Investment in Sunrise Energy (Condensed Balance Sheet - Sunrise) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets	$ 107,135	$ 39,361
Total assets	610,957	260,413
Total liabilities	428,069	77,079
Total liabilities and stockholders' equity	610,957	260,413
Sunrise Energy [Member]
Current assets	3,496
Oil and gas properties, net	6,745
Total assets	10,241
Total liabilities	724
Members' capital	9,517
Total liabilities and stockholders' equity	$ 10,241