Organization and Nature of Operations - Redemption of CW Units (Details) - $ / shares			1 Months Ended			3 Months Ended	12 Months Ended
	Mar. 20, 2019	Feb. 12, 2018	Apr. 30, 2019	Mar. 31, 2019	Jul. 31, 2018	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2019	Dec. 31, 2018	Feb. 07, 2018
Redemptions of CW Units
CW Units held by legacy CW Unit Holders as of February 7, 2018			28,718,409	28,718,409		37,236,142	37,236,142	28,718,409	37,236,142	60,557,613
CW Units held by legacy CW Unit Holders at beginning of the period			28,718,409			37,236,142
CW Unit redemptions						(43,820)	(7,068)
CW Units held by legacy CW Unit Holders at end of the period				28,718,409		28,718,409	37,236,142
IPO
Redemptions of CW Units
CW Unit redemptions		(12,117,841)
July 2018 follow-on offering
Redemptions of CW Units
CW Unit redemptions					(11,196,562)
March 2019 Secondary Offering
Redemptions of CW Units
CW Unit redemptions	8,473,913			(8,473,913)
Class A Common Stock
Organization and Nature of Operations
Common stock, par value								$ 0.01	$ 0.01
Redemptions of CW Units
Redemption ratio, shares of common stock per unit redeemed								1
Class B Common Stock
Organization and Nature of Operations
Common stock, par value			$ 0.01					$ 0.01	$ 0.01