Income Taxes (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 17, 2018 agreement	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Operating Loss Carryforwards [Line Items]
Effective combined income tax rate				14.90%	15.00%
Income tax (benefit) expense		$ (11,363)	$ 7,083	$ (11,102)	$ 13,143
NOL carryback refund		9,300		9,300
Number of tax receivable agreements | agreement	2
Taxes payable		51,100		51,100		$ 50,300
Deferred tax asset		52,900		52,900		49,900
Taxes payable, current		5,400		5,400		1,800
Taxes payable, noncurrent		45,678		45,678		$ 48,481
Tax Receivable Agreement
Operating Loss Carryforwards [Line Items]
Payment for tax benefit				2,000
Shares of Class B Common Stock | Tax Receivable Agreement | Common Stock
Operating Loss Carryforwards [Line Items]
Taxes payable		2,600	5,100	2,600	5,100
Deferred tax asset		$ 3,000	$ 6,000	$ 3,000	$ 6,000