Schedule I - Condensed Financial Information of Registrant - Condensed Balance Sheets (Parenthetical) (Detail) - shares	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Common stock, shares issued	121,662,540	120,788,159
Common stock, shares outstanding	94,461,576	93,622,934
Common stock held in treasury, shares at cost	27,200,964	27,165,225
Party City Holdco Inc. [Member]
Condensed Financial Statements, Captions [Line Items]
Common stock, shares issued	121,662,540	120,788,159
Common stock, shares outstanding	94,461,576	93,622,934
Common stock held in treasury, shares at cost	27,200,964	27,165,225