Investment in Laramie Energy, LLC - Summarized Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
ASSETS
Current assets	$ 612,515		$ 1,032,174
Current liabilities	727,875		1,034,322
REVENUE
Income from operations	(181,173)	$ 21,423
Net income (loss)	(222,337)	61,092
Laramie Energy Company
ASSETS
Current assets	13,839		23,367
Non-current assets	385,353		393,575
Current liabilities	17,983		229,687
Non-current liabilities	278,659		$ 85,287
REVENUE
Natural gas and oil revenues	34,713	67,924
Income from operations	1,369	13,743
Net income (loss)	$ 574	$ (2,983)