitiza 105.0 266.4 444.7 64.6 Segment operating income 1,182.4 1,412.7 1,505.4 359.8 Unallocated amounts: Corporate and allocated expenses (1) (155.8 ) (125.2 ) (117.7 ) (123.1 ) Intangible asset amortization (740.2 ) (694.5 ) (700.1 ) (175.7 ) Restructuring and related charges, net (2) (108.2 ) (36.4 ) (37.6 ) (5.3 ) Non-restructuring impairments (3,893.1 ) (63.7 ) (16.9 ) (214.3 ) Separation costs (3) (6.0 ) — — — Operating income $ (3,720.9 ) $ 492.9 $ 633.1 $ (158.6 ) Depreciation and amortization (4) : Specialty Brands $ 696.0 $ 712.0 $ 715.7 $ 178.2 Specialty Generics and Amitiza 156.1 96.3 97.9 25.0 $ 852.1 $ 808.3 $ 813.6 $ 203.2 (1) Includes administration expenses and certain compensation, environmental and other costs not charged to the Company's operating segments. (2) Includes restructuring-related accelerated depreciation. (3) Represents costs incurred related to the separation of the Company’s Specialty Generics and Amitiza segment, which are included in selling, general and administrative expenses. (4) Depreciation for certain shared facilities is allocated based on occupancy percentage.	[1],[2]
Schedule of Net Sales from External Customers by Products	Net sales by product family within the Company's segments are as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 H.P. Acthar Gel $ 1,110.1 $ 1,195.1 $ 1,160.4 $ 325.4 Inomax 542.7 505.2 474.3 118.3 Ofirmev 341.9 302.5 284.3 72.5 Therakos 231.2 214.9 207.6 47.4 BioVectra 53.1 54.7 49.5 7.4 Other (1) 27.2 79.6 112.7 29.1 Specialty Brands 2,306.2 2,352.0 2,288.8 600.1 Hydrocodone (API) and hydrocodone-containing tablets 65.9 85.3 146.5 23.2 Oxycodone (API) and oxycodone-containing tablets (1) 66.1 88.0 139.9 27.2 Acetaminophen (API) (1) 192.7 185.5 169.1 40.8 Amitiza (2) 183.8 — — — Other controlled substances (1) 343.8 412.0 543.9 117.4 Other (1), (3) 57.1 98.8 92.6 21.2 Specialty Generics and Amitiza 909.4 869.6 1,092.0 229.8 Net Sales $ 3,215.6 $ 3,221.6 $ 3,380.8 $ 829.9 (1) Prior year amounts have been reclassified to conform to current year presentation. (2) Amitiza net sales consist of both product and royalty net sales. Refer to Note 5 for further details on Amitiza's revenues. (3) Includes net sales from an ongoing, post-divestiture supply agreement with the acquirer of the CMDS business. Amounts for periods prior to the divestiture represent the reclassification of intercompany sales to third-party sales to conform with the expected presentation of the ongoing supply agreement.	[3]
Schedule of Net Sales and Long-Lived Assets by Geographical Area	Selected information by geographic area excluding assets held-for-sale is as follows: Fiscal Year Ended Three Months Ended December 28, 2018 December 29, 2017 September 30, 2016 December 30, 2016 Net sales (1) : U.S. $ 2,834.5 $ 2,899.0 $ 3,095.4 $ 763.7 Europe, Middle East and Africa 256.8 242.3 211.8 52.8 Other 124.3 80.3 73.6 13.4 $ 3,215.6 $ 3,221.6 $ 3,380.8 $ 829.9 Fiscal Year Ended Long-lived assets (2) : December 28, 2018 December 29, 2017 U.S. $ 770.7 $ 788.5 Europe, Middle East and Africa (3) 146.7 127.0 Other 76.8 63.5 $ 994.2 $ 979.0 (1) Net sales are attributed to regions based on the location of the entity that records the transaction, none of which relate to the country of Ireland. (2) Long-lived assets are primarily composed of property, plant and equipment, net. (3) Includes long-lived assets located in Ireland of $145.2 million and $126.0 million as of December 28, 2018 and December 29, 2017 , respectively.	[4],[5],[6]
[1]	Includes administration expenses and certain compensation, environmental and other costs not charged to the Company's operating segments.
[2]	Includes restructuring-related accelerated depreciation.
[3]	Prior year amounts have been reclassified to conform to current year presentation.
[4]	Includes long-lived assets located in Ireland of $145.2 million and $126.0 million as of December 28, 2018 and December 29, 2017 , respectively.
[5]	Long-lived assets are primarily composed of property, plant and equipment, net.
[6]	Net sales are attributed to regions based on the location of the entity that records the transaction, none of which relate to the country of Ireland.

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 28, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Selected Quarterly Financial Data (Unaudited)	For the Quarter Ended (1) March 30, June 29, September 28, December 28, Net sales $ 755.3 $ 825.5 $ 799.9 $ 834.9 Gross profit (2) 347.5 394.0 366.4 363.3 (Loss) income from continuing operations (3) (20.9 ) 3.2 114.2 (3,718.4 ) Income (loss) from discontinued operations 2.9 12.4 (0.4 ) — Net (loss) income (18.0 ) 15.6 113.8 (3,718.4 ) Basic (loss) earnings per share from continuing operations (4) $ (0.24 ) $ 0.04 $ 1.37 $ (44.64 ) Diluted (loss) earnings per share from continuing operations (4) (0.24 ) 0.04 1.34 (44.64 ) For the Quarter Ended March 31, June 30, September 29, December 29, Net sales $ 810.9 $ 824.5 $ 793.9 $ 792.3 Gross profit (2) 419.8 416.1 400.6 421.0 Income from continuing operations (3) 28.9 70.6 64.3 1,607.4 Income (loss) from discontinued operations 370.3 (7.8 ) (0.6 ) 1.3 Net income 399.2 62.8 63.7 1,608.7 Basic earnings per share from continuing operations (4) $ 0.28 $ 0.72 $ 0.66 $ 17.43 Diluted earnings per share from continuing operations (4) 0.28 0.72 0.66 17.40 (1) The Specialty Generics Disposal Group was included within discontinued operations during the first three quarters of fiscal 2018, and has subsequently been recast to be included within continuing operations. In accordance with U.S. GAAP, depreciation and amortization are not recorded during the period in which a disposal group is classified as held-for-sale, thus the Company's financial results during the first three quarters of fiscal 2018 did not include $17.7 million and $6.8 million of depreciation and amortization expense, respectively, related to the Specialty Generics Disposal Group. During the fourth quarter of 2018, the Specialty Generics Disposal Group was reclassified to held and used and measured at its carrying amount before it was classified as held-for-sale, adjusted for depreciation and amortization expense that would have been recognized had the disposal group been continuously classified as held and used. The total adjustment of $24.5 million was reflected in loss from continuing operations during the fourth quarter of 2018, the period in which the held-for-sale criteria were no longer met. (2) Financial data for each period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of ASU 2017-07. See Note 4 for further information. (3) (Loss) income from continuing operations for the quarter ended December 28, 2018 reflects impairment charges for goodwill and an IPR&D asset. See Note 13 for further information. Income from continuing operations for the quarter ended December 29, 2017 reflects one-time effects for the completion of the reorganization of the Company's legal entity ownership and the impact of the TCJA. (4)	[1],[2]
[1]	Financial data for each period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of ASU 2017-07. See Note 4 for further information.
[2]	The Specialty Generics Disposal Group was included within discontinued operations during the first three quarters of fiscal 2018, and has subsequently been recast to be included within continuing operations. In accordance with U.S. GAAP, depreciation and amortization are not recorded during the period in which a disposal group is classified as held-for-sale, thus the Company's financial results during the first three quarters of fiscal 2018 did not include $17.7 million and $6.8 million of depreciation and amortization expense, respectively, related to the Specialty Generics Disposal Group. During the fourth quarter of 2018, the Specialty Generics Disposal Group was reclassified to held and used and measured at its carrying amount before it was classified as held-for-sale, adjusted for depreciation and amortization expense that would have been recognized had the disposal group been continuously classified as held and used. The total adjustment of $24.5 million

Condensed Consolidating and C_2

Condensed Consolidating and Combining Financial Statements (Tables)	12 Months Ended
	Dec. 28, 2018
Condensed Consolidating Financial Statements [Abstract]
Schedule of Condensed Consolidating Balance Sheets	MALLINCKRODT PLC CONDENSED CONSOLIDATING BALANCE SHEET As of December 28, 2018 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Assets Current Assets: Cash and cash equivalents $ 0.4 $ 140.8 $ 207.7 $ — $ 348.9 Accounts receivable, net — — 623.3 — 623.3 Inventories — — 322.3 — 322.3 Prepaid expenses and other current assets 3.9 0.2 128.6 — 132.7 Notes receivable — — — — — Intercompany receivable 131.1 29.2 1,087.9 (1,248.2 ) — Total current assets 135.4 170.2 2,369.8 (1,248.2 ) 1,427.2 Property, plant and equipment, net — — 982.0 — 982.0 Goodwill — — — — — Intangible assets, net — — 8,282.8 — 8,282.8 Investment in subsidiaries 2,481.6 25,506.1 8,362.1 (36,349.8 ) — Intercompany loan receivable 497.7 — 12,343.0 (12,840.7 ) — Other assets — — 185.3 — 185.3 Total Assets $ 3,114.7 $ 25,676.3 $ 32,525.0 $ (50,438.7 ) $ 10,877.3 — Liabilities and Shareholders' Equity Current Liabilities: Current maturities of long-term debt $ — $ 22.1 $ 0.3 $ — $ 22.4 Accounts payable 0.1 — 147.4 — 147.5 Accrued payroll and payroll-related costs — — 124.0 — 124.0 Accrued interest — 48.7 28.9 — 77.6 Income taxes payable — — 25.0 — 25.0 Accrued and other current liabilities 0.6 0.4 546.2 — 547.2 Intercompany payable 226.7 827.8 193.7 (1,248.2 ) — Total current liabilities 227.4 899.0 1,065.5 (1,248.2 ) 943.7 Long-term debt — 3,566.9 2,502.3 — 6,069.2 Pension and postretirement benefits — — 60.5 — 60.5 Environmental liabilities — — 59.7 — 59.7 Deferred income taxes — — 324.3 — 324.3 Other income tax liabilities — — 228.0 — 228.0 Intercompany loans payable — 12,840.7 — (12,840.7 ) — Other liabilities — 7.6 297.0 — 304.6 Total liabilities 227.4 17,314.2 4,537.3 (14,088.9 ) 7,990.0 Shareholders' equity 2,887.3 8,362.1 27,987.7 (36,349.8 ) 2,887.3 Total Liabilities and Shareholders' Equity $ 3,114.7 $ 25,676.3 $ 32,525.0 $ (50,438.7 ) $ 10,877.3 MALLINCKRODT PLC CONDENSED CONSOLIDATING BALANCE SHEET As of December 29, 2017 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Assets Current Assets: Cash and cash equivalents $ 0.7 $ 908.8 $ 351.4 $ — $ 1,260.9 Accounts receivable, net — — 445.8 — 445.8 Inventories — — 340.4 — 340.4 Prepaid expenses and other current assets 1.0 0.2 82.9 — 84.1 Notes receivable — — 154.0 — 154.0 Intercompany receivable 70.0 173.4 831.4 (1,074.8 ) — Total current assets 71.7 1,082.4 2,205.9 (1,074.8 ) 2,285.2 Property, plant and equipment, net — — 966.8 — 966.8 Goodwill — — 3,482.7 — 3,482.7 Intangible assets, net — — 8,375.0 — 8,375.0 Investment in subsidiaries 6,551.6 23,217.8 12,356.2 (42,125.6 ) — Intercompany loan receivable 593.1 — 4,664.8 (5,257.9 ) — Other assets — — 171.2 — 171.2 Total Assets $ 7,216.4 $ 24,300.2 $ 32,222.6 $ (48,458.3 ) $ 15,280.9 Liabilities and Shareholders' Equity Current Liabilities: Current maturities of long-term debt $ — $ 313.5 $ 0.2 $ — $ 313.7 Accounts payable 0.1 — 113.2 — 113.3 Accrued payroll and payroll-related costs — — 98.5 — 98.5 Accrued interest — 53.0 4.0 — 57.0 Income taxes payable — — 15.8 15.8 Accrued and other current liabilities 0.8 0.4 450.9 — 452.1 Intercompany payable 693.5 104.6 276.7 (1,074.8 ) — Total current liabilities 694.4 471.5 959.3 (1,074.8 ) 1,050.4 Long-term debt — 6,206.8 214.1 — 6,420.9 Pension and postretirement benefits — — 67.1 — 67.1 Environmental liabilities — — 73.2 — 73.2 Deferred income taxes — — 689.0 — 689.0 Other income tax liabilities — — 94.1 — 94.1 Intercompany loans payable — 5,257.9 — (5,257.9 ) — Other liabilities — 7.8 356.4 — 364.2 Total liabilities 694.4 11,944.0 2,453.2 (6,332.7 ) 8,758.9 Shareholders' equity 6,522.0 12,356.2 29,769.4 (42,125.6 ) 6,522.0 Total Liabilities and Shareholders' Equity $ 7,216.4 $ 24,300.2 $ 32,222.6 $ (48,458.3 ) $ 15,280.9
Schedule of Condensed Consolidating and Combining Statements of Comprehensive Income	MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Fiscal year ended December 28, 2018 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 3,215.6 $ — $ 3,215.6 Cost of sales 2.0 — 1,742.4 — 1,744.4 Gross (loss) profit (2.0 ) — 1,473.2 — 1,471.2 Selling, general and administrative expenses 38.8 0.7 794.6 — 834.1 Research and development expenses 4.7 — 356.4 — 361.1 Restructuring charges, net — — 103.0 — 103.0 Non-restructuring impairment charges — — 3,893.1 — 3,893.1 Loss on divestiture — — 0.8 — 0.8 Operating loss (45.5 ) (0.7 ) (3,674.7 ) — (3,720.9 ) Interest expense (7.8 ) (460.8 ) (63.4 ) 161.8 (370.2 ) Interest income 9.5 2.5 158.0 (161.8 ) 8.2 Other income, net 9.9 8.7 12.3 — 30.9 Intercompany interest and fees (18.5 ) (0.1 ) 18.6 — — Equity in net income of subsidiaries (3,561.0 ) (2,726.0 ) (3,170.9 ) 9,457.9 — Loss from continuing operations before income taxes (3,613.4 ) (3,176.4 ) (6,720.1 ) 9,457.9 (4,052.0 ) Benefit from income taxes (6.4 ) (5.4 ) (418.3 ) — (430.1 ) Loss from continuing operations (3,607.0 ) (3,171.0 ) (6,301.8 ) 9,457.9 (3,621.9 ) Income from discontinued operations, net of income taxes — 0.1 14.8 — 14.9 Net loss (3,607.0 ) (3,170.9 ) (6,287.0 ) 9,457.9 (3,607.0 ) Other comprehensive loss, net of tax (9.9 ) (9.9 ) (20.5 ) 30.4 (9.9 ) Comprehensive loss $ (3,616.9 ) $ (3,180.8 ) $ (6,307.5 ) $ 9,488.3 $ (3,616.9 ) MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Fiscal year ended December 29, 2017 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 3,221.6 $ — $ 3,221.6 Cost of sales 2.6 — 1,561.5 — 1,564.1 Gross (loss) profit (2.6 ) — 1,660.1 — 1,657.5 Selling, general and administrative expenses 59.5 0.7 789.5 — 849.7 Research and development expenses 5.1 — 271.8 — 276.9 Restructuring charges, net — — 31.2 — 31.2 Non-restructuring impairments — — 63.7 — 63.7 Gains on divestiture — — (56.9 ) — (56.9 ) Operating (loss) income (67.2 ) (0.7 ) 560.8 — 492.9 Interest expense (13.8 ) (353.9 ) (74.2 ) 72.8 (369.1 ) Interest income 7.3 1.2 68.9 (72.8 ) 4.6 Other income (expense), net 20.3 (1.7 ) (85.4 ) — (66.8 ) Intercompany interest and fees (18.3 ) — 18.3 — — Equity in net income of subsidiaries 2,200.0 2,901.8 2,549.9 (7,651.7 ) — Income from continuing operations before income taxes 2,128.3 2,546.7 3,038.3 (7,651.7 ) 61.6 Benefit from income taxes (6.1 ) (5.3 ) (1,698.2 ) — (1,709.6 ) Income from continuing operations 2,134.4 2,552.0 4,736.5 (7,651.7 ) 1,771.2 (Loss) income from discontinued operations, net of income taxes — (2.1 ) 365.3 — 363.2 Net income 2,134.4 2,549.9 5,101.8 (7,651.7 ) 2,134.4 Other comprehensive income, net of tax 59.6 59.6 118.2 (177.8 ) 59.6 Comprehensive income $ 2,194.0 $ 2,609.5 $ 5,220.0 $ (7,829.5 ) $ 2,194.0 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Fiscal year ended September 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 3,380.8 $ — $ 3,380.8 Cost of sales — — 1,523.2 — 1,523.2 Gross profit — — 1,857.6 — 1,857.6 Selling, general and administrative expenses 51.3 0.8 861.6 — 913.7 Research and development expenses — — 261.2 — 261.2 Restructuring charges, net — — 32.7 — 32.7 Non-restructuring impairments — — 16.9 — 16.9 Operating (loss) income (51.3 ) (0.8 ) 685.2 — 633.1 Interest expense (230.3 ) (327.0 ) (82.4 ) 255.1 (384.6 ) Interest income — 0.5 255.9 (255.1 ) 1.3 Other income (expense), net 90.0 1.7 (108.1 ) — (16.4 ) Intercompany interest and fees (16.1 ) — 16.1 — — Equity in net income of subsidiaries 820.8 1,327.2 1,057.9 (3,205.9 ) — Income from continuing operations before income taxes 613.1 1,001.6 1,824.6 (3,205.9 ) 233.4 Benefit from income taxes (30.6 ) (18.1 ) (206.9 ) — (255.6 ) Income from continuing operations 643.7 1,019.7 2,031.5 (3,205.9 ) 489.0 Income from discontinued operations, net of income taxes — 38.2 116.5 — 154.7 Net income 643.7 1,057.9 2,148.0 (3,205.9 ) 643.7 Other comprehensive loss, net of tax (86.5 ) (86.5 ) (173.5 ) 260.0 (86.5 ) Comprehensive income $ 557.2 $ 971.4 $ 1,974.5 $ (2,945.9 ) $ 557.2 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME Three months ended December 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Net sales $ — $ — $ 829.9 $ — $ 829.9 Cost of sales — — 383.2 — 383.2 Gross profit — — 446.7 — 446.7 Selling, general and administrative expenses 13.4 0.2 307.5 — 321.1 Research and development expenses — — 66.1 — 66.1 Restructuring charges, net — — 3.8 — 3.8 Non-restructuring impairments — — 214.3 — 214.3 Operating loss (13.4 ) (0.2 ) (145.0 ) — (158.6 ) Interest expense (2.9 ) (81.1 ) (17.9 ) 10.6 (91.3 ) Interest income — 0.1 11.0 (10.6 ) 0.5 Other income (expense), net 1.8 0.7 (51.6 ) — (49.1 ) Intercompany interest and fees (4.4 ) — 4.4 — — Equity in net income of subsidiaries (136.5 ) 35.2 (44.5 ) 145.8 — Loss from continuing operations before income taxes (155.4 ) (45.3 ) (243.6 ) 145.8 (298.5 ) Benefit from income taxes (2.2 ) (0.3 ) (119.2 ) — (121.7 ) Loss from continuing operations (153.2 ) (45.0 ) (124.4 ) 145.8 (176.8 ) Income from discontinued operations, net of income taxes — 0.4 23.2 — 23.6 Net loss (153.2 ) (44.6 ) (101.2 ) 145.8 (153.2 ) Other comprehensive income, net of tax 13.1 13.1 26.0 (39.1 ) 13.1 Comprehensive loss $ (140.1 ) $ (31.5 ) $ (75.2 ) $ 106.7 $ (140.1 )
Schedule of Condensed Consolidating and Combining Statements of Cash Flows	MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Fiscal year ended December 28, 2018 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 438.9 $ 80.1 $ 1,702.5 $ (1,556.0 ) $ 665.5 Cash Flows From Investing Activities: Capital expenditures — — (127.0 ) — (127.0 ) Acquisitions, net of cash acquired — — (699.9 ) — (699.9 ) Proceeds from disposal of discontinued operations, net of cash — — 313.0 — 313.0 Intercompany loan investment (385.6 ) (90.1 ) (502.0 ) 977.7 — Investment in subsidiary — (220.0 ) — 220.0 — Proceeds from sale of subsidiary — — — — — Acquisition of subsidiary — — — — — Other — — 33.6 — 33.6 Net cash from investing activities (385.6 ) (310.1 ) (982.3 ) 1,197.7 (480.3 ) Cash Flows From Financing Activities: Issuance of external debt — 600.0 90.3 — 690.3 Repayment of external debt and capital leases — (1,289.4 ) (404.2 ) — (1,693.6 ) Debt financing costs — (12.1 ) — — (12.1 ) Proceeds from exercise of share options 1.0 — — — 1.0 Intercompany loan borrowings — 977.7 — (977.7 ) — Intercompany dividends — (814.2 ) (741.8 ) 1,556.0 — Capital contribution — — 220.0 (220.0 ) — Repurchase of shares (57.5 ) — — — (57.5 ) Other 2.9 — (26.0 ) — (23.1 ) Net cash from financing activities (53.6 ) (538.0 ) (861.7 ) 358.3 (1,095.0 ) Effect of currency rate changes on cash — — (1.8 ) — (1.8 ) Net decrease in cash, cash equivalents and restricted cash (0.3 ) (768.0 ) (143.3 ) — (911.6 ) Cash, cash equivalents and restricted cash at beginning of period 0.7 908.8 369.6 — 1,279.1 Cash, cash equivalents and restricted cash at end of period $ 0.4 $ 140.8 $ 226.3 $ — $ 367.5 Cash and cash equivalents at end of period $ 0.4 $ 140.8 $ 207.7 $ — $ 348.9 Restricted cash included in prepaid expenses and other assets at end of period — — — — — Restricted cash included in other long-term assets at end of period — — 18.6 — 18.6 Cash, cash equivalents and restricted cash at end of period $ 0.4 $ 140.8 $ 226.3 $ — $ 367.5 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Fiscal year ended December 29, 2017 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 1,233.2 $ 1,139.4 $ 2,274.9 $ (3,920.2 ) $ 727.3 Cash Flows From Investing Activities: Capital expenditures — — (186.1 ) — (186.1 ) Acquisitions, net of cash acquired — — (76.3 ) — (76.3 ) Proceeds from disposal of discontinued operations, net of cash — — 576.9 — 576.9 Intercompany loan investment (589.5 ) — (1,157.9 ) 1,747.4 — Investment in subsidiary — (1,475.3 ) — 1,475.3 — Other — — 3.9 — 3.9 Net cash from investing activities (589.5 ) (1,475.3 ) (839.5 ) — 3,222.7 318.4 Cash Flows From Financing Activities: Issuance of external debt — 1,400.0 65.0 — 1,465.0 Repayment of external debt and capital leases — (764.5 ) (152.7 ) — (917.2 ) Debt financing costs — (12.7 ) — — (12.7 ) Proceeds from exercise of share options 4.1 — — — 4.1 Intercompany loan borrowings — 1,747.4 — (1,747.4 ) — Intercompany dividends — (1,170.0 ) (2,750.2 ) 3,920.2 — Capital contribution — — 1,475.3 (1,475.3 ) — Repurchase of shares (651.7 ) — — — (651.7 ) Other 4.1 — (21.8 ) — (17.7 ) Net cash from financing activities (643.5 ) 1,200.2 — (1,384.4 ) 697.5 (130.2 ) Effect of currency rate changes on cash — — 2.5 — 2.5 Net increase in cash, cash equivalents and restricted cash 0.2 864.3 53.5 — 918.0 Cash, cash equivalents and restricted cash at beginning of period 0.5 44.5 316.1 — 361.1 Cash, cash equivalents and restricted cash at end of period $ 0.7 $ 908.8 $ 369.6 $ — $ 1,279.1 Cash and cash equivalents at end of period $ 0.7 $ 908.8 $ 351.4 $ — $ 1,260.9 Restricted cash included in prepaid expenses and other assets at end of period — — — — — Restricted cash included in other long-term assets at end of period — — 18.2 — 18.2 Cash, cash equivalents and restricted cash at end of period $ 0.7 $ 908.8 $ 369.6 $ — $ 1,279.1 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Fiscal year ended September 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 17.9 $ (47.4 ) $ 1,214.1 $ — $ 1,184.6 Cash Flows From Investing Activities: Capital expenditures — — (182.9 ) — (182.9 ) Acquisitions, net of cash acquired — — (245.4 ) — (245.4 ) Proceeds from disposal of discontinued operations, net of cash — 234.0 32.7 — 266.7 Intercompany loan investment — (175.2 ) (1,714.5 ) 1,889.7 — Investment in subsidiary — (861.2 ) — 861.2 — Proceeds from sale of subsidiary 3.4 — — (3.4 ) — Acquisition of subsidiary — — (3.4 ) 3.4 — Other — — 6.0 — 6.0 Net cash from investing activities 3.4 (802.4 ) (2,107.5 ) — 2,750.9 (155.6 ) Cash Flows From Financing Activities: Issuance of external debt — — 98.3 — 98.3 Repayment of external debt and capital leases — (549.2 ) (19.4 ) — (568.6 ) Debt financing costs — — (0.1 ) — (0.1 ) Proceeds from exercise of share options 14.0 — — — 14.0 Intercompany loan borrowings 617.8 1,271.9 — (1,889.7 ) — Capital contribution — — 861.2 (861.2 ) — Repurchase of shares (652.9 ) — — — (652.9 ) Other — — (53.0 ) — (53.0 ) Net cash from financing activities (21.1 ) 722.7 — 887.0 (2,750.9 ) (1,162.3 ) Effect of currency rate changes on cash — — 0.3 — 0.3 Net increase (decrease) in cash, cash equivalents and restricted cash 0.2 (127.1 ) (6.1 ) — (133.0 ) Cash, cash equivalents and restricted cash at beginning of period 0.1 152.1 280.4 — 432.6 Cash, cash equivalents and restricted cash at end of period $ 0.3 $ 25.0 $ 274.3 $ — $ 299.6 Cash and cash equivalents at end of period $ 0.3 $ 25.0 $ 255.2 $ — $ 280.5 Restricted cash included in prepaid expenses and other assets at end of period — — 0.1 — 0.1 Restricted cash included in other long-term assets at end of period — — 19.0 — 19.0 Cash, cash equivalents and restricted cash at end of period $ 0.3 $ 25.0 $ 274.3 $ — $ 299.6 MALLINCKRODT PLC CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS Three months ended December 30, 2016 (in millions) Mallinckrodt plc Mallinckrodt International Finance S.A. Other Subsidiaries Eliminations Consolidated Cash Flows From Operating Activities: Net cash from operating activities $ 17.4 $ (94.0 ) $ 272.2 $ — $ 195.6 Cash Flows From Investing Activities: Capital expenditures — — (65.2 ) — (65.2 ) Acquisitions, net of cash acquired — — (1.8 ) — (1.8 ) Intercompany loan investment — — (424.7 ) 424.7 — Subsidiary dividend proceeds — — — — — Investment in subsidiary — (260.0 ) — 260.0 — Other — — (10.2 ) — (10.2 ) Net cash from activities — (260.0 ) (501.9 ) — 684.7 (77.2 ) Cash Flows From Financing Activities: Issuance of external debt — 175.0 15.0 — 190.0 Repayment of external debt and capital leases — (86.2 ) (0.5 ) — (86.7 ) Debt financing costs — — — — — Proceeds from exercise of share options 0.4 — — — 0.4 Subsidiary dividend payment — — — — — Intercompany loan borrowings 140.0 284.7 — (424.7 ) — Capital contribution — — 260.0 (260.0 ) — Repurchase of shares (158.8 ) — — — (158.8 ) Other 1.2 — — — 1.2 Net cash from financing activities (17.2 ) 373.5 — 274.5 (684.7 ) (53.9 ) Effect of currency rate changes on cash — — (3.0 ) — (3.0 ) Net increase in cash, cash equivalents and restricted cash 0.2 19.5 41.8 — 61.5 Cash, cash equivalents and restricted cash at beginning of period 0.3 25.0 274.3 — 299.6 Cash, cash equivalents and restricted cash at end of period $ 0.5 $ 44.5 $ 316.1 $ — $ 361.1 Cash and cash equivalents at end of period $ 0.5 $ 44.5 $ 297.0 $ — $ 342.0 Restricted cash included in prepaid expenses and other assets at end of period — — 0.1 — 0.1 Restricted cash included in other long-term assets at end of period — — 19.0 — 19.0 Cash, cash equivalents and restricted cash at end of period $ 0.5 $ 44.5 $ 316.1 $ — $ 361.1

