Goodwill and Intangible Assets - Intangible Assets Narrative (Details) - USD ($)		3 Months Ended					12 Months Ended
		Dec. 31, 2019	Sep. 28, 2019	Jun. 29, 2019	Sep. 29, 2018	Jun. 30, 2018	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017	Sep. 29, 2019	Sep. 30, 2018
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Amortization of intangible assets							$ 305,500,000		$ 333,600,000		$ 349,600,000
Goodwill impairment charge							109,200,000		136,700,000
Goodwill		$ 4,116,700,000					4,116,700,000		3,979,800,000		4,175,400,000
Impairment charges		$ 141,600,000	$ 10,900,000	$ 27,800,000	$ 221,800,000		$ 184,500,000		224,400,000		47,500,000
Impairment of intangible assets, indefinite-lived			$ 18,100,000			$ 53,200,000
RX
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, definite-lived intangible											18,500,000
Reporting unit, percentage of fair value in excess of carrying amount (RX US more than percent in Sept. 2018, less than % at Dec. 31, 2019; CSC UK and Australia less than %; BCS and Oral Care International less than %; CSCA and Rx UK greater than %)		10.00%		10.00%			10.00%						25.00%
Goodwill impairment charge				$ 0			$ 109,200,000	[1]	0	[1]
Goodwill	[1]	$ 1,013,900,000					1,013,900,000		1,114,800,000		1,122,300,000
CSCI
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Goodwill impairment charge	[2]						0		0
Goodwill	[2]	1,203,700,000					1,203,700,000		1,151,300,000		1,205,700,000
CSCA
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount (RX US more than percent in Sept. 2018, less than % at Dec. 31, 2019; CSC UK and Australia less than %; BCS and Oral Care International less than %; CSCA and Rx UK greater than %)												20.00%
Goodwill impairment charge							0		136,700,000
Goodwill		$ 1,899,100,000					1,899,100,000		1,713,700,000		1,847,400,000
Generic Product Acquisition | RX
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment charges							27,800,000
In-process research and development
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, indefinite-lived							5,800,000		$ 8,700,000		$ 12,700,000
Generic Benzaclin Product | RX
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, definite-lived intangible							21,200,000
Licensed Pain Relief Products | CSCI
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, definite-lived intangible							9,700,000
Evamist Branded Product | RX
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, definite-lived intangible							$ 10,800,000
Animal health | CSCA
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Reclassified intangible assets					5,400,000
Goodwill impairment charge					136,700,000
Animal health | Brand | CSCA
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, indefinite-lived					27,700,000
Animal health | Developed Product Technology and Distribution Agreements | CSCA
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, definite-lived intangible					41,600,000
Animal health | Supply Agreement | CSCA
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, definite-lived intangible					2,800,000
Animal health | Trade name and trademark | CSCA
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Impairment of intangible assets, definite-lived intangible					$ 4,500,000
UK | RX
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount (RX US more than percent in Sept. 2018, less than % at Dec. 31, 2019; CSC UK and Australia less than %; BCS and Oral Care International less than %; CSCA and Rx UK greater than %)												20.00%
CSC UK and Australia | CSCI
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount (RX US more than percent in Sept. 2018, less than % at Dec. 31, 2019; CSC UK and Australia less than %; BCS and Oral Care International less than %; CSCA and Rx UK greater than %)												20.00%
BCS | CSCI
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount (RX US more than percent in Sept. 2018, less than % at Dec. 31, 2019; CSC UK and Australia less than %; BCS and Oral Care International less than %; CSCA and Rx UK greater than %)												10.00%
Oral Care International | CSCI
Schedule of Definite and Indefinite Intangible Asset [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount (RX US more than percent in Sept. 2018, less than % at Dec. 31, 2019; CSC UK and Australia less than %; BCS and Oral Care International less than %; CSCA and Rx UK greater than %)												10.00%

[1] We had accumulated impairments of $109.2 million as of December 31, 2019.

[2] (1) We had accumulated impairments of $868.4 million as of December 31, 2019 and December 31, 2018.