Restructuring and Related Charges (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 30, 2016
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment asset impairment		$ 2.3
Employee terminations
Restructuring Cost and Reserve [Line Items]
Accelerated share based compensation expense	$ 9.8	35.1
2013 Mallinckrodt program | Minimum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range			$ 100.0
2013 Mallinckrodt program | Maximum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range			125.0
2016 Mallinckrodt Program | Minimum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range			100.0
2016 Mallinckrodt Program | Maximum
Restructuring Cost and Reserve [Line Items]
Mallinckrodt program expected cost range			$ 125.0
Consulting costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs		$ 8.5