Transition Period (Details)

Transition Period (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 28, 2018		Sep. 28, 2018		Jun. 29, 2018		Mar. 30, 2018		Dec. 29, 2017		Sep. 29, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 30, 2016	Dec. 25, 2015		Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Transition Period Income Statement [Abstract]
Net sales	$ 834.9		$ 799.9		$ 825.5		$ 755.3		$ 792.3		$ 793.9		$ 824.5		$ 810.9		$ 829.9	$ 811.2		$ 3,215.6	$ 3,221.6	$ 3,380.8
Cost of sales																	383.2	360	[1]	1,744.4	1,564.1	1,523.2
Gross profit	363.3	[2]	366.4	[2]	394	[2]	347.5	[2]	421	[2]	400.6	[2]	416.1	[2]	419.8	[2]	446.7	451.2	[1]	1,471.2	1,657.5	1,857.6
Selling, general and administrative expenses																	321.1	221.8	[1]	834.1	849.7	913.7
Research and development expenses																	66.1	61.3	[1]	361.1	276.9	261.2
Restructuring Charges																	3.8	4.1		103	31.2	32.7
Non-restructuring impairment charges																	214.3	0		3,893.1	63.7	16.9
Operating Income (Loss)																	158.6	164	[1]	3,720.9	(492.9)	(633.1)
Interest expense																	(91.3)	(97.8)		(370.2)	(369.1)	(384.6)
Interest income																	0.5	0.2		8.2	4.6	1.3
Other income (expense), net																	(49.1)	0.1	[1]	30.9	(66.8)	(16.4)
(Loss) income from continuing operations before income taxes																	(298.5)	66.5		(4,052)	61.6	233.4
Benefit from income taxes																	(121.7)	(37.3)		(430.1)	(1,709.6)	(255.6)
Income (loss) from continuing operations	(3,718.4)	[3]	114.2	[3]	3.2	[3]	(20.9)	[3]	1,607.4	[3]	64.3	[3]	70.6	[3]	28.9	[3]	(176.8)	103.8		(3,621.9)	1,771.2	489
Income (loss) from discontinued operations, net of income taxes	0		(0.4)		12.4		2.9		1.3		(0.6)		(7.8)		370.3		23.6	107.3		14.9	363.2	154.7
Net (loss) income	$ (3,718.4)		$ 113.8		$ 15.6		$ (18)		$ 1,608.7		$ 63.7		$ 62.8		$ 399.2		$ (153.2)	$ 211.1		$ (3,607)	$ 2,134.4	$ 643.7
Income (Loss) from Continuing Operations, Per Basic Share	$ (44.64)	[4]	$ 1.37	[4]	$ 0.04	[4]	$ (0.24)	[4]	$ 17.43	[4]	$ 0.66	[4]	$ 0.72	[4]	$ 0.28	[4]	$ (1.67)	$ 0.90		$ (43.12)	$ 18.13	$ 4.42
Income from discontinued operations, net of income taxes																	0.22	0.93		0.18	3.72	1.40
Earnings Per Share, Basic																	$ (1.45)	$ 1.83		$ (42.94)	$ 21.85	$ 5.82
Basic weighted-average shares outstanding																	105.7	115.4		84	97.7	110.6
(Loss) income from continuing operations	$ (44.64)	[4]	$ 1.34	[4]	$ 0.04	[4]	$ (0.24)	[4]	$ 17.40	[4]	$ 0.66	[4]	$ 0.72	[4]	$ 0.28	[4]	$ (1.67)	$ 0.89		$ (43.12)	$ 18.09	$ 4.39
Income (Loss) from Discontinued Operations, Per Diluted Share																	0.22	0.92		0.18	3.71	1.39
Earnings Per Share, Diluted																	$ (1.45)	$ 1.82		$ (42.94)	$ 21.80	$ 5.77
Weighted Average Number of Shares Outstanding, Diluted																	105.7	116.3		84	97.9	111.5
[1]	Financial data for this period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of Accounting Standards Update ("ASU") 2017-07. See Note 4 for further information on this ASU.
[2]	Financial data for each period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of ASU 2017-07. See Note 4 for further information.
[3]	(Loss) income from continuing operations for the quarter ended December 28, 2018 reflects impairment charges for goodwill and an IPR&D asset. See Note 13 for further information. Income from continuing operations for the quarter ended December 29, 2017 reflects one-time effects for the completion of the reorganization of the Company's legal entity ownership and the impact of the TCJA.
[4]	Quarterly and annual computations are prepared independently. Therefore, the sum of each quarter may not necessarily total the fiscal period amounts noted elsewhere within this Annual Report on Form 10-K.

Transition Period Transition Pe

Transition Period Transition Period Cash Flow (Details) - USD ($) $ in Millions	3 Months Ended										12 Months Ended
	Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Transition Period Income Statement [Abstract]
Net (loss) income	$ (3,718.4)	$ 113.8	$ 15.6	$ (18)	$ 1,608.7	$ 63.7	$ 62.8	$ 399.2	$ (153.2)	$ 211.1	$ (3,607)	$ 2,134.4	$ 643.7
Depreciation and amortization									203.2	206	852.1	808.3	834.5
Share-based compensation									11	8.5	34.6	59.2	42.9
Deferred income taxes									(204.3)	(108.9)	(541.5)	(1,744.1)	(432.9)
Asset Impairment Charges									214.3	0	3,893.1	63.7	16.9
Inventory provisions									8.5	1.2	37.9	34.1	29.2
Gain (Loss) on Disposition of Business									0	(97)	(0.8)	418.1	95.3
Other Noncash Income (Expense)									9.2	2.9	50.9	21.4	(29.6)
Increase (Decrease) in Accounts Receivable									36.5	68.4	145.8	16.2	(31.2)
Increase (Decrease) in Inventories									(26.3)	(14.5)	(63.1)	23.6	17.3
Accounts payable									5.4	(13)	24.6	(25.8)	(9.7)
Income taxes									0.6	82.3	99	(34.2)	93.9
Increase (Decrease) in Other Operating Assets and Liabilities, Net									109.1	(35.6)	(5.5)	89	(17.9)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations									195.6	311.4	665.5	727.3	1,184.6
Capital expenditures									(65.2)	(49)	(127)	(186.1)	(182.9)
Payments to Acquire Businesses, Net of Cash Acquired									(1.8)	0	699.9	76.3	245.4
Proceeds from Divestiture of Businesses, Net of Cash Divested									0	263.7	313	576.9	266.7
Other									(10.2)	0.7	(33.6)	(3.9)	(6)
Net cash from investing activities									(77.2)	215.4	(480.3)	318.4	(155.6)
Issuance of external debt									190	62	690.3	1,465	98.3
Repayment of external debt and capital lease obligation									(86.7)	(129.6)	(1,693.6)	(917.2)	(568.6)
Debt financing costs									0	(0.1)	(12.1)	(12.7)	(0.1)
Proceeds from exercise of share options									0.4	3.6	1	4.1	14
Repurchase of shares									(158.8)	(275.4)	(57.5)	(651.7)	(652.9)
Other									1.2	(30)	(23.1)	(17.7)	(53)
Net cash from financing activities									(53.9)	(369.5)	(1,095)	(130.2)	(1,162.3)
Effect of currency rate changes on cash									(3)	(1.5)	(1.8)	2.5	0.3
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect									61.5	155.8	(911.6)	918	(133)
Cash and cash equivalents	348.9				1,260.9				342	521.9	348.9	1,260.9	280.5
Restricted Cash and Investments, Current	0				0				0.1	47.5	0	0	0.1
Restricted Cash and Investments, Noncurrent	18.6				18.2				19	19	18.6	18.2	19
Cash and Cash Equivalents, Including Restricted Cash	$ 367.5				$ 1,279.1				$ 361.1	$ 588.4	$ 367.5	$ 1,279.1	$ 299.6	$ 432.6

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Schedule of Significant Accounting Policies [Line Items]
Foreign Currency Transaction Gain (Loss), before Tax	$ 9	$ (3.1)	$ 2.5	$ (3.6)
Foreign currency transactions gain (loss), derivative instruments	(8.9)	$ 2.7	(4.1)	0.2
Customer relationships
Schedule of Significant Accounting Policies [Line Items]
Finite-lived intangible assets - useful lives		12 years
Minimum | Completed Technology
Schedule of Significant Accounting Policies [Line Items]
Finite-lived intangible assets - useful lives		5 years
Minimum | Licensing Agreements
Schedule of Significant Accounting Policies [Line Items]
Finite-lived intangible assets - useful lives		7 years
Minimum | Trademarks
Schedule of Significant Accounting Policies [Line Items]
Finite-lived intangible assets - useful lives		13 years
Minimum | Buildings
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		10 years
Minimum | Leasehold improvements
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		1 year
Minimum | Capitalized software
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		1 year
Minimum | Machinery and equipment
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		1 year
Maximum | Completed Technology
Schedule of Significant Accounting Policies [Line Items]
Finite-lived intangible assets - useful lives		25 years
Maximum | Licensing Agreements
Schedule of Significant Accounting Policies [Line Items]
Finite-lived intangible assets - useful lives		30 years
Maximum | Trademarks
Schedule of Significant Accounting Policies [Line Items]
Finite-lived intangible assets - useful lives		30 years
Maximum | Buildings
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		45 years
Maximum | Leasehold improvements
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		20 years
Maximum | Capitalized software
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		10 years
Maximum | Machinery and equipment
Schedule of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life		20 years
Shipping and Handling [Member]
Schedule of Significant Accounting Policies [Line Items]
Shipping costs	$ 3.4	$ 12.8	$ 13.9	$ 12.4

Recently Issued Accounting St_3

Recently Issued Accounting Standards Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Dec. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 1.1	$ (72.1)
Accounting Standards Update 2016-18 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification			47.3
Other Assets | Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		67.2
Prepaid Expenses and Other Current Assets [Member] | Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		7.8
Retained Earnings | Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		75
Retained Earnings | ASU 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets	$ 2.9
Retained Earnings | Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					$ 1.5
Retained Earnings | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets					$ 1.1
Retained Earnings | Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification		$ 85
Other Nonoperating Income (Expense) [Member] | Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	48.2		72.8	$ 15.8
Selling, general and administrative | Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	47.2		71.2	11.6
Cost of Sales | Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	0.9		1.2	2.6
Research and Development Expense [Member] | Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	0.1		0.4	1
Restructuring Charges [Member] | Accounting Standards Update 2017-07 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	$ 0		$ 0	$ 0.6

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended										12 Months Ended
	Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Disaggregation of Revenue [Line Items]
Revenue Reserves	$ 405.4				$ 376.6						$ 405.4	$ 376.6
Contract with Customer, Liability, Noncurrent	15.1				6.6						15.1	6.6
Contract with Customer, Liability	35.5				20.6						35.5	20.6
Revenue Reserve Provision											2,387.5
Capitalized Contract Cost, Gross	28.4										28.4
Contract with Customer, Liability, Current	20.4				14						20.4	14
Deferred Revenue, Revenue Recognized											12.5
Revenue Reserve Payments or Credits											(2,358.7)
Net sales	834.9	$ 799.9	$ 825.5	$ 755.3	792.3	$ 793.9	$ 824.5	$ 810.9	$ 829.9	$ 811.2	3,215.6	3,221.6	$ 3,380.8
Capitalized Contract Cost, Amortization											$ 7.4
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Transferred over Time											17.10%
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Transferred at Point in Time											82.90%
Royalty [Member]
Disaggregation of Revenue [Line Items]
Net sales											$ 81.3
Sales Returns and Allowances
Disaggregation of Revenue [Line Items]
Revenue Reserves	34				34.5						34	34.5
Revenue Reserve Provision											39.3
Revenue Reserve Payments or Credits											(39.8)
Rebates and Chargebacks [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves	354.3				327.4						354.3	327.4
Revenue Reserve Provision											2,281.3
Revenue Reserve Payments or Credits											(2,254.4)
Other Sales Deductions [Member]
Disaggregation of Revenue [Line Items]
Revenue Reserves	$ 17.1				$ 14.7						17.1	$ 14.7
Revenue Reserve Provision											66.9
Revenue Reserve Payments or Credits											$ (64.5)

Revenue from Contracts with C_4

Revenue from Contracts with Customers Future Performance Obligations (Details) $ in Millions	Dec. 28, 2018USD ($)
Current Fiscal Year [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 145
Year Two [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	127.3
Year Three [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	32.6
Thereafter [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 3.2

Discontinued Operations and D_3

Discontinued Operations and Divestitures (Income (loss) from Discontinued Operations) (Details) - USD ($) $ in Millions		3 Months Ended										12 Months Ended
		Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Jan. 27, 2017	Nov. 27, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations, net of income taxes		$ 0	$ 0.4	$ (12.4)	$ (2.9)	$ (1.3)	$ 0.6	$ 7.8	$ (370.3)	$ (23.6)	$ (107.3)	$ (14.9)	$ (363.2)	$ (154.7)
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal										0		(0.8)	56.9	0
U.K.										0		(0.2)	0.4	0.3
Discontinued Operation, Tax Effect of Discontinued Operation										15.3		1.4	5.4	43.5
Benefit from income taxes										(121.7)	$ (37.3)	(430.1)	(1,709.6)	(255.6)
Goodwill, Impairment Loss												3,672.8
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	[1],[2]									(123)		(235.7)	(219.9)	(249.3)
Non-U.K.										82		113	37.7	120.5
U.K.										(0.5)		1.4	0.6	0.7
International Deferred										203.2		$ 544.3	1,748.3	377.1
Contrast Media and Delivery Systems
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration																$ 270
Net sales														61
Cost of sales														46.9
Selling, general and administrative														20.3
Other														1.2
Loss from discontinued operations														(7.4)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax														95.3
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax														87.9
Income tax expense (benefit)														(2.5)
Income from discontinued operations net of tax														90.4
Nuclear Imaging
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration															$ 690
Disposal Group, Including Discontinued Operation, Upfront Consideration															574
Discontinued Operation, Amounts of Material Contingent Liabilities Remaining															$ 77
Net sales										99.4			31.6	418.6
Cost of sales										44.7			15.6	216.6
Selling, general and administrative										16.4			7.8	83.7
Restructuring charges, net										0			0	2.3
Other										0.2			0.2	5.7
Loss from discontinued operations				15						38.1			8.4	110.3
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax										0			362.8	0
Discontinued Operation, Tax Effect of Discontinued Operation										15.3			5.2	49
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax										38.1			371.2	110.3
Income from discontinued operations net of tax				13.6						22.8			366	61.3
Discontinued Operation, Amount of Adjustment to Prior Period Gain (Loss) on Disposal, before Income Tax				6
Contingent consideration received, equity certificates				9
Interest Rate, Equity Certificates												10.00%
Discontinued Operation, Tax Effect of Adjustment to Prior Period Gain (Loss) on Disposal				$ 1.4
Mallinckrodt Baker
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations, net of income taxes										$ (0.6)		$ 0.3	$ 0.6	$ (3)
[1]	During the three months ended December 30, 2016, the rate difference between U.K. and non-U.K. jurisdictions was favorably impacted by a benefit of $16.1 million on a $102.0 million settlement with the Federal Trade Commission and a benefit of $34.5 million on a $207.0 million
[2]	Includes the impact of certain recurring valuation allowances for U.K. and non-U.K. jurisdictions.

Discontinued Operations and D_4

Discontinued Operations and Divestitures, Significant Cash and Non-Cash Transactions (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 29, 2017	Sep. 30, 2016
Contrast Media and Delivery Systems
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Capital expenditures			$ 1.6
Nuclear Imaging
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation	$ 0	$ 0	20.9
Capital expenditures	$ 2	$ 0.3	$ 9.7

Discontinued Operations and D_5

Discontinued Operations and Divestitures (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended										12 Months Ended
		Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Mar. 16, 2018	Mar. 17, 2017	Jan. 27, 2017	Nov. 27, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill, Period Increase (Decrease)												$ (190.1)
Non-restructuring impairment charges										$ 214.3		3,893.1	$ 63.7	$ 16.9
Goodwill, Impairment Loss												3,672.8
Provision for (benefit from) income taxes										121.7	$ 37.3	430.1	1,709.6	255.6
Tax (benefit) expense on income (loss) from discontinued operations										15.3		1.4	5.4	43.5
Income (loss) from discontinued operations, net of income taxes		$ 0	$ 0.4	$ (12.4)	$ (2.9)	$ (1.3)	$ 0.6	$ 7.8	$ (370.3)	(23.6)	$ (107.3)	(14.9)	(363.2)	(154.7)
Losses (gains) on divestiture												(0.8)	(56.9)
Non-U.K.										82		113	37.7	120.5
Deferred Foreign Income Tax Expense (Benefit)										(203.2)		(544.3)	(1,748.3)	(377.1)
Deferred Income Tax Expense (Benefit)										203.7		542.9	1,747.7	376.4
U.K.										0		(0.2)	0.4	0.3
Losses (gains) on divestiture										0		0.8	(56.9)	0
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	[1],[2]									(123)		$ (235.7)	(219.9)	(249.3)
Nuclear Imaging
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Capital expenditures										2			0.3	9.7
Consideration																	$ 690
Disposal Group, Including Discontinued Operation, Upfront Consideration																	574
Tax (benefit) expense on income (loss) from discontinued operations										15.3			5.2	49
Discontinued Operation, Amounts of Material Contingent Liabilities Remaining																	$ 77
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax										0			362.8	0
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax				15						38.1			8.4	110.3
Discontinued Operation, Amount of Adjustment to Prior Period Gain (Loss) on Disposal, before Income Tax				6
Contingent consideration received, equity certificates				9
Interest Rate, Equity Certificates												10.00%
Discontinued Operation, Tax Effect of Adjustment to Prior Period Gain (Loss) on Disposal				1.4
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax				$ 13.6						22.8			366	61.3
Contrast Media and Delivery Systems
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Capital expenditures														1.6
Consideration																		$ 270
Income tax expense (benefit)														(2.5)
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax														95.3
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax														(7.4)
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax														90.4
Mallinckrodt Baker
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations, net of income taxes										$ (0.6)		$ 0.3	0.6	$ (3)
Hemostasis Products
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill, Period Increase (Decrease)												51.5
Disposal Group, Including Discontinued Operation, Upfront Consideration															$ 153
Disposal Group, Including Discontinued Operation, Intangible Assets, Noncurrent															(49.9)
Disposal Group, Not Discontinued Operation, Consideration															185
Disposal Group, Not Discontinued Operation, Contingent Consideration															(12.1)
Losses (gains) on divestiture												(0.8)
Disposal Group, Not Discontinued Operations, Account Receivable Consideration															$ 13.7
Intrathecal Therapy [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Consideration																$ 203
Disposal Group, Not Discontinued Operation, Fixed Consideration																171
Disposal Group, Not Discontinued Operation, Contingent Consideration																32
Disposal Group, Not Discontinued Operation, Upfront Consideration																17
Disposal Group, Not Discontinued Operation, Note Receivable Consideration																154
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal, Pre-tax												56.6
Proceeds from Collection of Notes Receivable												154
Disposal Group, Not Discontinued Operation, Other Commitment		$ 3.1				$ 6.5						3.1	$ 6.5			$ 7.3
Other | Intrathecal Therapy [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Losses (gains) on divestiture												48.7
Goodwill [Member] | Intrathecal Therapy [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Losses (gains) on divestiture												$ 49.8
[1]	During the three months ended December 30, 2016, the rate difference between U.K. and non-U.K. jurisdictions was favorably impacted by a benefit of $16.1 million on a $102.0 million settlement with the Federal Trade Commission and a benefit of $34.5 million on a $207.0 million
[2]	Includes the impact of certain recurring valuation allowances for U.K. and non-U.K. jurisdictions.

