Condensed Consolidated Statement of Changes in Equity - 9 months ended Sep. 30, 2015 - USD ($) $ in Thousands	Total	Members' Equity [Member]	Accumulated Other Comprehensive 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, 2014	$ 151,749	$ 146,156	$ (636)			$ 6,229
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		72,603
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)
Net income subsequent to the recapitalization transactions	6,214				1,621	4,593
Tax benefit arrangement liability and deferred taxes arising from the recapitalization transactions and IPO	(19,135)				(19,135)
Equity-based compensation expense subsequent to the recapitalization transactions	122			$ 122
Distributions paid to non- controlling unit holders	(6,408)					(6,408)
Other comprehensive loss subsequent to the recapitalization transactions	(198)		(198)
Ending balance at Sep. 30, 2015	$ (14,202)		$ (1,888)	$ 122	$ (17,376)	$ 4,930		$ 4		$ 6
Ending balance (shares) at Sep. 30, 2015							36,598,000	36,598,000	62,112,000	62,112,000