Condensed Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Class A common stock Common Stock [Member]	Class B common stock Common Stock [Member]	Retained Earnings / (Accumulated Deficit)	Accumulated Other Comprehensive Loss	Additional Paid-In Capital	Non-controlling Interest	Total
Beginning Balance at Dec. 31, 2018	$ 22	$ 7	$ (4,450)	$ (1,316)	$ 262,219	$ 64,496	$ 320,977
Beginning Balance (in shares) at Dec. 31, 2018	21,620	6,547
Increase (Decrease) in Stockholders' Equity
Exchange of LLC Interests held by LLC Owners				4	10,808	(10,812)
Exchange of LLC Interests held by LLC Owners (in shares)	1,085	(1,085)
Net increase in deferred tax asset from LLC Interest transactions					6,093		6,093
Accrued tax distributions						(1,054)	(1,054)
Other comprehensive income (loss)				(15)		(12)	(27)
Stock based compensation expense					2,425	721	3,146
Exercise of Options to purchase Common Stock					798		798
Exercise of Options to purchase Common Stock (in shares)	38
Issuance of stock for vesting of RSU's, net of tax with holdings (in shares)	7
Net (loss) income			5,426			2,818	8,244
Ending Balance at Jun. 30, 2019	$ 22	$ 7	976	(1,327)	282,343	56,157	338,177
Ending Balance (in shares) at Jun. 30, 2019	22,750	5,462
Beginning Balance at Mar. 31, 2019	$ 22	$ 6	(2,839)	(941)	271,916	60,418	328,582
Beginning Balance (in shares) at Mar. 31, 2019	22,157	6,028
Increase (Decrease) in Stockholders' Equity
Exchange of LLC Interests held by LLC Owners		$ 1		35	5,759	(5,794)
Exchange of LLC Interests held by LLC Owners (in shares)	566	(566)
Net increase in deferred tax asset from LLC Interest transactions					2,955		2,955
Accrued tax distributions						(797)	(797)
Other comprehensive income (loss)				(421)		(105)	(526)
Stock based compensation expense					1,230	332	1,562
Exercise of Options to purchase Common Stock					483		483
Exercise of Options to purchase Common Stock (in shares)	22
Issuance of stock for vesting of RSU's, net of tax with holdings (in shares)	5
Net (loss) income			3,815			2,103	5,918
Ending Balance at Jun. 30, 2019	$ 22	$ 7	976	(1,327)	282,343	56,157	338,177
Ending Balance (in shares) at Jun. 30, 2019	22,750	5,462
Beginning Balance at Dec. 31, 2019	$ 23	$ 5	(15,903)	(1,131)	300,120	45,196	328,310
Beginning Balance (in shares) at Dec. 31, 2019	23,554	4,752
Increase (Decrease) in Stockholders' Equity
Exchange of LLC Interests held by LLC Owners	$ 1	$ (1)		(60)	8,732	(8,672)
Exchange of LLC Interests held by LLC Owners (in shares)	982	(982)
Net increase in deferred tax asset from LLC Interest transactions					5,786		5,786
Accrued tax distributions						(310)	(310)
Other comprehensive income (loss)				(583)		(95)	(678)
Stock based compensation expense					3,736	666	4,402
Equity component of convertible notes, net of tax					36,597	6,519	43,116
Payment for capped call share options					(12,580)	(2,241)	(14,821)
Exercise of Options to purchase Common Stock					2,171		$ 2,171
Exercise of Options to purchase Common Stock (in shares)	100						100
Issuance of stock for vesting of RSU's, net of tax with holdings					(292)		$ (292)
Issuance of stock for vesting of RSU's, net of tax with holdings (in shares)	22
Net (loss) income			(3,994)			(599)	(4,593)
Ending Balance at Jun. 30, 2020	$ 24	$ 4	(19,897)	(1,774)	344,270	40,464	363,091
Ending Balance (in shares) at Jun. 30, 2020	24,658	3,770
Beginning Balance at Mar. 31, 2020	$ 24	$ 4	(18,006)	(1,655)	312,874	38,262	331,503
Beginning Balance (in shares) at Mar. 31, 2020	24,318	4,049
Increase (Decrease) in Stockholders' Equity
Exchange of LLC Interests held by LLC Owners				(17)	2,067	(2,050)
Exchange of LLC Interests held by LLC Owners (in shares)	279	(279)
Net increase in deferred tax asset from LLC Interest transactions					2,585		2,585
Accrued tax distributions						(206)	(206)
Other comprehensive income (loss)				(102)		(2)	(104)
Stock based compensation expense					1,594	250	1,844
Equity component of convertible notes, net of tax					36,597	6,519	43,116
Payment for capped call share options					(12,580)	(2,241)	(14,821)
Exercise of Options to purchase Common Stock					1,169		1,169
Exercise of Options to purchase Common Stock (in shares)	54
Issuance of stock for vesting of RSU's, net of tax with holdings					(37)		(37)
Issuance of stock for vesting of RSU's, net of tax with holdings (in shares)	7
Net (loss) income			(1,891)			(69)	(1,960)
Ending Balance at Jun. 30, 2020	$ 24	$ 4	$ (19,897)	$ (1,774)	$ 344,270	$ 40,464	$ 363,091
Ending Balance (in shares) at Jun. 30, 2020	24,658	3,770