Investment in Sunrise Energy (Condensed Statement of Operations - Sunrise) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Revenue	$ 98,001		$ 35,767
Expenses	(86,998)		(31,065)
Net income	7,591	[1]	3,526	[1]
Sunrise Energy [Member]
Revenue	617		782
Expenses	(537)		(605)
Net income	$ 80		$ 177

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