Business Segments and Geographic Information - Segment Information (Detail) (USD $)	3 Months Ended	6 Months Ended
Mar. 28, 2015	Mar. 29, 2014	Mar. 28, 2015	Mar. 29, 2014	Sep. 27, 2014
Segment Reporting Information [Line Items]
Total revenues	$ 655,500,000us-gaap_Revenues	$ 625,000,000us-gaap_Revenues	$ 1,308,300,000us-gaap_Revenues	$ 1,237,400,000us-gaap_Revenues
Operating income (loss)	109,800,000us-gaap_OperatingIncomeLoss	50,200,000us-gaap_OperatingIncomeLoss	213,300,000us-gaap_OperatingIncomeLoss	111,500,000us-gaap_OperatingIncomeLoss
Depreciation and amortization	126,600,000	130,000,000	248,600,000	257,900,000
Capital expenditures	18,700,000	21,300,000	39,700,000	37,800,000
Identifiable assets	8,031,800,000us-gaap_Assets		8,031,800,000us-gaap_Assets		8,414,700,000us-gaap_Assets
Diagnostics
Segment Reporting Information [Line Items]
Total revenues	296,700,000	290,800,000	600,800,000	576,500,000
Operating income (loss)	27,100,000	15,200,000	55,300,000	20,000,000
Depreciation and amortization	91,900,000	94,600,000	180,500,000	186,800,000
Capital expenditures	11,400,000	14,800,000	26,200,000	25,100,000
Identifiable assets	4,208,200,000		4,208,200,000		4,383,500,000
Breast Health
Segment Reporting Information [Line Items]
Total revenues	255,500,000	238,700,000	497,500,000	465,200,000
Operating income (loss)	75,400,000	25,800,000	135,900,000	69,700,000
Depreciation and amortization	8,300,000	9,200,000	15,900,000	18,500,000
Capital expenditures	3,000,000	2,300,000	5,500,000	4,100,000
Identifiable assets	838,000,000		838,000,000		859,800,000
GYN Surgical
Segment Reporting Information [Line Items]
Total revenues	79,100,000	72,000,000	163,500,000	150,900,000
Operating income (loss)	4,500,000	6,600,000	17,700,000	17,700,000
Depreciation and amortization	26,000,000	26,000,000	51,500,000	52,100,000
Capital expenditures	2,400,000	2,200,000	4,400,000	4,000,000
Identifiable assets	1,698,200,000		1,698,200,000		1,748,200,000
Skeletal Health
Segment Reporting Information [Line Items]
Total revenues	24,200,000	23,500,000	46,500,000	44,800,000
Operating income (loss)	2,800,000	2,600,000	4,400,000	4,100,000
Depreciation and amortization	400,000	200,000	700,000	500,000
Capital expenditures	100,000	0	200,000	200,000
Identifiable assets	24,000,000		24,000,000		26,100,000
Corporate
Segment Reporting Information [Line Items]
Capital expenditures	1,800,000	2,000,000	3,400,000	4,400,000
Identifiable assets	$ 1,263,400,000		$ 1,263,400,000		$ 1,397,100,000

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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