(6) Equity Investment in Savoy (Details) - Savoy: Oil and Gas Reserves 2 (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Proved Developed
Future cash flows:
Oil	$ 70,582
NGLs	2,551
Natgas	1,365
Total cash flows	74,498
Future production costs	(12,213)
Future net cash flows	62,285
10% annual discount for estimated timing of cash flows	(14,355)
Standardized measure of discounted future net cash flows	47,930
PUDs
Future cash flows:
Oil	70,662
NGLs	1,669
Natgas	976
Total cash flows	73,307
Future production costs	(12,233)
Future development costs	(3,073)
Future net cash flows	58,001
10% annual discount for estimated timing of cash flows	(15,111)
Standardized measure of discounted future net cash flows	42,890
Total Proved
Future cash flows:
Oil	141,244
NGLs	4,220
Natgas	2,341
Total cash flows	147,805
Future production costs	(24,446)
Future development costs	(3,073)
Future net cash flows	120,286
10% annual discount for estimated timing of cash flows	(29,466)
Standardized measure of discounted future net cash flows	$ 90,820