Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended
	Apr. 30, 2019	Apr. 15, 2019	Apr. 02, 2019	Mar. 31, 2019	Mar. 31, 2018
Subsequent Event [Line Items]
Deferred Tax Assets, Exchanges				$ 6,340
Non cash Transaction Initial Establishment of Amounts Payable Under Tax Receivable Agreements				$ 5,389	$ 15,054
Subsequent Event
Subsequent Event [Line Items]
Distribution made to limited partner, Cash distributions declared	$ 34,300
Units exchanged (in shares)			452,629
Deferred Tax Assets, Exchanges			$ 3,500
Non cash Transaction Initial Establishment of Amounts Payable Under Tax Receivable Agreements			$ 3,000
Tax Receivable Agreement Payments		$ 19,000
Quarterly | Class A Common Stock | Subsequent Event
Subsequent Event [Line Items]
Dividends declared (in dollars per share)	$ 0.55