CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-controlling Interest	Class A Common Stock Common stock	Class B Common Stock Common stock
Balance at the beginning of the period (in shares) at Dec. 31, 2018						37,654	37,236
Balance at the beginning of the period at Dec. 31, 2018	$ 362,328	$ 126,418	$ 51,683	$ (820)	$ 184,670	$ 377	$ 0
Statement of Stockholders'/Members' Equity
Adjustment to prior periods		14,035		488	(14,523)
Member distributions	(3,848)				(3,848)
Effect of CW Unit redemptions (in shares)						9,216	(9,216)
Effect of CW Unit redemptions		48,305		(57)	(48,340)	$ 92
Adjustment to deferred tax asset from CW Unit redemptions	(9,751)	(9,751)
Tax impact of equity transactions	14,652	14,652
Equity award vestings (in shares)						223
Equity award vestings	(1,514)	(4,067)			2,551	$ 2
Other comprehensive income (loss)	(101)			(109)	8
Stock-based compensation	3,568	3,568
Net income	89,196		48,215		40,981
Balance at the end of the period (in shares) at Jun. 30, 2019						47,093	28,020
Balance at the end of the period at Jun. 30, 2019	454,530	193,160	99,898	(498)	161,499	$ 471	$ 0
Balance at the beginning of the period (in shares) at Mar. 31, 2019						46,391	28,718
Balance at the beginning of the period at Mar. 31, 2019	416,361	189,902	78,490	(259)	147,764	$ 464	$ 0
Statement of Stockholders'/Members' Equity
Member distributions	(3,613)				(3,613)
Effect of CW Unit redemptions (in shares)						698	(698)
Effect of CW Unit redemptions		4,406		(7)	(4,406)	$ 7
Adjustment to deferred tax asset from CW Unit redemptions	(1,519)	(1,519)
Tax impact of equity transactions	1,072	1,072
Equity award vestings (in shares)						4
Equity award vestings	(42)	(2,593)			2,551
Other comprehensive income (loss)	(371)			(232)	(139)
Stock-based compensation	1,892	1,892
Net income	40,750		21,408		19,342
Balance at the end of the period (in shares) at Jun. 30, 2019						47,093	28,020
Balance at the end of the period at Jun. 30, 2019	454,530	193,160	99,898	(498)	161,499	$ 471	$ 0
Balance at the beginning of the period (in shares) at Dec. 31, 2019						47,159	27,958
Balance at the beginning of the period at Dec. 31, 2019	516,395	194,456	132,990	(452)	188,929	$ 472	$ 0
Statement of Stockholders'/Members' Equity
Member distributions	(4,712)				(4,712)
Effect of CW Unit redemptions (in shares)						74	(74)
Effect of CW Unit redemptions		539		0	(540)	$ 1
Tax impact of equity transactions	62	62
Equity award vestings (in shares)						245
Equity award vestings	(1,386)	(218)			(1,170)	$ 2
Other comprehensive income (loss)	(204)			(117)	(87)
Stock-based compensation	4,204	2,645			1,559
Cash dividends declared on Class A common Stock	(8,645)		(8,645)
Net income	42,193		25,011		17,182
Balance at the end of the period (in shares) at Jun. 30, 2020						47,478	27,884
Balance at the end of the period at Jun. 30, 2020	547,907	197,484	149,356	(569)	201,161	$ 475	$ 0
Balance at the beginning of the period (in shares) at Mar. 31, 2020						47,398	27,958
Balance at the beginning of the period at Mar. 31, 2020	542,426	195,381	147,670	(1,067)	199,968	$ 474	$ 0
Statement of Stockholders'/Members' Equity
Member distributions	(2,509)				(2,509)
Effect of CW Unit redemptions (in shares)						74	(74)
Effect of CW Unit redemptions		539			(540)	$ 1
Tax impact of equity transactions	156	156
Equity award vestings (in shares)						6
Equity award vestings	(29)	3			(32)
Other comprehensive income (loss)	879			498	381
Stock-based compensation	2,231	1,405			826
Cash dividends declared on Class A common Stock	(4,342)		(4,342)
Net income	9,095		6,028		3,067
Balance at the end of the period (in shares) at Jun. 30, 2020						47,478	27,884
Balance at the end of the period at Jun. 30, 2020	$ 547,907	$ 197,484	$ 149,356	$ (569)	$ 201,161	$ 475	$ 0