Murphy Oil (MUR) 10-Q 6 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013
Document And Entity Information [Abstract]	'
Document Type	'10-Q
Amendment Flag	'false
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	'2013
Document Fiscal Period Focus	'Q3
Trading Symbol	'MUR
Entity Registrant Name	'MURPHY OIL CORP /DE
Entity Central Index Key	'0000717423
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Large Accelerated Filer
Entity Common Stock, Shares Outstanding	186,982,610

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Thousands, unless otherwise specified
Current assets	'		'
Cash and cash equivalents	$1,033,937		$947,316
Canadian government securities with maturities greater than 90 days at the date of acquisition	289,793		115,603
Accounts receivable, less allowance for doubtful accounts of $2,051 in 2013 and $6,697 in 2012	1,387,986		1,853,364
Inventories, at lower of cost or market	'		'
Crude oil	189,505		226,541
Finished products	126,770		266,307
Materials and supplies	311,558		259,462
Prepaid expenses	371,213		335,831
Deferred income taxes	60,044		89,040
Assets held for sale	0		15,119
Total current assets	3,770,806		4,108,583
Property, plant and equipment, at cost less accumulated depreciation, depletion and amortization of $8,660,920 in 2013 and $8,138,587 in 2012	13,543,554		13,011,606
Goodwill	41,482		43,103
Deferred charges and other assets	135,244		151,183
Assets held for sale	0		208,168
Total assets	17,491,086		17,522,643
Current liabilities	'		'
Current maturities of long-term debt	21,782		46
Accounts payable and accrued liabilities	2,769,454		3,141,717
Income taxes payable	392,990		219,847
Liabilities associated with assets held for sale	0		47,471
Total current liabilities	3,184,226		3,409,081
Long-term debt	2,583,210		2,245,201
Deferred income taxes	1,501,391		1,544,336
Asset retirement obligations	818,433		724,273
Deferred credits and other liabilities	485,780		516,540
Liabilities associated with assets held for sale	0		141,177
Stockholders' equity	'		'
Cumulative Preferred Stock, par $100, authorized 400,000 shares, none issued	0		0
Common Stock, par $1.00, authorized 450,000,000 shares, issued 194,861,200 shares in 2013 and 194,616,470 shares in 2012	194,861		194,616
Capital in excess of par value	894,600		873,934
Retained earnings	8,035,049		7,717,389
Accumulated other comprehensive income	278,960	[1]	408,901	[1]
Treasury stock, 7,878,590 shares of Common Stock in 2013 and 3,975,153 shares of Common Stock in 2012, at cost	-485,424		-252,805
Total stockholders' equity	8,918,046		8,942,035
Total liabilities and stockholders' equity	$17,491,086		$17,522,643
[1]	All amounts are presented net of income taxes.

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Accounts receivable, allowance for doubtful accounts	$2,051	$6,697
Property, plant and equipment, accumulated depreciation, depletion and amortization	$8,660,920	$8,138,587
Cumulative Preferred Stock, par	$100	$100
Cumulative Preferred Stock, authorized	400,000	400,000
Cumulative Preferred Stock, issued	'	'
Common Stock, par	$1	$1
Common Stock, authorized	450,000,000	450,000,000
Common Stock, issued	194,861,200	194,616,470
Treasury stock, shares of Common Stock	7,878,590	3,975,153

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	3 Months Ended			9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
REVENUES	'	'		'		'
Sales and other operating revenues	$2,904,791	$2,655,356	[1]	$8,276,488		$7,979,649	[1]
Loss on sale of assets	-34	-120	[1]	-320		-69	[1]
Interest and other income (expense)	53,100	-8,508	[1]	61,722		5,407	[1]
Total revenues	2,957,857	2,646,728	[1]	8,337,890	[1]	7,984,987	[1]
COSTS AND EXPENSES	'	'		'		'
Crude oil and product purchases	1,459,649	1,445,983	[1]	4,039,634		4,358,893	[1]
Operating expenses	355,004	340,813	[1]	1,134,710		1,009,663	[1]
Exploration expenses, including undeveloped lease amortization	147,845	94,063	[1]	345,110		243,714	[1]
Selling and general expenses	106,102	66,143	[1]	285,108		197,008	[1]
Depreciation, depletion and amortization	406,565	311,255	[1]	1,174,500		916,937	[1]
Impairment of properties	0	0	[1]	21,587		0	[1]
Accretion of asset retirement obligations	12,539	9,760	[1]	36,396		28,316	[1]
Interest expense	33,535	12,941	[1]	90,156		36,278	[1]
Interest capitalized	-13,011	-11,461	[1]	-40,877		-27,360	[1]
Total costs and expenses	2,508,228	2,269,497	[1]	7,086,324		6,763,449	[1]
Income from continuing operations before income taxes	449,629	377,231	[1]	1,251,566		1,221,538	[1]
Income tax expense	197,514	165,551	[1]	566,646		503,252	[1]
Income from continuing operations	252,115	211,680	[1]	684,920		718,286	[1]
Income from discontinued operations, net of taxes	32,694	15,001	[1]	363,132		93,903	[1]
NET INCOME	$284,809	$226,681	[1]	$1,048,052	[1]	$812,189	[1]
INCOME PER COMMON SHARE - BASIC	'	'		'		'
Income from continuing operations	$1.35	$1.09	[1]	$3.63		$3.70	[1]
Income from discontinued operations	$0.17	$0.08	[1]	$1.92		$0.48	[1]
Net income	$1.52	$1.17	[1]	$5.55		$4.18	[1]
INCOME PER COMMON SHARE - DILUTED	'	'		'		'
Income from continuing operations	$1.34	$1.08	[1]	$3.60		$3.69	[1]
Income from discontinued operations	$0.17	$0.08	[1]	$1.91		$0.48	[1]
Net income	$1.51	$1.16	[1]	$5.51		$4.17	[1]
Average common shares outstanding	'	'		'		'
Basic	186,938,328	194,290,277	[1]	188,914,000		194,126,104	[1]
Diluted	188,337,511	195,057,952	[1]	190,245,166		194,874,572	[1]
[1]	Reclassified to conform to current presentation.

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]	'	'		'		'
Net income	$284,809	$226,681	[1]	$1,048,052	[1]	$812,189	[1]
Other comprehensive income (loss), net of tax	'	'		'		'
Net gain (loss) from foreign currency translation	95,065	127,142		-139,943		142,844
Retirement and postretirement benefit plan amounts reclassified to net income	1,279	2,121		8,549		7,793
Deferred loss on interest rate hedges:	'	'		'		'
Increase in deferred loss associated with contract revaluation and settlement	0	0		0		-2,407
Amount of loss reclassified to interest expense in consolidated statements of income	483	484		1,453		724
COMPREHENSIVE INCOME	$381,636	$356,428		$918,111		$961,143
[1]	Reclassified to conform to current presentation.

