Condensed consolidated statements of operations - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue:
Franchise		$ 23,046	$ 16,148	$ 70,042	$ 51,806
Commission income		4,179	3,646	14,338	11,624
Corporate-owned stores		26,675	25,153	78,756	73,674
Equipment		33,107	23,870	98,686	87,588
Total revenue		87,007	68,817	261,822	224,692
Operating costs and expenses:
Cost of revenue		25,925	18,858	77,365	70,104
Store operations		15,181	14,305	45,673	43,354
Selling, general and administrative		12,244	17,348	36,470	43,840
Depreciation and amortization		7,745	7,976	23,127	24,160
Other gain		(241)	(9)	(406)	(76)
Total operating costs and expenses		60,854	58,478	182,229	181,382
Income from operations		26,153	10,339	79,593	43,310
Other expense, net:
Interest expense, net		(6,291)	(6,556)	(18,819)	(17,872)
Other income (expense)		(204)	(1,815)	30	(2,627)
Total other expense, net		(6,495)	(8,371)	(18,789)	(20,499)
Income before income taxes		19,658	1,968	60,804	22,811
Provision for income taxes		4,795	1,230	11,504	1,921
Net income		14,863	738	49,300	20,890
Less net income attributable to non-controlling interests		11,438	4,631	38,374	4,857
Net income (loss) attributable to Planet Fitness, Inc.		$ 3,425	$ (3,893)	$ 10,926	$ 16,033
Class A Common Stock [Member]
Net income per share of Class A common stock:
Basic	[1]	$ 0.08	$ 0.05	$ 0.28	$ 0.05
Diluted	[1]	$ 0.08	$ 0.04	$ 0.28	$ 0.04
Weighted-average shares of Class A common stock outstanding(1):
Basic	[1]	44,668,875	35,661	39,394,318	35,661
Diluted	[1]	44,685,696	98,710	39,397,486	98,710

[1] For the three and nine months ended September 30, 2015, represents earnings per share of Class A common stock and weighted-average shares of Class A common stock outstanding for the period from August 6, 2015 through September 30, 2015, the period following the recapitalization transactions and IPO (see Note 9).