Acquisitions and License Agre_3

Acquisitions and License Agreements (Narrative) (Details) - USD ($)		Aug. 06, 2018	Feb. 13, 2018	Dec. 11, 2017		Oct. 02, 2017	Sep. 25, 2017	Aug. 31, 2016	Feb. 01, 2016	Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015		Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 26, 2014	Aug. 04, 2018	Apr. 05, 2018	Jan. 06, 2017	Aug. 31, 2014
Business Acquisition [Line Items]
Payments to Acquire Businesses, Net of Cash Acquired																		$ (1,800,000)	$ 0		$ 699,900,000	$ 76,300,000	$ 245,400,000
Long-term Debt, Gross										$ 6,134,000,000				$ 6,492,600,000							6,134,000,000	6,492,600,000
Net sales										834,900,000	$ 799,900,000	$ 825,500,000	$ 755,300,000	792,300,000	$ 793,900,000	$ 824,500,000	$ 810,900,000	829,900,000	811,200,000		3,215,600,000	3,221,600,000	3,380,800,000
Non-cash impairment charges																		214,300,000	0		3,893,100,000	63,700,000	16,900,000
Impairment of Intangible Assets, Finite-lived																		7,300,000
Operating Income (Loss)																		(158,600,000)	$ (164,000,000)	[1]	(3,720,900,000)	492,900,000	633,100,000
Intangible asset amortization																		175,700,000			740,200,000	694,500,000	700,100,000
Noninterest Income, Other Operating Income																					15,500,000
Sucampo [Member]
Business Acquisition [Line Items]
Contingent consideration			$ 0
Total consideration			847,600,000
Cash used to acquire business			1,200,000,000
Total Debt			366,300,000
Net sales																					190,500,000
Operating Income (Loss)																					(369,100,000)
Intangible asset amortization																					62,900,000
CPP [Member]
Business Acquisition [Line Items]
Payment for License Option Exercised																										$ 10,000,000
Contingent consideration, potential maximum																									$ 185,000,000
Potential reduction of future payment																									$ 15,000,000
Business Combination, Contingent Consideration, Payment		$ 5,000,000
Ocera [Member]
Business Acquisition [Line Items]
Contingent consideration	[2]			$ 22,000,000
Business Combination, Consideration Transferred, Other				42,400,000
Total consideration				64,400,000	[2]																1,900,000	40,500,000
Cash used to acquire business													1,900,000
Total Debt	[3]			0
Contingent consideration, potential maximum				$ 75,000,000
InfaCare [Member]
Business Acquisition [Line Items]
Contingent consideration	[4]						$ 35,000,000
Business Combination, Consideration Transferred, Other							80,400,000
Total consideration							73,100,000
Total Debt	[4]						30,000,000
Contingent consideration, potential maximum							345,000,000
Business Combination, Cash Paid for Consideration							37,200,000
Other liabilities (non-current)							$ 43,200,000
Stratatech [Member]
Business Acquisition [Line Items]
Contingent consideration								$ 54,900,000
Business Combination, Consideration Transferred, Other								76,000,000
Total consideration								130,900,000
Total Debt								1,000,000
Contingent consideration, potential maximum								$ 121,000,000
Hemostasis Products
Business Acquisition [Line Items]
Contingent consideration	[5]								$ 52,000,000
Business Combination, Consideration Transferred, Other									173,500,000
Total consideration									225,500,000
Total Debt	[5]								0
Contingent consideration, potential maximum									$ 395,000,000
NeuroproteXeon [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred, Other						$ 10,000,000
Business Combination, Contingent Consideration, Potential Payment						$ 25,000,000
Milestone Payment																					5,000,000
Contingent payment, maximum additional amount																					20,000,000
Mesoblast [Member]
Business Acquisition [Line Items]
Payments to Acquire Marketable Securities																						21,500,000
Available-for-sale Securities, Current																											$ 19,700,000
Intangible Assets, Current																											$ 1,800,000
Proceeds from Sale of Available-for-sale Securities, Equity																					25,500,000
Marketable Securities, Realized Gain (Loss)																					3,400,000
Questcor Pharmaceuticals, Inc.
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability										76,200,000				111,800,000							76,200,000	111,800,000						$ 195,400,000
Contingent consideration, potential maximum										115,000,000											115,000,000
Raplixa [Member]
Business Acquisition [Line Items]
Impairment of Intangible Assets, Finite-lived																						63,700,000
PreveLeak [Member] | Hemostasis Products
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Payment													$ 12,000,000
Bristol-Myers Squibb | Licensing Agreements
Business Acquisition [Line Items]
Royalties paid																		14,700,000			76,900,000	53,900,000	46,300,000
Depomed | Licensing Agreements
Business Acquisition [Line Items]
Contingent payment, maximum additional amount																					64,000,000
Milestone Payments																					22,000,000			$ 10,000,000
Xartemis [Member]
Business Acquisition [Line Items]
Impairment of Intangible Assets, Finite-lived																		7,300,000
Prepaid Expenses and Other Current Assets [Member] | CPP [Member]
Business Acquisition [Line Items]
Payment for License Option Exercised, Capitalized																					2,700,000
Term Loan due 2025 [Member] | Secured Debt
Business Acquisition [Line Items]
Loans Payable										597,000,000				0							597,000,000	0
Long-term Debt, Gross										591,000,000				0							591,000,000	0
Term Loan due 2025 [Member] | Secured Debt | Sucampo [Member]
Business Acquisition [Line Items]
Loans Payable			600,000,000
2017 Revolving Credit Facility | Debentures
Business Acquisition [Line Items]
Long-term Debt, Gross			900,000,000							$ 220,000,000				$ 900,000,000							220,000,000	900,000,000
Sucampo 2021 Notes [Member] | Convertible Debt Securities [Member]
Business Acquisition [Line Items]
Long-term Debt, Gross			$ 300,000,000
Stated interest rate			3.25%
Debt instrument, face amount			$ 1,000
Debt Conversion, Converted Instrument, Amount			$ 1,221
Cost of Sales
Business Acquisition [Line Items]
Amortization Of Inventory Step-Up To Cost Of Sales																		$ 3,600,000			120,800,000	$ 10,100,000	$ 24,300,000
Cost of Sales | Sucampo [Member]
Business Acquisition [Line Items]
Amortization Of Inventory Step-Up To Cost Of Sales																					118,800,000
Research and Development Expense [Member] | CPP [Member]
Business Acquisition [Line Items]
Payment for License Option Exercised, Expensed																					$ 7,300,000
[1]	Financial data for this period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of Accounting Standards Update ("ASU") 2017-07. See Note 4 for further information on this ASU.
[2]	(1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date.
[3]	(1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million
[4]	During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million
[5]	During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information.

Acquisitions and License Agre_4

Acquisitions and License Agreements (Schedule of Fair Value of Identifiable Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Millions		Feb. 13, 2018	Dec. 11, 2017		Sep. 25, 2017	Aug. 31, 2016	Feb. 01, 2016	Sep. 28, 2018	Dec. 28, 2018	Dec. 29, 2017
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Goodwill (non-tax deductible)									$ 0	$ 3,482.7
Sucampo [Member]
Business Acquisition [Line Items]
Receivables		$ 35.7
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Cash		149.6
Inventory		153.2
Intangible assets		919.5
Goodwill, Acquired During Period	[1]							$ 248.6
Other assets, current and non-current		25.8
Total assets acquired		1,532.4
Current liabilities		109.4
Other liabilities (non-current)		33.3
Deferred tax liabilities, net (non-current)		175.8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities		0
Contingent consideration (non-current)		0
Total Debt		366.3
Total liabilities assumed		684.8
Net assets acquired		847.6
Total consideration		$ 847.6
Stratatech [Member]
Business Acquisition [Line Items]
Receivables						$ 1.3
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Cash						0.2
Inventory						0
Goodwill (non-tax deductible)	[1]					55.1
Other assets, current and non-current						1.9
Total assets acquired						158.3
Current liabilities						4.3
Other liabilities (non-current)						0
Deferred tax liabilities, net (non-current)						22.1
Contingent consideration (non-current)						54.9
Total Debt						1
Total liabilities assumed						82.3
Net assets acquired						76
Total consideration						130.9
Ocera [Member]
Business Acquisition [Line Items]
Receivables	[2]		$ 0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Cash	[2],[3]		1
Inventory	[2]		0
Goodwill, Acquired During Period	[1],[2]								18
Other assets, current and non-current	[2]		0.4
Total assets acquired	[2]		83.9
Current liabilities	[2]		12
Other liabilities (non-current)	[2]		0
Deferred tax liabilities, net (non-current)			16.7	[2]						23.2
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Non-Current Contingent Consideration	[2]		12.8
Contingent consideration (non-current)	[3]		22
Total Debt	[2]		0
Total liabilities assumed	[2]		41.5
Net assets acquired	[2],[3]		42.4
Total consideration			64.4	[3]					1.9	40.5
InfaCare [Member]
Business Acquisition [Line Items]
Receivables	[4]				$ 0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Cash	[4]				1.3
Inventory	[4]				0
Goodwill, Acquired During Period	[1],[4]								11.4
Other assets, current and non-current	[4]				0.1
Total assets acquired	[4]				126.3
Current liabilities	[4]				14.5
Other liabilities (non-current)	[4]				0
Deferred tax liabilities, net (non-current)	[4]				8.7
Contingent consideration (non-current)	[4]				35
Total Debt	[4]				30
Total liabilities assumed	[4]				88.2
Net assets acquired	[4]				38.1
Total consideration					73.1
Hemostasis Products
Business Acquisition [Line Items]
Receivables	[5]						$ 0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Cash	[5]						3.3
Inventory	[5]						94.6
Intangible assets	[5]						132.7
Goodwill (non-tax deductible)	[1],[5]						3.3
Other assets, current and non-current	[5]						7.9
Total assets acquired	[5]						241.8
Current liabilities	[5]						3.6
Other liabilities (non-current)	[5]						10.6
Deferred tax liabilities, net (non-current)	[5]						2.1
Contingent consideration (non-current)	[5]						52
Total Debt	[5]						0
Total liabilities assumed	[5]						68.3
Net assets acquired	[5]						173.5
Total consideration							$ 225.5
MNK-6105 [Member] | Ocera [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Indefinite lived intangible assets acquired	[2]		64.5
Stannsoporfin [Member] | InfaCare [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Indefinite lived intangible assets acquired	[4]				$ 113.5
StrataGraft [Member] | In-process research and development | Stratatech [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Indefinite lived intangible assets acquired						$ 99.8
Fair Value, Measurements, Recurring
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Contingent consideration (non-current)									151.4	42.7
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Contingent consideration (non-current)									151.4	0
Fair Value, Measurements, Recurring | MNK-6105 [Member] | Fair Value, Inputs, Level 3 | Ocera [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Contingent consideration (non-current)			$ 22						21.5
Fair Value, Measurements, Recurring | Stannsoporfin [Member] | Fair Value, Inputs, Level 3 | InfaCare [Member]
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Less Noncontrolling Interest [Abstract]
Contingent consideration (non-current)									0	$ 35
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)									$ (35)
[1]	Refer to Note 13 for further information relating to the full goodwill impairment recorded in fiscal 2018.
[2]	(1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million
[3]	(1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date.
[4]	During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million
[5]	During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information.

Acquisitions and License Agre_5

Acquisitions and License Agreements (Schedule of Reconciliation of Total Consideration) (Details) - USD ($) $ in Millions		Feb. 13, 2018	Dec. 11, 2017		Sep. 25, 2017	Aug. 31, 2016	Feb. 01, 2016	Mar. 30, 2018	Dec. 28, 2018	Dec. 29, 2017
Ocera [Member]
Business Acquisition [Line Items]
Total consideration, net of cash	[1]		$ 63.4
Plus: cash assumed in acquisition	[1],[2]		1
Total consideration			64.4	[1]					$ 1.9	$ 40.5
Cash used to acquire business								$ 1.9
Business Combination, Consideration Transferred, Other			42.4
Less: non-cash contingent consideration	[1]		(22)
Net assets acquired	[1],[2]		$ 42.4
InfaCare [Member]
Business Acquisition [Line Items]
Total consideration, net of cash					$ 71.8
Plus: cash assumed in acquisition	[3]				1.3
Total consideration					73.1
Business Combination, Consideration Transferred, Other					80.4
Less: non-cash contingent consideration	[3]				(35)
Net assets acquired	[3]				$ 38.1
Stratatech [Member]
Business Acquisition [Line Items]
Total consideration, net of cash						$ 130.7
Plus: cash assumed in acquisition						0.2
Total consideration						130.9
Business Combination, Consideration Transferred, Other						76
Less: non-cash contingent consideration						(54.9)
Net assets acquired						$ 76
Hemostasis Products
Business Acquisition [Line Items]
Total consideration, net of cash							$ 222.2
Plus: cash assumed in acquisition	[4]						3.3
Total consideration							225.5
Business Combination, Consideration Transferred, Other							173.5
Less: non-cash contingent consideration	[4]						(52)
Net assets acquired	[4]						$ 173.5
Sucampo [Member]
Business Acquisition [Line Items]
Total consideration, net of cash		$ 698
Plus: cash assumed in acquisition		149.6
Total consideration		847.6
Cash used to acquire business		1,200
Less: non-cash contingent consideration		0
Net assets acquired		$ 847.6
[1]	(1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date.
[2]	(1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million
[3]	During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million
[4]	During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information.

Acquisitions and License Agre_6

Acquisitions and License Agreements (Schedule of Intangible Assets Acquired) (Details) - USD ($) $ in Millions		Feb. 13, 2018	Dec. 11, 2017	Sep. 25, 2017	Aug. 31, 2016	Feb. 01, 2016
Sucampo [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Net assets acquired		$ 847.6
Ocera [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Net assets acquired	[1],[2]		$ 42.4
InfaCare [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Net assets acquired	[3]			$ 38.1
Hemostasis Products
Intangible Assets Acquired as Part of Business Combination [Line Items]
Net assets acquired	[4]					$ 173.5
Stratatech [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Net assets acquired					$ 76
Amitiza | Sucampo [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 634
Intangible assets acquired, weighted-average useful life		9 years
Cash flow discount rate		14.00%
Rescula [Member] | Sucampo [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 11
Intangible assets acquired, weighted-average useful life		8 years
Cash flow discount rate		14.00%
VTS-270 [Member] | Sucampo [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Indefinite lived intangible assets acquired		$ 274.5
Cash flow discount rate		15.00%
MNK-6105 [Member] | Ocera [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Indefinite lived intangible assets acquired	[1]		$ 64.5
Cash flow discount rate			15.50%
Stannsoporfin [Member] | InfaCare [Member]
Intangible Assets Acquired as Part of Business Combination [Line Items]
Indefinite lived intangible assets acquired	[3]			$ 113.5
Cash flow discount rate				13.50%
StrataGraft [Member] | Stratatech [Member] | In-process research and development
Intangible Assets Acquired as Part of Business Combination [Line Items]
Indefinite lived intangible assets acquired					$ 99.8
Cash flow discount rate					16.50%
Raplixa [Member] | Hemostasis Products
Intangible Assets Acquired as Part of Business Combination [Line Items]
Intangible assets acquired, weighted-average useful life	[5]					15 years
Indefinite lived intangible assets acquired	[5]					$ 73
Cash flow discount rate	[5]					17.00%
Recothrom [Member] | Hemostasis Products
Intangible Assets Acquired as Part of Business Combination [Line Items]
Intangible assets acquired, weighted-average useful life	[6]					13 years
Indefinite lived intangible assets acquired	[6]					$ 42.7
Cash flow discount rate	[6]					16.00%
PreveLeak [Member] | Hemostasis Products
Intangible Assets Acquired as Part of Business Combination [Line Items]
Intangible assets acquired, weighted-average useful life	[6]					13 years
Indefinite lived intangible assets acquired	[6]					$ 17
Cash flow discount rate	[6]					17.00%
[1]	(1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million
[2]	(1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date.
[3]	During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million
[4]	During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information.
[5]	(1)During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to the Raplixa intangible asset. Refer to Note 13 for further information.
[6]	During fiscal 2018, the Company sold the Recothrom and PreveLeak assets to Baxter. Refer to Note 6 for further information.

Acquisitions and License Agre_7

Acquisitions and License Agreements (Schedule of Financial Results and Acquisition Costs of Acquirees) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Sucampo [Member]
Business Acquisition [Line Items]
Acquisition Related Costs	$ 0	$ 5.2	$ 4.2	$ 0
Ocera [Member]
Business Acquisition [Line Items]
Acquisition Related Costs	0	0.5	0.9	0
InfaCare [Member]
Business Acquisition [Line Items]
Acquisition Related Costs	0	0	1.2	0
Stratatech [Member]
Business Acquisition [Line Items]
Acquisition Related Costs	0	0	0	3.7
Hemostasis Products
Business Acquisition [Line Items]
Acquisition Related Costs	0.1	0	0	2.7
Others
Business Acquisition [Line Items]
Acquisition Related Costs	0	0.1	0.1	0.5
Total Acquisitions
Business Acquisition [Line Items]
Acquisition Related Costs	$ 0.1	$ 5.8	$ 6.4	$ 6.9

Acquisitions and License Agre_8

Acquisitions and License Agreements (Schedule of Intangible Asset Amortization by Acquiree) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Intangible asset amortization	$ 175.7	$ 740.2	$ 694.5	$ 700.1
Cost of Sales
Schedule of Intangible Asset Amortization by Acquiree [Line Items]
Amortization Of Inventory Step-Up To Cost Of Sales	$ 3.6	$ 120.8	$ 10.1	$ 24.3

Restructuring and Related Cha_3

Restructuring and Related Charges (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Feb. 01, 2018	Jul. 01, 2016	Sep. 27, 2013
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	$ 3.8	$ 4.1	$ 103	$ 31.2	$ 32.7
2013 Mallinckrodt program | Minimum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range								$ 100
2013 Mallinckrodt program | Maximum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range								$ 125
Restructuring Fiscal 2018 Plan [Member] | Minimum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range						$ 100
Restructuring Fiscal 2018 Plan [Member] | Maximum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range						$ 125
2016 Mallinckrodt Program | Minimum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range							$ 100
2016 Mallinckrodt Program | Maximum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range							$ 125
Raplixa [Member] | Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net			$ 51.1

Restructuring and Related Cha_4

Restructuring and Related Charges (Schedule of Restructuring and Related Charges by Segment) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		$ 5.3		$ 108.2	$ 36.4	$ 37.6
Less: accelerated depreciation		(1.5)		(5.2)	(5.2)	(4.9)
Restructuring charges, net		3.8	$ 4.1	103	31.2	32.7
Specialty Brands [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		2.6		52.2	25.4	23.3
Specialty Generics and Amitiza [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		0.8		29	7.7	3.4
Corporate
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		1.9		27	3.3	10.9
Other Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	[1],[2]	$ 0		$ 0	$ 0	$ 0.6
[1]	(1) Charges incurred under restructuring programs related to pension that were reclassified to other income (expense) due to the adoption of ASU 2017-07.
[2]	(1) Charges incurred under restructuring programs related to pension that were reclassified to other income (expense), net due to the adoption of ASU 2017-07.

Restructuring and Related Cha_5

Restructuring and Related Charges (Schedule of Net Restructuring and Related Charges) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		$ 5.3		$ 108.2	$ 36.4	$ 37.6
Less: non-cash charges, including accelerated depreciation and impairments		(1.5)		(5.2)	(5.2)	(4.9)
Total charges expected to be settled in cash		3.8		103	31.2	32.7
Restructuring charges, net		3.8	$ 4.1	103	31.2	32.7
Restructuring Fiscal 2018 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		0		5.2	0	0
2016 Mallinckrodt Program
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		5.2		71.6	36.2	(8.3)
2013 Mallinckrodt program
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		0		0	(0.7)	25.6
Acquisition programs
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges		0.1		31.4	0.9	3.7
Other Expense [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges, net	[1],[2]	$ 0		$ 0	$ 0	$ 0.6
[1]	(1) Charges incurred under restructuring programs related to pension that were reclassified to other income (expense) due to the adoption of ASU 2017-07.
[2]	(1) Charges incurred under restructuring programs related to pension that were reclassified to other income (expense), net due to the adoption of ASU 2017-07.

