Restructuring and Related Charges (Schedule of Restructuring Reserves by Type of Cost) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 25, 2015	Sep. 26, 2014	Sep. 27, 2013
Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		$ 34.9	$ 25.5	$ 8.9
Charges		40.7	57.2	26.1
Changes in estimate from continuing operations		(10.1)	(13.3)	(2.4)
Cash payments		(44.3)	(55.0)	(15.1)
Reclassifications	[1]	(3.0)	(2.3)	(1.5)
Currency translation		(0.6)	(1.1)
Ending Balance		18.0	34.9	25.5
Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		1.0	26.4	9.7
Changes in estimate, discontinued operations		(0.6)	2.5	(0.2)
Acquisition programs | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		7.9	0.0	0.0
Charges		25.3	22.9	0.0
Changes in estimate from continuing operations		(1.5)	(1.6)	0.0
Cash payments		(21.7)	(13.4)	0.0
Reclassifications	[1]	0.0	0.0	0.0
Currency translation		0.0	0.0
Ending Balance		10.0	7.9	0.0
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		0.4	10.6	8.9
Charges		0.0	1.4	17.6
Changes in estimate from continuing operations		(0.3)	(4.1)	(2.4)
Cash payments		(0.1)	(6.8)	(15.1)
Reclassifications	[1]	0.0	(1.0)	(1.5)
Currency translation		0.0	(0.1)
Ending Balance		0.0	0.4	10.6
Other programs | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		0.0	1.1	3.3
Changes in estimate, discontinued operations		0.0	0.7	(0.2)
2013 Mallinckrodt program | Continuing Operations
Restructuring Reserve [Roll Forward]
Beginning Balance		26.6	14.9	0.0
Charges		15.4	32.9	8.5
Changes in estimate from continuing operations		(8.3)	(7.6)	0.0
Cash payments		(22.5)	(34.8)	0.0
Reclassifications	[1]	(3.0)	(1.3)	0.0
Currency translation		0.6	(1.0)
Ending Balance		8.0	26.6	14.9
2013 Mallinckrodt program | Discontinued Operations, Held-for-sale
Restructuring Reserve [Roll Forward]
Charges, discontinued operations		1.0	25.3	6.4
Changes in estimate, discontinued operations		$ (0.6)	$ 1.8	$ 0.0

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