Cover Page - USD ($) $ in Billions	12 Months Ended
Cover Page - USD ($) $ in Billions	Dec. 31, 2019	Apr. 27, 2020	Jun. 30, 2019
Document Information [Line Items]
Document Type	10-K/A
Amendment Flag	true
Amendment Description	This Amendment No. 1 to the Annual Report on Form 10-K (this “Amendment”) amends Part III, Items 10 through 14 of the previously filed Annual Report on Form 10-K for the fiscal year ended December 31, 2019, originally filed on February 18, 2020 (the “Original Filing”) by Allergan plc and Warner Chilcott Limited (collectively, “we,” “our,” “us,” the “Company” or “Allergan”). We are filing this Amendment to include information previously omitted from the Original Filing in reliance on General Instruction G(3) to Form 10-K, which provides that registrants may incorporate by reference certain information from a definitive proxy statement that involves the election of directors, provided that the definitive proxy statement is filed with the Securities and Exchange Commission (“SEC”) within 120 days after the end of the fiscal year. Due to the Company’s previously announced and pending transaction with AbbVie Inc. (the “AbbVie Transaction”), the Company does not anticipate that a definitive proxy statement that involves the election of directors will be filed within 120 days of the end of the Company’s fiscal year. Accordingly, Part III of the Original Filing is hereby amended as set forth below. In addition, as required by Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), new certifications by our principal executive officer and principal financial officer are filed as exhibits under Item 15 of Part IV to this Amendment. Except as stated herein, this Amendment does not reflect events occurring after the filing of the Original Filing and no attempt has been made in this Amendment to modify or update other disclosures presented in the Original Filing. Among other things, forward-looking statements made in the Original Filing have not been revised to reflect events that occurred or facts that became known to the Company after the filing of the Original Filing, and such forward-looking statements should be read in their historical context. Accordingly, this Amendment should be read in conjunction with the Original Filing and the Company’s other filings with the SEC subsequent to the filing of the Original Filing.
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity File Number	001-36867
Entity Incorporation, State or Country Code	L2
Entity Tax Identification Number	98-1114402
Entity Address, Address Line One	Clonshaugh Business and Technology Park
Entity Address, Address Line Two	Coolock
Entity Address, City or Town	Dublin
Entity Address, Country	IE
Entity Address, Postal Zip Code	E400
City Area Code	862
Local Phone Number	261-7000
Entity Registrant Name	Allergan plc
Entity Central Index Key	0001578845
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		329,765,537
Entity Public Float			$ 54.8
Document Annual Report	true
Document Transition Report	false
Allergan plc Ordinary Shares [Member]
Document Information [Line Items]
Trading Symbol	AGN
Title of 12(b) Security	Allergan plc Ordinary Shares, $0.0001 par value
Security Exchange Name	NYSE
Floating Rate Notes Due 2020 [Member]
Document Information [Line Items]
Trading Symbol	AGN20A
Title of 12(b) Security	Floating rate notes due 2020
Security Exchange Name	NYSE
0.500% Notes Due 2021 [Member]
Document Information [Line Items]
Trading Symbol	AGN21
Title of 12(b) Security	0.500% notes due 2021
Security Exchange Name	NYSE
1.500% Notes Due 2023 [Member]
Document Information [Line Items]
Trading Symbol	AGN 23A
Title of 12(b) Security	1.500% notes due 2023
Security Exchange Name	NYSE
1.250% Notes Due 2024 [Member]
Document Information [Line Items]
Trading Symbol	AGN 24A
Title of 12(b) Security	1.250% notes due 2024
Security Exchange Name	NYSE
2.625% Notes Due 2028 [Member]
Document Information [Line Items]
Trading Symbol	AGN28
Title of 12(b) Security	2.625% notes due 2028
Security Exchange Name	NYSE
2.125% Notes Due 2029 [Member]
Document Information [Line Items]
Trading Symbol	AGN29
Title of 12(b) Security	2.125% notes due 2029
Security Exchange Name	NYSE
Warner Chilcott Limited [Member]
Document Information [Line Items]
Document Type	10-K/A
Amendment Flag	true
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity File Number	001-36887
Entity Incorporation, State or Country Code	D0
Entity Tax Identification Number	98-0496358
Entity Address, Address Line One	Victoria Place
Entity Address, Address Line Two	5th Floor
Entity Address, City or Town	Hamilton
Entity Address, Country	BM
Entity Address, Postal Zip Code	HM 10
City Area Code	441
Local Phone Number	295-2244
Entity Registrant Name	Warner Chilcott Limited
Entity Central Index Key	0001620602
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false

Allergan plc 10-K/A