Document and Entity Information - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Feb. 26, 2021	Jun. 30, 2020
Cover [Abstract]
Entity Registrant Name	Party City Holdco Inc.
Document Type	10-K
Trading Symbol	PRTY
Current Fiscal Year End Date	--12-31
Entity Public Float			$ 140,692,691
Entity Common Stock, Shares Outstanding		110,733,170
Amendment Flag	false
Entity Central Index Key	0001592058
Entity Filer Category	Accelerated Filer
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Security Exchange Name	NYSE
Entity File Number	001-37344
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-0539758
Entity Address, Address Line One	80 Grasslands Road
Entity Address, City or Town	Elmsford
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10523
City Area Code	914
Local Phone Number	345-2020
Document Annual Report	true
Document Transition Report	false
Title of 12(b) Security	Common Stock
ICFR Auditor Attestation Flag	false
Documents Incorporated by Reference	Portions of the registrant’s definitive proxy statement relating to its 2021 annual meeting of stockholders, to be held on June 10, 2021, are incorporated by reference in Part III.