Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Additional Paid in Capital	Retained Earnings	Total Stockholders’ Equity	Non-controlling Interest	Shares of Class A Common Stock	Shares of Class A Common Stock Common Stock	Shares of Class B Common Stock	Shares of Class B Common Stock Common Stock
Beginning balance at Dec. 31, 2018	$ 740,814	$ 312,659	$ 119,274	$ 433,069	$ 307,745		$ 684		$ 452
Beginning balance (in shares) at Dec. 31, 2018							68,360,000		45,207,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchanges of Class B Common Stock for Class A Common Stock (shares)							1,637,000		(1,637,000)
Exchange of Class B Common Stock for Class A Common Stock	0	11,413		11,413	(11,413)		$ 16		$ (16)
Effect of exchange on deferred tax asset, net of liability under tax receivable agreements	896	896		896
Class A Common Stock dividend	(7,107)		(7,107)	(7,107)
Distributions to non-controlling unitholders	(4,358)				(4,358)
Other distributions and advance payments to non-controlling interest unitholders	(547)				(547)
Share repurchase (shares)							(1,303,000)
Share repurchases	(17,098)	(13,017)		(13,030)	(4,068)		$ (13)
Stock based compensation expense	6,451	6,451		6,451	0
Vesting of restricted stock units (shares)							268,000
Vesting of restricted stock units	(1,039)	(303)		(300)	(739)		$ 3
Restricted stock and RSU forfeitures (shares)							0
Restricted stock and RSU forfeitures	2	0	2	2	0		$ 0
Net (loss) income	74,432		40,153	40,153	34,279
Ending balance (in shares) at Jun. 30, 2019							68,962,000		43,570,000
Ending balance at Jun. 30, 2019	792,446	318,099	152,322	471,547	320,899		$ 690		$ 436
Beginning balance at Mar. 31, 2019	755,482	314,967	133,877	449,967	305,515		$ 687		$ 436
Beginning balance (in shares) at Mar. 31, 2019							68,744,000		43,570,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Class A Common Stock dividend	(3,588)		(3,588)	(3,588)
Distributions to non-controlling unitholders	(2,179)				(2,179)
Other distributions and advance payments to non-controlling interest unitholders	(325)				(325)
Stock based compensation expense	3,571	3,571		3,571
Vesting of restricted stock units (shares)							218,000
Vesting of restricted stock units	(1,039)	(439)		(436)	(603)		$ 3
Restricted stock and RSU forfeitures (shares)							0
Restricted stock and RSU forfeitures	1	0	1	1	0		$ 0
Net (loss) income	40,523		22,032	22,032	18,491
Ending balance (in shares) at Jun. 30, 2019							68,962,000		43,570,000
Ending balance at Jun. 30, 2019	792,446	318,099	152,322	471,547	320,899		$ 690		$ 436
Beginning balance at Dec. 31, 2019	781,492	410,596	143,105	554,827	226,665		$ 819		$ 307
Beginning balance (in shares) at Dec. 31, 2019						81,885,384	81,885,000	30,638,960	30,639,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchanges of Class B Common Stock for Class A Common Stock (shares)							2,558,000		(2,558,000)
Exchange of Class B Common Stock for Class A Common Stock	0	18,201		18,201	(18,201)		$ 26		$ (26)
Effect of exchange on deferred tax asset, net of liability under tax receivable agreements	454	454		454
Class A Common Stock dividend	(4,244)		(4,244)	(4,244)
Distributions to non-controlling unitholders	(1,532)				(1,532)
Other distributions and advance payments to non-controlling interest unitholders	(805)	(1)		(1)	(804)
Stock based compensation expense	8,407	6,172		6,172	2,235
Vesting of restricted stock units (shares)							414,000
Vesting of restricted stock units	(403)	472		476	(879)		$ 4
Restricted stock and RSU forfeitures (shares)							(4,000)
Restricted stock and RSU forfeitures	6	(9)	7	(3)	9		$ (1)
Net (loss) income	(63,418)		(44,051)	(44,051)	(19,367)
Ending balance (in shares) at Jun. 30, 2020						84,853,084	84,853,000	28,080,525	28,081,000
Ending balance at Jun. 30, 2020	719,957	435,885	94,817	531,831	188,126		$ 848		$ 281
Beginning balance at Mar. 31, 2020	781,453	413,664	140,581	555,371	226,082		$ 819		$ 307
Beginning balance (in shares) at Mar. 31, 2020							81,920,000		30,639,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchanges of Class B Common Stock for Class A Common Stock (shares)							2,558,000		(2,558,000)
Exchange of Class B Common Stock for Class A Common Stock	0	18,201		18,201	(18,201)		$ 26		$ (26)
Effect of exchange on deferred tax asset, net of liability under tax receivable agreements	454	454		454
Other distributions and advance payments to non-controlling interest unitholders	(1)	(1)		(1)	0
Stock based compensation expense	4,283	3,171		3,171	1,112
Vesting of restricted stock units (shares)							379,000
Vesting of restricted stock units	(403)	405		409	(812)		$ 4
Restricted stock and RSU forfeitures (shares)							(4,000)
Restricted stock and RSU forfeitures	6	(9)	7	(3)	9		$ (1)
Net (loss) income	(65,835)		(45,771)	(45,771)	(20,064)
Ending balance (in shares) at Jun. 30, 2020						84,853,084	84,853,000	28,080,525	28,081,000
Ending balance at Jun. 30, 2020	$ 719,957	$ 435,885	$ 94,817	$ 531,831	$ 188,126		$ 848		$ 281