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012
OPERATING ACTIVITIES	'		'
Net income	$1,048,052	[1]	$812,189	[1]
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Income from discontinued operations	-363,132		-93,905	[1]
Depreciation, depletion and amortization	1,174,500		916,937	[1]
Impairment of assets	21,587		'	[1]
Amortization of deferred major repair costs	17,353		16,366	[1]
Expenditures for asset retirements	-24,408		-22,949	[1]
Dry hole costs	160,540		89,645	[1]
Amortization of undeveloped leases	53,287		107,151	[1]
Accretion of asset retirement obligations	36,396		28,316	[1]
Deferred and noncurrent income tax charges	133,725		163,995	[1]
Pretax loss from disposition of assets	320		69	[1]
Net (increase) decrease in noncash operating working capital	223,981		-252,134	[1]
Other operating activities, net	-3,749		120,862	[1]
Net cash provided by continuing operations	2,478,452		1,886,542	[1]
Net cash provided by discontinued operations	200,064		214,685	[1]
Net cash provided by operating activities	2,678,516		2,101,227	[1]
INVESTING ACTIVITIES	'		'
Property additions and dry hole costs	-2,719,911	[2]	-2,156,616	[1],[2]
Proceeds from sales of assets	1,375		194	[1]
Purchase of investment securities	-670,615	[3]	-1,360,746	[1],[3]
Proceeds from maturity of investment securities	496,425	[3]	1,401,235	[1],[3]
Expenditures for major repairs	-11,821		-10,508	[1]
Investing activities of discontinued operations:	'		'
Sales proceeds	282,202		0	[1]
Other	-129,648		-112,640	[1]
Other, net	6,123		8,898	[1]
Net cash required by investing activities	-2,745,870		-2,230,183	[1]
FINANCING ACTIVITIES	'		'
Borrowings of long-term debt	0	[2]	934,899	[1],[2]
Maturities of notes payable	0		-350,000	[1]
Purchase of treasury stock	-250,000		0	[1]
Proceeds from exercise of stock options and employee stock purchase plans	2,778		11,138	[1]
Excess tax benefits related to exercise of stock options	283		1,957	[1]
Withholding tax on stock-based incentive awards	-12,713		-3,522	[1]
Issue cost of notes payable and debt facility	-3,317		-4,285	[1]
Cash dividends paid	-177,805		-167,520	[1]
Separation of retail business:	'		'
Cash distributed to Murphy Oil by Murphy USA	650,000		0	[1]
Cash held and retained by Murphy USA upon separation	-55,506		0	[1]
Net cash provided by financing activities	153,720		422,667	[1]
Effect of exchange rate changes on cash and cash equivalents	255		9,110	[1]
Net increase in cash and cash equivalents	86,621		302,821	[1]
Cash and cash equivalents, beginning	947,316		513,873	[1]
Cash and cash equivalents, ending	$1,033,937		$816,694	[1]
[1]	Reclassified to conform to current presentation.
[2]	Excludes non-cash asset and long-term obligation of $354,818 in 2013 associated with lease commencement for production equipment at the Kakap field offshore Malaysia.
[3]	Investments are Canadian government securities with maturities greater than 90 days at the date of acquisition.

CONSOLIDATED_STATEMENTS_OF_CAS1

CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Non-cash asset and long-term obligation	354,818
Minimum [Member]	'
Maturity of Canadian government securities	'90 days

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Total		Cumulative Preferred Stock - par $100, authorized 400,000 shares, none issued	Common Stock - par $1.00, authorized 450,000,000 shares, issued 194,861,200 at September 30, 2013 and 194,452,935 shares at September 30, 2012	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
In Thousands
Balance at beginning of period at Dec. 31, 2011	'		$0	$193,909	$817,974	$7,460,942	$310,420	($4,848)
Exercise of stock options	'		'	320	12,020	'	'	'
Net income for the period	812,189	[1]	'	'	'	812,189	'	'
Foreign currency translation gains, net of income taxes	142,844		'	'	'	'	142,844	'
Purchase of treasury shares	'		'	'	'	'	'	0
Restricted stock transactions and other	'		'	'	-5,257	'	'	'
Cash dividends	'		'	'	'	-167,520	'	'
Retirement and postretirement benefit plan adjustments, net of income taxes	7,793		'	'	'	'	7,793	'
Stock-based compensation	'		'	'	33,842	'	'	'
Distribution of common stock of Murphy USA Inc. to shareholders	'		'	'	'	0	'	'
Change in deferred loss on interest rate hedges, net of income taxes	-2,407		'	'	'	'	-1,683	'
Sale of stock under employee stock purchase plans	'		'	'	1,735	'	'	1,854
Other	'		'	'	0	'	'	'
Awarded restricted stock	'		'	224	'	'	'	0
Balance at end of period at Sep. 30, 2012	9,616,758		0	194,453	860,314	8,105,611	459,374	-2,994
Balance at beginning of period at Dec. 31, 2012	8,942,035		0	194,616	873,934	7,717,389	408,901	-252,805
Exercise of stock options	'		'	245	1,194	'	'	'
Net income for the period	1,048,052	[1]	'	'	'	1,048,052	'	'
Foreign currency translation gains, net of income taxes	-139,943		'	'	'	'	-139,943	'
Purchase of treasury shares	'		'	'	'	'	'	-250,000
Restricted stock transactions and other	'		'	'	-24,485	'	'	'
Cash dividends	'		'	'	'	-177,805	'	'
Retirement and postretirement benefit plan adjustments, net of income taxes	8,549		'	'	'	'	8,549	'
Stock-based compensation	'		'	'	44,079	'	'	'
Distribution of common stock of Murphy USA Inc. to shareholders	'		'	'	'	-552,587	'	'
Change in deferred loss on interest rate hedges, net of income taxes	0		'	'	'	'	1,453	'
Sale of stock under employee stock purchase plans	'		'	'	0	'	'	836
Other	'		'	'	-122	'	'	'
Awarded restricted stock	'		'	0	'	'	'	16,545
Balance at end of period at Sep. 30, 2013	$8,918,046		$0	$194,861	$894,600	$8,035,049	$278,960	($485,424)
[1]	Reclassified to conform to current presentation.

CONSOLIDATED_STATEMENTS_OF_STO1

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
Statement Of Stockholders Equity [Abstract]	'	'	'
Cumulative Preferred Stock, par	$100	$100	$100
Cumulative Preferred Stock, authorized	400,000	400,000	400,000
Cumulative Preferred Stock, issued	'	'	'
Common Stock, par	$1	$1	$1
Common Stock, authorized	450,000,000	450,000,000	450,000,000
Common Stock, issued	194,861,200	194,616,470	194,452,935

Interim_Financial_Statements

Interim Financial Statements	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Interim Financial Statements	'
	Note A – Interim Financial Statements
	The consolidated financial statements of the Company presented herein have not been audited by independent auditors, except for the Consolidated Balance Sheet at December 31, 2012. In the opinion of Murphy’s management, the unaudited financial statements presented herein include all accruals necessary to present fairly the Company’s financial position at September 30, 2013, and the results of operations, cash flows and changes in stockholders’ equity for the three-month and nine-month periods ended September 30, 2013 and 2012, in conformity with accounting principles generally accepted in the United States. In preparing the financial statements of the Company in conformity with accounting principles generally accepted in the United States, management has made a number of estimates and assumptions related to the reporting of assets, liabilities, revenues, and expenses and the disclosure of contingent assets and liabilities. Actual results may differ from the estimates.
	Financial statements and notes to consolidated financial statements included in this Form 10-Q report should be read in conjunction with the Company’s 2012 Form 10-K report, as certain notes and other pertinent information have been abbreviated or omitted in this report. Financial results for the three-month and nine-month periods ended September 30, 2013 are not necessarily indicative of future results.

