Selected Quarterly Financial Data - Equity Statement (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 719,957	$ 792,446	$ 781,492	$ 740,814
Exchange of Class B Common Stock for Class A Common Stock	0	0	0	0
Offering Costs		(1,499)		(1,499)
Effect of exchange on deferred tax asset, net of liability under tax receivable agreements	324	3,570	778	4,466
Deferred tax impact of ownership changes from exchanges and repurchases		(7,148)		(7,148)
Class A Common Stock dividend		(3,871)	(4,244)	(10,978)
Distributions to non-controlling unitholders		(1,857)	(1,532)	(6,215)
Other distributions and advance payments to non-controlling interest unitholders	549	(557)	(256)	(1,104)
Share repurchases				(17,098)
Stock based compensation expense	4,487	3,542	12,894	9,993
RSU Vesting	1	0	(402)	(1,039)
Restricted stock and RSU forfeitures	2	(1)	8	1
Net (loss) income	(49,025)	18,840	(112,443)	93,272
Ending balance	676,295	$ 803,465	$ 676,295	$ 803,465
Common stock dividend (in dollars per share)		$ 0.05	$ 0.05	$ 0.15
Distributions to noncontrolling unitholders (in dollars per share)		$ 0.05	$ 0.05	$ 0.15
Additional Paid in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	435,885	$ 318,099	$ 410,596	$ 312,659
Exchange of Class B Common Stock for Class A Common Stock	6,561	52,652	24,762	64,065
Offering Costs		(1,001)		(1,001)
Effect of exchange on deferred tax asset, net of liability under tax receivable agreements	324	3,570	778	4,466
Deferred tax impact of ownership changes from exchanges and repurchases		(7,148)		(7,148)
Other distributions and advance payments to non-controlling interest unitholders	0		(1)
Share repurchases				(13,017)
Stock based compensation expense	3,385	2,351	9,557	8,802
RSU Vesting	0	1	472	(302)
Restricted stock and RSU forfeitures	0	(22)	(9)	(22)
Ending balance	446,155	368,502	446,155	368,502
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	94,817	152,322	143,105	119,274
Class A Common Stock dividend		(3,871)	(4,244)	(10,978)
Restricted stock and RSU forfeitures	2	(1)	9	1
Net (loss) income	(34,502)	10,998	(78,553)	51,151
Ending balance	60,317	159,448	60,317	159,448
Total Stockholders’ Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	531,831	471,547	554,827	433,069
Exchange of Class B Common Stock for Class A Common Stock	6,561	52,652	24,762	64,065
Offering Costs		(1,001)		(1,001)
Effect of exchange on deferred tax asset, net of liability under tax receivable agreements	324	3,570	778	4,466
Deferred tax impact of ownership changes from exchanges and repurchases		(7,148)		(7,148)
Class A Common Stock dividend		(3,871)	(4,244)	(10,978)
Other distributions and advance payments to non-controlling interest unitholders	0		(1)
Share repurchases				(13,030)
Stock based compensation expense	3,385	2,351	9,557	8,802
RSU Vesting	1	1	477	(299)
Restricted stock and RSU forfeitures	2	(23)	(1)	(21)
Net (loss) income	(34,502)	10,998	(78,553)	51,151
Ending balance	507,602	529,076	507,602	529,076
Non-controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	188,126	320,899	226,665	307,745
Exchange of Class B Common Stock for Class A Common Stock	(6,561)	(52,652)	(24,762)	(64,065)
Offering Costs		(498)		(498)
Deferred tax impact of ownership changes from exchanges and repurchases		0		0
Distributions to non-controlling unitholders		(1,857)	(1,532)	(6,215)
Other distributions and advance payments to non-controlling interest unitholders	549	(557)	(255)	(1,104)
Share repurchases				(4,068)
Stock based compensation expense	1,102	1,191	3,337	1,191
RSU Vesting	0	(1)	(879)	(740)
Restricted stock and RSU forfeitures	0	22	9	22
Net (loss) income	(14,523)	7,842	(33,890)	42,121
Ending balance	$ 168,693	$ 274,389	$ 168,693	$ 274,389
Shares of Class A Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)			81,885,384
Ending balance (in shares)	85,866,440		85,866,440
Shares of Class A Common Stock | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	84,853,000	68,962,000	81,885,000	68,360,000
Beginning balance	$ 848	$ 690	$ 819	$ 684
Exchange of Class B Common Stock for Class A Common Stock	$ 10	$ 69	$ 36	$ 85
Exchanges of Class B Common Stock for Class A Common Stock (shares)	1,013,000	6,914,000	3,571,000	8,551,000
Share repurchase (shares)				(1,303,000)
Share repurchases				$ (13)
RSU Vesting (in shares)	0	0	414,000	268,000
RSU Vesting	$ 1	$ 0	$ 5	$ 3
Restricted stock and RSU forfeitures (shares)	0	(8,000)	(4,000)	(8,000)
Restricted stock and RSU forfeitures	$ 0	$ 0	$ (1)	$ 0
Ending balance (in shares)	85,866,000	75,868,000	85,866,000	75,868,000
Ending balance	$ 859	$ 759	$ 859	$ 759
Common stock dividend (in dollars per share)			$ 0.05
Shares of Class B Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)			30,638,960
Ending balance (in shares)	27,067,247		27,067,247
Shares of Class B Common Stock | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	28,081,000	43,570,000	30,639,000	45,207,000
Beginning balance	$ 281	$ 436	$ 307	$ 452
Exchange of Class B Common Stock for Class A Common Stock	$ (10)	$ (69)	$ (36)	$ (85)
Exchanges of Class B Common Stock for Class A Common Stock (shares)	(1,013,000)	(6,914,000)	(3,571,000)	(8,551,000)
Ending balance (in shares)	27,068,000	36,656,000	27,068,000	36,656,000
Ending balance	$ 271	$ 367	$ 271	$ 367