Tax Receivable Agreement (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended
	Jan. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Tax receivable agreement, percentage of income taxes		90.00%
Liability for tax receivable agreement		$ 117,900		$ 134,600
Reduction in tax receivable agreement liability	$ 16,700	$ 16,667	$ 0