Restructuring and Related Cha_6

Restructuring and Related Charges (Schedule of Restructuring Reserves by Type of Cost) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 18.5	$ 15.5	$ 14.8	$ 18
Charges	3.8	109	36.7	35.4
Changes in estimate from continuing operations		(6)	(5.5)	(2.7)
Cash payments	(7.5)	(45.6)	(30.8)	(33.7)
Reclassifications		(1.9)	0.3	(0.7)	[1]
Ending Balance	14.8	71	15.5	18.5
Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations				2.5
Changes in estimate, discontinued operations				(0.3)
Acquisition programs | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance	0.5	0.8	0.2	10
Charges	0.1	29.9	0.9	5
Changes in estimate from continuing operations		(0.7)	0	(1.3)
Cash payments	(0.4)	(22.2)	(0.3)	(13.2)
Reclassifications		0	0	0	[1]
Ending Balance	0.2	7.8	0.8	0.5
Acquisition programs | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations				0
Changes in estimate, discontinued operations				0
Restructuring Fiscal 2018 Plan [Member] | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance	0	0	0	0
Charges	0	2.2	0	0
Changes in estimate from continuing operations		0	0	0
Cash payments	0	0	0	0
Reclassifications		0	0	0	[1]
Ending Balance	0	2.2	0	0
Restructuring Fiscal 2018 Plan [Member] | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations				0
Changes in estimate, discontinued operations				0
2016 Mallinckrodt Program | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance	6.2	14.7	9.5	0
Charges	3.7	76.9	35.8	6.4
Changes in estimate from continuing operations		(5.3)	(4.8)	0
Cash payments	(0.4)	(23.4)	(26.1)	(0.2)
Reclassifications		(1.9)	0.3	0	[1]
Ending Balance	9.5	61	14.7	6.2
2016 Mallinckrodt Program | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations				0
Changes in estimate, discontinued operations				0
2013 Mallinckrodt program | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance	11.8	0	5.1	8
Charges	0	0	0	24
Changes in estimate from continuing operations		0	(0.7)	(1.4)
Cash payments	(6.7)	0	(4.4)	(20.3)
Reclassifications		0	0	(0.7)	[1]
Ending Balance	$ 5.1	$ 0	$ 0	11.8
2013 Mallinckrodt program | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations				2.5
Changes in estimate, discontinued operations				$ (0.3)
[1]	Represents the reclassification of pension and other postretirement benefits from restructuring reserves to pension and postretirement obligations.

Restructuring and Related Cha_7

Restructuring and Related Charges (Schedule of Restructuring Charges Incurred Cumulative to Date) (Details) $ in Millions	Dec. 28, 2018USD ($)
2013 Mallinckrodt program
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	$ 124.7
2013 Mallinckrodt program | Specialty Brands [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	18.8
2013 Mallinckrodt program | Specialty Generics and Amitiza [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	18.3
2013 Mallinckrodt program | Nuclear Imaging
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	69.9
2013 Mallinckrodt program | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	17.7
Restructuring Fiscal 2018 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	5.2
Restructuring Fiscal 2018 Plan [Member] | Specialty Brands [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	3
Restructuring Fiscal 2018 Plan [Member] | Specialty Generics and Amitiza [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	0
Restructuring Fiscal 2018 Plan [Member] | Nuclear Imaging
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	0
Restructuring Fiscal 2018 Plan [Member] | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	2.2
2016 Mallinckrodt Program
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	122.2
2016 Mallinckrodt Program | Specialty Brands [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	81.7
2016 Mallinckrodt Program | Specialty Generics and Amitiza [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	14.6
2016 Mallinckrodt Program | Nuclear Imaging
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	0
2016 Mallinckrodt Program | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs incurred cumulative to date	$ 25.9

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)		3 Months Ended	12 Months Ended
		Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Mar. 16, 2018	Feb. 13, 2018	Dec. 11, 2017	[5]	Sep. 25, 2017	Aug. 31, 2016	Feb. 01, 2016
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Foreign Income Tax Rate Differential, Amount	[1],[2]	$ (123,000,000)	$ (235,700,000)	$ (219,900,000)	$ (249,300,000)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		20.00%	19.00%	19.00%	20.00%
Increase (Decrease) Tax Expense (Benefit), Change in Operating Income			$ 4,700,000	$ 23,400,000
Current Income Tax Expense (Benefit)		$ 82,000,000	112,800,000	38,100,000	$ 120,800,000
Increase (Decrease) Tax Benefit, Jurisdiction Rate Difference			15,800,000	29,400,000
Deferred income taxes			324,300,000	689,000,000
Income Taxes Paid, Net		95,600,000	12,400,000	73,400,000	165,400,000
Income Tax Holiday, Aggregate Dollar Amount		0	1,000,000	1,800,000	1,000,000
Decrease in Unrecognized Tax Benefits is Reasonably Possible			136,900,000
Increase (Decrease) Deferred Tax Liability Resulting From Tax Reform, TCJA			8,500,000	444,800,000
Decrease in Interest and Penalties is Reasonably Possible			32,800,000
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		7,100,000	37,100,000	7,100,000	7,400,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		116,900,000	275,800,000	180,800,000	113,100,000
Unrecognized Tax Benefits, Interest on Income Taxes Expense		200,000	(33,200,000)	0	(1,900,000)
Tax Credit Carryforward, Amount			61,800,000
Increase (Decrease) Deferred Tax Liability Resulting From Legal Reorganization			281,500,000
Increase (Decrease) Deferred Tax Liability Resulting From Tax Reform			135,900,000
Increase (Decrease) Deferred Tax Liability Resulting from Installment Note Payments			(49,100,000)
Increase (Decrease), Deferred Tax Liability Due to Amortization of Intangible Assets			(28,900,000)
Increase (Decrease) Deferred Tax Liability, Inventory Step-Up			23,600,000
Increase (Decrease) Deferred Tax Assets Resulting from Legal Settlements			6,500,000
Increase (Decrease) Deferred Tax Liability Resulting from Acquisitions			169,300,000
Tax Credit Carryforwards, Not Subject to Expiration			4,600,000
Increase (Decrease) Tax Expense (Benefit) Due to Divestiture			22,200,000	37,600,000
Increase (Decrease) Tax Expense (Benefit) Due to U.S. Tax Reform			80,200,000	15,200,000
Unrecognized Tax Benefits, Decrease Resulting from Acquisition			11,800,000
Increase (Decrease) Tax Benefit, Non-Restructuring Impairment Charges			90,300,000
Excess in Book over Tax Basis, Foreign Subsidiaries			41,600,000
Deferred Tax Liabilities, Undistributed Foreign Earnings			$ 9,100,000
Effective Tax Rate Impact, TCJA			0.20%
Sucampo [Member]
Income Tax Contingency [Line Items]
Increase (Decrease), Deferred Tax Assets, Other			$ 4,100,000
Deferred Tax Liabilities, Inventory							$ 25,700,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent							$ 175,800,000
Increase (Decrease) in Deferred Tax Liability, Intangible Assets			179,300,000
Increase (Decrease) Deferred Tax Liability Resulting from Acquisitions			175,800,000
Increase (Decrease) Deferred Tax Asset, Tax Loss and Credit Carryforwards			25,100,000
Hemostasis Products
Income Tax Contingency [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent	[3]											$ 2,100,000
InfaCare [Member]
Income Tax Contingency [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent	[4]									$ 8,700,000
Stratatech [Member]
Income Tax Contingency [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent											$ 22,100,000
Ocera [Member]
Income Tax Contingency [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent				23,200,000				$ 16,700,000
Hemostasis Products
Income Tax Contingency [Line Items]
Increase (Decrease), Deferred Tax Assets, Other			1,500,000
Increase (Decrease) Deferred Tax Liability Resulting from Divestiture			2,700,000
Deferred Tax Liabilities, Inventory						$ 2,700,000
Increase (Decrease) in Deferred Tax Liability, Intangible Assets			4,200,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			8,400,000
Increase (Decrease) Deferred Tax Asset, Tax Loss and Credit Carryforwards			$ 2,700,000
IRELAND
Income Tax Contingency [Line Items]
Tax years that remain subject to examination			2,013
Non-U.K.
Income Tax Contingency [Line Items]
Tax Credit Carryforward Utilization		2,000,000		5,600,000	9,500,000
Operating Loss Carry back				27,200,000
Operating Loss Carryforwards		300,000	$ 13,700,000	57,200,000	29,200,000
Deferred Tax Assets, Operating Loss Carryforwards			1,817,800,000
Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration			1,484,400,000
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration			$ 333,400,000
Non-U.K. | Hemostasis Products
Income Tax Contingency [Line Items]
Operating Loss Carryforwards					17,900,000
Internal Revenue Service (IRS) [Member]
Income Tax Contingency [Line Items]
Tax years that remain subject to examination			2,014
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Tax years that remain subject to examination			2,009
U.K.
Income Tax Contingency [Line Items]
Operating Loss Carryforwards			$ 8,500,000	$ 14,300,000	$ 1,000,000
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration			108,200,000
Retained Earnings | Accounting Standards Update 2016-16 [Member]
Income Tax Contingency [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			(75,000,000)
Retained Earnings | Accounting Standards Update 2016-09 [Member]
Income Tax Contingency [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ (2,900,000)
Other Assets [Member] | Accounting Standards Update 2016-16 [Member]
Income Tax Contingency [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			(67,200,000)
Prepaid Expenses and Other Current Assets [Member] | Accounting Standards Update 2016-16 [Member]
Income Tax Contingency [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets			(7,800,000)
Intercompany Financing and Legal Entity Ownership Reorganization [Member]
Income Tax Contingency [Line Items]
Current Income Tax Expense (Benefit)			25,500,000
Increase (Decrease) in Deferred Tax Liability, Intangible Assets			58,900,000
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount			39,700,000
Increase (Decrease) in Deferred Tax Liabilities, Other			9,300,000
Increase (Decrease) Deferred Tax Asset, Tax Loss and Credit Carryforwards			$ 1,300,000
[1]	During the three months ended December 30, 2016, the rate difference between U.K. and non-U.K. jurisdictions was favorably impacted by a benefit of $16.1 million on a $102.0 million settlement with the Federal Trade Commission and a benefit of $34.5 million on a $207.0 million
[2]	Includes the impact of certain recurring valuation allowances for U.K. and non-U.K. jurisdictions.
[3]	During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information.
[4]	During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million
[5]	(1) Of the $42.4 million net assets acquired for Ocera, $40.5 million and $1.9 million

Income Taxes (Schedule of Compo

Income Taxes (Schedule of Components of Income from Continuing Operations Before Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Operating Loss Carryforwards [Line Items]
U.K.	$ (97.4)		$ (233.7)	$ (165.9)	$ (275.3)
Non-U.K.	(201.1)		(3,818.3)	227.5	508.7
Income (loss) from continuing operations before income taxes	$ (298.5)	$ 66.5	$ (4,052)	$ 61.6	$ 233.4

Income Taxes (Schedule of Signi

Income Taxes (Schedule of Significant Components of Income Taxes Related to Continuing Operations) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Current:
U.K.	$ 0		$ (0.2)	$ 0.4	$ 0.3
Non-U.K.	82		113	37.7	120.5
Current income tax provision	82		112.8	38.1	120.8
Deferred:
U.K.	(0.5)		1.4	0.6	0.7
Non-U.K.	(203.2)		(544.3)	(1,748.3)	(377.1)
Deferred income tax benefit	(203.7)		(542.9)	(1,747.7)	(376.4)
Provision for (benefit from) income taxes	$ (121.7)	$ (37.3)	$ (430.1)	$ (1,709.6)	$ (255.6)

Income Taxes (Schedule of Recon

Income Taxes (Schedule of Reconciliation of Income Taxes at Statutory Rate and Tax Provision) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Income Taxes [Line Items]
Income tax expense (benefit), intercompany financing and legal entity reorganization		$ (203.7)		$ (542.9)	$ (1,747.7)	$ (376.4)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		20.00%		19.00%	19.00%	20.00%
(Benefit) provision for income taxes at U.K. statutory income tax rate (1)	[1]	$ (59.7)		$ (770.1)	$ 11.7	$ 46.6
Adjustments to reconcile to income tax provision:
Rate difference between non-U.S. and U.S. jurisdictions	[2],[3]	(123)		(235.7)	(219.9)	(249.3)
Goodwill, Impairment Loss				3,672.8
Litigation Settlement, Expense		102
Valuation allowances, nonrecurring		0		0	(3.7)	2.1
Adjustments to accrued income tax liabilities and uncertain tax positions		0.9		60.1	5.1	(14.9)
Interest and penalties on accrued income tax liabilities and uncertain tax positions		(0.1)		13.1	0.2	(16.4)
Investment in partnership		(12.7)		0	0	0
Credits, principally research	[4]	(0.7)		(25.9)	(13.8)	(33.7)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Impairment Losses, Amount		75.3		788.7	0	0
Permanently nondeductible and nontaxable items		1.6		7.2	6.4	7.9
Effective income tax rate reconciliation, pension plan settlement		0		0	(2.4)	0
Effective Income Tax Rate Reconciliation, Disposition of Business, Amount	[5]	0		(2.7)	18.2	0
Income tax benefit, tax cut and jobs act	[6]	0		(8.5)	(456.9)	0
Other		(3.3)		(0.3)	0.3	2.1
Income tax benefit, Legal Reorganization	[7]	0		(256)	(1,054.8)	0
Tax Adjustments, Settlements, and Unusual Provisions						27.4
Tax Benefit Resulting from Legal Settlement	[3]	16.1
Increase (Decrease) Deferred Tax Assets Resulting from Legal Settlements				(6.5)
Provision for (benefit from) income taxes		(121.7)	$ (37.3)	$ (430.1)	$ (1,709.6)	$ (255.6)
IRELAND
Income Taxes [Line Items]
Tax years that remain subject to examination				2,013
Specialty Generics [Member]
Adjustments to reconcile to income tax provision:
Rate difference between non-U.S. and U.S. jurisdictions	[3]	34.5
Goodwill, Impairment Loss		$ 207
Intercompany Financing and Legal Entity Ownership Reorganization [Member]
Income Taxes [Line Items]
Income tax expense (benefit), intercompany financing and legal entity reorganization				$ (281.5)
Adjustments to reconcile to income tax provision:
Increase (Decrease) in Deferred Tax Liability, Installment Sales				310.6
Increase (Decrease) Deferred Tax Liabilities, Investment in Partnership				58.9
Increase (Decrease) in Deferred Tax Liability, Intangible Assets				$ 58.9
[1]	The statutory tax rate reflects the U.K. statutory tax rate of 19% for fiscal 2018 and 2017 and 20%
[2]	During the three months ended December 30, 2016, the rate difference between U.K. and non-U.K. jurisdictions was favorably impacted by a benefit of $16.1 million on a $102.0 million settlement with the Federal Trade Commission and a benefit of $34.5 million on a $207.0 million
[3]	Includes the impact of certain recurring valuation allowances for U.K. and non-U.K. jurisdictions.
[4]	During fiscal 2018, the research and orphan drug credits increased in conjunction with the Company's increased investment in qualified research. During fiscal 2016, the Company realized a tax benefit of $27.4 million
[5]	During fiscal 2018, the Company completed the sale of a portion of its Hemostasis business. During fiscal 2017, the Company completed the sale of the Intrathecal Therapy Business.
[6]	For fiscal 2018, the Company completed its analysis of the TCJA and recognized an additional tax benefit. Other line items, to the extent U.S. related, are reflected at the current U.S. statutory income tax rate of 21%. For fiscal 2017, the benefit reflects the redetermination of the Company’s end of year net deferred tax liabilities as a result of the new U.S. statutory income tax rate of 21%. Other line items, to the extent U.S. related, are reflected at the former U.S. statutory income tax rate of 35%.
[7]	Associated unrecognized tax benefit netted within this line.

Income Taxes (Schedule of Unrec

Income Taxes (Schedule of Unrecognized Tax Benefit Activity) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of period	$ 114.8	$ 182.5	$ 118.7	$ 89.2
Additions related to current year tax positions	5	19.6	79.9	63.8
Additions related to prior period tax positions	0	125.1	0.3	10.8
Reductions related to prior period tax positions	(1.1)	(32.7)	(13.6)	(37.8)
Unrecognized Tax Benefits, Decrease Resulting from disposal of business	0	0	0	(6.6)
Settlements	0	(2)	0	(2.6)
Lapse of statute of limitations	0	(4.8)	(2.8)	(2)
Balance at end of period	$ 118.7	$ 287.7	$ 182.5	$ 114.8

Income Taxes (Schedule of Unr_2

Income Taxes (Schedule of Unrecognized Tax Benefits Balance Sheet Location) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 28, 2018	Dec. 29, 2017	Dec. 30, 2016	Sep. 30, 2016	Sep. 25, 2015
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Interest on Income Taxes Release	$ 3.2
Unrecognized Tax Benefits	287.7	$ 182.5	$ 118.7	$ 114.8	$ 89.2
Accrued and other current liabilities
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	1	1.5
Other Income Tax Liabilities
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	189.9	82.6
Deferred income tax liability (non-current)
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	96.8	98.4
Liabilities, Total [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 287.7	$ 182.5

Income Taxes (Schedule of Incom

Income Taxes (Schedule of Income Taxes Payable) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Operating Loss Carryforwards [Line Items]
Other income tax liabilities	$ 228	$ 94.1
Total income taxes payable	253	109.9
Accrued and Other Current Liabilities
Operating Loss Carryforwards [Line Items]
Income taxes payable	25	15.8
Other Income Tax Liabilities
Operating Loss Carryforwards [Line Items]
Other income tax liabilities	$ 228	$ 94.1

Income Taxes (Schedule of Inc_2

Income Taxes (Schedule of Income Tax Receivables and Other Assets) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Income Tax Disclosure [Abstract]
Other assets	$ 3	$ 0
Prepaid expenses and other current assets	16.2	6.1
Total	$ 19.2	$ 6.1

Income Taxes (Schedule of Defer

Income Taxes (Schedule of Deferred Taxes Activity) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Deferred tax assets:
Accrued liabilities and reserves	$ 56.3	$ 62.7
Tax loss and credit carryforwards	1,987.8	1,734.5
Deferred Tax Assets, Goodwill and Intangible Assets	757.7	575.1
Other	204.6	113.3
Total deferred tax assets, gross	3,006.4	2,485.6
Deferred tax liabilities:
Intangible assets	(264.7)	(181)
Interest-bearing deferred tax obligations	(227.5)	(553.5)
Investment in partnership	(170.2)	(108.8)
Deferred Tax Liabilities, Other	(42.9)	(47)
Total deferred tax liabilities, gross	(705.3)	(890.3)
Net deferred tax asset before valuation allowances	2,301.1	1,595.3
Valuation allowances	(2,604.9)	(2,267.9)
Deferred Tax Liabilities, Net	$ (303.8)	$ (672.6)

Income Taxes (Schedule of Def_2

Income Taxes (Schedule of Deferred Taxes Balance Sheet Location) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 28, 2018	Dec. 29, 2017
Other assets	$ 20.5	$ 16.4
Allowance for doubtful accounts	5	3.9
Deferred income taxes (non-current liability)	(324.3)	(689)
Deferred Tax Liabilities, Net	(303.8)	$ (672.6)
Increase (Decrease) Deferred Tax Liability Resulting From Legal Reorganization	(281.5)
Increase (Decrease), Deferred Tax Liability Due to Amortization of Intangible Assets	28.9
Increase (Decrease) Deferred Tax Assets Resulting from Legal Settlements	6.5
Increase (Decrease) Deferred Tax Liability Resulting from Acquisitions	$ 169.3

Income Taxes Tax Year Examinati

Income Taxes Tax Year Examination (Details)	12 Months Ended
	Dec. 28, 2018
Internal Revenue Service (IRS) [Member]
Income Tax Examination [Line Items]
Tax years that remain subject to examination	2,014
State and Local Jurisdiction [Member]
Income Tax Examination [Line Items]
Tax years that remain subject to examination	2,009
IRELAND
Income Tax Examination [Line Items]
Tax years that remain subject to examination	2,013

Earnings (Loss) per Share (Deta

Earnings (Loss) per Share (Details) - shares shares in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Earnings (Loss) per Share [Abstract]
Weighted Average Number of Shares Outstanding, Basic	105.7	115.4	84	97.7	110.6
Weighted Average Number of Shares Outstanding, Diluted	0		0	0.2	0.9
Weighted-average shares for diluted earnings (loss) per share (in shares)	105.7	116.3	84	97.9	111.5
Antidilutive securities excluded from weighted-average shares (in shares)	2.4		3.3	4.2	1.7

Earnings (Loss) per Share Sched

Earnings (Loss) per Share Schedule of Earnings per Share Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																		12 Months Ended
	Dec. 28, 2018		Sep. 28, 2018		Jun. 29, 2018		Mar. 30, 2018		Dec. 29, 2017		Sep. 29, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ (3,718.4)	[1]	$ 114.2	[1]	$ 3.2	[1]	$ (20.9)	[1]	$ 1,607.4	[1]	$ 64.3	[1]	$ 70.6	[1]	$ 28.9	[1]	$ (176.8)	$ 103.8	$ (3,621.9)	$ 1,771.2	$ 489
Income (Loss) From Continuing Operations Attributable To Common Stockholders																	(176.8)		(3,621.9)	1,771.2	489
Income (loss) from discontinued operations, net of income taxes	$ 0		$ (0.4)		$ 12.4		$ 2.9		$ 1.3		$ (0.6)		$ (7.8)		$ 370.3		23.6	$ 107.3	14.9	363.2	154.7
Net Income (Loss) Available to Common Stockholders, Basic																	$ (153.2)		$ (3,607)	$ 2,134.4	$ 643.7
Weighted Average Number of Shares Outstanding, Basic																	105.7	115.4	84	97.7	110.6
Weighted Average Number of Shares Outstanding, Diluted																	0		0	0.2	0.9
Weighted Average Number of Shares Outstanding, Diluted																	105.7	116.3	84	97.9	111.5
Income (Loss) from Continuing Operations, Per Basic Share	$ (44.64)	[2]	$ 1.37	[2]	$ 0.04	[2]	$ (0.24)	[2]	$ 17.43	[2]	$ 0.66	[2]	$ 0.72	[2]	$ 0.28	[2]	$ (1.67)	$ 0.90	$ (43.12)	$ 18.13	$ 4.42
Income (Loss) from Discontinued Operations, Per Basic Share																	0.22	0.93	0.18	3.72	1.40
Earnings Per Share, Basic																	(1.45)	1.83	(42.94)	21.85	5.82
(Loss) income from continuing operations	$ (44.64)	[2]	$ 1.34	[2]	$ 0.04	[2]	$ (0.24)	[2]	$ 17.40	[2]	$ 0.66	[2]	$ 0.72	[2]	$ 0.28	[2]	(1.67)	0.89	(43.12)	18.09	4.39
Income (Loss) from Discontinued Operations, Per Diluted Share																	0.22	0.92	0.18	3.71	1.39
Earnings Per Share, Diluted																	$ (1.45)	$ 1.82	$ (42.94)	$ 21.80	$ 5.77
[1]	(Loss) income from continuing operations for the quarter ended December 28, 2018 reflects impairment charges for goodwill and an IPR&D asset. See Note 13 for further information. Income from continuing operations for the quarter ended December 29, 2017 reflects one-time effects for the completion of the reorganization of the Company's legal entity ownership and the impact of the TCJA.
[2]	Quarterly and annual computations are prepared independently. Therefore, the sum of each quarter may not necessarily total the fiscal period amounts noted elsewhere within this Annual Report on Form 10-K.

