Condensed consolidated statements of comprehensive income (loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net (loss) income including non-controlling interests	$ (3,284)	$ 29,692	$ (24,886)	$ 101,158
Other comprehensive income (loss), net:
Foreign currency translation adjustments	19	(62)	(341)	95
Total other comprehensive income (loss), net	19	(62)	(341)	95
Total comprehensive (loss) income including non-controlling interests	(3,265)	29,630	(25,227)	101,253
Less: total comprehensive (loss) income attributable to non-controlling interests	(173)	3,915	(1,205)	13,128
Total comprehensive (loss) income attributable to Planet Fitness, Inc.	$ (3,092)	$ 25,715	$ (24,022)	$ 88,125