Business Segment Information - Business Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 681.6	$ 578.2	$ 524.9	$ 646.2	$ 691.6	$ 679.4	$ 654.3	$ 628.1	$ 2,430.9	$ 2,653.4	$ 2,532.8
Operating income (loss)									311.8	546.7	403.1
Interest expense									36.8	68.0	82.7
Other expense (income), net									8.5	1.3	(11.5)
Income before income taxes									266.5	477.4	331.9
Identifiable assets	6,737.5				6,274.5				6,737.5	6,274.5	6,112.8
Depreciation expense									149.9	135.0	128.4
Amortization expense									137.2	145.8	146.7
Capital expenditures									310.4	292.1	193.6
CooperVision
Segment Reporting Information [Line Items]
Net sales									1,843.0	1,972.9	1,882.0
CooperSurgical
Segment Reporting Information [Line Items]
Net sales									587.9	680.5	650.8
Corporate
Segment Reporting Information [Line Items]
Net sales									0.0	0.0	0.0
Operating income (loss)									(49.2)	(47.6)	(56.8)
Identifiable assets	207.4				173.1				207.4	173.1	165.1
Depreciation expense									0.0	0.2	0.2
Amortization expense									0.0	0.0	0.0
Capital expenditures									0.0	0.0	0.1
Operating Segments | CooperVision
Segment Reporting Information [Line Items]
Net sales									1,843.0	1,972.9	1,882.0
Operating income (loss)									375.7	506.4	479.8
Identifiable assets	4,236.3				3,911.6				4,236.3	3,911.6	3,746.0
Depreciation expense									138.2	125.8	120.1
Amortization expense									32.4	40.9	43.6
Capital expenditures									260.3	259.0	178.4
Operating Segments | CooperSurgical
Segment Reporting Information [Line Items]
Net sales									587.9	680.5	650.8
Operating income (loss)									(14.7)	87.9	(19.9)
Identifiable assets	$ 2,293.8				$ 2,189.8				2,293.8	2,189.8	2,201.7
Depreciation expense									11.7	9.0	8.1
Amortization expense									104.8	104.9	103.1
Capital expenditures									$ 50.1	$ 33.1	$ 15.1