Property_Plant_and_Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2013
Property Plant And Equipment [Abstract]	'
Property, Plant and Equipment	'
	Note B – Property, Plant and Equipment
	Under U.S. generally accepted accounting principles for companies that use the successful efforts method of accounting, exploratory well costs should continue to be capitalized when the well has found a sufficient quantity of reserves to justify its completion as a producing well and the company is making sufficient progress assessing the reserves and the economic and operating viability of the project.
	At September 30, 2013, the Company had total capitalized exploratory well costs pending the determination of proved reserves of $421.0 million. The following table reflects the net changes in capitalized exploratory well costs during the nine-month periods ended September 30, 2013 and 2012.
	(Thousands of dollars)	2013			2012
	Beginning balance at January 1	$	445,697			556,412
	Additions pending the determination of proved reserves		28,168			143,863
	Reclassifications to proved properties based on the determination of proved reserves		(52,865	)		(76,633	)
	Capitalized exploratory well costs charged to expense		0			(51,866	)
	Balance at September 30	$	421,000			571,776
	The following table provides an aging of capitalized exploratory well costs based on the date the drilling was completed for each individual well and the number of projects for which exploratory well costs have been capitalized. The projects are aged based on the last well drilled in the project.
		September 30,
		2013								2012
	(Thousands of dollars)	Amount			No. of			No. of		Amount		No. of		No. of
					Wells			Projects				Wells		Projects
	Aging of capitalized well costs:
	Zero to one year	$	36,424			2			2	$	82,521		8		5
	One to two years		51,444			6			0		90,390		7		3
	Two to three years		35,504			3			3		114,532		6		1
	Three years or more		297,628			27			5		284,333		26		6
		$	421,000			38			10	$	571,776		47		15
	Of the $384.6 million of exploratory well costs capitalized more than one year at September 30, 2013, $262.1 million is in Malaysia, $115.9 million is in the U.S. and $6.6 million is in Brunei. In Malaysia either further appraisal or development drilling is planned and/or development studies/plans are in various stages of completion. In the U.S. drilling and development operations are planned. In Brunei field development plans are being prepared by the operator.
	See also Note E for discussion regarding a capital lease of production equipment at the Kakap field.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2013
Inventory Disclosure [Abstract]	'
Inventories	'
	Note C – Inventories
	Inventories are carried at the lower of cost or market. The cost of crude oil and finished products is predominantly determined on the last-in, first-out (LIFO) method. At September 30, 2013 and December 31, 2012, the carrying value of inventories under the LIFO method was $285.9 million and $571.2 million, respectively, less than such inventories would have been valued using the first-in, first-out (FIFO) method.

Discontinued_Operations

Discontinued Operations	9 Months Ended
	Sep. 30, 2013
Discontinued Operations And Disposal Groups [Abstract]	'
Discontinued Operations	'
	Note D – Discontinued Operations
	The Company sold its oil and gas assets in the United Kingdom during 2013. After-tax gains on sale of the assets were $216.2 million in the nine-months ended September 30, 2013. The Company has accounted for these U.K. upstream operations as discontinued operations in its consolidated financial statements for all periods presented.
	In addition, the Company completed the spin-off of its U.S. retail marketing business on August 30, 2013. The spin-off was effected through a distribution of all shares of Murphy USA Inc. (MUSA) at a rate of one share of MUSA for every four shares of the Company held. Immediately prior to the spin-off, MUSA paid a cash dividend of $650.0 million to the Company. MUSA is now a separate, publicly owned company. The Company has accounted for these U.S. retail operations as discontinued operations for all periods presented.
	The results of operations associated with these discontinued operations for the three-month and nine-month periods ended September 30, 2013 and 2012 were as follows:
		Three-Months				Nine-Months
		Ended September 30,				Ended September 30,
	(Thousands of dollars)	2013		2012		2013		2012
	Revenues	$	2,963,739		4,507,328		11,686,213		13,353,927
	Income before income taxes, including pretax gain on disposals of $130,568 during the nine-month periods in 2013	$	52,371		40,039		381,941		184,105
	Income tax expense		19,677		25,038		18,809		90,202
	Income from discontinued operations	$	32,694		15,001		363,132		93,903
	In July 2012, the United Kingdom enacted tax changes that limited tax relief on oil and gas decommissioning costs to 50%, a reduction from the 62% tax relief previously allowed for these costs. This tax rate change led to a net increase in tax expense of discontinued operations of $5.5 million in the three-month and nine-month periods of 2012.
	The Company has previously announced that its Board of Directors had approved plans to exit the U.K. refining and marketing business. These operations are presented as the U.K. refining and marketing segment in Note P. The sale process for the U.K. downstream assets continues in 2013. Based on current market conditions, it is possible that the Company could incur a loss when the U.K. downstream assets are sold. If the sale of the U.K. downstream assets continues to progress, the results of these operations are likely to be presented as discontinued operations beginning in a future period.

Financing_Arrangements_and_Deb

Financing Arrangements and Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Financing Arrangements and Debt	'
	Note E – Financing Arrangements and Debt
	In May 2013, the Company increased the capacity of its committed credit facility to $2.0 billion, and it extended the facility for one year such that it now expires in June 2017. Borrowings under the facility continue to bear interest at 1.25% above LIBOR based on the Company’s current credit rating as of September 30, 2013. In addition, facility fees of 0.25% are charged on the full $2.0 billion commitment. The Company also has a shelf registration statement on file with the U.S. Securities and Exchange Commission that permits the offer and sale of debt and/or equity securities through October 2015.
	During June 2013, the Company and its partners entered into a 25-year lease of production equipment at the Kakap field offshore Malaysia. The lease has been accounted for as a capital lease, and payments under the agreement are to be made over a 15-year period through June 2028. The original lease asset, which was recorded in Property, Plant and Equipment, and the associated debt obligation, which was recorded in Current Maturities of Long-Term Debt and Long-Term Debt, amounted to $354.8 million.

Cash_Flow_Disclosures

Cash Flow Disclosures	9 Months Ended
	Sep. 30, 2013
Supplemental Cash Flow Elements [Abstract]	'
Cash Flow Disclosures	'
	Note F – Cash Flow Disclosures
	Additional disclosures regarding cash flow activities are provided below.
		Nine Months
		Ended September 30,
	(Thousands of dollars)	2013			2012
	Net (increase) decrease in operating working capital other than cash and cash equivalents (from continuing operations):
	(Increase) decrease in accounts receivable	$	(60,558	)		94,145
	Increase in inventories		(92,916	)		(156,973	)
	Increase in prepaid expenses		(53,554	)		(141,267	)
	Decrease in deferred income tax assets		41,714			35,277
	Increase (decrease) in accounts payable and accrued liabilities		199,301			(131,701	)
	Increase in current income tax liabilities		189,994			48,385
	Total	$	223,981			(252,134	)
	Supplementary disclosures (including discontinued operations):
	Cash income taxes paid	$	323,965			414,676
	Interest paid, net of amounts capitalized		16,063			1,077

