Condensed Consolidated and Combined Statements of Changes in Equity - USD ($) $ in Thousands	Class A common stock Common Stock	Class B common stock Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit).	Parent Company Investment	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	Total
Balance at beginning of period at Dec. 31, 2013						$ 308,444	$ 926		$ 309,370
Changes in Equity
Net income (loss)						29,768			29,768
Net cash distributions to Parent						(80,983)			(80,983)
Equity-based compensation						13,834			13,834
Equity-based contributions to joint venture and Parent's advisory board						1,223			1,223
Pre-offering distribution to partners						(195,017)			(195,017)
Other non-cash distributions						(1,105)			(1,105)
Other comprehensive income (loss)							1		1
Establishment of deferred tax asset related to reorganization				$ 3,261					3,261
Reorganization of equity structure	$ 77			12,475		(76,164)		$ 63,612
Reorganization of equity structure (in shares)	7,699,851
Issuance of common stock		$ 362		138					500
Issuance of common stock (in shares)		36,158,698
Balance at end of period at Apr. 21, 2014	$ 77	$ 362		15,874			927	63,612	80,852
Balance at end of the period (in shares) at Apr. 21, 2014	7,699,851	36,158,698
Balance at beginning of period at Dec. 31, 2013						$ 308,444	926		309,370
Changes in Equity
Net income (loss)									(5,733)
Balance at end of period at Sep. 30, 2014	$ 153	$ 362		94,367	$ (15,517)		521	94,802	174,688
Balance at end of the period (in shares) at Sep. 30, 2014	15,260,806	36,149,180
Balance at beginning of period at Apr. 21, 2014	$ 77	$ 362		15,874			927	63,612	80,852
Balance at beginning of the period (in shares) at Apr. 21, 2014	7,699,851	36,158,698
Changes in Equity
Distributions of IPO proceeds to partners				(139,429)					(139,429)
Equity-based compensation	$ 1			33,185				65,706	98,892
Equity-based compensation (in shares)	77,693
Dividends and distributions				437	(3,007)			(8,324)	(10,894)
Equity-based contributions to joint venture and Parent's advisory board				5,692				123	5,815
Other comprehensive income (loss)							(406)	(1,037)	(1,443)
Initial establishment of deferred tax assets, net of amounts payable under tax receivable agreement				10,854					10,854
Increase in deferred tax asset related to IPO				1,302					1,302
Tax benefit related to appreciation units				4,308					4,308
Issuance of common stock	$ 75			162,032					162,107
Issuance of common stock (in shares)	7,483,442
Other				112				(2,287)	(2,175)
Other (in shares)	(180)	(9,518)
Net income (loss)					(12,510)			(22,991)	(35,501)
Balance at end of period at Sep. 30, 2014	$ 153	$ 362		94,367	(15,517)		521	94,802	174,688
Balance at end of the period (in shares) at Sep. 30, 2014	15,260,806	36,149,180
Balance at beginning of period at Dec. 31, 2014	$ 198	$ 316		136,896	(24,118)		85	61,008	174,385
Balance at beginning of the period (in shares) at Dec. 31, 2014	19,770,893	31,621,542
Changes in Equity
Net income (loss)					22,557			58,889	81,446
Equity-based compensation	$ 1			30,479				2,857	33,337
Equity-based compensation (in shares)	84,841	(5,412)
Dividends and distributions				2,732	(16,792)			(50,334)	(64,394)
Treasury Stock Purchases			$ (7,006)						$ (7,006)
Treasury Stock Purchases (in shares)			(242,619)						(242,619)
Class A Partnership Units and other equity purchased or converted into Class A Common Stock	$ 5	$ (2)		5,112				(727)	$ 4,388
Class A Partnership Units and other equity purchased or converted into Class A Common Stock (in shares)	545,115	(257,401)
Net excess tax benefit from equity-based compensation				435					435
Other comprehensive income (loss)							(19)	2	(17)
Balance at end of period at Sep. 30, 2015	$ 204	$ 314	$ (7,006)	$ 175,654	$ (18,353)		$ 66	$ 71,695	$ 222,574
Balance at end of the period (in shares) at Sep. 30, 2015	20,400,849	31,358,729	(242,619)