Summary of Significant Accounting Policies - Rollforward of Accumulated Goodwill Impairment Losses by Reportable Segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 27, 2014	Sep. 28, 2013	Sep. 29, 2012
Accumulated Goodwill Impairment Losses by Reportable Segment [Roll Forward]
Balance at September 28, 2013			$ 3,539.9
Impairment charge	(1,100.0)	(5.8)	0	(1,117.4)	(5.8)
Balance at September 27, 2014	3,539.9		3,539.9	3,539.9
Diagnostics [Member]
Accumulated Goodwill Impairment Losses by Reportable Segment [Roll Forward]
Balance at September 28, 2013			2,025.7
Impairment charge			0
Balance at September 27, 2014			2,025.7
Breast Health [Member]
Accumulated Goodwill Impairment Losses by Reportable Segment [Roll Forward]
Balance at September 28, 2013			348.4
Impairment charge			0
Balance at September 27, 2014			348.4
GYN Surgical [Member]
Accumulated Goodwill Impairment Losses by Reportable Segment [Roll Forward]
Balance at September 28, 2013			1,165.8
Impairment charge			0
Balance at September 27, 2014			$ 1,165.8