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Inventory, Net [Abstract]
Raw materials and supplies	$ 69.2	$ 70
Work in process	167.6	167.1
Finished goods	85.5	103.3
Inventories	$ 322.3	$ 340.4

Property, Plant and Equipment_2

Property, Plant and Equipment (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 1,936.2	$ 1,842
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment		954.2	875.2
Depreciation	$ 27.5	$ 111.9	$ 113.8	$ 113.3

Property, Plant and Equipment_3

Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Property, Plant and Equipment [Line Items]
Depreciation	$ 27.5	$ 111.9	$ 113.8	$ 113.3
Property, plant and equipment, gross		1,936.2	1,842
Less: accumulated depreciation		(954.2)	(875.2)
Property, plant and equipment, net		982	966.8
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		43.9	44
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		379.5	355.5
Capitalized Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		130.8	109
Machinery and Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		1,137.3	1,123.8
Construction in Progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross		$ 244.7	$ 209.7

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets Narrative (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended	12 Months Ended
		Dec. 30, 2016	Dec. 25, 2015	Sep. 28, 2018	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible asset amortization		$ 175.7			$ 740.2	$ 694.5	$ 700.1
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)					220.3
Impairment of Intangible Assets, Finite-lived		7.3
Goodwill, Period Increase (Decrease)					(190.1)
Other Asset Impairment Charges		$ 214.3	$ 0		3,893.1	63.7	$ 16.9
Goodwill, Impaired, Accumulated Impairment Loss					3,879.8	207
Goodwill					0	3,482.7
Goodwill, Impairment Loss					3,672.8
Indefinite-lived intangible assets, gross					668.3	612.1
Hemostasis Products
Finite-Lived Intangible Assets [Line Items]
Goodwill, Period Increase (Decrease)					$ 51.5
Specialty Brands [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Cost of Capital, Rate					12.50%
Goodwill, Impaired, Accumulated Impairment Loss					$ (3,672.8)	0
Specialty Generics and Amitiza [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Cost of Capital, Rate		9.50%
Goodwill, Impaired, Accumulated Impairment Loss					(207)	(207)
Goodwill, Impairment Loss		$ 207
Specialty Generics [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill, Impairment Loss		$ 207
Raplixa [Member]
Finite-Lived Intangible Assets [Line Items]
Impairment of Intangible Assets, Finite-lived						$ 63.7
Sucampo [Member]
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible asset amortization					62.9
Finite-Lived Intangible Assets [Line Items]
Goodwill, Acquired During Period	[1]			$ 248.6
Sucampo [Member] | VTS-270 [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross					274.5
InfaCare [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill, Acquired During Period	[1],[2]				11.4
InfaCare [Member] | Stannsoporfin [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross					$ 113.5
[1]	Refer to Note 13 for further information relating to the full goodwill impairment recorded in fiscal 2018.
[2]	During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Schedule Of Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017
Goodwill [Line Items]
Goodwill, Period Increase (Decrease)		$ 190.1
Goodwill, Gross		3,879.8	$ 3,689.7
Goodwill, Impaired, Accumulated Impairment Loss		(3,879.8)	(207)
Goodwill, Impairment Loss		3,672.8
Specialty Brands [Member]
Goodwill [Line Items]
Goodwill, Gross		3,672.8	3,482.7
Goodwill, Impaired, Accumulated Impairment Loss		$ 3,672.8	0
Weighted Average Cost of Capital, Rate		12.50%
Specialty Generics and Amitiza [Member]
Goodwill [Line Items]
Goodwill, Gross		$ 207	207
Goodwill, Impaired, Accumulated Impairment Loss		$ 207	$ 207
Goodwill, Impairment Loss	$ 207
Weighted Average Cost of Capital, Rate	9.50%

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Schedule of Intangible Asset by Major Class [Line Items]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)			$ 220.3
Impairment of Intangible Assets, Finite-lived	$ 7.3
Other Asset Impairment Charges	214.3	$ 0	3,893.1	$ 63.7	$ 16.9
Intangible asset amortization	$ 175.7		740.2	694.5	$ 700.1
Amortizable:
Finite-lived intangible assets, gross			10,697.4	10,180.1
Accumulated amortization			3,082.9	2,417.2
Non-Amortizable:
Indefinite-lived intangible assets, gross			668.3	612.1
Trademarks
Non-Amortizable:
Indefinite-lived intangible assets, gross			35	35
In-process research and development
Non-Amortizable:
Indefinite-lived intangible assets, gross			633.3	577.1
Completed Technology
Amortizable:
Finite-lived intangible assets, gross			10,467.9	9,882.8
Accumulated amortization			2,980.6	2,260.8
Licensing Agreements
Amortizable:
Finite-lived intangible assets, gross			120.1	177.1
Accumulated amortization			70.1	121.1
Customer relationships
Amortizable:
Finite-lived intangible assets, gross			27.5	29.5
Accumulated amortization			14.1	12.2
Trademarks
Amortizable:
Finite-lived intangible assets, gross			81.9	82.1
Accumulated amortization			18.1	14.5
Other
Amortizable:
Finite-lived intangible assets, gross			0	8.6
Accumulated amortization			0	$ 8.6
Sucampo [Member]
Schedule of Intangible Asset by Major Class [Line Items]
Intangible asset amortization			62.9
Stannsoporfin [Member] | InfaCare [Member]
Non-Amortizable:
Indefinite-lived intangible assets, gross			113.5
VTS-270 [Member] | Sucampo [Member]
Non-Amortizable:
Indefinite-lived intangible assets, gross			$ 274.5

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets (Schedule of Future Amortization Expense, Intangible Assets) (Details) $ in Millions	Dec. 28, 2018USD ($)
Finite-Lived Intangible Assets [Line Items]
Fiscal 2,019	$ 748.4
Fiscal 2,020	748
Fiscal 2,021	747.8
Fiscal 2,022	620.8
Fiscal 2,023	$ 584.8

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	Feb. 13, 2018	Jul. 28, 2017	Feb. 28, 2017	Sep. 24, 2015	Apr. 15, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 28, 2018	Aug. 31, 2014	Apr. 30, 2013
Debt Instrument [Line Items]
Long-term Debt, Gross						$ 6,134,000,000	$ 6,492,600,000
Term Loan due Sept 2024 [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt						225,000,000
2023 Notes
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage				100.00%
Prior To April 15, 2018 | 2025 Notes
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage					40.00%
Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage									4.64%
Debentures | 5.625% notes due October 2023
Debt Instrument [Line Items]
Long-term Debt, Gross						731,400,000	738,000,000
Debentures | 2017 Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 900,000,000
Variable interest rate			2.25%
Long-term Debt, Gross	$ 900,000,000					220,000,000	900,000,000
Debentures | 2015 Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Debt, Gross							900,000,000
Debentures | 2020 Notes
Debt Instrument [Line Items]
Debt instrument, face amount					$ 700,000,000
Stated interest rate					4.875%
Debentures | 2023 Notes
Debt Instrument [Line Items]
Debt instrument, face amount				$ 750,000,000
Stated interest rate				5.625%
Debentures | 2025 Notes
Debt Instrument [Line Items]
Debt instrument, face amount					$ 700,000,000
Stated interest rate					5.50%
Line of Credit
Debt Instrument [Line Items]
Borrowings, outstanding								$ 0
Senior Notes | 3.50% notes due April 2018
Debt Instrument [Line Items]
Debt instrument, face amount											$ 300,000,000
Stated interest rate											3.50%
Senior Notes | 4.75% notes due April 2023
Debt Instrument [Line Items]
Debt instrument, face amount											$ 600,000,000
Stated interest rate											4.75%
Long-term Debt, Gross						500,200,000	526,500,000
Senior Notes | 5.75% notes due August 2022
Debt Instrument [Line Items]
Debt instrument, face amount										$ 900,000,000
Stated interest rate										5.75%
Long-term Debt, Gross						835,200,000	884,000,000
Secured Debt | Term Loan due Sept 2024 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross						1,597,400,000	1,837,200,000
Loans Payable						1,613,800,000	1,851,200,000
Long-term Debt, Weighted Average Interest Rate, at Point in Time									5.14%
Secured Debt | Term Loan and New Term Loan
Debt Instrument [Line Items]
Write off of Deferred Debt Issuance Cost							10,000,000
Variable interest rate			2.75%
Quarterly amortization payments			0.25%
Long-term Debt, Gross			$ 1,865,000,000
Secured Debt | Receivable securitization, Maturity Date of July 2020 [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 250,000,000
Line Of Credit Facility, Future Contingent Maximum Borrowing Capacity		$ 300,000,000
Facility fees for letters of credit		0.40%
Variable interest rate		0.90%
Debt Instrument, Interest Rate, Effective Percentage									3.22%
Long-term Debt, Gross						250,000,000	200,000,000
Secured Debt | Term Loan due 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross						591,000,000	0
Loans Payable						$ 597,000,000	$ 0
Long-term Debt, Weighted Average Interest Rate, at Point in Time									5.62%
2017 Revolving Credit Facility | Term loan due March 2021
Debt Instrument [Line Items]
Facility fees for letters of credit						0.275%
Option A | 5.75% notes due August 2022
Debt Instrument [Line Items]
Repurchase percentage								101.00%
Option A | 2023 Notes
Debt Instrument [Line Items]
Repurchase percentage				101.00%
Option A | 2025 Notes
Debt Instrument [Line Items]
Repurchase percentage					101.00%
Option B | 5.75% notes due August 2022
Debt Instrument [Line Items]
Repurchase percentage								100.00%
Option B | 2023 Notes
Debt Instrument [Line Items]
Repurchase percentage				100.00%
Option B | 2025 Notes
Debt Instrument [Line Items]
Repurchase percentage					100.00%
Letter of Credit | 2017 Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 50,000,000
Sucampo [Member] | Secured Debt | Term Loan due 2025 [Member]
Debt Instrument [Line Items]
Variable interest rate	3.00%
Debt instrument, discount percentage	0.25%
Loans Payable	$ 600,000,000

Debt (Schedule of Long term deb

Debt (Schedule of Long term debt and Capital lease obligation) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Feb. 13, 2018	Dec. 29, 2017
Current maturities of long-term debt:
Long-term Debt, Current Maturities	$ 22.7		$ 314.2
Debt Issuance Costs, Current, Net	0.3		0.5
Long-term debt:
Long-term Debt, Gross	6,134		6,492.6
Debt, Long-term and Short-term, Combined Amount	6,156.7		6,806.6
Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net	65.1		72.2
Long-term Debt and Capital Lease Obligations, Including Current Maturities			6,806.8
Capital Lease Obligations [Member]
Current maturities of long-term debt:
Debt Issuance Costs, Current, Net			0
Capital lease obligation and vendor financing agreements			0.2
Long-term Debt [Member]
Long-term debt:
Debt Issuance Costs, Net	64.8		71.7
Senior Notes | 3.50% notes due April 2018
Current maturities of long-term debt:
Long-term Debt, Current Maturities	0		300
Debt Issuance Costs, Current, Net	0		0.2
Senior Notes | 4.75% notes due April 2023
Long-term debt:
Long-term Debt, Gross	500.2		526.5
Debt Issuance Costs, Net	3.5		4.5
Senior Notes | 5.75% notes due August 2022
Long-term debt:
Long-term Debt, Gross	835.2		884
Debt Issuance Costs, Net	7		9.5
Debentures | Four Point Eight Eight Percent Notes [Member]
Long-term debt:
Long-term Debt, Gross	700		700
Debt Issuance Costs, Net	3.2		5.7
Debentures | 5.625% notes due October 2023
Long-term debt:
Long-term Debt, Gross	731.4		738
Debt Issuance Costs, Net	8		9.7
Debentures | Five Point Five Percent Notes [Member]
Long-term debt:
Long-term Debt, Gross	692.1		692.1
Debt Issuance Costs, Net	7.7		9
Debentures | 2015 Revolving Credit Facility
Long-term debt:
Long-term Debt, Gross			900
Debt Issuance Costs, Net			5.9
Debentures | 2017 Revolving Credit Facility
Long-term debt:
Long-term Debt, Gross	220	$ 900	900
Debt Issuance Costs, Net	4.5
Debentures | ACOA Loan due 2028 [Member]
Current maturities of long-term debt:
Long-term Debt, Current Maturities	0.3
Debt Issuance Costs, Current, Net	0
Long-term debt:
Long-term Debt, Gross	1.9		0
Debt Issuance Costs, Noncurrent, Net	0		0
Secured Debt | Receivable securitization, Maturity Date of July 2020 [Member]
Long-term debt:
Long-term Debt, Gross	250		200
Debt Issuance Costs, Net	0.4		0.7
Secured Debt | Term Loan due Sept 2024 [Member]
Current maturities of long-term debt:
Long-term Debt, Current Maturities	16.4		14
Debt Issuance Costs, Current, Net	0.2		0.3
Long-term debt:
Long-term Debt, Gross	1,597.4		1,837.2
Debt Issuance Costs, Noncurrent, Net	19.8		26.7
Secured Debt | Term Loan due 2025 [Member]
Current maturities of long-term debt:
Long-term Debt, Current Maturities	6		0
Debt Issuance Costs, Current, Net	0.1		0
Long-term debt:
Long-term Debt, Gross	591		0
Debt Issuance Costs, Noncurrent, Net	10.7		0
Debentures | 8.00% debentures due March 2023
Long-term debt:
Long-term Debt, Gross	4.4		4.4
Debt Issuance Costs, Net	0		0
Debentures | 9.50% debentures due May 2022
Long-term debt:
Long-term Debt, Gross	10.4		10.4
Debt Issuance Costs, Net	$ 0		$ 0

Debt (Schedule of Maturities of

Debt (Schedule of Maturities of Long-term Debt including Capital Lease Obligation) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Debt Disclosure [Abstract]
Long-term Debt, Gross	$ 6,134	$ 6,492.6
Fiscal 2,019	22.7
Fiscal 2,020	972.7
Fiscal 2,021	28.2
Fiscal 2,022	1,088.2
Fiscal 2,023	$ 1,258.6

Debt Schedule of Outstanding Bo

Debt Schedule of Outstanding Borrowings and Applicable Rates (Details) - USD ($) $ in Millions	Dec. 28, 2018	Sep. 28, 2018	Feb. 13, 2018	Dec. 29, 2017
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 6,134			$ 6,492.6
Secured Debt | Term Loan due Sept 2024 [Member]
Debt Instrument [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time		5.14%
Loans Payable	1,613.8			1,851.2
Long-term Debt, Gross	1,597.4			1,837.2
Secured Debt | Term Loan due 2025 [Member]
Debt Instrument [Line Items]
Long-term Debt, Weighted Average Interest Rate, at Point in Time		5.62%
Loans Payable	597			0
Long-term Debt, Gross	591			0
Secured Debt | Receivable securitization, Maturity Date of July 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage		3.22%
Long-term Debt, Gross	250			200
Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage		4.64%
Debentures | 2017 Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 220		$ 900	$ 900

Retirement Plans Narrative (Det

Retirement Plans Narrative (Details) $ in Millions	12 Months Ended
	Dec. 28, 2018USD ($)contract	Dec. 29, 2017USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of Life Insurance Contract Held in Rabbi Trust | contract	118
Deferred Compensation Plan Assets	$ 58.4	$ 58.1
Deferred Compensation Plan Assets, Death Benefit on Insurance Contracts	142.9	145.8
Deferred Compensation Plan Assets, Loans Outstanding Against Insurance Contracts	43.8	44.5
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan		212.9
Defined Benefit Plan, Plan Assets, Payment for Settlement		62.3
Employer contributions	2.4	68
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement		70.5
Refund for plan settlement	3.4
Moody's, Aa1 Rating [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Lower Threshold for Discount Rate Basis, Corporate Bonds	$ 250
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Percentage of Projected Benefit Obligation	36.00%
OUS
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred Compensation Plan Assets, Collateral For Plan Benefits	$ 8	$ 8.8

Retirement Plans (Schedule of N

Retirement Plans (Schedule of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0.8	$ 0.2	$ 1.4	$ 1.8
Interest cost	2	0.6	2.3	13.2
Expected return on plan assets	(2.3)	0	(1.3)	(16.7)
Amortization of net actuarial loss	3.5	0.5	2.7	11.3
Amortization of prior service cost	0.1	0.1	0.2	0
Loss on plan settlements	45	0.1	71.1	8.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement and Curtailment	0	0	(1)	0
Net period benefit cost (credit)	49.1	1.5	75.4	17.7
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.1	0	0	0.1
Interest cost	0.4	1.5	1.7	2
Amortization of net actuarial loss	0	0.1	0	0
Amortization of prior service cost	(0.5)	(2.1)	(2)	(2.1)
Loss on plan settlements	0	(0.7)	(0.9)	0
Net period benefit cost (credit)	$ 0	$ (1.2)	$ (1.2)	$ 0

Retirement Plans (Schedule of B

Retirement Plans (Schedule of Benefit Obligation, Plan Assets and Funded Status of Plans) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Pension Benefits
Change in benefit obligations:
Projected benefit obligations at beginning of year		$ 27.8	$ 257.4
Service cost	$ 0.8	0.2	1.4	$ 1.8
Interest cost	2	0.6	2.3	13.2
Actuarial loss (gain)		0.7	(9)
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(1.6)	(9.4)
Plan settlements		(0.8)	(217)
Currency translation		(0.8)	2.1
Projected benefit obligations at end of year	257.4	26.1	27.8
Change in plan assets:
Fair value of plan assets at beginning of year		0	161
Actual return on plan assets		0	0.3
Employer contributions		2.4	68
Defined Benefit Plan, Plan Assets, Benefits Paid		(1.6)	(9.4)
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan		0	(2.9)
Plan settlements		(0.8)	(217)
Fair value of plan assets at end of year	161	0	0
Funded status at end of year		(26.1)	(27.8)
Postretirement Benefits
Change in benefit obligations:
Projected benefit obligations at beginning of year		45.6	47.5
Service cost	0.1	0	0	0.1
Interest cost	0.4	1.5	1.7	$ 2
Actuarial loss (gain)		(3.9)	0.2
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(2.7)	(2.9)
Plan settlements		(0.7)	(0.9)
Currency translation		0	0
Projected benefit obligations at end of year	47.5	39.8	45.6
Change in plan assets:
Fair value of plan assets at beginning of year		0	0
Actual return on plan assets		0	0
Employer contributions		2.7	2.9
Defined Benefit Plan, Plan Assets, Benefits Paid		(2.7)	(2.9)
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan		0	0
Plan settlements		0	0
Fair value of plan assets at end of year	$ 0	0	0
Funded status at end of year		$ (39.8)	$ (45.6)

Retirement Plans (Schedule of A

Retirement Plans (Schedule of Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Amounts recognized on the consolidated balance sheet:
Non-current liabilities	$ (60.5)	$ (67.1)
Pension Benefits
Amounts recognized on the consolidated balance sheet:
Current liabilities	(2)	(2.4)
Non-current liabilities	(24.1)	(25.4)
Net amount recognized on the consolidated balance sheet	(26.1)	(27.8)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial (loss) gain	(8.4)	(8.6)
Prior service (cost) credit	(0.4)	(0.5)
Net amount recognized in accumulated other comprehensive loss	(8.8)	(9.1)
Postretirement Benefits
Amounts recognized on the consolidated balance sheet:
Current liabilities	(3.4)	(3.9)
Non-current liabilities	(36.4)	(41.7)
Net amount recognized on the consolidated balance sheet	(39.8)	(45.6)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial (loss) gain	0.9	(3)
Prior service (cost) credit	8.1	10.2
Net amount recognized in accumulated other comprehensive loss	$ 9	$ 7.2

Retirement Plans (Schedule of_2

Retirement Plans (Schedule of Amounts to be Amortized From Accumulated Other Comprehensive Income) (Details) $ in Millions	Dec. 28, 2018USD ($)
Pension Benefits
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
Amortization of net actuarial loss	$ 0.5
Amortization of prior service cost (credit)	0.1
Postretirement Benefits
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
Amortization of net actuarial loss	0
Amortization of prior service cost (credit)	$ (2.1)

Retirement Plans (Schedule of P

Retirement Plans (Schedule of Plans with Accumulated Benefit Obligations in Excess of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Accumulated benefit obligation	$ 25.6	$ 27.3

Retirement Plans (Schedule of_3

Retirement Plans (Schedule of Actuarial Assumptions) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
U.S.
Weighted Average-Assumptions Used in Calculating Net Periodic Benefit Cost
Discount rate	2.20%	3.30%	3.00%	3.90%
Expected return on plan assets	3.50%	0.00%	3.50%	5.80%
Rate of compensation increase	0.00%	0.00%	0.00%	0.00%
Weighted-Average Assumptions Used in Calculating Benefit Obligations
Discount rate	3.00%	4.00%	3.30%	2.30%
Rate of compensation increase	0.00%	0.00%	0.00%	0.00%
OUS
Weighted Average-Assumptions Used in Calculating Net Periodic Benefit Cost
Discount rate	1.30%	1.90%	1.80%	2.00%
Expected return on plan assets	0.00%	0.00%	0.00%	2.00%
Rate of compensation increase	0.00%	2.50%	2.50%	0.00%
Weighted-Average Assumptions Used in Calculating Benefit Obligations
Discount rate	1.80%	2.00%	1.90%	1.30%
Rate of compensation increase	0.30%	2.50%	2.50%	0.00%
Postretirement Benefits
Weighted Average-Assumptions Used in Calculating Net Periodic Benefit Cost
Discount rate	3.20%	3.40%	3.70%	4.00%
Weighted-Average Assumptions Used in Calculating Benefit Obligations
Discount rate	3.80%	4.10%	3.40%	3.20%
Healthcare Cost Trend Assumptions
Healthcare cost trend rate assumed for next fiscal year		6.30%	6.90%
Rate to which the cost trend rate is assumed to decline		4.50%	4.50%
Fiscal year the ultimate trend rate is achieved		2,038	2,038
Effect of One-Percentage Point Change in Assumed Healthcare Cost Trend Rates
One-Percentage-Point Increase, effect on total of service and interest cost		$ 0
One-Percentage-Point Decrease, effect on total of service and interest cost		0
One-Percentage-Point Increase, effect on postretirement benefit obligation		0.2
One-Percentage-Point Decrease, effect on postretirement obligation		$ (0.2)

Retirement Plans (Schedule of E

Retirement Plans (Schedule of Expected Benefit Payments) (Details) $ in Millions	Dec. 28, 2018USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fiscal 2,019	$ 2
Fiscal 2,020	1.7
Fiscal 2,021	1.7
Fiscal 2,022	1.6
Fiscal 2,023	1.6
Fiscal 2024 - 2028	7.4
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fiscal 2,019	3.5
Fiscal 2,020	3.4
Fiscal 2,021	3.2
Fiscal 2,022	3.1
Fiscal 2,023	3
Fiscal 2024 - 2028	$ 13.4

Retirement Plans (Defined Contr

Retirement Plans (Defined Contribution Plan) (Details) - Defined Contribution Plan, 401 K [Member] - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Defined Contribution Plan Disclosure [Line Items]
Employer matching contribution, percent of match		50.00%
Defined Contribution Plan, Cost	$ 4.2	$ 25.3	$ 25.2	$ 25.3

Equity (Details)

Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Mar. 01, 2017	Mar. 16, 2016	Nov. 19, 2015	Jan. 23, 2015
Class of Stock [Line Items]
Preferred shares, shares authorized (in shares)		500,000,000	500,000,000
Preferred shares, par value (in usd per share)		$ 0.20	$ 0.20
Preferred shares, shares issued (in shares)		0	0
Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards	$ 0.4	$ 0	$ 5.1	$ 2.3
Treasury Stock, Shares, Canceled			26,500,000
Treasury Stock, Canceled, Value			$ 5.3
November 2015 Share Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount							$ 500
January 2015 Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount								$ 300
March 2016 Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount						$ 350
March 2017 Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount					$ 1,000