Employee_and_Retiree_Benefit_P

Employee and Retiree Benefit Plans	9 Months Ended
	Sep. 30, 2013
Compensation And Retirement Disclosure [Abstract]	'
Employee and Retiree Benefit Plans	'
	Note G – Employee and Retiree Benefit Plans
	The Company has defined benefit pension plans that are principally noncontributory and cover most full-time employees. All pension plans are funded except for the U.S. and Canadian nonqualified supplemental plans and the U.S. directors’ plan. All U.S. tax qualified plans meet the funding requirements of federal laws and regulations. Contributions to foreign plans are based on local laws and tax regulations.
	Effective with the spin-off of the Company’s former U.S. retail marketing operation (MUSA) on August 30, 2013, significant modifications were made to the U.S. defined benefit pension plan. Certain employees’ benefits under the U.S. plan were frozen at that time. No further benefit service will accrue for the affected employees, however, the plan will recognize future compensation increases after the spin-off. In addition, all previously unvested benefits became fully vested at the spin-off date. For those affected active employees of the Company, additional U.S. retirement plan benefits will accrue in future periods under a cash balance formula. Upon the spin-off of MUSA, the Company retained all vested pension defined benefit and other postretirement benefit obligations associated with current and former employees of this business. No additional benefit will accrue for employees of MUSA under the Company’s retirement plan after the spin-off date.
	The Company also sponsors health care and life insurance benefit plans, which are not funded, that cover most active and retired U.S. employees. Additionally, most U.S. retired employees are covered by a life insurance benefit plan. The health care benefits are contributory; the life insurance benefits are noncontributory.
	The table that follows provides the components of net periodic benefit expense for the three-month and nine-month periods ended September 30, 2013 and 2012.
		Three Months Ended September 30,
								Other
		Pension Benefits						Postretirement Benefits
	(Thousands of dollars)	2013			2012			2013			2012
	Service cost	$	7,252			6,030			1,232			1,049
	Interest cost		8,450			7,549			1,352			1,342
	Expected return on plan assets		(8,257	)		(6,520	)		0			0
	Amortization of prior service cost		262			313			(35	)		(42	)
	Amortization of transitional asset		125			112			2			2
	Recognized actuarial loss		4,591			3,846			391			453
	Special termination benefits		849			0			0			0
	Curtailments		1,366			0			(443	)		0
	Net periodic benefit expense	$	14,638			11,330			2,499			2,804
		Nine Months Ended September 30,
								Other
		Pension Benefits						Postretirement Benefits
	(Thousands of dollars)	2013			2012			2013			2012
	Service cost	$	21,949			17,953			3,629			3,139
	Interest cost		22,581			22,386			3,865			4,133
	Expected return on plan assets		(21,526	)		(19,345	)		0			0
	Amortization of prior service cost		841			938			(121	)		(131	)
	Amortization of transitional asset		366			339			6			6
	Recognized actuarial loss		12,882			11,460			1,321			1,394
	Special termination benefits		849			6,170			0			0
	Curtailments		1,366			0			(443	)		0
	Net periodic benefit expense	$	39,308			39,901			8,257			8,541
	During the nine-month period ended September 30, 2013, the Company made contributions of $41.2 million to its defined benefit pension and postretirement benefit plans. Remaining funding in 2013 for the Company’s defined benefit pension and postretirement plans is anticipated to be $7.3 million.
	In March 2010, the United States Congress enacted a health care reform law. Along with other provisions, the law (a) eliminates the tax free status of federal subsidies to companies with qualified retiree prescription drug plans that are actuarially equivalent to Medicare Part D plans beginning in 2013; (b) imposes a 40% excise tax on high-cost health plans as defined in the law beginning in 2018; (c) eliminated lifetime or annual coverage limits and required coverage for preventative health services beginning in September 2010; and (d) imposed a fee of $2 (subsequently adjusted for inflation) for each person covered by a health insurance policy beginning in September 2010. The Company provides a health care benefit plan to eligible U.S. employees and eligible U.S. retired employees. The law did not significantly affect the Company’s Consolidated Balance Sheets as of September 30, 2013 and December 31, 2012 and the Consolidated Statements of Income for the three-month and nine-month periods ended September 30, 2013 and 2012. The Company continues to evaluate the various components of the law as further guidance is issued and cannot predict with certainty all the ways it may impact the Company. However, based on the information available to date, the Company currently believes that the health care reform law will not have a material effect on its financial condition, net income or cash flow in future periods.

Incentive_Plans

Incentive Plans	9 Months Ended
	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Incentive Plans	'
	Note H – Incentive Plans
	The costs resulting from all share-based payment transactions are recognized as an expense in the Consolidated Statements of Income using a fair value-based measurement method over the periods that the awards vest.
	The 2012 Annual Incentive Plan (2012 Annual Plan) authorizes the Executive Compensation Committee (the Committee) to establish specific performance goals associated with annual cash awards that may be earned by officers, executives and other key employees. Cash awards under the 2012 Annual Plan are determined based on the Company’s actual financial and operating results as measured against the performance goals established by the Committee. The 2012 Long-Term Incentive Plan (2012 Long-Term Plan) authorizes the Committee to make grants of the Company’s Common Stock and other stock-based incentives to employees. These grants may be in the form of stock options (nonqualified or incentive), stock appreciation rights (SAR), restricted stock, restricted stock units, performance units, performance shares, dividend equivalents and other stock-based incentives. The 2012 Long-Term Plan expires in 2022. A total of 8,700,000 shares are issuable during the life of the 2012 Long-Term Plan, with annual grants limited to 1% of Common shares outstanding. The Company has an Employee Stock Purchase Plan that permits the issuance of up to 980,000 shares through September 30, 2017. The Company also has a Stock Plan for Non-Employee Directors that permits the issuance of restricted stock and stock options or a combination thereof to the Company’s Directors.
	During 2013, the Committee has granted stock options for 1,320,176 shares at exercise prices ranging between $60.015 and $70.725 per share. The Black-Scholes valuation for these awards was between $15.81 and $20.62 per option. The Committee also granted 496,076 performance-based restricted stock units during 2013. The fair value of the performance-based restricted stock units, using a Monte Carlo valuation model, ranged from $39.50 to $68.01 per unit. Additionally, on February 5, 2013, the Committee granted 851,000 stock appreciation rights (SAR) and 93,200 units of restricted stock-cash (RSU-C) to certain employees. The SAR and RSU-C are to be settled in cash, net of applicable income taxes, and are accounted for as liability-type awards. The initial fair values of these SAR were equivalent to the stock options granted, while the initial value of RSU-C were equivalent to restricted stock units granted. During 2013, the Committee granted 38,184 shares of time-based restricted stock units to the Company’s Directors under the Non-employee Director Plan. These shares vest on the third anniversary of the date of grant. The fair value of these awards was estimated based on the fair market value of the Company’s stock on the date of grant, which ranged between $60.30 and $69.67 per share. During 2013, the Committee also granted 25,000 shares of time-based restricted stock units that vest on January 2, 2014 to a former executive officer. The fair value of this award was estimated based on the fair market value of the Company’s stock on the date of grant, which was $69.67 per share.
	Cash received from options exercised under all share-based payment arrangements for the nine-month periods ended September 30, 2013 and 2012 was $2.8 million and $11.1 million, respectively. The actual income tax benefit realized for the tax deductions from option exercises of the share-based payment arrangements totaled $6.3 million and $3.3 million for the nine-month periods ended September 30, 2013 and 2012, respectively.
	Amounts recognized in the financial statements with respect to share-based plans are as follows:
		Nine Months Ended
		September 30,
	(Thousands of dollars)	2013		2012
	Compensation charged against income before tax benefit	$	51,085		33,952
	Related income tax benefit recognized in income		9,494		8,007

Earnings_per_Share

Earnings per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings per Share	'
	Note I – Earnings per Share
	Net income was used as the numerator in computing both basic and diluted income per Common share for the three-month and nine-month periods ended September 30, 2013 and 2012. The following table reconciles the weighted-average shares outstanding used for these computations.
		Three Months Ended				Nine Months Ended
		September 30,				September  30,
	(Weighted-average shares)	2013		2012		2013		2012
	Basic method		186,938,328		194,290,277		188,914,000		194,126,104
	Dilutive stock options and restricted stock units		1,399,183		767,675		1,331,166		748,468
	Diluted method		188,337,511		195,057,952		190,245,166		194,874,572
	The following table reflects certain options to purchase shares of common stock that were outstanding during the 2013 and 2012 periods but were not included in the computation of diluted EPS above because the incremental shares from assumed conversion were antidilutive.
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Antidilutive stock options excluded from diluted shares		1,165,464		3,538,507		941,155		3,276,850
	Weighted average price of these options	$	54.56	$	63.83	$	54.4	$	65.01

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Note J – Income Taxes
	The Company’s effective income tax rate generally exceeds the statutory U.S. tax rate of 35%. The effective tax rate is calculated as the amount of income tax expense divided by income before income tax expense. For the three-month and nine-month periods in 2013 and 2012, the Company’s effective income tax rates were as follows:
		2013			2012
	Three months ended September 30		43.9	%		43.9	%
	Nine months ended September 30		45.3	%		41.2	%
	The effective tax rates for the periods presented exceeded the U.S. statutory tax rate of 35% due to several factors, including: the effects of income generated in foreign tax jurisdictions, certain of which have income tax rates that are higher than the U.S. Federal rate; U.S. state tax expense; and certain expenses, including exploration and other expenses in certain foreign jurisdictions, for which no income tax benefits are available or are not presently being recorded due to a lack of reasonable certainty of adequate future revenue against which to utilize these expenses as deductions.
	The Company recognized a $13.7 million tax benefit during the third quarter 2013 related to a previously recorded U.S. tax liability that was written back into net income due to the passage of time.
	The Company’s tax returns in multiple jurisdictions are subject to audit by taxing authorities. These audits often take years to complete and settle. Although the Company believes that recorded liabilities for unsettled issues are adequate, additional gains or losses could occur in future years from resolution of outstanding unsettled matters. As of September 30, 2013, the earliest years remaining open for audit and/or settlement in our major taxing jurisdictions are as follows: United States – 2010; Canada – 2007; United Kingdom – 2011; and Malaysia – 2006.

