Investment in Sunrise Energy (Condensed Statement of Operations - Sunrise) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue		$ 82,013	$ 66,322	$ 275,267	$ 140,549
Expenses		(76,203)	(73,531)	(249,146)	(139,546)
Net income (loss)	[1]	$ 5,144	$ (5,768)	19,588	826
Sunrise Energy [Member]
Revenue				1,773	2,328
Expenses				(1,725)	(1,945)
Net income (loss)				$ 48	$ 383

[1] There is no material difference between net income (loss) and comprehensive income (loss).