Information about Oil and Gas Producing Activities (Schedule of Changes in the Standardized Measure for Discounted Cash Flows) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Information about Oil and Gas Producing Activities [Abstract]    
Net change in sales and transfer prices and in production costs related to future production $ 2,364 $ (697)
Sales and transfers of oil and gas produced during the period (1,983) (3,365)
Net change due to extensions, discoveries, and improved recovery 5,342 3,445
Changes in estimated future development costs 1,081 1,782
Net change due to revisions in quantities estimates 2,949 1,113
Accretion of discount 833 668
Other (1,569) (1,292)
Aggregate change in the standardized measure of discounted future net cash flows for the year $ 9,017 $ 1,654