Schedule I: Condensed Financial Information of Registrant - CONDENSED STATEMENTS OF INCOME (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Intercompany revenue	$ 1,029,293	$ 652,537	$ 795,122
Selling, general, and administrative expenses	244,331	181,234	193,803
Total operating expenses	933,828	628,994	748,509
Income from operations	95,465	23,543	46,613
Interest expense, net	7,167	10,712	14,342
Tax receivable agreement liability adjustment	1,590	87	152
Income before income taxes	84,915	11,788	32,296
Income tax expense (benefit)	17,061	2,025	4,476
Net income	67,854	9,763	27,820
Parent Company
Segment Reporting Information [Line Items]
Intercompany revenue	82	307	739
Selling, general, and administrative expenses	13,163	10,269	11,211
Total operating expenses	13,163	10,269	11,211
Income from operations	(13,081)	(9,962)	(10,472)
Interest expense, net	3	(36)	0
Tax receivable agreement liability adjustment	(1,590)	(87)	(152)
Equity in net income of subsidiaries	72,916	13,674	24,525
Income before income taxes	58,248	3,589	13,901
Income tax expense (benefit)	14,348	(372)	2,176
Net income	$ 43,900	$ 3,961	$ 11,725