Equity Investment in Sunrise Energy (Condensed Statement of Operations - Sunrise) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013
Revenue	$ 241,171		$ 153,870
Expenses	(230,470)		(124,272)
Net income	10,219	[1]	22,423	[1]
Sunrise Energy [Member]
Revenue	3,203		3,399
Expenses	(2,707)		(2,141)
Net income	$ 496		$ 1,258

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