Business Segments and Geographic Information - Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Sep. 30, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 824.0	$ 806.1	$ 2,404.5	$ 2,255.9
Income (loss) from operations	133.1	115.0	(336.9)	1,260.9
Depreciation and amortization	120.5	118.3	361.2	328.7
Capital expenditures	24.7	24.3	73.5	74.0
Identifiable assets	7,091.4		7,091.4		$ 7,979.6
Diagnostics
Segment Reporting Information [Line Items]
Total revenues	294.2	284.1	858.5	905.4
Income (loss) from operations	32.3	36.8	103.1	1,007.8
Depreciation and amortization	64.6	64.7	193.4	214.0
Capital expenditures	12.8	13.0	38.7	34.7
Identifiable assets	2,487.7		2,487.7		2,621.6
Breast Health
Segment Reporting Information [Line Items]
Total revenues	307.9	283.7	896.0	837.4
Income (loss) from operations	100.0	99.2	291.2	277.1
Depreciation and amortization	5.8	5.0	16.2	14.7
Capital expenditures	4.5	3.2	11.8	7.2
Identifiable assets	866.1		866.1		824.0
Medical Aesthetics
Segment Reporting Information [Line Items]
Total revenues	91.7	110.0	268.5	126.1
Income (loss) from operations	(22.2)	(45.4)	(805.3)	(69.9)
Depreciation and amortization	26.9	24.7	82.4	27.3
Capital expenditures	1.6	3.3	6.7	3.7
Identifiable assets	939.1		939.1		1,751.2
GYN Surgical
Segment Reporting Information [Line Items]
Total revenues	107.7	106.5	314.7	322.4
Income (loss) from operations	22.9	25.6	71.1	52.9
Depreciation and amortization	23.0	23.7	68.7	72.2
Capital expenditures	2.5	3.5	8.2	10.9
Identifiable assets	1,434.2		1,434.2		1,494.6
Skeletal Health
Segment Reporting Information [Line Items]
Total revenues	22.5	21.8	66.8	64.6
Income (loss) from operations	0.1	(1.2)	3.0	(7.0)
Depreciation and amortization	0.2	0.2	0.5	0.5
Capital expenditures	1.3	0.2	2.1	0.5
Identifiable assets	28.1		28.1		25.5
Corporate
Segment Reporting Information [Line Items]
Capital expenditures	2.0	$ 1.1	6.0	$ 17.0
Identifiable assets	$ 1,336.2		$ 1,336.2		$ 1,262.7

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
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