Equity Stock Repurchase Program

Equity Stock Repurchase Program (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015	Mar. 01, 2017	Mar. 16, 2016	Nov. 19, 2015	Jan. 23, 2015
Class of Stock [Line Items]
Employee Service Share-based Compensation, Cash Flow Effect, Cash Used to Settle Awards	$ 0.4	$ 0	$ 5.1	$ 2.3
March 2016 Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount							$ 350
Repurchase of ordinary shares, shares	1,501,676	0	5,366,741	0	0
Repurchase of ordinary shares, value	$ 84	$ 0	$ 266	$ 0	$ 0
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 0
November 2015 Share Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount								$ 500
Repurchase of ordinary shares, shares	1,063,337	0	0	6,510,824	0
Repurchase of ordinary shares, value	$ 74.4	$ 0	$ 0	$ 425.6	$ 0
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 0
January 2015 Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount									$ 300
Repurchase of ordinary shares, shares	0	0	0	3,199,279	823,592
Repurchase of ordinary shares, value	$ 0	$ 0	$ 0	$ 225	$ 75
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 0
March 2017 Repurchase Program [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount						$ 1,000
Repurchase of ordinary shares, shares	0	3,610,968	13,490,448	0	0
Repurchase of ordinary shares, value	$ 0	$ 55.2	$ 380.6	$ 0	$ 0
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 564.2

Share Plans (Narrative) (Detail

Share Plans (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 26, 2014	May 16, 2018	Mar. 19, 2015	Jul. 01, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation cost	$ 10,600,000	$ 34,600,000	$ 58,500,000	$ 41,400,000
Tax benefit from share-based compensation cost	3,600,000	0	11,000,000	13,100,000
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options			16,000,000
Employee Service Share-based Compensation, Tax Benefit from U.S. Tax Reform Measurement			5,000,000
Intrinsic value of options vested	300,000	200,000	1,400,000	15,300,000
Tax benefit from stock options exercised	$ 100,000	$ 100,000	$ 500,000	$ 5,700,000
Performance Shares Award, Performance Period		3 years
Share Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award Vesting Period		4 years
Expiration period		10 years
Unrecognized compensation cost, share options		$ 29,600,000
Weighted-average period to recognize unrecognized compensation cost, share options		2 years 4 months 24 days
Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value, granted restricted share units	$ 69.08	$ 14.58	$ 50.74	$ 70.10
Award Vesting Period		4 years
Weighted-average period to recognize unrecognized compensation cost, share options		2 years 2 months 12 days
Fair value of restricted share units granted in period		$ 17,800,000
Fair value of restricted share units vested in period		25,100,000
Unrecognized compensation cost, restricted share units		$ 29,600,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employer matching contribution, percent of match				25.00%	15.00%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date		15.00%
ESPP employer match - maximum employee contribution				$ 25,000
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value, granted restricted share units		$ 13.80	$ 51.73	$ 83
Unrecognized compensation cost		$ 12,600,000
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value, granted restricted share units		$ 70.88
Fair value of restricted share units vested in period		$ 200,000
2013 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under 2013 Plan								5,700,000
2015 Mallinckrodt Pharmaceuticals Stock and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under 2013 Plan							17,800,000
2018 Mallinckrodt Pharmaceuticals Stock and Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized under 2013 Plan						26,800,000
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of ordinary shares to be awarded		0.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of ordinary shares to be awarded		200.00%
New ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount		$ 25,000

Share Plans (Schedule of Share

Share Plans (Schedule of Share Option Award Status Upon Completion of the Conversion) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 28, 2018	Dec. 29, 2017	Dec. 30, 2016	Sep. 30, 2016	Sep. 25, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share options outstanding	7,007,051	4,643,984	3,386,694	3,421,856	2,786,443
Weighted-average exercise price, outstanding share options	$ 38.74	$ 57.78	$ 61.24	$ 61.17	$ 52.76
Weighted-average remaining contractual term, outstanding share options	4 years 9 months 18 days
Aggregate intrinsic value, outstanding share options	$ 6.5
Share options exerciseable	2,414,968
Weighted-average exercise price, exercisable share options	$ 55.24
Weighted-average remaining contractual term, exercisable share options	4 years 10 months 24 days
Aggregate intrinsic value, exercisable share options	$ 0.1

Share Plans (Schedule of the Va

Share Plans (Schedule of the Valuation Assumptions Used in the Conversion) (Details) - $ / shares	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Weighted Average Assumptions
Expected share price volatility	35.00%	38.00%	36.00%	31.00%
Risk-free interest rate	1.23%	2.64%	2.00%	1.74%
Expected annual dividend per share	0.00%	0.00%	0.00%	0.00%
Expected life of options (in years)	5 years 3 months 18 days	5 years 3 months 18 days	5 years 3 months 18 days	5 years 3 months 18 days
Fair value per option	$ 20.04	$ 5.32	$ 18.36	$ 22.82
Share options outstanding	3,386,694	7,007,051	4,643,984	3,421,856	2,786,443

Share Plans (Schedule of Shar_2

Share Plans (Schedule of Share Option Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 20.04	$ 5.32	$ 18.36	$ 22.82
Intrinsic value of options vested	$ 0.3	$ 0.2	$ 1.4	$ 15.3
Share Option Activity [Roll Forward]
Beginning balance	3,421,856	4,643,984	3,386,694	2,786,443
Granted	3,742	3,159,521	1,719,532	1,248,828
Exercised	(16,382)	(39,949)	(113,605)	(413,830)
Expired/Forfeited	(22,522)	(756,505)	(348,637)	(199,585)
Ending balance	3,386,694	7,007,051	4,643,984	3,421,856
Share options vested and unvested expected to vest		6,114,782
Share options exerciseable		2,414,968
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted-average exercise price, outstanding share options	$ 61.24	$ 38.74	$ 57.78	$ 61.17	$ 52.76
Weighted-average exercise price, granted share options	60.01	13.92	51.57	72.44
Weighted-average exercise price, exercised share options	36.42	32	47.74	32.76
Weighted-average exercise price, expired and forfeited share options	$ 70.82	52.63	$ 68.08	$ 72.65
Weighted-average exercise price, vested and unvested expected to vest share options		39.94
Weighted-average exercise price, exercisable share options		$ 55.24
Weighted-average remaining contractual term, outstanding share options		4 years 9 months 18 days
Weighted-average remaining contractual term, vested and unvested expected to vest share options		7 years 7 months 6 days
Weighted-average remaining contractual term, exercisable share options		4 years 10 months 24 days
Aggregate intrinsic value, outstanding share options		$ 6.5
Aggregate intrinsic value, vested and unvested expected to vest share options		5.5
Aggregate intrinsic value, exercisable share options		0.1
Tax benefit from stock options exercised	$ 0.1	$ 0.1	$ 0.5	$ 5.7

Share Plans (Schedule of Restri

Share Plans (Schedule of Restricted Share Unit Activity) (Details) - $ / shares	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period to recognize unrecognized compensation cost, share options		2 years 2 months 12 days
Restricted Share Unit Activity [Roll Forward]
Beginning balance	894,459	1,105,766	883,462	572,494
Granted	36,731	1,222,568	655,282	615,074
Exercised	(30,919)	(433,354)	(263,189)	(193,849)
Expired/Forfeited	(16,809)	(209,879)	(169,789)	(99,260)
Ending balance	883,462	1,685,101	1,105,766	894,459
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant date fair value, restricted share units	$ 71.03	$ 29.54	$ 60.08	$ 70.40	$ 73.45
Weighted-average grant date fair value, granted restricted share units	69.08	14.58	50.74	70.10
Weighted-average grant date fair value, vested restricted share units	47.54	57.93	69.14	69.27
Weighted-average grant date fair value, forfeited restricted share units	$ 49.62	$ 44.38	$ 68.57	$ 79.95
Restricted Stock
Restricted Share Unit Activity [Roll Forward]
Beginning balance	16,866	4,675	14,868	34,562
Exercised	(1,087)	(3,970)	(7,970)	(9,760)
Expired/Forfeited	(911)	(705)	(2,223)	(7,936)
Ending balance	14,868	0	4,675	16,866
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant date fair value, granted restricted share units		$ 70.88

Share Plans (Schedule of Perfor

Share Plans (Schedule of Performance Share Unit Activity) (Details) - $ / shares		3 Months Ended	12 Months Ended
		Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016		Sep. 25, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Performance Shares Award, Performance Period			3 years
Performance Shares
Performance Share Unit Activity [Roll Forward]
Beginning balance	[1]	266,645	504,451	265,648	130,974
Granted			770,714	348,963	145,192	[1]
Exercised	[1]		(24,022)	(61,554)
Expired/Forfeited	[1]	(997)	(89,614)	(48,606)	(9,521)
Ending balance	[1]	265,648	1,161,529	504,451	266,645
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant date fair value, restricted share units		$ 88.51	$ 28.61	$ 64.44	$ 88.59		$ 96.05
Weighted-average grant date fair value, granted restricted share units			13.80	51.73	83
Weighted-average grant date fair value, vested restricted share units			98.27	62.65
Weighted-average grant date fair value, forfeited restricted share units		$ 154.42	$ 59.18	$ 107	$ 96.30
Restricted Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms			1 year 10 months 24 days
Weighted-average period to recognize unrecognized compensation cost, share options			2 years 2 months 12 days
Performance Share Unit Activity [Roll Forward]
Beginning balance		894,459	1,105,766	883,462	572,494
Granted		36,731	1,222,568	655,282	615,074
Exercised		(30,919)	(433,354)	(263,189)	(193,849)
Expired/Forfeited		(16,809)	(209,879)	(169,789)	(99,260)
Ending balance		883,462	1,685,101	1,105,766	894,459
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant date fair value, restricted share units		$ 71.03	$ 29.54	$ 60.08	$ 70.40		$ 73.45
Weighted-average grant date fair value, granted restricted share units		69.08	14.58	50.74	70.10
Weighted-average grant date fair value, vested restricted share units		47.54	57.93	69.14	69.27
Weighted-average grant date fair value, forfeited restricted share units		$ 49.62	$ 44.38	$ 68.57	$ 79.95
Award Vesting Period			4 years
[1]	The number of shares disclosed within this table are at the target number of 100%.

Share Plans (Schedule of Fair V

Share Plans (Schedule of Fair Value Assumptions for Performance Share Unit) (Details)	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected share price volatility	35.00%	38.00%	36.00%	31.00%
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected share price volatility	48.00%	57.00%	48.00%	41.00%
Peer group stock price volatility	40.00%	39.00%	40.00%	36.00%
Correlation of returns	17.00%	2.00%	17.00%	24.00%

Share Plans (Schedule of Rest_2

Share Plans (Schedule of Restricted Stock Award Activity) (Details) - Restricted Stock - $ / shares	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Restricted Stock Activity [Roll Forward]
Beginning balance	16,866	4,675	14,868	34,562
Exercised	(1,087)	(3,970)	(7,970)	(9,760)
Expired/Forfeited	(911)	(705)	(2,223)	(7,936)
Ending balance	14,868	0	4,675	16,866
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted-average grant date fair value, granted restricted share units		$ 70.88

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Schedule of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Dec. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Adjusted for ASU	[1]			$ (14.4)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			$ (12.9)	(72.5)
Other comprehensive loss before reclassifications			(9.1)	22.7
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, before Tax		$ 0	0	1.5	$ 0
Amounts reclassified from accumulated other comprehensive income			(0.8)	35.4
Ending balance		(72.5)	(24.3)	(12.9)
Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(8.2)	(19.5)
Other comprehensive loss before reclassifications			(12.2)	16
Amounts reclassified from accumulated other comprehensive income			0	(4.7)
Ending balance		(19.5)	(20.4)	(8.2)
Unrecognized Loss on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(4.7)	(5.7)
Other comprehensive loss before reclassifications			0	0
Amounts reclassified from accumulated other comprehensive income			0.7	1
Ending balance		(5.7)	(4)	(4.7)
Unrecognized (Loss) Gain on Benefit Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(1.5)	(47.3)
Other comprehensive loss before reclassifications			3.1	5.2
Amounts reclassified from accumulated other comprehensive income			(1.5)	40.6
Ending balance		(47.3)	0.1	(1.5)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			0	0
Other comprehensive loss before reclassifications				1.5
Amounts reclassified from accumulated other comprehensive income			0	(1.5)
Ending balance		$ 0	$ 0	$ 0
Retained Earnings | Accounting Standards Update 2016-01 [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets						$ 1.5
[1]	Upon adoption of ASU 2016-01, a reclassification of $1.5 million

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Schedule of Reclassifications out of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 28, 2018	Dec. 29, 2017	Dec. 30, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications for the period		$ (0.8)	$ 35.4
Amortization of pension and post-retirement benefit plans:
Net actuarial loss	[1]	0.6	2.7
Prior service credit	[1]	(2)	(1.9)
Plan settlements	[1]	(0.6)	70.2
Disposal of discontinued operations		0	(3.1)
Total before tax		(2)	67.9
Income tax effect		0.5	(27.3)
Income tax provision		(0.2)	(0.3)
Amortization of unrealized loss on derivatives		0.9	1.3
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of income taxes		0.7	1
Amortization of pension and post-retirement benefit plans:
Net of income taxes		(1.5)	40.6
Recognized gain on equity securities (2)	[2]	0	(1.5)
Currency translation		$ 0	$ (4.7)
Accounting Standards Update 2016-01 [Member] | Retained Earnings
Amortization of pension and post-retirement benefit plans:
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets				$ 1.5
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 15 for additional details.
[2]	Upon adoption of ASU 2016-01, a reclassification of $1.5 million

Guarantees (Narrative) (Details

Guarantees (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 28, 2018	Dec. 29, 2017
Others
Guarantor Obligations [Line Items]
Maximum future payments	$ 38.7
Mallinckrodt Baker | Indemnification Agreement
Guarantor Obligations [Line Items]
Guarantor obligations, obligation term	17 years
Maximum future payments	$ 70.2
Escrow	30
Mallinckrodt Baker | Indemnification Agreement | Other Liabilities
Guarantor Obligations [Line Items]
Guarantors obligation	14.6	$ 14.9
Mallinckrodt Baker | Indemnification Agreement | Other Assets
Guarantor Obligations [Line Items]
Escrow	18.6	18.3
Mallinckrodt Baker | Enviornmental, Health and Safety Matters | Indemnification Agreement | Other Liabilities
Guarantor Obligations [Line Items]
Guarantors obligation	$ 11.8	$ 12.1

Guarantees Non-Printing (Detail

Guarantees Non-Printing (Details) - Mallinckrodt Baker - Indemnification Agreement - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Escrow	$ 30
Other Liabilities
Guarantors obligation	14.6	$ 14.9
Other Assets
Escrow	$ 18.6	$ 18.3

Commitments and Contingencies_2

Commitments and Contingencies (Narrative) (Details)

Jun. 30, 2018Defendent

Sep. 28, 2018USD ($)

Dec. 30, 2016USD ($)

Dec. 28, 2018USD ($)lawsuitCase

Dec. 29, 2017USD ($)

Sep. 30, 2016USD ($)Defendent

Sep. 25, 2015order

Aug. 07, 2018USD ($)

Dec. 11, 2017USD ($)

Aug. 31, 2016USD ($)

Mar. 25, 2016USD ($)

Apr. 11, 2014USD ($)

Apr. 01, 2014USD ($)

Loss Contingencies [Line Items]

Payments for Legal Settlements

$ 35,000,000

Litigation Settlement, Expense

$ 102,000,000

Environmental liabilities

$ 61,800,000

Deferred Tax Liabilities Installment Sales

227,500,000

553,500,000

Increase (Decrease) Deferred Tax Liability Resulting From Tax Reform

(326,000,000)

Interest Expense, Installment Sales

15,900,000

23,700,000

69,300,000

$ 73,800,000

Installment note deferred asset write off, net

8,400,000

Interest Payable, Installment Sales

56,000,000

46,000,000

Rent expense

$ 7,200,000

24,800,000

30,400,000

$ 23,900,000

Tax Matters Agreement | Covidien

Loss Contingencies [Line Items]

Tax agreement, tax threshold

$ 200,000,000

Occidental, Lower Passaic River [Member]

Loss Contingencies [Line Items]

Number of defendants | Defendent

120

Lower Passaic River, New Jersey

Loss Contingencies [Line Items]

Environmental liabilities

$ 26,200,000

Remedial cost, estimate

$ 1,380,000,000

$ 1,700,000,000

Loss Contingency, Settlement Agreement, Amount

$ 280,600

Accrual for Environmental Loss Contingencies, Period Increase (Decrease)

$ (11,800,000)

Asbestos Matters

Loss Contingencies [Line Items]

Pending claims | Case

11,700

Estimation of liability, historical term

5 years

Estimation of liability, expected future term of claims

7 years

Other current liabilities

Loss Contingencies [Line Items]

Environmental liabilities, current

$ 2,100,000

Mallinckrodt Veterinary, Inc., Millsboro, Delaware [Member]

Loss Contingencies [Line Items]

Number of Administrative Orders of Consent Entered Into | order

3

Lower Passaic River, New Jersey

Loss Contingencies [Line Items]

Number of defendants | Defendent

70

Minimum

Loss Contingencies [Line Items]

Remedial cost, estimate

36,400,000

Minimum | Lower Passaic River, New Jersey

Loss Contingencies [Line Items]

Remedial cost, estimate

$ 365,000,000

Maximum

Loss Contingencies [Line Items]

Remedial cost, estimate

86,500,000

Maximum | Lower Passaic River, New Jersey

Loss Contingencies [Line Items]

Remedial cost, estimate

$ 3,200,000,000

Mesoblast [Member]

Loss Contingencies [Line Items]

Proceeds from Sale of Available-for-sale Securities, Equity

25,500,000

Marketable Securities, Realized Gain (Loss)

3,400,000

Stratatech [Member]

Loss Contingencies [Line Items]

Contingent consideration

$ 54,900,000

Ocera [Member]

Loss Contingencies [Line Items]

Contingent consideration

[1]

$ 22,000,000

Fair Value, Measurements, Recurring

Loss Contingencies [Line Items]

Contingent consideration

151,400,000

42,700,000

Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3

Loss Contingencies [Line Items]

Contingent consideration

151,400,000

0

Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Stratatech [Member]

Loss Contingencies [Line Items]

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability

53,700,000

$ 53,500,000

Fair Value, Measurements, Recurring | MNK-6105 [Member] | Fair Value, Inputs, Level 3 | Ocera [Member]

Loss Contingencies [Line Items]

Contingent consideration

$ 21,500,000

$ 22,000,000

Cities, Counties, and/or Other Government-related Persons/Entities [Member] | opioid crisis [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

1,487

Hospitals, Health Systems, Unions, Health and Welfare Fund or Third-Party Payers [Member] | opioid crisis [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

104

Individuals [Member] | opioid crisis [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

15

State Attorney Generals [Member] | opioid crisis [Member]

Loss Contingencies [Line Items]

Loss Contingency, Number of Plaintiffs | lawsuit

6

[1]

(1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date.

Commitments and Contingencies_3

Commitments and Contingencies (Schedule of Purchase Oligations) (Details) $ in Millions	Dec. 28, 2018USD ($)
Unrecorded Unconditional Purchase Obligation [Line Items]
Fiscal 2,019	$ 110.3
Fiscal 2,020	43.5
Fiscal 2,021	2.2
Fiscal 2,022	2.1
Fiscal 2,023	$ 1.7

Commitments and Contingencies_4

Commitments and Contingencies (Schedule of Minimum Lease Payments for Non-cancelable Leases) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 7.2	$ 24.8	$ 30.4	$ 23.9
Operating Leases
Operating leases, fiscal 2019		22.3
Operating leases, fiscal 2020		16.4
Operating leases, fiscal 2021		12.8
Operating leases, fiscal 2022		10.6
Operating leases, fiscal 2023		10.3
Operating leases, thereafter		39.2
Operating Leases, Future Minimum Payments Due		$ 111.6

Financial Instruments and Fai_3

Financial Instruments and Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions

3 Months Ended

12 Months Ended

Sep. 28, 2018

Jun. 29, 2018

Mar. 30, 2018

Dec. 28, 2018

Dec. 29, 2017

Mar. 16, 2018

Dec. 11, 2017

Sep. 25, 2017

Aug. 31, 2016

Feb. 01, 2016

Aug. 31, 2014

Apr. 30, 2013

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Business Combination, Contingent Consideration, Liability, Current

$ 34.1

Business Combination, Contingent Consideration, Liability, Noncurrent

117.3

Notes receivable

0

$ 154

Increase (Decrease) in Notes Receivable, Current

154

Novartis 2015 and 2016

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Business Combination, Contingent Consideration, Annual Payments

25

Novartis, Subsequent to 2016 till FDA Approval

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Business Combination, Contingent Consideration, Annual Payments

25

Novartis, Subsequent to FDA Approval

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Business Combination, Contingent Consideration, Potential Payment

25

Questcor Pharmaceuticals, Inc.

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Maximum contingent payments for acquisition

$ 115

Discount rate

4.70%

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability

$ 76.2

111.8

$ 195.4

Hemostasis Products

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

[1]

$ 52

Maximum contingent payments for acquisition

$ 395

Stratatech [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

$ 54.9

Maximum contingent payments for acquisition

$ 121

InfaCare [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

[2]

$ 35

Maximum contingent payments for acquisition

$ 345

Ocera [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

[3]

$ 22

Maximum contingent payments for acquisition

75

Debentures | 8.00% debentures due March 2023 | Level 2

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

8.00%

Debentures | 9.50% debentures due May 2022 | Level 2

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

9.50%

Senior Notes | 3.50% notes due April 2018

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

3.50%

Senior Notes | 3.50% notes due April 2018 | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

3.50%

Senior Notes | 4.75% notes due April 2023

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

4.75%

Senior Notes | 4.75% notes due April 2023 | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

4.75%

Senior Notes | 5.75% notes due August 2022

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

5.75%

Senior Notes | 5.75% notes due August 2022 | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

5.75%

Debentures | Four Point Eight Eight Percent Notes [Member] | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

4.875%

Debentures | Five Point Five Percent Notes [Member] | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

5.50%

Debentures | 5.625% notes due October 2023 | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Stated interest rate

5.625%

Carrying Value | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Restricted cash

$ 18.6

18.3

Carrying Value | Fair Value, Inputs, Level 3

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Cash surrender value of life insurance

66.4

67

PreveLeak [Member] | Hemostasis Products

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Business Combination, Contingent Consideration, Payment

$ 12

Raplixa [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Liabilities, Fair Value Adjustment

(54.6)

Fair Value, Measurements, Recurring

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

151.4

42.7

Debt and equity securities held in rabbi trusts

33.1

35.4

Fair Value, Measurements, Recurring | Level 1

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

0

0

Debt and equity securities held in rabbi trusts

22.4

24

Fair Value, Measurements, Recurring | Level 2

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

0

42.7

Debt and equity securities held in rabbi trusts

10.7

11.4

Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

151.4

0

Debt and equity securities held in rabbi trusts

0

0

Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Stratatech [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability

53.7

53.5

Fair Value, Measurements, Recurring | PreveLeak [Member] | Fair Value, Inputs, Level 3 | Hemostasis Products

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability

17.1

Fair Value, Measurements, Recurring | Raplixa [Member] | Fair Value, Inputs, Level 3 | Hemostasis Products

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

7

Fair Value, Measurements, Recurring | Stannsoporfin [Member] | Fair Value, Inputs, Level 3 | InfaCare [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

0

$ 35

Liabilities, Fair Value Adjustment

35

Fair Value, Measurements, Recurring | MNK-6105 [Member] | Fair Value, Inputs, Level 3 | Ocera [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair value of contingent consideration upon acquisition

21.5

$ 22

Contingent Consideration | Fair Value, Measurements, Recurring | Total Acquisitions

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value

$ 151.4

Hemostasis Products

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Disposal Group, Not Discontinued Operation, Contingent Consideration

$ 12.1

Nuclear Imaging

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Contingent consideration received, equity certificates

$ 9

Nuclear Imaging | Fair Value, Inputs, Level 3

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Contingent consideration received, equity certificates

$ 9

[1]

During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information.

