Related Party Transactions (Details) - Flatonia Energy, LLC - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Payments made to related party	$ 6,200,000	$ 7,200,000
Payments received from related party	2,100,000	$ 1,500,000
Amounts receivable from related party	600,000		$ 1,300,000
Amounts payable to related party	$ 0		$ 0
Class A Common Stock
Related Party Transaction [Line Items]
Percentage of common stock acquired	10.50%
Common Stock
Related Party Transaction [Line Items]
Percentage of common stock acquired	4.70%