Condensed Consolidating Financial Statements (Schedule of Condensed Consolidating Statements of Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Sep. 29, 2017	Sep. 30, 2016
Condensed Consolidating Financial Statements
Net sales	$ 793.9	$ 887.2	$ 2,429.3	$ 2,569.6
Cost of sales	393.3	397.0	1,194.0	1,165.5
Gross profit	400.6	490.2	1,235.3	1,404.1
Selling, general and administrative expenses	205.7	267.8	745.9	702.0
Research and development expenses	59.5	67.9	190.9	200.8
Restructuring charges, net	14.3	6.8	32.1	29.2
Non-restructuring impairment charges	0.0	0.0	0.0	16.9
Losses (gains) on divestiture and license	(0.4)	0.0	56.6	0.0
Operating income	120.7	147.7	323.0	455.2
Interest expense	(92.6)	(94.0)	(279.0)	(286.8)
Interest income	1.3	0.5	2.8	1.1
Other income (expense), net	3.7	(0.6)	6.2	(2.6)
Intercompany Interest And Fees	0.0	0.0	0.0	0.0
Income (Loss) from Equity Method Investments	0.0	0.0	0.0	0.0
Income from continuing operations before income taxes	33.1	53.6	53.0	166.9
Income tax benefit	(31.2)	(56.4)	(110.8)	(218.3)
Income (Loss) from Continuing Operations	64.3	110.0	163.8	385.2
(Loss) income from discontinued operations, net of income taxes	(0.6)	5.0	361.9	47.4
Net Income (Loss)	63.7	115.0	525.7	432.6
Other Comprehensive Income (Loss), Net of Tax	(5.1)	(19.9)	59.4	(20.3)
Comprehensive Income (Loss)	58.6	95.1	585.1	412.3
Mallinckrodt plc
Condensed Consolidating Financial Statements
Net sales	0.0	0.0	0.0	0.0
Cost of sales	0.9	0.0	1.8	0.0
Gross profit	(0.9)	0.0	(1.8)	0.0
Selling, general and administrative expenses	13.4	14.7	46.7	40.9
Research and development expenses	1.8	0.0	3.6	0.0
Restructuring charges, net	0.0	0.0	0.0	0.0
Non-restructuring impairment charges	0.0	0.0	0.0	0.0
Losses (gains) on divestiture and license	0.0	0.0	0.0	0.0
Operating income	(16.1)	(14.7)	(52.1)	(40.9)
Interest expense	(3.3)	(36.1)	(10.0)	(162.3)
Interest income	2.2	0.0	5.3	0.0
Other income (expense), net	1.4	7.4	19.0	22.3
Intercompany Interest And Fees	(4.3)	(5.6)	(13.3)	(12.9)
Income (Loss) from Equity Method Investments	82.4	157.1	572.1	609.8
Income from continuing operations before income taxes	62.3	108.1	521.0	416.0
Income tax benefit	(1.4)	(6.9)	(4.7)	(16.6)
Income (Loss) from Continuing Operations	63.7	115.0	525.7	432.6
(Loss) income from discontinued operations, net of income taxes	0.0	0.0	0.0	0.0
Net Income (Loss)	63.7	115.0	525.7	432.6
Other Comprehensive Income (Loss), Net of Tax	(5.1)	(19.9)	59.4	(20.3)
Comprehensive Income (Loss)	58.6	95.1	585.1	412.3
Mallinckrodt International Finance S.A.