[2]

During fiscal 2018, the Company reduced the contingent consideration liability related to this acquisition to zero through the recognition of a $35.0 million

[3]

(1) $1.9 million of the total consideration, net of cash was paid in fiscal 2018, subsequent to the Company's December 11, 2017 acquisition date.

(Schedule of Fair Value of Asse

(Schedule of Fair Value of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017
Assets:
Debt and equity securities held in rabbi trusts	$ 33.1	$ 35.4
Other Assets, Fair Value Disclosure	0	22.7
Total assets at fair value	33.1	58.1
Liabilities:
Deferred compensation liabilities	38.5
Contingent consideration	151.4	42.7
Foreign exchange forward and option contracts		246.4
Total liabilities at fair value	189.9	289.1
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Debt and equity securities held in rabbi trusts	22.4	24
Other Assets, Fair Value Disclosure	0	22.7
Total assets at fair value	22.4	46.7
Liabilities:
Deferred compensation liabilities	0
Contingent consideration	0	0
Foreign exchange forward and option contracts		0
Total liabilities at fair value	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Debt and equity securities held in rabbi trusts	10.7	11.4
Other Assets, Fair Value Disclosure	0	0
Total assets at fair value	10.7	11.4
Liabilities:
Deferred compensation liabilities	38.5
Contingent consideration	0	42.7
Foreign exchange forward and option contracts		0
Total liabilities at fair value	38.5	42.7
Significant Unobservable Inputs (Level 3)
Assets:
Debt and equity securities held in rabbi trusts	0	0
Other Assets, Fair Value Disclosure	0	0
Total assets at fair value	0	0
Liabilities:
Deferred compensation liabilities	0
Contingent consideration	151.4	0
Foreign exchange forward and option contracts		246.4
Total liabilities at fair value	$ 151.4	$ 246.4

(Schedule of Reconciliation of

(Schedule of Reconciliation of Changes in Fair Value of Contingent Consideration) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 28, 2018	Dec. 29, 2017	Mar. 16, 2018	Aug. 31, 2016	Feb. 01, 2016	Aug. 31, 2014
Questcor Pharmaceuticals, Inc.
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability		$ 76.2	$ 111.8				$ 195.4
Hemostasis Products
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration	[1]					$ 52
Stratatech [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration					$ 54.9
Fair Value, Measurements, Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration		151.4	42.7
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration		151.4	0
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Stratatech [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability		53.7	53.5
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Contingent Liabilities [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance		246.4
Payments		(37)
Fair value adjustment		4.3
Ending balance		151.4	246.4
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)		$ (50.2)
Raplixa [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Period Increase (Decrease)			54.6
Raplixa [Member] | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Hemostasis Products
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration			7
PreveLeak [Member] | Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring | Hemostasis Products
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability			$ 17.1
Hemostasis Products
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Disposal Group, Not Discontinued Operation, Contingent Consideration				$ (12.1)
[1]	During fiscal 2017, the Company recorded a non-restructuring impairment charge relating to its Raplixa intangible asset and reduced the associated contingent consideration liability. During fiscal 2018, the Company sold its Recothrom and PreveLeak assets to Baxter. Refer to Notes 6, 13 and 21, respectively, for further information.

(Schedule of Carrying Amount an

(Schedule of Carrying Amount and Fair Value of Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Feb. 13, 2018	Dec. 29, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 5,269.1		$ 6,348.8
Long-term Debt, Current Maturities	22.7		314.2
Long-term Debt, Gross	6,134		6,492.6
Debt, Long-term and Short-term, Combined Amount	6,156.7		6,806.6
4.00% term loan due February 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan payable			0
Loans Payable			0
ACOA Loan due 2028 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan payable	2.2
Loans Payable	2.2
Secured Debt | Receivable securitization, Maturity Date of July 2020 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Gross	250		200
Secured Debt | Term Loan due 2025 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan payable	548		0
Long-term Debt, Current Maturities	6		0
Loans Payable	597		0
Long-term Debt, Gross	591		0
Secured Debt | Term Loan due Sept 2024 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loan payable	1,472.4		1,848.7
Long-term Debt, Current Maturities	16.4		14
Loans Payable	1,613.8		1,851.2
Long-term Debt, Gross	1,597.4		1,837.2
Debentures | 9.50% debentures due May 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	9.7		10.9
Long-term Debt, Gross	10.4		10.4
Debentures | 8.00% debentures due March 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	3.8		4.4
Long-term Debt, Gross	4.4		4.4
Senior Notes | 3.50% notes due April 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	0		299.1
Long-term Debt, Current Maturities	0		300
Senior Notes | 5.75% notes due August 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	713.6		804.8
Long-term Debt, Gross	835.2		884
Senior Notes | 4.75% notes due April 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	336.7		412.4
Long-term Debt, Gross	500.2		526.5
Debentures | Four Point Eight Eight Percent Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	676.6		675.2
Long-term Debt, Gross	700		700
Debentures | Five Point Five Percent Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	479.1		564.5
Long-term Debt, Gross	692.1		692.1
Debentures | 2017 Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	220		900
Long-term Debt, Gross	220	$ 900	900
Debentures | 5.625% notes due October 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	557		628.8
Long-term Debt, Gross	731.4		738
Debentures | ACOA Loan due 2028 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Current Maturities	0.3
Long-term Debt, Gross	1.9		0
Fair Value | Receivable securitization, Maturity Date of July 2020 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Gross	$ 250		$ 200

(Schedules of Concentration of

(Schedules of Concentration of Risk) (Details)	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Distributor Concentration Risk | Net Sales Attributable to Distributors | CuraScript, Inc [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	43.00%	35.00%	40.00%	38.00%
Distributor Concentration Risk | Net Sales Attributable to Distributors | McKesson Corporation [Member]
Concentration Risk [Line Items]
Concentration risk, percentage	10.00%			12.00%
Distributor Concentration Risk | Accounts Receivable Attributable to Distributors | CuraScript, Inc [Member]
Concentration Risk [Line Items]
Concentration risk, percentage		13.00%	14.00%
Distributor Concentration Risk | Accounts Receivable Attributable to Distributors | McKesson Corporation [Member]
Concentration Risk [Line Items]
Concentration risk, percentage		22.00%	26.00%
Distributor Concentration Risk | Accounts Receivable Attributable to Distributors | Cardinal Health, Inc. [Member]
Concentration Risk [Line Items]
Concentration risk, percentage			11.00%
Distributor Concentration Risk | Accounts Receivable Attributable to Distributors | Amerisource Bergen Corporation [Member]
Concentration Risk [Line Items]
Concentration risk, percentage		26.00%	15.00%
Product Concentration Risk | Net Sales Attributable to Products | H.P. Acthar Gel
Concentration Risk [Line Items]
Concentration risk, percentage	39.00%	35.00%	37.00%	34.00%
Product Concentration Risk | Net Sales Attributable to Products | Inomax
Concentration Risk [Line Items]
Concentration risk, percentage	14.00%	17.00%	16.00%	14.00%

Segment and Geographical Data_2

Segment and Geographical Data (Schedule of Segment Reporting Information by Business Segment) (Details) - USD ($) $ in Millions		3 Months Ended											12 Months Ended
		Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015		Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 26, 2014	Sep. 27, 2013
Segment Reporting Information [Line Items]
Total Assets		$ 10,900				$ 15,300							$ 10,900	$ 15,300
Assets		10,877.3				15,280.9							10,877.3	15,280.9
Net sales		$ 834.9	$ 799.9	$ 825.5	$ 755.3	$ 792.3	$ 793.9	$ 824.5	$ 810.9	$ 829.9	$ 811.2		3,215.6	3,221.6	$ 3,380.8
Operating income (loss)										(158.6)	(164)	[1]	(3,720.9)	492.9	633.1
Intangible asset amortization										(175.7)			(740.2)	(694.5)	(700.1)
Restructuring and related charges, net										(5.3)			(108.2)	(36.4)	(37.6)
Non-restructuring impairment										214.3			3,893.1	63.7	16.9
Depreciation and amortization										203.2	$ 206		852.1	808.3	834.5
Restructuring and related costs, accelerated depreciation										1.5			5.2	5.2	4.9
Specialty Brands [Member]
Segment Reporting Information [Line Items]
Restructuring and related charges, net										(2.6)			(52.2)	(25.4)	(23.3)
Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Restructuring and related charges, net										(0.8)			(29)	(7.7)	(3.4)
Operating Segments
Segment Reporting Information [Line Items]
Operating income (loss)										359.8			1,182.4	1,412.7	1,505.4
Depreciation and amortization	[2]									203.2			852.1	808.3	813.6
Operating Segments | Specialty Brands [Member]
Segment Reporting Information [Line Items]
Net sales										600.1			2,306.2	2,352	2,288.8
Operating income (loss)										295.2			1,077.4	1,146.3	1,060.7
Depreciation and amortization	[2]									178.2			696	712	715.7
Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales										229.8			909.4	869.6	1,092
Operating income (loss)										64.6			105	266.4	444.7
Depreciation and amortization	[2]									25			156.1	96.3	97.9
Corporate, Non-Segment
Segment Reporting Information [Line Items]
Corporate and allocated expenses	[3]									(123.1)			(155.8)	(125.2)	(117.7)
Intangible asset amortization										(175.7)			(740.2)	(694.5)	(700.1)
Restructuring and related charges, net	[4]									(5.3)			(108.2)	(36.4)	(37.6)
Non-restructuring impairment										(214.3)			(3,893.1)	(63.7)	(16.9)
Separation costs	[5]									$ 0			$ (6)	$ 0	$ 0
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net sales																$ 0	$ 0
[1]	Financial data for this period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of Accounting Standards Update ("ASU") 2017-07. See Note 4 for further information on this ASU.
[2]	Depreciation for certain shared facilities is allocated based on occupancy percentage.
[3]	Includes administration expenses and certain compensation, environmental and other costs not charged to the Company's operating segments.
[4]	Includes restructuring-related accelerated depreciation.
[5]	Represents costs incurred related to the separation of the Company’s Specialty Generics and Amitiza segment, which are included in selling, general and administrative expenses.

Segment and Geographical Data_3

Segment and Geographical Data (Schedule of Net Sales from External Costumers by Product) (Details) - USD ($) $ in Millions		3 Months Ended										12 Months Ended
		Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net sales		$ 834.9	$ 799.9	$ 825.5	$ 755.3	$ 792.3	$ 793.9	$ 824.5	$ 810.9	$ 829.9	$ 811.2	$ 3,215.6	$ 3,221.6	$ 3,380.8
Operating Segments | Specialty Brands [Member]
Segment Reporting Information [Line Items]
Net sales										600.1		2,306.2	2,352	2,288.8
Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales										229.8		909.4	869.6	1,092
Hydrocodone (API) and hydrocodone-containing tablets | Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales										23.2		65.9	85.3	146.5
Oxycodone (API) and oxycodone-containing tablets | Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales	[1]									27.2		66.1	88	139.9
Acetaminophen (API) | Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales	[1]									40.8		192.7	185.5	169.1
Amitiza | Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales	[2]									0		183.8	0	0
Other controlled substances | Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales	[1]									117.4		343.8	412	543.9
H.P. Acthar Gel | Operating Segments | Specialty Brands [Member]
Segment Reporting Information [Line Items]
Net sales										325.4		1,110.1	1,195.1	1,160.4
Ofirmev | Operating Segments | Specialty Brands [Member]
Segment Reporting Information [Line Items]
Net sales										72.5		341.9	302.5	284.3
BioVectra | Operating Segments | Specialty Brands [Member]
Segment Reporting Information [Line Items]
Net sales										7.4		53.1	54.7	49.5
Therakos | Operating Segments | Specialty Brands [Member]
Segment Reporting Information [Line Items]
Net sales										47.4		231.2	214.9	207.6
Other Products | Operating Segments | Specialty Brands [Member]
Segment Reporting Information [Line Items]
Net sales	[1]									29.1		27.2	79.6	112.7
Other Products | Operating Segments | Specialty Generics and Amitiza [Member]
Segment Reporting Information [Line Items]
Net sales	[1],[3]									21.2		57.1	98.8	92.6
Product Concentration Risk | Net Sales Attributable to Products | Inomax
Segment Reporting Information [Line Items]
Net sales										$ 118.3		$ 542.7	$ 505.2	$ 474.3
[1]	Prior year amounts have been reclassified to conform to current year presentation.
[2]	Amitiza net sales consist of both product and royalty net sales. Refer to Note 5 for further details on Amitiza's revenues.
[3]	Includes net sales from an ongoing, post-divestiture supply agreement with the acquirer of the CMDS business. Amounts for periods prior to the divestiture represent the reclassification of intercompany sales to third-party sales to conform with the expected presentation of the ongoing supply agreement.

Segment and Geographical Data_4

Segment and Geographical Data (Schedule of Net Sales and Long-Lived Assets by Geographic Area) (Details) - USD ($) $ in Millions		3 Months Ended										12 Months Ended
		Dec. 28, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 29, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Schedule of Net Sales and Long-Lived Assets by Geographic Area [Line Items]
Net sales		$ 834.9	$ 799.9	$ 825.5	$ 755.3	$ 792.3	$ 793.9	$ 824.5	$ 810.9	$ 829.9	$ 811.2	$ 3,215.6	$ 3,221.6	$ 3,380.8
Long-Lived Assets		994.2				979						994.2	979
United States
Schedule of Net Sales and Long-Lived Assets by Geographic Area [Line Items]
Net sales	[1]									763.7		2,834.5	2,899	3,095.4
Long-Lived Assets		770.7				788.5						770.7	788.5
EMEA
Schedule of Net Sales and Long-Lived Assets by Geographic Area [Line Items]
Net sales	[1]									52.8		256.8	242.3	211.8
Long-Lived Assets	[2],[3]	146.7				127						146.7	127
EMEA | IRELAND
Schedule of Net Sales and Long-Lived Assets by Geographic Area [Line Items]
Long-Lived Assets		145.2				126						145.2	126
Other Countries
Schedule of Net Sales and Long-Lived Assets by Geographic Area [Line Items]
Net sales	[1]									$ 13.4		124.3	80.3	$ 73.6
Long-Lived Assets		$ 76.8				$ 63.5						$ 76.8	$ 63.5
[1]	Net sales are attributed to regions based on the location of the entity that records the transaction, none of which relate to the country of Ireland.
[2]	Includes long-lived assets located in Ireland of $145.2 million and $126.0 million as of December 28, 2018 and December 29, 2017 , respectively.
[3]	Long-lived assets are primarily composed of property, plant and equipment, net.

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 28, 2018		Sep. 28, 2018		Jun. 29, 2018		Mar. 30, 2018		Dec. 29, 2017		Sep. 29, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 30, 2016	Dec. 25, 2015		Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Quarterly Financial Information Disclosure [Abstract]
Depreciation Expense on Reclassified Assets																				$ 17.7
Amortization Expense on Reclassified Assets																				6.8
Depreciation and Amortization Expense on Reclassified Assets																				24.5
Net sales	$ 834.9		$ 799.9		$ 825.5		$ 755.3		$ 792.3		$ 793.9		$ 824.5		$ 810.9		$ 829.9	$ 811.2		3,215.6	$ 3,221.6	$ 3,380.8
Gross profit	363.3	[1]	366.4	[1]	394	[1]	347.5	[1]	421	[1]	400.6	[1]	416.1	[1]	419.8	[1]	446.7	451.2	[2]	1,471.2	1,657.5	1,857.6
Income (loss) from continuing operations	(3,718.4)	[3]	114.2	[3]	3.2	[3]	(20.9)	[3]	1,607.4	[3]	64.3	[3]	70.6	[3]	28.9	[3]	(176.8)	103.8		(3,621.9)	1,771.2	489
Income (loss) from discontinued operations, net of income taxes	0		(0.4)		12.4		2.9		1.3		(0.6)		(7.8)		370.3		23.6	107.3		14.9	363.2	154.7
Net (loss) income	$ (3,718.4)		$ 113.8		$ 15.6		$ (18)		$ 1,608.7		$ 63.7		$ 62.8		$ 399.2		$ (153.2)	$ 211.1		$ (3,607)	$ 2,134.4	$ 643.7
Income (Loss) from Continuing Operations, Per Basic Share	$ (44.64)	[4]	$ 1.37	[4]	$ 0.04	[4]	$ (0.24)	[4]	$ 17.43	[4]	$ 0.66	[4]	$ 0.72	[4]	$ 0.28	[4]	$ (1.67)	$ 0.90		$ (43.12)	$ 18.13	$ 4.42
Diluted earnings (loss) per share from continuing operations (in usd per share)	$ (44.64)	[4]	$ 1.34	[4]	$ 0.04	[4]	$ (0.24)	[4]	$ 17.40	[4]	$ 0.66	[4]	$ 0.72	[4]	$ 0.28	[4]	$ (1.67)	$ 0.89		$ (43.12)	$ 18.09	$ 4.39
[1]	Financial data for each period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of ASU 2017-07. See Note 4 for further information.
[2]	Financial data for this period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of Accounting Standards Update ("ASU") 2017-07. See Note 4 for further information on this ASU.
[3]	(Loss) income from continuing operations for the quarter ended December 28, 2018 reflects impairment charges for goodwill and an IPR&D asset. See Note 13 for further information. Income from continuing operations for the quarter ended December 29, 2017 reflects one-time effects for the completion of the reorganization of the Company's legal entity ownership and the impact of the TCJA.
[4]	Quarterly and annual computations are prepared independently. Therefore, the sum of each quarter may not necessarily total the fiscal period amounts noted elsewhere within this Annual Report on Form 10-K.

Condensed Consolidating and C_3

Condensed Consolidating and Combining Financial Statements (Schedule of Condensed Consolidating Balance Sheets) (Details) - USD ($) $ in Millions	Dec. 28, 2018	Dec. 29, 2017	Dec. 30, 2016	Sep. 30, 2016	Dec. 25, 2015	Sep. 25, 2015
Current Assets:
Cash and cash equivalents	$ 348.9	$ 1,260.9	$ 342	$ 280.5	$ 521.9
Accounts receivable, net	623.3	445.8
Inventories	322.3	340.4
Prepaid expenses and other current assets	132.7	84.1
Notes receivable	0	154
Intercompany receivable	0	0
Total current assets	1,427.2	2,285.2
Property, plant and equipment, net	982	966.8
Goodwill	0	3,482.7
Intangible assets, net	8,282.8	8,375
Investment in subsidiaries	0	0
Intercompany loan receivable	0	0
Other assets	185.3	171.2
Total Assets	10,877.3	15,280.9
Current Liabilities:
Current maturities of long-term debt	22.4	313.7
Accounts payable	147.5	113.3
Accrued payroll and payroll-related costs	124	98.5
Interest Payable, Current	77.6	57
Taxes Payable, Current	25	15.8
Accrued and other current liabilities	547.2	452.1
Intercompany payable	0	0
Total current liabilities	943.7	1,050.4
Long-term debt	6,069.2	6,420.9
Pension and postretirement benefits	60.5	67.1
Environmental liabilities	59.7	73.2
Deferred income taxes	324.3	689
Other income tax liabilities	228	94.1
Intercompany loans payable	0	0
Other liabilities	304.6	364.2
Total Liabilities	7,990	8,758.9
Shareholders' equity	2,887.3	6,522	4,984.3	5,270.7		$ 5,311.2
Total Liabilities and Shareholders' Equity	10,877.3	15,280.9
Mallinckrodt plc
Current Assets:
Cash and cash equivalents	0.4	0.7	0.5	0.3
Accounts receivable, net	0	0
Inventories	0	0
Prepaid expenses and other current assets	3.9	1
Notes receivable	0	0
Intercompany receivable	131.1	70
Total current assets	135.4	71.7
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Investment in subsidiaries	2,481.6	6,551.6
Intercompany loan receivable	497.7	593.1
Other assets	0	0
Total Assets	3,114.7	7,216.4
Current Liabilities:
Current maturities of long-term debt	0	0
Accounts payable	0.1	0.1
Accrued payroll and payroll-related costs	0	0
Interest Payable, Current	0	0
Taxes Payable, Current	0	0
Accrued and other current liabilities	0.6	0.8
Intercompany payable	226.7	693.5
Total current liabilities	227.4	694.4
Long-term debt	0	0
Pension and postretirement benefits	0	0
Environmental liabilities	0	0
Deferred income taxes	0	0
Other income tax liabilities	0	0
Intercompany loans payable	0	0
Other liabilities	0	0
Total Liabilities	227.4	694.4
Shareholders' equity	2,887.3	6,522
Total Liabilities and Shareholders' Equity	3,114.7	7,216.4
Mallinckrodt International Finance S.A.
Current Assets:
Cash and cash equivalents	140.8	908.8	44.5	25
Accounts receivable, net	0	0
Inventories	0	0
Prepaid expenses and other current assets	0.2	0.2
Notes receivable	0	0
Intercompany receivable	29.2	173.4
Total current assets	170.2	1,082.4
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Investment in subsidiaries	25,506.1	23,217.8
Intercompany loan receivable	0	0
Other assets	0	0
Total Assets	25,676.3	24,300.2
Current Liabilities:
Current maturities of long-term debt	22.1	313.5
Accounts payable	0	0
Accrued payroll and payroll-related costs	0	0
Interest Payable, Current	48.7	53
Taxes Payable, Current	0	0
Accrued and other current liabilities	0.4	0.4
Intercompany payable	827.8	104.6
Total current liabilities	899	471.5
Long-term debt	3,566.9	6,206.8
Pension and postretirement benefits	0	0
Environmental liabilities	0	0
Deferred income taxes	0	0
Other income tax liabilities	0	0
Intercompany loans payable	12,840.7	5,257.9
Other liabilities	7.6	7.8
Total Liabilities	17,314.2	11,944
Shareholders' equity	8,362.1	12,356.2
Total Liabilities and Shareholders' Equity	25,676.3	24,300.2
Other Subsidiaries
Current Assets:
Cash and cash equivalents	207.7	351.4	297	255.2
Accounts receivable, net	623.3	445.8
Inventories	322.3	340.4
Prepaid expenses and other current assets	128.6	82.9
Notes receivable	0	154
Intercompany receivable	1,087.9	831.4
Total current assets	2,369.8	2,205.9
Property, plant and equipment, net	982	966.8
Goodwill	0	3,482.7
Intangible assets, net	8,282.8	8,375
Investment in subsidiaries	8,362.1	12,356.2
Intercompany loan receivable	12,343	4,664.8
Other assets	185.3	171.2
Total Assets	32,525	32,222.6
Current Liabilities:
Current maturities of long-term debt	0.3	0.2
Accounts payable	147.4	113.2
Accrued payroll and payroll-related costs	124	98.5
Interest Payable, Current	28.9	4
Taxes Payable, Current	25	15.8
Accrued and other current liabilities	546.2	450.9
Intercompany payable	193.7	276.7
Total current liabilities	1,065.5	959.3
Long-term debt	2,502.3	214.1
Pension and postretirement benefits	60.5	67.1
Environmental liabilities	59.7	73.2
Deferred income taxes	324.3	689
Other income tax liabilities	228	94.1
Intercompany loans payable	0	0
Other liabilities	297	356.4
Total Liabilities	4,537.3	2,453.2
Shareholders' equity	27,987.7	29,769.4
Total Liabilities and Shareholders' Equity	32,525	32,222.6
Eliminations
Current Assets:
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts receivable, net	0	0
Inventories	0	0
Prepaid expenses and other current assets	0	0
Notes receivable	0	0
Intercompany receivable	(1,248.2)	(1,074.8)
Total current assets	(1,248.2)	(1,074.8)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Investment in subsidiaries	(36,349.8)	(42,125.6)
Intercompany loan receivable	(12,840.7)	(5,257.9)
Other assets	0	0
Total Assets	(50,438.7)	(48,458.3)
Current Liabilities:
Current maturities of long-term debt	0	0
Accounts payable	0	0
Accrued payroll and payroll-related costs	0	0
Interest Payable, Current	0	0
Taxes Payable, Current	0
Accrued and other current liabilities	0	0
Intercompany payable	(1,248.2)	(1,074.8)
Total current liabilities	(1,248.2)	(1,074.8)
Long-term debt	0	0
Pension and postretirement benefits	0	0
Environmental liabilities	0	0
Deferred income taxes	0	0
Other income tax liabilities	0	0
Intercompany loans payable	(12,840.7)	(5,257.9)
Other liabilities	0	0
Total Liabilities	(14,088.9)	(6,332.7)
Shareholders' equity	(36,349.8)	(42,125.6)
Total Liabilities and Shareholders' Equity	$ (50,438.7)	$ (48,458.3)

