Current and Long-Term Obligations - Summary of Long-Term Obligations (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Feb. 28, 2021	Dec. 31, 2020	Jun. 30, 2020
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	$ 1,240,205
Total long-term obligations, Gross Carrying Amount	1,380,591
Total long term obligations, Deferred Financing Costs	(20,410)
Total long-term obligations, Net Carrying Amount	1,360,181		$ 1,343,384	$ 1,571,386
Current portion, Net Carrying Amount	(1,265)		(13,576)	(13,810)
Long-term obligations excluding current portion, Principal Amount	1,238,940
Long-term obligations excluding current portion, Gross Carrying Amount	1,379,326
Long-term obligations excluding current portion, Deferred Financing	(20,410)
Long-term obligations excluding current portion, Net Carrying Amount	1,358,916		1,329,808	1,557,576
Senior Secured Term Loan Facility [Member] | Term Loan Credit Agreement [Member]
Debt Instrument [Line Items]
Total long-term obligations, Net Carrying Amount			690,165	713,789
8.75% Senior Secured First Lien Notes due 2026 [Member]
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	750,000	$ 750,000
Total long-term obligations, Gross Carrying Amount	750,000
Total long term obligations, Deferred Financing Costs	(18,695)
Total long-term obligations, Net Carrying Amount	731,305
6.125% Senior Notes due 2023 [Member]
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	22,924
Total long-term obligations, Gross Carrying Amount	22,924
Total long term obligations, Deferred Financing Costs	(118)
Total long-term obligations, Net Carrying Amount	22,806		22,779	347,427
6.625% Senior Notes due 2026 [Member]
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	92,254
Total long-term obligations, Gross Carrying Amount	92,254
Total long term obligations, Deferred Financing Costs	(735)
Total long-term obligations, Net Carrying Amount	91,519		106,315	495,297
Finance lease obligations [Member]
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	13,398
Total long-term obligations, Gross Carrying Amount	13,398
Total long-term obligations, Net Carrying Amount	13,398		13,983	$ 14,873
First Lien Party City Notes due 2025 [Member]
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	161,669
Total long-term obligations, Gross Carrying Amount	202,588
Total long-term obligations, Net Carrying Amount	202,588		206,775
First Lien Anagram Notes due 2025 [Member]
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	112,979
Total long-term obligations, Gross Carrying Amount	151,313
Total long term obligations, Deferred Financing Costs	(862)
Total long-term obligations, Net Carrying Amount	150,451		151,335
Second Lien Anagram Notes due 2026 [Member]
Debt Instrument [Line Items]
Total long-term obligations, Principal Amount	86,981
Total long-term obligations, Gross Carrying Amount	148,114
Total long-term obligations, Net Carrying Amount	$ 148,114		$ 152,032