Restructuring and Related Charges (Schedule of Restructuring Reserves by Type of Cost) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		$ 18.0	$ 34.9	$ 25.5
Charges		36.0	37.0	43.5
Changes in estimate from continuing operations		(2.7)	(1.8)	(13.0)
Cash payments		(33.7)	(44.3)	(55.0)
Reclassifications	[1]	(1.3)	(3.0)	(2.3)
Currency translation			(0.6)	(1.1)
Ending Balance		18.5	18.0	34.9
Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		2.5	4.7	40.1
Changes in estimate, discontinued operations		(0.3)	(8.9)	(2.8)
Acquisition programs | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		10.0	7.9	0.0
Charges		5.0	25.3	22.9
Changes in estimate from continuing operations		(1.3)	(1.5)	(1.6)
Cash payments		(13.2)	(21.7)	(13.4)
Reclassifications	[1]	0.0	0.0	0.0
Currency translation			0.0	0.0
Ending Balance		0.5	10.0	7.9
Acquisition programs | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		0.0	0.0	0.0
Changes in estimate, discontinued operations		0.0	0.0	0.0
Other programs | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		0.0	0.4	10.6
Charges		0.0	0.0	1.4
Changes in estimate from continuing operations		0.0	(0.3)	(4.1)
Cash payments		0.0	(0.1)	(6.8)
Reclassifications	[1]	0.0	0.0	(1.0)
Currency translation			0.0	(0.1)
Ending Balance		0.0	0.0	0.4
Other programs | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		0.0	0.0	1.1
Changes in estimate, discontinued operations		0.0	0.0	(0.7)
2016 Mallinckrodt Program | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		0.0	0.0	0.0
Charges		6.4	0.0	0.0
Changes in estimate from continuing operations		0.0	0.0	0.0
Cash payments		(0.2)	0.0	0.0
Reclassifications	[1]	0.0	0.0	0.0
Currency translation			0.0	0.0
Ending Balance		6.2	0.0	0.0
2016 Mallinckrodt Program | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		0.0	0.0	0.0
Changes in estimate, discontinued operations		0.0	0.0	0.0
2013 Mallinckrodt program | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		8.0	26.6	14.9
Charges		24.6	11.7	19.2
Changes in estimate from continuing operations		(1.4)	0.0	(7.3)
Cash payments		(20.3)	(22.5)	(34.8)
Reclassifications	[1]	(1.3)	(3.0)	(1.3)
Currency translation			(0.6)	(1.0)
Ending Balance		11.8	8.0	26.6
2013 Mallinckrodt program | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		2.5	4.7	39.0
Changes in estimate, discontinued operations		$ (0.3)	$ (8.9)	$ (2.1)

[1] Represents the reclassification of pension and other postretirement benefits from restructuring reserves to pension and postretirement obligations.