Income Taxes and Related Payments - Components of deferred tax assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Deferred tax assets:
Amortizable basis	$ 435,750		$ 408,140
Other	31,223		27,757
Total deferred tax assets	466,973		435,897
Less: valuation allowance	0		0
Deferred tax assets	466,973		$ 435,897
Deferred Tax Assets, Exchanges	14,873
Non cash Transaction Initial Establishment of Amounts Payable Under Tax Receivable Agreements	30,853	$ 5,389
Follow On Offering
Deferred Tax Assets, Exchanges	21,424
Non cash Transaction Initial Establishment of Amounts Payable Under Tax Receivable Agreements	$ 18,211