Financial_Instruments_and_Risk

Financial Instruments and Risk Management	9 Months Ended
	Sep. 30, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Financial Instruments and Risk Management	'
	Note K – Financial Instruments and Risk Management
	Murphy periodically utilizes derivative instruments to manage certain risks related to commodity prices, foreign currency exchange rates and interest rates. The use of derivative instruments for risk management is covered by operating policies and is closely monitored by the Company’s senior management. The Company does not hold any derivatives for speculative purposes, and it does not use derivatives with leveraged or complex features. Derivative instruments are traded primarily with creditworthy major financial institutions or over national exchanges. The Company has a risk management control system to monitor commodity price risks and any derivatives obtained to manage a portion of such risks. For accounting purposes, the Company has not designated commodity and foreign currency derivative contracts as hedges, and therefore, it recognizes all gains and losses on these derivative contracts in its Consolidated Statements of Income. Certain interest rate derivative contracts are accounted for as hedges and the gain or loss associated with recording the fair value of these contracts has been deferred in Accumulated Other Comprehensive Income until the anticipated transactions occur.
	Commodity Purchase Price Risks
	The Company is subject to commodity price risk related to the sales price for crude oil and natural gas it produces worldwide. To manage a portion of this risk, the Company has entered into a series of West Texas Intermediate (WTI) crude oil price swap financial contracts to hedge a portion of its Eagle Ford Shale production from October 2013 through September 2014. Under these contracts, which mature monthly, the Company will pay the average monthly price in effect and will receive the fixed contract prices. WTI open contracts were as follows:
	Dates	Volumes				Swap Prices
		(barrels per day)
	October – December 2013		10,000			$	101.55 per barrel
	January – March 2014		20,000			$	98.47 per barrel
	April – June 2014		20,000			$	96.48 per barrel
	July – September 2014		6,000			$	95.27 per barrel
	In addition, the Company has entered into crude oil swap contracts to hedge about 1,500 barrels per day of Seal heavy oil production during the fourth quarter 2013. The estimated netback price of these contracts is $55.05 per barrel.
	The impact of marking to market these commodity derivative contracts increased income from continuing operations before taxes by $1.6 million during the nine months ended September 30, 2013.
	The Company’s former U.S. retail marketing subsidiary had ethanol production operations that were subject to commodity price risk related to corn that it purchased for feedstock and also had price risk related to wet and dried distillers grain with solubles that it sold. In 2013 and 2012, the former subsidiary had physical delivery commitment contracts for purchases of corn at fixed prices and had physical delivery commitment contracts for sale of wet and dried distillers gain with solubles at fixed prices. To address the risks associated with these fixed price physical delivery contracts, certain of those contracts were hedged with derivative contracts. The effects of these physical delivery and associated derivative contracts increased income from discontinued operations before taxes by $1.6 million in the nine-month period ended September 30, 2013, and reduced income from discontinued operations before taxes by $38.0 million in the nine-month period ended September 30, 2012.
	Foreign Currency Exchange Risks
	The Company is subject to foreign currency exchange risk associated with operations in countries outside the United States. Short-term derivative instruments were outstanding at September 30, 2013 and 2012 to manage the risk of certain future income taxes that are payable in Malaysian ringgits. The equivalent U.S. dollar values of Malaysian ringgit derivative contracts open at September 30, 2013 and 2012 were approximately $76.0 million and $97.6 million, respectively. Short-term derivative instrument contracts totaling $28.0 million U.S. dollars were also outstanding at September 30, 2013 to manage the risk of certain U.S. dollar accounts receivable associated with sale of crude oil production in Canada. The impact from marking to market these foreign currency derivative contracts reduced income from continuing operations before taxes by $4.1 million for the nine-month period ended September 30, 2013 and increased income from continuing operations before taxes by $3.1 million for the nine-month period ended September 30, 2012.
	At September 30, 2013 and December 31, 2012, the fair value of derivative instruments not designated as hedging instruments are presented in the following table.
		September 30, 2013						December 31, 2012
	(Thousands of dollars)	Asset (Liability) Derivatives						Asset (Liability) Derivatives
	Type of Derivative Contract	Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Commodity	Accounts receivable		$	1,385			Accounts receivable		$	3,043
	Commodity	Accounts payable			(1,138	)		Accounts payable			(102	)
	Foreign exchange	Accounts payable			(4,096	)		Accounts payable			(1,031	)
	For the three-month and nine-month periods ended September 30, 2013 and 2012, the gains and losses recognized in the Consolidated Statements of Income for derivative instruments not designated as hedging instruments are presented in the following table.
				Gain (Loss)
	(Thousands of dollars)	Statement of Income		Three Months Ended								Nine Months Ended
				September 30,								September 30,
	Type of Derivative Contract	Location		2013				2012				2013				2012
	Commodity	Sales and other operating revenues		$	(1,305	)			0				(1,305	)			0
	Commodity	Discontinued operations			2,980				(40,241	)			1,604				(37,978	)
	Foreign exchange	Interest and other income			(2,557	)			6,585				(6,703	)			15,782
				$	(882	)			(33,656	)			(6,404	)			(22,196	)
	Interest Rate Risks
	The Company had ten-year notes totaling $350 million that matured on May 1, 2012. The Company expected to replace these notes at maturity with new ten-year notes, and it therefore had risk associated with the interest rate related to the anticipated sale of these notes in 2012. To manage this risk, in 2011 the Company entered into a series of derivative contracts known as forward starting interest rate swaps that matured in May 2012. The Company utilized hedge accounting to defer any gain or loss on these contracts associated with the payment of interest on these anticipated notes in 2012 through 2022. During the nine-month periods ended September 30, 2013 and 2012, $2.3 million and $1.1 million, respectively, of the deferred loss on the interest rate swaps were charged to income. The remaining loss deferred on these matured contracts at September 30, 2013 was $25.6 million, which is recorded, net of income taxes of $9.0 million, in Accumulated Other Comprehensive Income in the Consolidated Balance Sheet.
	The Company expects to charge approximately $0.7 million of this deferred loss to income in the form of interest expense during the remaining three months of 2013.
	The Company carries certain assets and liabilities at fair value in its Consolidated Balance Sheets. The fair value hierarchy is based on the quality of inputs used to measure fair value, with Level 1 being the highest quality and Level 3 being the lowest quality. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included within Level 1. Level 3 inputs are unobservable inputs which reflect assumptions about pricing by market participants.
	The carrying value of assets and liabilities recorded at fair value on a recurring basis at September 30, 2013 and December 31, 2012 are presented in the following table.
		September 30, 2013																December 31, 2012
	(Thousands of dollars)	Level 1				Level 2				Level 3				Total				Level 1			Level 2			Level 3		Total
	Assets
	Commodity derivative contracts	$	0				1,385				0				1,385				0			3,043			0		3,043
	Liabilities
	Nonqualified employee savings plans	$	(12,219	)			0				0				(12,219	)			(10,293	)		0			0		(10,293	)
	Commodity derivative contracts		0				(1,138	)			0				(1,138	)			0			(102	)		0		(102	)
	Foreign currency exchange derivative contracts		0				(4,096	)			0				(4,096	)			0			(1,031	)		0		(1,031	)
		$	(12,219	)			(5,234	)			0				(17,453	)			(10,293	)		(1,133	)		0		(11,426	)
	The fair value of West Texas Intermediate (WTI) crude oil contracts was based on active market quotes for WTI crude oil. The fair value of Canadian crude oil contracts was based on active market quotes for Western Canadian Sour crude oil. The fair value of commodity derivative contracts for corn and wet and dried distillers grain was determined based on market quotes for No. 2 yellow corn. The fair value of foreign exchange derivative contracts was based on market quotes for similar contracts at the balance sheet date. The income effect of changes in fair value of crude oil derivative contracts is recorded in Sales and Other Operating Revenues in the Consolidated Statements of Income and the effect of changes in fair value of foreign exchange derivative contracts is recorded in Interest and Other Income. The nonqualified employee savings plan is an unfunded savings plan through which participants seek a return via phantom investments in equity securities and/or mutual funds. The fair value of this liability was based on quoted prices for these equity securities and mutual funds. The income effect of changes in the fair value of the nonqualified employee savings plan is recorded in Selling and General Expenses.
	The Company offsets certain assets and liabilities related to derivative contracts when the legal right of offset exists. No offsetting of assets and liabilities on derivative contracts occurred at September 30, 2013. Derivative assets and liabilities which have offsetting positions at December 31, 2012 are presented in the following tables.
		Gross Amounts				Gross Amounts				Net Amounts of
		of Recognized				Offset in the				Assets Presented
						Consolidated				in the Consolidated
		Assets				Balance Sheet				Balance Sheet
	(Thousands of dollars)
	At December 31, 2012
	Commodity derivatives	$	3,111				(2,169	)			942
		Gross Amounts				Gross Amounts				Net Amounts of
		of Recognized				Offset in the				Liabilities Presented
		Liabilities				Consolidated				in the Consolidated
						Balance Sheet				Balance Sheet
	(Thousands of dollars)
	At December 31, 2012
	Commodity derivatives	$	2,271				(2,169	)			102
	All commodity derivatives above with offsetting positions were corn-based contracts associated with the Company’s former U.S. ethanol plants. Net derivative assets in the table above are included in Accounts Receivable presented in the table on page 13 and on the Consolidated Balance Sheet; likewise, net derivative liabilities in the above table are included in Accounts Payable in the table on page 13 and are included in Accounts Payable and Accrued Liabilities on the Consolidated Balance Sheet. Separate derivative agreements existed for each of the ethanol plants. These contracts permitted net settlement and the Company generally availed itself of this right to settle net.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Accumulated Other Comprehensive Income	'
	Note L – Accumulated Other Comprehensive Income
	The components of Accumulated Other Comprehensive Income (AOCI) on the Consolidated Balance Sheets at September 30, 2013 and the changes during the three month periods ended September 30, 2013 are presented net of taxes in the following table.
			Foreign			Retirement			Deferred			Total1
			Currency			and			Loss on
			Translation			Postretirement			Interest
			Gains			Benefit Plan			Rate
			(Losses)1			Adjustments1			Derivative
									Hedges1
	(Thousands of dollars)
	Balance at January 1, 2013			613,492			(186,539	)		(18,052	)		408,901
	Components of other comprehensive income (loss):
	Before reclassifications to income			(139,944	)		(237	)		0			(140,181	)
	Reclassifications to income			0			8,787	2		1,453	3		10,240
	Net other comprehensive income (loss)			(139,944	)		8,550			1,453			(129,941	)
	Balance at September 30, 2013			473,548			(177,989	)		(16,599	)		278,960
	1	All amounts are presented net of income taxes.
	2	Reclassifications before taxes of $15,610 for the nine-month period ended September 30, 2013 are included in the computation of net periodic benefit expense. See Note G for additional information. Related income taxes of $6,823 for the nine-month period ended September 30, 2013 are included in Income tax expense.
	3	Reclassifications before taxes of $2,223 for the nine-month period ended September 30, 2013 are included in Interest expense. Related income taxes of $770 for the nine-month period ended September 30, 2013 are included in Income tax expense.

