Investment in Sunrise Energy (Condensed Statement of Operations - Sunrise) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenue	$ 75,885	$ 98,001
Expenses	(67,985)	(86,998)
Net income	6,162	7,591
Sunrise Energy [Member]
Revenue	458	617
Expenses	(607)	(537)
Net income	$ (149)	$ 80