Condensed Consolidating and C_4

Condensed Consolidating and Combining Financial Statements (Schedule of Condensed Consolidating and Combining Statements of Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended																			12 Months Ended
	Dec. 28, 2018		Sep. 28, 2018		Jun. 29, 2018		Mar. 30, 2018		Dec. 29, 2017		Sep. 29, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 30, 2016	Dec. 25, 2015		Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Condensed Consolidating Financial Statements
Net sales	$ 834.9		$ 799.9		$ 825.5		$ 755.3		$ 792.3		$ 793.9		$ 824.5		$ 810.9		$ 829.9	$ 811.2		$ 3,215.6	$ 3,221.6	$ 3,380.8
Cost of sales																	383.2	360	[1]	1,744.4	1,564.1	1,523.2
Gross profit	363.3	[2]	366.4	[2]	394	[2]	347.5	[2]	421	[2]	400.6	[2]	416.1	[2]	419.8	[2]	446.7	451.2	[1]	1,471.2	1,657.5	1,857.6
Selling, general and administrative expenses																	321.1	221.8	[1]	834.1	849.7	913.7
Research and development expenses																	66.1	61.3	[1]	361.1	276.9	261.2
Restructuring charges, net																	3.8	4.1		103	31.2	32.7
Non-restructuring impairment charges																	214.3			3,893.1	63.7	16.9
Losses (gains) on divestiture																				0.8	56.9
Operating income (loss)																	(158.6)	(164)	[1]	(3,720.9)	492.9	633.1
Interest expense																	(91.3)	(97.8)		(370.2)	(369.1)	(384.6)
Interest income																	0.5	0.2		8.2	4.6	1.3
Other income (expense), net																	(49.1)	0.1	[1]	30.9	(66.8)	(16.4)
Intercompany interest and fees																	0			0	0	0
Equity in net income of subsidiaries																	0			0	0	0
Income (loss) from continuing operations before income taxes																	(298.5)	66.5		(4,052)	61.6	233.4
Income Tax Expense (Benefit)																	(121.7)	(37.3)		(430.1)	(1,709.6)	(255.6)
Income (loss) from continuing operations	(3,718.4)	[3]	114.2	[3]	3.2	[3]	(20.9)	[3]	1,607.4	[3]	64.3	[3]	70.6	[3]	28.9	[3]	(176.8)	103.8		(3,621.9)	1,771.2	489
Income (loss) from discontinued operations, net of income taxes	0		(0.4)		12.4		2.9		1.3		(0.6)		(7.8)		370.3		23.6	107.3		14.9	363.2	154.7
Net income (loss)	$ (3,718.4)		$ 113.8		$ 15.6		$ (18)		$ 1,608.7		$ 63.7		$ 62.8		$ 399.2		(153.2)	$ 211.1		(3,607)	2,134.4	643.7
Other comprehensive loss, net of tax																	13.1			(9.9)	59.6	(86.5)
Comprehensive income (loss)																	(140.1)			(3,616.9)	2,194	557.2
Mallinckrodt plc
Condensed Consolidating Financial Statements
Net sales																	0			0	0	0
Cost of sales																	0			2	2.6	0
Gross profit																	0			(2)	(2.6)	0
Selling, general and administrative expenses																	13.4			38.8	59.5	51.3
Research and development expenses																	0			4.7	5.1	0
Restructuring charges, net																	0			0	0	0
Non-restructuring impairment charges																	0			0	0	0
Losses (gains) on divestiture																				0	0
Operating income (loss)																	(13.4)			(45.5)	(67.2)	(51.3)
Interest expense																	(2.9)			(7.8)	(13.8)	230.3
Interest income																	0			9.5	7.3	0
Other income (expense), net																	1.8			9.9	20.3	90
Intercompany interest and fees																	4.4			18.5	18.3	16.1
Equity in net income of subsidiaries																	(136.5)			(3,561)	2,200	820.8
Income (loss) from continuing operations before income taxes																	(155.4)			(3,613.4)	2,128.3	613.1
Income Tax Expense (Benefit)																	(2.2)			(6.4)	(6.1)	(30.6)
Income (loss) from continuing operations																	(153.2)			(3,607)	2,134.4	643.7
Income (loss) from discontinued operations, net of income taxes																	0			0	0	0
Net income (loss)																	(153.2)			(3,607)	2,134.4	643.7
Other comprehensive loss, net of tax																	13.1			(9.9)	59.6	(86.5)
Comprehensive income (loss)																	(140.1)			(3,616.9)	2,194	557.2
Mallinckrodt International Finance S.A.
Condensed Consolidating Financial Statements
Net sales																	0			0	0	0
Cost of sales																	0			0	0	0
Gross profit																	0			0	0	0
Selling, general and administrative expenses																	0.2			0.7	0.7	0.8
Research and development expenses																	0			0	0	0
Restructuring charges, net																	0			0	0	0
Non-restructuring impairment charges																	0			0	0	0
Losses (gains) on divestiture																				0	0
Operating income (loss)																	(0.2)			(0.7)	(0.7)	(0.8)
Interest expense																	(81.1)			(460.8)	(353.9)	(327)
Interest income																	0.1			2.5	1.2	0.5
Other income (expense), net																	0.7			8.7	(1.7)	1.7
Intercompany interest and fees																	0			0.1	0	0
Equity in net income of subsidiaries																	35.2			(2,726)	2,901.8	1,327.2
Income (loss) from continuing operations before income taxes																	(45.3)			(3,176.4)	2,546.7	1,001.6
Income Tax Expense (Benefit)																	(0.3)			(5.4)	(5.3)	(18.1)
Income (loss) from continuing operations																	(45)			(3,171)	2,552	1,019.7
Income (loss) from discontinued operations, net of income taxes																	0.4			0.1	(2.1)	38.2
Net income (loss)																	(44.6)			(3,170.9)	2,549.9	1,057.9
Other comprehensive loss, net of tax																	13.1			(9.9)	59.6	(86.5)
Comprehensive income (loss)																	(31.5)			(3,180.8)	2,609.5	971.4
Other Subsidiaries
Condensed Consolidating Financial Statements
Net sales																	829.9			3,215.6	3,221.6	3,380.8
Cost of sales																	383.2			1,742.4	1,561.5	1,523.2
Gross profit																	446.7			1,473.2	1,660.1	1,857.6
Selling, general and administrative expenses																	307.5			794.6	789.5	861.6
Research and development expenses																	66.1			356.4	271.8	261.2
Restructuring charges, net																	3.8			103	31.2	32.7
Non-restructuring impairment charges																	214.3			3,893.1	63.7	16.9
Losses (gains) on divestiture																				(0.8)	56.9
Operating income (loss)																	(145)			(3,674.7)	560.8	685.2
Interest expense																	(17.9)			(63.4)	(74.2)	(82.4)
Interest income																	11			158	68.9	255.9
Other income (expense), net																	(51.6)			12.3	(85.4)	(108.1)
Intercompany interest and fees																	(4.4)			(18.6)	(18.3)	(16.1)
Equity in net income of subsidiaries																	(44.5)			(3,170.9)	2,549.9	1,057.9
Income (loss) from continuing operations before income taxes																	(243.6)			(6,720.1)	3,038.3	1,824.6
Income Tax Expense (Benefit)																	(119.2)			(418.3)	(1,698.2)	(206.9)
Income (loss) from continuing operations																	(124.4)			(6,301.8)	4,736.5	2,031.5
Income (loss) from discontinued operations, net of income taxes																	23.2			14.8	365.3	116.5
Net income (loss)																	(101.2)			(6,287)	5,101.8	2,148
Other comprehensive loss, net of tax																	26			(20.5)	118.2	(173.5)
Comprehensive income (loss)																	(75.2)			(6,307.5)	5,220	1,974.5
Eliminations
Condensed Consolidating Financial Statements
Net sales																	0			0	0	0
Cost of sales																	0			0	0	0
Gross profit																	0			0	0	0
Selling, general and administrative expenses																	0			0	0	0
Research and development expenses																	0			0	0	0
Restructuring charges, net																	0			0	0	0
Non-restructuring impairment charges																	0			0	0	0
Losses (gains) on divestiture																				0	0
Operating income (loss)																	0			0	0	0
Interest expense																	10.6			161.8	72.8	255.1
Interest income																	(10.6)			(161.8)	(72.8)	(255.1)
Other income (expense), net																	0			0	0	0
Intercompany interest and fees																	0			0	0	0
Equity in net income of subsidiaries																	145.8			9,457.9	(7,651.7)	(3,205.9)
Income (loss) from continuing operations before income taxes																	145.8			9,457.9	(7,651.7)	(3,205.9)
Income Tax Expense (Benefit)																	0			0	0	0
Income (loss) from continuing operations																	145.8			9,457.9	(7,651.7)	(3,205.9)
Income (loss) from discontinued operations, net of income taxes																	0			0	0	0
Net income (loss)																	145.8			9,457.9	(7,651.7)	(3,205.9)
Other comprehensive loss, net of tax																	(39.1)			30.4	(177.8)	260
Comprehensive income (loss)																	$ 106.7			$ 9,488.3	$ (7,829.5)	$ (2,945.9)
[1]	Financial data for this period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of Accounting Standards Update ("ASU") 2017-07. See Note 4 for further information on this ASU.
[2]	Financial data for each period has been adjusted to reflect the change in accounting for pension and postretirement costs with the adoption of ASU 2017-07. See Note 4 for further information.
[3]	(Loss) income from continuing operations for the quarter ended December 28, 2018 reflects impairment charges for goodwill and an IPR&D asset. See Note 13 for further information. Income from continuing operations for the quarter ended December 29, 2017 reflects one-time effects for the completion of the reorganization of the Company's legal entity ownership and the impact of the TCJA.

Condensed Consolidating and C_5

Condensed Consolidating and Combining Financial Statements (Schedule of Condensed Consolidating and Combining Statements of Cash Flows) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Condensed Consolidating Financial Statements
Restricted Cash and Investments, Current	$ 0.1	$ 47.5	$ 0	$ 0	$ 0.1
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities	195.6	311.4	665.5	727.3	1,184.6
Cash Flows From Investing Activities:
Capital expenditures	(65.2)	(49)	(127)	(186.1)	(182.9)
Payments to Acquire Businesses, Net of Cash Acquired	(1.8)	0	699.9	76.3	245.4
Proceeds from Divestiture of Businesses, Net of Cash Divested	0	263.7	313	576.9	266.7
Intercompany Loan Investment	0		0	0	0
Subsidiary dividend proceeds	0		0	0
Investment in subsidiary	0		0	0	0
Proceeds from Divestiture of Subsidiary			0		0
Payments to Acquire Interest in Subsidiaries and Affiliates					0
Payments to Acquire Subsidiary			0
Other	(10.2)	0.7	(33.6)	(3.9)	(6)
Net cash from investing activities	(77.2)	215.4	(480.3)	318.4	(155.6)
Cash Flows From Financing Activities:
Issuance of external debt	190	62	690.3	1,465	98.3
Repayment of capital leases	(86.7)	(129.6)	(1,693.6)	(917.2)	(568.6)
Debt financing costs	0	(0.1)	(12.1)	(12.7)	(0.1)
Proceeds from exercise of share options	0.4	3.6	1	4.1	14
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries	0
Intercompany loan borrowings	0		0	0	0
Capital contribution	0		0	0	0
Repurchase of shares	(158.8)	(275.4)	(57.5)	(651.7)	(652.9)
Other	1.2	(30)	(23.1)	(17.7)	(53)
Net cash provided by financing activities	(53.9)	(369.5)	(1,095)	(130.2)	(1,162.3)
Effect of currency rate changes on cash	(3)	(1.5)	(1.8)	2.5	0.3
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	61.5	155.8	(911.6)	918	(133)
Cash and cash equivalents	342	521.9	348.9	1,260.9	280.5
Restricted Cash and Investments, Noncurrent	19	19	18.6	18.2	19
Cash and Cash Equivalents, Including Restricted Cash	361.1	$ 588.4	367.5	1,279.1	299.6	$ 432.6
Mallinckrodt plc
Condensed Consolidating Financial Statements
Restricted Cash and Investments, Current	0		0	0	0
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities	17.4		438.9	1,233.2	17.9
Cash Flows From Investing Activities:
Capital expenditures	0		0	0	0
Payments to Acquire Businesses, Net of Cash Acquired	0		0	0	0
Proceeds from Divestiture of Businesses, Net of Cash Divested			0	0	0
Intercompany Loan Investment	0		(385.6)	(589.5)	0
Subsidiary dividend proceeds	0		0	0
Investment in subsidiary	0		0	0	0
Proceeds from Divestiture of Subsidiary			0		(3.4)
Payments to Acquire Interest in Subsidiaries and Affiliates					0
Payments to Acquire Subsidiary			0
Other	0		0	0	0
Net cash from investing activities	0		(385.6)	(589.5)	3.4
Cash Flows From Financing Activities:
Issuance of external debt	0		0	0	0
Repayment of capital leases	0		0	0	0
Debt financing costs	0		0	0	0
Proceeds from exercise of share options	0.4		1	4.1	14
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries	0
Intercompany loan borrowings	(140)		0	0	617.8
Capital contribution	0		0	0	0
Repurchase of shares	158.8		57.5	651.7	(652.9)
Other	1.2		2.9	4.1	0
Net cash provided by financing activities	(17.2)		(53.6)	(643.5)	(21.1)
Effect of currency rate changes on cash	0		0	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	0.2		(0.3)	0.2	0.2
Cash and cash equivalents	0.5		0.4	0.7	0.3
Restricted Cash and Investments, Noncurrent	0		0	0	0
Cash and Cash Equivalents, Including Restricted Cash	0.5		0.4	0.7	0.3	0.1
Mallinckrodt International Finance S.A.
Condensed Consolidating Financial Statements
Restricted Cash and Investments, Current	0		0	0	0
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities	(94)		80.1	1,139.4	(47.4)
Cash Flows From Investing Activities:
Capital expenditures	0		0	0	0
Payments to Acquire Businesses, Net of Cash Acquired	0		0	0	0
Proceeds from Divestiture of Businesses, Net of Cash Divested			0	0	234
Intercompany Loan Investment	0		(90.1)	0	(175.2)
Subsidiary dividend proceeds	0		(814.2)	(1,170)
Investment in subsidiary	260		(220)	(1,475.3)	(861.2)
Proceeds from Divestiture of Subsidiary			0		0
Payments to Acquire Interest in Subsidiaries and Affiliates					0
Payments to Acquire Subsidiary			0
Other	0		0	0	0
Net cash from investing activities	(260)		(310.1)	(1,475.3)	(802.4)
Cash Flows From Financing Activities:
Issuance of external debt	175		600	1,400	0
Repayment of capital leases	86.2		(1,289.4)	(764.5)	(549.2)
Debt financing costs	0		(12.1)	(12.7)	0
Proceeds from exercise of share options	0		0	0	0
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries	0
Intercompany loan borrowings	(284.7)		(977.7)	(1,747.4)	(1,271.9)
Capital contribution	0		0	0	0
Repurchase of shares	0		0	0	0
Other	0		0	0	0
Net cash provided by financing activities	373.5		(538)	1,200.2	722.7
Effect of currency rate changes on cash	0		0	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	19.5		(768)	864.3	(127.1)
Cash and cash equivalents	44.5		140.8	908.8	25
Restricted Cash and Investments, Noncurrent	0		0	0	0
Cash and Cash Equivalents, Including Restricted Cash	44.5		140.8	908.8	25	152.1
Other Subsidiaries
Condensed Consolidating Financial Statements
Restricted Cash and Investments, Current	0.1		0	0	0.1
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities	272.2		1,702.5	2,274.9	1,214.1
Cash Flows From Investing Activities:
Capital expenditures	65.2		(127)	(186.1)	(182.9)
Payments to Acquire Businesses, Net of Cash Acquired	1.8		699.9	76.3	245.4
Proceeds from Divestiture of Businesses, Net of Cash Divested			313	576.9	32.7
Intercompany Loan Investment	(424.7)		(502)	(1,157.9)	(1,714.5)
Subsidiary dividend proceeds	0		(741.8)	(2,750.2)
Investment in subsidiary	0		0	0	0
Proceeds from Divestiture of Subsidiary			0		0
Payments to Acquire Interest in Subsidiaries and Affiliates					3.4
Payments to Acquire Subsidiary			0
Other	(10.2)		(33.6)	(3.9)	(6)
Net cash from investing activities	(501.9)		(982.3)	(839.5)	(2,107.5)
Cash Flows From Financing Activities:
Issuance of external debt	15		90.3	65	98.3
Repayment of capital leases	0.5		(404.2)	(152.7)	(19.4)
Debt financing costs	0		0	0	(0.1)
Proceeds from exercise of share options	0		0	0	0
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries	0
Intercompany loan borrowings	0		0	0	0
Capital contribution	260		220	1,475.3	861.2
Repurchase of shares	0		0	0	0
Other	0		(26)	(21.8)	(53)
Net cash provided by financing activities	274.5		(861.7)	(1,384.4)	887
Effect of currency rate changes on cash	(3)		(1.8)	2.5	0.3
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	41.8		(143.3)	53.5	(6.1)
Cash and cash equivalents	297		207.7	351.4	255.2
Restricted Cash and Investments, Noncurrent	19		18.6	18.2	19
Cash and Cash Equivalents, Including Restricted Cash	316.1		226.3	369.6	274.3	280.4
Eliminations
Condensed Consolidating Financial Statements
Restricted Cash and Investments, Current	0		0	0	0
Cash Flows From Operating Activities:
Net cash (used in) provided by operating activities	0		(1,556)	(3,920.2)	0
Cash Flows From Investing Activities:
Capital expenditures	0		0	0	0
Payments to Acquire Businesses, Net of Cash Acquired	0		0	0	0
Proceeds from Divestiture of Businesses, Net of Cash Divested			0	0	0
Intercompany Loan Investment	(424.7)		(977.7)	(1,747.4)	(1,889.7)
Subsidiary dividend proceeds	0		(1,556)	(3,920.2)
Investment in subsidiary	(260)		220	1,475.3	861.2
Proceeds from Divestiture of Subsidiary			0		(3.4)
Payments to Acquire Interest in Subsidiaries and Affiliates					3.4
Payments to Acquire Subsidiary			0
Other	0		0	0	0
Net cash from investing activities	684.7		1,197.7	3,222.7	2,750.9
Cash Flows From Financing Activities:
Issuance of external debt	0		0	0	0
Repayment of capital leases	0		0	0	0
Debt financing costs	0		0	0	0
Proceeds from exercise of share options	0		0	0	0
SEC Schedule, 12-04, Cash Dividends Paid to Registrant, Consolidated Subsidiaries	0
Intercompany loan borrowings	424.7		977.7	1,747.4	1,889.7
Capital contribution	(260)		(220)	(1,475.3)	(861.2)
Repurchase of shares	0		0	0	0
Other	0		0	0	0
Net cash provided by financing activities	(684.7)		358.3	697.5	(2,750.9)
Effect of currency rate changes on cash	0		0	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	0		0	0	0
Cash and cash equivalents	0		0	0	0
Restricted Cash and Investments, Noncurrent	0		0	0	0
Cash and Cash Equivalents, Including Restricted Cash	$ 0		$ 0	$ 0	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Mar. 29, 2019	Dec. 30, 2016	Dec. 25, 2015	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Subsequent Event [Line Items]
Benefit from income taxes		$ (121.7)	$ (37.3)	$ (430.1)	$ (1,709.6)	$ (255.6)
Deferred Tax Liabilities Installment Sales				227.5	553.5
Current Income Tax Expense (Benefit)		82		112.8	38.1	120.8
Deferred Income Tax Expense (Benefit)		$ 203.7		542.9	$ 1,747.7	$ 376.4
Term Loan due Sept 2024 [Member]
Subsequent Event [Line Items]
Repayments of Long-term Debt				225
Intercompany Financing and Legal Entity Ownership Reorganization [Member]
Subsequent Event [Line Items]
Current Income Tax Expense (Benefit)				25.5
Deferred Income Tax Expense (Benefit)				$ 281.5
Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Repurchase Amount	$ 75
Subsequent Event [Member] | Term Loan due 2025 [Member]
Subsequent Event [Line Items]
Repayments of Long-term Debt	175
Subsequent Event [Member] | Term Loan due Sept 2024 [Member]
Subsequent Event [Line Items]
Repayments of Long-term Debt	25
Repayments of Debt	5.6
Subsequent Event [Member] | Minimum
Subsequent Event [Line Items]
Benefit from income taxes	125
Subsequent Event [Member] | Maximum
Subsequent Event [Line Items]
Benefit from income taxes	$ 175

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016	Dec. 28, 2018	Dec. 29, 2017	Sep. 30, 2016
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 4	$ 3.9	$ 4	$ 3.6
Charged to Income	0.1	3.8	0.6	0.3
Additions and Other	0	0	0	0
Deductions	(0.1)	(2.7)	(0.7)	0.1
Balance at End of Period	4	5	3.9	4
Sales Returns and Allowances
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	378	376.6	391.3	396.4
Charged to Income	515.3	2,387.5	2,008.5	2,030.8
Additions and Other	0	0	0	0
Deductions	(502)	(2,358.7)	(2,023.2)	(2,049.2)
Balance at End of Period	391.3	405.4	376.6	378
Tax valuation allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	564.9	2,267.9	1,398.3	233
Charged to Income	833.4	332.8	804.6	315.7
Additions and Other	0	4.2	4	15.8
Deductions	0	0	(61)	0.4
Balance at End of Period	$ 1,398.3	$ 2,604.9	$ 2,267.9	$ 564.9