Environmental_and_Other_Contin

Environmental and Other Contingencies	9 Months Ended
	Sep. 30, 2013
Environmental Remediation Obligations [Abstract]	'
Environmental and Other Contingencies	'
	Note M – Environmental and Other Contingencies
	The Company’s operations and earnings have been and may be affected by various forms of governmental action both in the United States and throughout the world. Examples of such governmental action include, but are by no means limited to: tax increases and retroactive tax claims; royalty and revenue sharing increases; import and export controls; price controls; currency controls; allocation of supplies of crude oil and petroleum products and other goods; expropriation of property; restrictions and preferences affecting the issuance of oil and gas or mineral leases; restrictions on drilling and/or production; laws and regulations intended for the promotion of safety and the protection and/or remediation of the environment; governmental support for other forms of energy; and laws and regulations affecting the Company’s relationships with employees, suppliers, customers, stockholders and others. Because governmental actions are often motivated by political considerations and may be taken without full consideration of their consequences, and may be taken in response to actions of other governments, it is not practical to attempt to predict the likelihood of such actions, the form the actions may take or the effect such actions may have on the Company.
	Murphy and other companies in the oil and gas industry are subject to numerous federal, state, local and foreign laws and regulations dealing with the environment. Violation of federal or state environmental laws, regulations and permits can result in the imposition of significant civil and criminal penalties, injunctions and construction bans or delays. A discharge of hazardous substances into the environment could, to the extent such event is not insured, subject the Company to substantial expense, including both the cost to comply with applicable regulations and claims by neighboring landowners and other third parties for any personal injury and property damage that might result.
	The Company currently owns or leases, and has in the past owned or leased, properties at which hazardous substances have been or are being handled. Although the Company has used operating and disposal practices that were standard in the industry at the time, hazardous substances may have been disposed of or released at properties owned or leased by the Company or at other locations where these wastes have been taken for disposal. In addition, many of these properties have been operated by third parties whose treatment and disposal or release of hydrocarbons or other wastes were not under Murphy’s control. Under existing laws the Company could be required to remove or remediate previously disposed wastes (including wastes disposed of or released by prior owners or operators), to clean up contaminated property (including contaminated groundwater) or to perform remedial plugging operations to prevent future contamination. While some of these historical properties are in various stages of negotiation, investigation, and/or cleanup, the Company is investigating the extent of any such liability and the availability of applicable defenses. With the sale of the U.S. refineries in 2011, the Company retained certain liabilities related to environmental matters at these sites. The Company also has insurance covering certain levels of environmental expenses at the refinery sites. The Company believes costs related to these current or former operating sites will not have a material adverse effect on its net income, financial condition or liquidity in a future period. With the spin-off of Murphy’s U.S. retail marketing business in 2013, the newly formed public company, Murphy USA Inc., has retained any environmental exposure associated with U.S. marketing operations.
	The U.S. Environmental Protection Agency (EPA) currently considers the Company to be a Potentially Responsible Party (PRP) at one Superfund site. The potential total cost to all parties to perform necessary remedial work at the Superfund site may be substantial. However, based on current negotiations and available information, the Company believes that it is a de minimis party as to ultimate responsibility at the Superfund site. The Company has not recorded a liability for remedial costs on the Superfund site. The Company could be required to bear a pro rata share of costs attributable to nonparticipating PRPs or could be assigned additional responsibility for remediation at this site or other Superfund sites. The Company believes that its share of the ultimate costs to clean-up the Superfund site will be immaterial and will not have a material adverse effect on its net income, financial condition or liquidity in a future period.
	There is the possibility that environmental expenditures could be required at currently unidentified sites, and new or revised regulations could require additional expenditures at known sites. However, based on information currently available to the Company, the amount of future remediation costs incurred at known or currently unidentified sites is not expected to have a material adverse effect on the Company’s future net income, cash flows or liquidity.
	Murphy and its subsidiaries are engaged in a number of other legal proceedings, all of which Murphy considers routine and incidental to its business. Based on information currently available to the Company, the ultimate resolution of these matters is not expected to have a material adverse effect on the Company’s net income, financial condition or liquidity in a future period.
	In the normal course of its business, the Company is required under certain contracts with various governmental authorities and others to provide financial guarantees or letters of credit that may be drawn upon if the Company fails to perform under those contracts. At September 30, 2013, the Company had contingent liabilities of $22.8 million on outstanding letters of credit. The Company has not accrued a liability in its Consolidated Balance Sheets related to these letters of credit because it is believed that the likelihood of having these drawn is remote.

