Restructuring and Related Charges (Schedule of Restructuring and Related Charges by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 30, 2016	Dec. 25, 2015	Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges	$ 5.3		$ 36.4	$ 38.2	$ 45.3
Less: accelerated depreciation	(1.5)		(5.2)	(4.9)	(0.3)
Restructuring charges, net	3.8	$ 4.1	31.2	33.3	45.0
Specialty Brands [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges	2.6		25.4	23.3	36.5
Specialty Generics [Member]
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges	0.8		7.7	3.4	4.5
Corporate
Restructuring Cost and Reserve [Line Items]
Total restructuring and related charges	$ 1.9		$ 3.3	$ 11.5	$ 4.3