Condensed Consolidating Financial Statements
Net sales	0.0	0.0	0.0	0.0
Cost of sales	0.0	0.0	0.0	0.0
Gross profit	0.0	0.0	0.0	0.0
Selling, general and administrative expenses	0.2	0.1	0.6	0.5
Research and development expenses	0.0	0.0	0.0	0.0
Restructuring charges, net	0.0	0.0	0.0	0.0
Non-restructuring impairment charges	0.0	0.0	0.0	0.0
Losses (gains) on divestiture and license	0.0	0.0	0.0	0.0
Operating income	(0.2)	(0.1)	(0.6)	(0.5)
Interest expense	(90.9)	(82.0)	(264.9)	(245.1)
Interest income	0.4	0.2	1.0	0.5
Other income (expense), net	1.7	0.0	(1.6)	0.0
Intercompany Interest And Fees	0.0	0.0	0.0	0.1
Income (Loss) from Equity Method Investments	261.8	302.7	1,113.5	1,015.2
Income from continuing operations before income taxes	172.8	220.8	847.4	770.2
Income tax benefit	(2.1)	(4.1)	(2.6)	(18.1)
Income (Loss) from Continuing Operations	174.9	224.9	850.0	788.3
(Loss) income from discontinued operations, net of income taxes	(0.2)	(0.4)	(1.9)	(2.1)
Net Income (Loss)	174.7	224.5	848.1	786.2
Other Comprehensive Income (Loss), Net of Tax	(5.1)	(19.9)	59.4	(20.3)
Comprehensive Income (Loss)	169.6	204.6	907.5	765.9
Other Subsidiaries
Condensed Consolidating Financial Statements
Net sales	793.9	887.2	2,429.3	2,569.6
Cost of sales	392.4	397.0	1,192.2	1,165.5
Gross profit	401.5	490.2	1,237.1	1,404.1
Selling, general and administrative expenses	192.1	253.0	698.6	660.6
Research and development expenses	57.7	67.9	187.3	200.8
Restructuring charges, net	14.3	6.8	32.1	29.2
Non-restructuring impairment charges	0.0	0.0	0.0	16.9
Losses (gains) on divestiture and license	(0.4)	0.0	56.6	0.0
Operating income	137.0	162.5	375.7	496.6
Interest expense	(19.0)	(19.4)	(57.9)	(61.4)
Interest income	19.3	43.8	50.3	182.6
Other income (expense), net	0.6	(8.0)	(11.2)	(24.9)
Intercompany Interest And Fees	4.3	5.6	13.3	12.8
Income (Loss) from Equity Method Investments	174.7	224.5	848.1	786.2
Income from continuing operations before income taxes	316.9	409.0	1,218.3	1,391.9
Income tax benefit	(27.7)	(45.4)	(103.5)	(183.6)
Income (Loss) from Continuing Operations	344.6	454.4	1,321.8	1,575.5
(Loss) income from discontinued operations, net of income taxes	(0.4)	5.4	363.8	49.5
Net Income (Loss)	344.2	459.8	1,685.6	1,625.0
Other Comprehensive Income (Loss), Net of Tax	(10.5)	(39.8)	117.9	(41.0)
Comprehensive Income (Loss)	333.7	420.0	1,803.5	1,584.0
Eliminations
Condensed Consolidating Financial Statements
Net sales	0.0	0.0	0.0	0.0
Cost of sales	0.0	0.0	0.0	0.0
Gross profit	0.0	0.0	0.0	0.0
Selling, general and administrative expenses	0.0	0.0	0.0	0.0
Research and development expenses	0.0	0.0	0.0	0.0
Restructuring charges, net	0.0	0.0	0.0	0.0
Non-restructuring impairment charges	0.0	0.0	0.0	0.0
Losses (gains) on divestiture and license	0.0	0.0	0.0	0.0
Operating income	0.0	0.0	0.0	0.0
Interest expense	20.6	43.5	53.8	182.0
Interest income	(20.6)	(43.5)	(53.8)	(182.0)
Other income (expense), net	0.0	0.0	0.0	0.0
Intercompany Interest And Fees	0.0	0.0	0.0	0.0
Income (Loss) from Equity Method Investments	(518.9)	(684.3)	(2,533.7)	(2,411.2)
Income from continuing operations before income taxes	(518.9)	(684.3)	(2,533.7)	(2,411.2)
Income tax benefit	0.0	0.0	0.0	0.0
Income (Loss) from Continuing Operations	(518.9)	(684.3)	(2,533.7)	(2,411.2)
(Loss) income from discontinued operations, net of income taxes	0.0	0.0	0.0	0.0
Net Income (Loss)	(518.9)	(684.3)	(2,533.7)	(2,411.2)
Other Comprehensive Income (Loss), Net of Tax	15.6	59.7	(177.3)	61.3
Comprehensive Income (Loss)	$ (503.3)	$ (624.6)	$ (2,711.0)	$ (2,349.9)