XML 48 R40.htm IDEA: XBRL DOCUMENT v2.4.0.6
SUPPLEMENTAL FINANCIAL INFORMATION ON OIL AND NATURAL GAS EXPLORATION, DEVELOPMENT AND PRODUCTION ACTIVITIES (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Oil & Gas properties [Abstract]      
Unproved oil and gas properties $ 9,169 $ 20,007  
Proved oil and gas properties 119,919 99,496  
Total capitalized costs 129,088 119,503  
DD&A per equivalent BOE (in dollars per BOE) 33.49 31.64 23.64
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]      
Acquisitions 228 7,947 994
Exploration 0 0 0
Development 0 0 0
Undeveloped property costs 228 7,947 994
Total Acquisitions 9,169    
Total Exploration 0    
Total Development 0    
Total undeveloped property costs 9,169 20,007  
Property acquisition costs:      
Proved 2,987 1,288 0
Unproved 1,416 10,679 14,237
Exploration costs 10,943 32,787 35,899
Development costs 20,134 4,550 4,846
Total costs incurred 35,480 49,304 54,982
Results of operations from oil and natural gas producing activities [Abstract]      
Oil and gas revenues 32,534 30,958 26,548
Operating expenses 10,788 11,552 6,073
Depreciation, depletion and amortization 14,893 13,997 10,610
Impairment 5,189 0 0
Total operating expenses 30,870 25,549 16,683
Operating income 1,664 5,409 9,865
Standardized measure of discounted future net cash flows relating to USE's ownership interests in proved oil and natural gas reserves [Abstract]      
Future cash inflows 237,148 259,533 124,629
Future costs:      
Production (96,616) (77,813) (36,299)
Development (21,461) (42,972) (6,774)
Future income tax expense (8,483) (19,790) (11,622)
Future net cash flows 110,588 118,958 69,934
10% discount factor (39,571) (56,767) (25,281)
Standardized measure of discounted future net cash flows 71,017 62,191 44,653
Period for calculating unescalated average prices prior to the end of reporting period 12 months    
Discount factor (in hundredths) 10.00%    
Changes in standardized measure of future net cash flows relating to proved oil and natural gas reserves [Roll Forward]      
Balance at beginning of period 62,191 44,653 19,984
Sales of oil and gas, net of production costs (21,747) (19,406) (20,476)
Net change in prices and production costs (4,548) 1,401 3,895
Net change in future development costs 0 0 0
Extensions and discoveries 23,297 26,574 40,011
Purchase of reserves in place 2,573 3,082 0
Sale of reserves in place (13,573) (1,947) 0
Revisions of previous quantity estimates (5,927) (3,158) (2,519)
Development costs incurred during year 22,808 14,930 0
Previously estimated development costs incurred (9,706) (2,719) 0
Net change in income taxes 7,261 (4,270) (2,138)
Accretion of discount 7,254 5,207 2,576
Changes in production rates, timing and other 1,134 (2,156) 3,320
Balance at end of period $ 71,017 $ 62,191 $ 44,653
Oil (BBLS) [Member]
      
Proved Developed and Undeveloped Reserves [Roll forward]      
Beginning of year 2,737,969 1,546,446  
Revisions of previous quantity estimates (145,596) 4,913  
Extensions, discoveries and improved recoveries 763,125 1,516,797  
Purchase of reserves in place 75,948 48,615  
Sales of reserves in place (444,272) (78,477)  
Production (373,531) (300,325)  
End of year 2,613,643 2,737,969 1,546,446
Proved developed reserves at end of year 1,770,659 1,884,068  
Pricing used in cash flow estimates (in BBLS or MCFE) 94.71 96.19 79.43
Natural Gas or NGL (MCFE) [Member]
      
Proved Developed and Undeveloped Reserves [Roll forward]      
Beginning of year 2,744,128 2,450,968  
Revisions of previous quantity estimates (481,583) (864,513)  
Extensions, discoveries and improved recoveries 369,169 2,004,535  
Purchase of reserves in place 30,457 49,065  
Sales of reserves in place (437,057) (43,716)  
Production (427,026) (852,211)  
End of year 1,798,088 2,744,128 2,450,968
Proved developed reserves at end of year 1,420,295 1,983,581  
Pricing used in cash flow estimates (in BBLS or MCFE) 2.757 4.12 4.38