Consolidated statement of changes in equity - USD ($) $ in Thousands	Total	Members' Equity [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Additional Paid-in capital [Member]	Accumulated Deficit [Member]	Non-Controlling Interests [Member]	Class A Common Stock [Member]	Class A Common Stock [Member] Common Stock [Member]	Class B Common Stock [Member]	Class B Common Stock [Member] Common Stock [Member]
Beginning balance at Dec. 31, 2013	$ 321,915	$ 315,623	$ 92			$ 6,200
Net income including non-controlling interests	37,295	36,808				487
Other comprehensive loss	(728)		(728)
Distributions to members	(206,733)	(206,275)				(458)
Ending balance at Dec. 31, 2014	151,749	146,156	(636)			6,229
Net income including non-controlling interests	38,130
Other comprehensive loss	(1,074)
Distributions to members prior to the recapitalization transactions	(164,693)	(164,693)
Net income prior to the recapitalization transactions	14,676	14,412				264
Other comprehensive loss prior to the recapitalization transactions	(1,054)		(1,054)
Equity-based compensation expense recorded in connection with recapitalization transactions	4,525	4,525
Effect of the recapitalization transactions		$ (400)			$ 138	252		$ 3		$ 7
Effect of the recapitalization transactions, shares							26,107,000		72,603,000
Issuance of Class A common stock in IPO, net of commissions								1		(1)
Issuance of Class A common stock in IPO, net of commissions, shares							10,491,000		(10,491,000)
Tax benefit arrangement liability and deferred taxes arising from the recapitalization transactions and IPO	(18,276)				(18,276)
Net income subsequent to the recapitalization transactions	23,454				4,106	19,348
Equity-based compensation expense	352			$ 352
Distributions to members of Pla-Fit Holdings subsequent to the recapitalization transactions	(11,793)					(11,793)
Other comprehensive loss subsequent to the recapitalization transactions	(20)		(20)
Ending balance at Dec. 31, 2015	(1,080)		(1,710)	352	(14,032)	14,300		4		6
Ending balance (shares) at Dec. 31, 2015							36,598,000		62,112,000
Net income including non-controlling interests	71,247				21,500	49,747
Other comprehensive loss	(150)		37			(187)
Distributions to members	(31,838)					(31,838)
Issuance of Class A common stock in IPO, net of commissions, shares							1,271,146
Equity-based compensation expense	1,728			1,749	(21)
Repurchase and retirement of Class B common stock	(1,583)			(441)	(1,142)				$ (222)
Exchanges of Class B common stock			499	10,976		(11,475)		2		(2)
Exchanges of Class B common stock, shares							24,705,000		(24,705,000)
Tax benefit arrangement liability and deferred taxes arising from secondary offerings and other exchanges	21,695			21,695
Exercise of stock options and vesting of restricted share units	136			136
Exercise of stock options and vesting of restricted share units, shares							11,000
Dividend paid to holders of Class A common stock	(169,282)				(169,282)
Dividend equivalents paid or payable	(105,628)				(1,085)	(104,543)
Ending balance at Dec. 31, 2016	$ (214,755)		$ (1,174)	$ 34,467	$ (164,062)	$ (83,996)		$ 6		$ 4
Ending balance (shares) at Dec. 31, 2016							61,314,000		37,185,000