Summary of Significant Accounting Policies - Rollforward of Goodwill Activity by Reportable Segments (Detail) $ in Millions	12 Months Ended
	Sep. 26, 2015 USD ($)
Goodwill [Line Items]
Goodwill Tax Adjustments	$ (1.3)
Goodwill [Roll Forward]
Balance at September 27, 2014	2,810.8
Foreign currency and other	(3.9)
Balance at September 26, 2015	2,808.2
Diagnostics [Member]
Goodwill [Line Items]
Goodwill Tax Adjustments	(0.6)
Goodwill [Roll Forward]
Balance at September 27, 2014	1,154.1
Foreign currency and other	(2.4)
Balance at September 26, 2015	1,152.3
Breast Health [Member]
Goodwill [Line Items]
Goodwill Tax Adjustments	(0.7)
Goodwill [Roll Forward]
Balance at September 27, 2014	631.7
Foreign currency and other	(0.6)
Balance at September 26, 2015	631.8
GYN Surgical [Member]
Goodwill [Line Items]
Goodwill Tax Adjustments	0.0
Goodwill [Roll Forward]
Balance at September 27, 2014	1,016.8
Foreign currency and other	(0.8)
Balance at September 26, 2015	1,016.0
Skeletal Health [Member]
Goodwill [Line Items]
Goodwill Tax Adjustments	0.0
Goodwill [Roll Forward]
Balance at September 27, 2014	8.2
Foreign currency and other	(0.1)
Balance at September 26, 2015	$ 8.1