Accounting_Matters

Accounting Matters	9 Months Ended
	Sep. 30, 2013
Accounting Changes And Error Corrections [Abstract]	'
Accounting Matters	'
	Note N – Accounting Matters
	In December 2011, the Financial Accounting Standards Board (FASB) issued an accounting standards update that requires enhanced disclosures about financial instruments and derivative instruments that are either offset in the balance sheet or are subject to an enforceable master netting arrangement or similar agreement. The guidance was effective for all interim and annual periods beginning on or after January 1, 2013. These disclosures are presented in Note K.
	In February 2013, the FASB issued an accounting standards update that requires additional disclosures for reclassification adjustments from accumulated other comprehensive income (AOCI). These additional disclosures include changes in AOCI balances by component and significant items reclassified out of AOCI. These disclosures must be presented either on the face of the affected financial statement or in the notes to the financial statements. The disclosures are effective for Murphy Oil beginning in the first quarter of 2013 and are to be provided on a prospective basis. These disclosures are presented in Note L.

Commitments

Commitments	9 Months Ended
	Sep. 30, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Commitments	'
	Note O – Commitments
	The Company has entered into forward sales contracts to mitigate the price risk for a portion of its 2013 heavy oil and 2013 and 2014 natural gas sales volumes in Western Canada. The heavy oil sales contracts call for deliveries of approximately 2,900 barrels per day during the fourth quarter 2013 that achieve netback values averaging Cdn$50.89 per barrel The natural gas contracts call for deliveries from October through December 2013 that average approximately 77 million cubic feet per day at a price of Cdn$3.76. Additionally for 2014, open gas contracts call for deliveries of 50 million cubic feet per day at an average price of Cdn$4.01 per MCF. The 2013 and 2014 natural gas contracts call for delivery at the NOVA inventory transfer sales point. These oil and natural gas contracts have been accounted for as normal sales for accounting purposes.

Business_Segments

Business Segments	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Business Segments	'
	Note P – Business Segments
					Three Months Ended						Three Months Ended
					Sept. 30, 2013						Sept. 30, 20121
	(Millions of dollars)		Total Assets		External			Income			External			Income
			at Sept. 30,		Revenues			(Loss)			Revenues			(Loss)
			2013
	Exploration and production2
	United States		$	4,278.60		512			151.3			248.8			33.5
	Canada			4,286.40		316.4			77.3			232.8			29.3
	Malaysia			5,953.70		538			183.8			602.2			215.7
	Republic of the Congo			78.5		0			(10.8	)		0			(4.7	)
	Other			107.3		0			(137.4	)		0			(52.7	)
	Total			14,704.50		1,366.40			264.2			1,083.80			221.1
	Refining and marketing – U.K.			1,161.50		1,538.40			(12.9	)		1,571.40			25.5
	Total operating segments			15,866.00		2,904.80			251.3			2,655.20			246.6
	Corporate			1,625.10		53.1			0.8			(8.5	)		(34.9	)
	Assets/revenue/income from continuing operations			17,491.10		2,957.90			252.1			2,646.70			211.7
	Discontinued operations, net of tax			0		0			32.7			0			15
	Total		$	17,491.10		2,957.90			284.8			2,646.70			226.7
					Nine Months Ended						Nine Months Ended
					Sept. 30, 2013						Sept. 30, 20121
					External			Income			External			Income
	(Millions of dollars)				Revenues			(Loss)			Revenues			(Loss)
	Exploration and production2
	United States				$	1,365.10			368			671.6			83.1
	Canada					894			142.3			804.7			146.3
	Malaysia					1,652.70			602.5			1,777.50			662.9
	Republic of the Congo					69.5			(37.3	)		57.6			(8.4	)
	Other					(.6	)		(289.2	)		0.1			(123.9	)
	Total					3,980.70			786.3			3,311.50			760
	Refining and marketing – U.K.					4,295.50			(22.7	)		4,668.10			35.7
	Total operating segments					8,276.20			763.6			7,979.60			795.7
	Corporate					61.7			(78.7	)		5.4			(77.4	)
	Revenue/income from continuing operations					8,337.90			684.9			7,985.00			718.3
	Discontinued operations, net of tax					0			363.1			0			93.9
	Total				$	8,337.90			1,048.00			7,985.00			812.2
	1	Reclassified to conform to current presentation.
	2	Additional details about results of oil and gas operations are presented in the tables on pages 24 and 25.

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2013
Property Plant And Equipment [Abstract]	'
Net Changes in Capitalized Exploratory Well Costs	'
	The following table reflects the net changes in capitalized exploratory well costs during the nine-month periods ended September 30, 2013 and 2012.
	(Thousands of dollars)	2013			2012
	Beginning balance at January 1	$	445,697			556,412
	Additions pending the determination of proved reserves		28,168			143,863
	Reclassifications to proved properties based on the determination of proved reserves		(52,865	)		(76,633	)
	Capitalized exploratory well costs charged to expense		0			(51,866	)
	Balance at September 30	$	421,000			571,776
Aging of Capitalized Exploratory Well Costs	'
	The following table provides an aging of capitalized exploratory well costs based on the date the drilling was completed for each individual well and the number of projects for which exploratory well costs have been capitalized. The projects are aged based on the last well drilled in the project.
		September 30,
		2013								2012
	(Thousands of dollars)	Amount			No. of			No. of		Amount		No. of		No. of
					Wells			Projects				Wells		Projects
	Aging of capitalized well costs:
	Zero to one year	$	36,424			2			2	$	82,521		8		5
	One to two years		51,444			6			0		90,390		7		3
	Two to three years		35,504			3			3		114,532		6		1
	Three years or more		297,628			27			5		284,333		26		6
		$	421,000			38			10	$	571,776		47		15

Discontinued_Operations_Tables

Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2013
Discontinued Operations And Disposal Groups [Abstract]	'
Results of Operations Associated with Discontinued Operations	'
	The results of operations associated with these discontinued operations for the three-month and nine-month periods ended September 30, 2013 and 2012 were as follows:
		Three-Months				Nine-Months
		Ended September 30,				Ended September 30,
	(Thousands of dollars)	2013		2012		2013		2012
	Revenues	$	2,963,739		4,507,328		11,686,213		13,353,927
	Income before income taxes, including pretax gain on disposals of $130,568 during the nine-month periods in 2013	$	52,371		40,039		381,941		184,105
	Income tax expense		19,677		25,038		18,809		90,202
	Income from discontinued operations	$	32,694		15,001		363,132		93,903

Cash_Flow_Disclosures_Tables

Cash Flow Disclosures (Tables)	9 Months Ended
	Sep. 30, 2013
Supplemental Cash Flow Elements [Abstract]	'
Cash Flow Activities	'
	Additional disclosures regarding cash flow activities are provided below.
		Nine Months
		Ended September 30,
	(Thousands of dollars)	2013			2012
	Net (increase) decrease in operating working capital other than cash and cash equivalents (from continuing operations):
	(Increase) decrease in accounts receivable	$	(60,558	)		94,145
	Increase in inventories		(92,916	)		(156,973	)
	Increase in prepaid expenses		(53,554	)		(141,267	)
	Decrease in deferred income tax assets		41,714			35,277
	Increase (decrease) in accounts payable and accrued liabilities		199,301			(131,701	)
	Increase in current income tax liabilities		189,994			48,385
	Total	$	223,981			(252,134	)
	Supplementary disclosures (including discontinued operations):
	Cash income taxes paid	$	323,965			414,676
	Interest paid, net of amounts capitalized		16,063			1,077

