Disclosures About Oil and Gas Producing Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2012

Oil And Gas Exploration And Production Industries Disclosures [Abstract]

Analyses of changes in proven reserves

	United States
	Oil	Natural Gas
	(MBbls)	(MMcf)
Reserves, December 31, 2009	29,185	3,736,601
Extensions, discoveries and additions	8,496	1,195,829
Production	(1,334)	(205,613)
Revisions	(4,663)	(526,662)
Reserves, December 31, 2010	31,684	4,200,155
Extensions, discoveries and additions	7,425	1,452,122
Production	(1,408)	(236,832)
Revisions	(4,620)	(636,891)
Reserves, December 31, 2011	33,081	4,778,554
Extensions, discoveries and additions	5,435	819,896
Production	(1,282)	(249,310)
Revisions(1)	(19,097)	(2,382,695)
Reserves, December 31, 2012	18,137	2,966,445
	United States
	Oil	Natural Gas
	(MBbls)	(MMcf)
Proved:
Developed	11,627	1,541,813
Undeveloped	17,558	2,194,788
Total Proved - 2009	29,185	3,736,601
Developed	11,013	1,678,697
Undeveloped	20,671	2,521,458
Total Proved - 2010	31,684	4,200,155
Developed	11,794	1,973,391
Undeveloped	21,287	2,805,163
Total Proved - 2011	33,081	4,778,554
Developed	10,531	1,820,994
Undeveloped	7,606	1,145,451
Total Proved - 2012	18,137	2,966,445

Standardized measure

		As of December 31,
		2012		2011		2010
Future cash inflows	$	9,380,970	$	22,196,913	$	19,186,072
Future production costs		(3,217,771)		(6,113,282)		(5,253,509)
Future development costs		(1,661,394)		(4,294,375)		(3,052,843)
Future income taxes		(733,855)		(3,340,516)		(3,198,413)
Future net cash flows		3,767,950		8,448,740		7,681,307
Discount at 10%		(1,873,633)		(4,652,684)		(4,155,739)
Standardized measure of discounted
future net cash flows	$	1,894,317	$	3,796,056	$	3,525,568

Summary of changes in the standardized measure of discounted future net cash flows

		December 31,
		2012		2011		2010
Standardized measure, beginning	$	3,796,056	$	3,525,568	$	2,026,700
Net revisions of previous quantity estimates		(2,516,159)		(964,987)		(807,877)
Extensions, discoveries and other changes		858,951		2,173,103		1,816,073
Changes in future development costs		952,067		(741,658)		(606,449)
Sales of oil and gas, net of production costs		(625,745)		(896,434)		(787,409)
Net change in prices and production costs		(2,912,698)		108,108		1,501,041
Development costs incurred during the
period that reduce future development costs		316,394		464,880		404,402
Accretion of discount		529,696		499,358		288,713
Net changes in production rates and other		363,788		(338,982)		297,957
Net change in income taxes		1,131,967		(32,900)		(607,583)
Aggregate changes		(1,901,739)		270,488		1,498,868
Standardized measure, ending	$	1,894,317	$	3,796,056	$	3,525,568

Costs incurred in oil and gas exploration and development activities

		Years Ended December 31,
		2012		2011		2010
United States
Property Acquisitions:
Unproved	$	47,979	$	91,983	$	472,339
Proved		-		-		-
Exploration*		199,569		746,085		634,503
Development		587,618		675,718		469,636
Total	$	835,166	$	1,513,786	$	1,576,478
* Exploration costs (as defined in Regulation S-X) includes costs spent on development of unproved reserves in the Pinedale Field.

Results of operations for oil and gas producing activities

F. RESULTS OF OPERATIONS FOR OIL AND GAS PRODUCING ACTIVITIES:
			Years Ended December 31,
			2012		2011		2010
	United States
	Oil and gas revenue	$	809,974	$	1,101,796	$	979,386
	Production expenses		(184,229)		(205,363)		(191,978)
	Depletion and depreciation		(388,985)		(346,394)		(241,796)
	Ceiling test and other impairments		(2,972,464)		-		-
	Income taxes		662,698		(197,464)		(193,692)
	Total	$	(2,073,006)	$	352,575	$	351,920

Capitalized Costs Relating to Oil and Gas Producing Activities

		December 31,		December 31,
		2012		2011
Proven Properties:
Acquisition, equipment, exploration, drilling and environmental costs	$	7,235,765	$	5,974,604
Less: Accumulated depletion, depreciation and amortization(1)		(5,578,265)		(2,322,982)
		1,657,500		3,651,622
Unproven Properties:
Acquisition and exploration costs not being amortized (2)		-		537,526
Net capitalized costs - oil and gas properties	$	1,657,500	$	4,189,148

G. CAPITALIZED COSTS RELATING TO OIL AND GAS PRODUCING ACTIVITIES:
			December 31,
			2012		2011
	Proven Properties:
	Acquisition, equipment, exploration, drilling and
	environmental costs	$	7,235,765	$	5,974,604
	Less: accumulated depletion, depreciation and amortization		(5,578,265)		(2,322,982)
			1,657,500		3,651,622
	Unproven Properties:
	Acquisition and exploration costs not being amortized		-		537,526
		$	1,657,500	$	4,189,148