Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Schedule of Reconciliation Between Basic and Diluted Income Per Share

A reconciliation between basic and diluted income per share is as follows:

	Fiscal Year Ended December 31,
	2020			2019			2018
Net (loss) income attributable to common shareholders of    Party City Holdco Inc.:	$	(528,238	)	$	(532,495	)	$	123,259
Weighted average shares — Basic:		100,804,944			93,295,692			96,133,144
Effect of dilutive restricted stock units:		—			—			9,661
Effect of dilutive stock options:		—			—			1,128,245
Weighted average shares — Diluted:		100,804,944			93,295,692			97,271,050
Net (loss) income per share attributable to common    shareholders of Party City Holdco Inc. —    Basic:	$	(5.24	)	$	(5.71	)	$	1.28
Net (loss) income per share attributable to common     shareholders of Party City Holdco Inc. —     Diluted:	$	(5.24	)	$	(5.71	)	$	1.27