Restructuring and Related Charges (Schedule of Net Restructuring and Related Charges) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 25, 2015	Dec. 26, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, net	$ 6.4	$ 7.3
Less: non-cash charges, including accelerated share-based compensation expense	(0.1)	(6.9)
Total charges expected to be settled in cash	6.3	0.4
2013 Mallinckrodt program
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, net	5.7	(4.9)
Acquisitions
Restructuring Cost and Reserve [Line Items]
Restructuring and related charges, net	$ 0.7	12.2
Severance
Restructuring Cost and Reserve [Line Items]
Accelerated share-based compensation expense		$ 6.8