Investment in Savoy (Condensed Balance Sheet - Savoy) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets	$ 77,042	$ 84,409
Total assets	563,398	579,585
Total liabilities	356,051	389,710
Total liabilities and stockholders' equity	563,398	$ 579,585
Savoy [Member]
Current assets	11,709
Oil and gas properties, net	26,522
Total assets	38,231
Total liabilities	5,152
Partners' capital	33,079
Total liabilities and stockholders' equity	$ 38,231