Condensed Consolidated Statements of Operations and Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 553,046	$ 560,109	$ 1,621,881	$ 1,581,986
Expenses:
Cost of sales	349,641	357,523	996,084	978,142
Wholesale selling expenses	17,538	16,274	53,581	47,946
Retail operating expenses	103,833	100,739	285,019	281,981
Franchise expenses	862	3,636	8,624	10,666
General and administrative expenses	42,239	37,971	136,230	125,763
Art and development costs	5,573	5,898	17,278	17,638
Development stage expenses	1,622	680	5,620	7,092
Total expenses	521,308	522,721	1,502,436	1,469,228
Income from operations	31,738	37,388	119,445	112,758
Interest expense, net	27,705	23,228	76,481	65,214
Other expense, net	5,696	593	9,076	860
(Loss) income before income taxes	(1,663)	13,567	33,888	46,684
Income tax expense	777	3,483	9,443	16,301
Net (loss) income	(2,440)	10,084	24,445	30,383
Add: Net loss attributable to redeemable securities holder	(8)		402
Less: Net loss attributable to noncontrolling interests	(28)		(87)
Net (loss) income attributable to common shareholders of Party City Holdco Inc.	$ (2,420)	$ 10,084	$ 24,934	$ 30,383
Net (loss) income per share attributable to common shareholders of Party City Holdco Inc. - Basic	$ (0.03)	$ 0.08	$ 0.26	$ 0.25
Net (loss) income per share attributable to common shareholders of Party City Holdco Inc. - Diluted	$ (0.03)	$ 0.08	$ 0.26	$ 0.25
Weighted-average number of common shares-Basic	96,494,565	119,587,339	96,449,011	119,546,451
Weighted-average number of common shares-Diluted	96,494,565	120,912,849	97,684,290	120,907,979
Dividends declared per share	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Comprehensive (loss) income	$ (2,003)	$ 15,329	$ 20,889	$ 45,839
Add: Comprehensive loss attributable to redeemable securities holder	(8)		402
Less: Comprehensive loss attributable to noncontrolling interests	(35)		(108)
Comprehensive (loss) income attributable to common shareholders of Party City Holdco Inc.	(1,976)	15,329	21,399	45,839
Net Sales [Member]
Revenues:
Revenues	550,840	557,350	1,614,049	1,572,966
Royalties and Franchise Fees [Member]
Revenues:
Revenues	$ 2,206	$ 2,759	$ 7,832	$ 9,020