Employee_and_Retiree_Benefit_P1

Employee and Retiree Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Compensation And Retirement Disclosure [Abstract]	'
Components of Net Periodic Benefit Expense	'
	The table that follows provides the components of net periodic benefit expense for the three-month and nine-month periods ended September 30, 2013 and 2012.
		Three Months Ended September 30,
								Other
		Pension Benefits						Postretirement Benefits
	(Thousands of dollars)	2013			2012			2013			2012
	Service cost	$	7,252			6,030			1,232			1,049
	Interest cost		8,450			7,549			1,352			1,342
	Expected return on plan assets		(8,257	)		(6,520	)		0			0
	Amortization of prior service cost		262			313			(35	)		(42	)
	Amortization of transitional asset		125			112			2			2
	Recognized actuarial loss		4,591			3,846			391			453
	Special termination benefits		849			0			0			0
	Curtailments		1,366			0			(443	)		0
	Net periodic benefit expense	$	14,638			11,330			2,499			2,804
		Nine Months Ended September 30,
								Other
		Pension Benefits						Postretirement Benefits
	(Thousands of dollars)	2013			2012			2013			2012
	Service cost	$	21,949			17,953			3,629			3,139
	Interest cost		22,581			22,386			3,865			4,133
	Expected return on plan assets		(21,526	)		(19,345	)		0			0
	Amortization of prior service cost		841			938			(121	)		(131	)
	Amortization of transitional asset		366			339			6			6
	Recognized actuarial loss		12,882			11,460			1,321			1,394
	Special termination benefits		849			6,170			0			0
	Curtailments		1,366			0			(443	)		0
	Net periodic benefit expense	$	39,308			39,901			8,257			8,541

Incentive_Plans_Tables

Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Share-Based Plans, Amounts Recognized	'
	Amounts recognized in the financial statements with respect to share-based plans are as follows:
		Nine Months Ended
		September 30,
	(Thousands of dollars)	2013		2012
	Compensation charged against income before tax benefit	$	51,085		33,952
	Related income tax benefit recognized in income		9,494		8,007

Earnings_per_Share_Tables

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Weighted-Average Shares Outstanding for Computation of Basic and Diluted Income Per Common Share	'
	The following table reconciles the weighted-average shares outstanding used for these computations.
		Three Months Ended				Nine Months Ended
		September 30,				September  30,
	(Weighted-average shares)	2013		2012		2013		2012
	Basic method		186,938,328		194,290,277		188,914,000		194,126,104
	Dilutive stock options and restricted stock units		1,399,183		767,675		1,331,166		748,468
	Diluted method		188,337,511		195,057,952		190,245,166		194,874,572
Anti Dilutive Securities Not Included in Computation of Diluted EPS	'
	The following table reflects certain options to purchase shares of common stock that were outstanding during the 2013 and 2012 periods but were not included in the computation of diluted EPS above because the incremental shares from assumed conversion were antidilutive.
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2013		2012		2013		2012
	Antidilutive stock options excluded from diluted shares		1,165,464		3,538,507		941,155		3,276,850
	Weighted average price of these options	$	54.56	$	63.83	$	54.4	$	65.01

Income_Taxes_Tables

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Effective Income Tax Rates	'
	For the three-month and nine-month periods in 2013 and 2012, the Company’s effective income tax rates were as follows:
		2013			2012
	Three months ended September 30		43.9	%		43.9	%
	Nine months ended September 30		45.3	%		41.2	%

Financial_Instruments_and_Risk1

Financial Instruments and Risk Management (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
WTI Open Contracts	'
	WTI open contracts were as follows:
	Dates	Volumes				Swap Prices
		(barrels per day)
	October – December 2013		10,000			$	101.55 per barrel
	January – March 2014		20,000			$	98.47 per barrel
	April – June 2014		20,000			$	96.48 per barrel
	July – September 2014		6,000			$	95.27 per barrel
Fair Value of Derivative Instruments Not Designated as Hedging Instruments	'
	At September 30, 2013 and December 31, 2012, the fair value of derivative instruments not designated as hedging instruments are presented in the following table.
		September 30, 2013						December 31, 2012
	(Thousands of dollars)	Asset (Liability) Derivatives						Asset (Liability) Derivatives
	Type of Derivative Contract	Balance Sheet Location		Fair Value				Balance Sheet Location		Fair Value
	Commodity	Accounts receivable		$	1,385			Accounts receivable		$	3,043
	Commodity	Accounts payable			(1,138	)		Accounts payable			(102	)
	Foreign exchange	Accounts payable			(4,096	)		Accounts payable			(1,031	)
Recognized Gains and Losses for Derivative Instruments Not Designated as Hedging Instruments	'
	For the three-month and nine-month periods ended September 30, 2013 and 2012, the gains and losses recognized in the Consolidated Statements of Income for derivative instruments not designated as hedging instruments are presented in the following table.
				Gain (Loss)
	(Thousands of dollars)	Statement of Income		Three Months Ended								Nine Months Ended
				September 30,								September 30,
	Type of Derivative Contract	Location		2013				2012				2013				2012
	Commodity	Sales and other operating revenues		$	(1,305	)			0				(1,305	)			0
	Commodity	Discontinued operations			2,980				(40,241	)			1,604				(37,978	)
	Foreign exchange	Interest and other income			(2,557	)			6,585				(6,703	)			15,782
				$	(882	)			(33,656	)			(6,404	)			(22,196	)
Carrying Value of Assets and Liabilities Recorded at Fair Value on Recurring Basis	'
	The carrying value of assets and liabilities recorded at fair value on a recurring basis at September 30, 2013 and December 31, 2012 are presented in the following table.
		September 30, 2013																December 31, 2012
	(Thousands of dollars)	Level 1				Level 2				Level 3				Total				Level 1			Level 2			Level 3		Total
	Assets
	Commodity derivative contracts	$	0				1,385				0				1,385				0			3,043			0		3,043
	Liabilities
	Nonqualified employee savings plans	$	(12,219	)			0				0				(12,219	)			(10,293	)		0			0		(10,293	)
	Commodity derivative contracts		0				(1,138	)			0				(1,138	)			0			(102	)		0		(102	)
	Foreign currency exchange derivative contracts		0				(4,096	)			0				(4,096	)			0			(1,031	)		0		(1,031	)
		$	(12,219	)			(5,234	)			0				(17,453	)			(10,293	)		(1,133	)		0		(11,426	)
Offsetting of Assets and Liabilities Related to Derivative Contracts	'
	The Company offsets certain assets and liabilities related to derivative contracts when the legal right of offset exists. No offsetting of assets and liabilities on derivative contracts occurred at September 30, 2013. Derivative assets and liabilities which have offsetting positions at December 31, 2012 are presented in the following tables.
		Gross Amounts				Gross Amounts				Net Amounts of
		of Recognized				Offset in the				Assets Presented
						Consolidated				in the Consolidated
		Assets				Balance Sheet				Balance Sheet
	(Thousands of dollars)
	At December 31, 2012
	Commodity derivatives	$	3,111				(2,169	)			942
		Gross Amounts				Gross Amounts				Net Amounts of
		of Recognized				Offset in the				Liabilities Presented
		Liabilities				Consolidated				in the Consolidated
						Balance Sheet				Balance Sheet
	(Thousands of dollars)
	At December 31, 2012
	Commodity derivatives	$	2,271				(2,169	)			102

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Components of Accumulated Other Comprehensive Income	'
	The components of Accumulated Other Comprehensive Income (AOCI) on the Consolidated Balance Sheets at September 30, 2013 and the changes during the three month periods ended September 30, 2013 are presented net of taxes in the following table.
		Foreign			Retirement			Deferred			Total1
		Currency			and			Loss on
		Translation			Postretirement			Interest
		Gains			Benefit Plan			Rate
		(Losses)1			Adjustments1			Derivative
								Hedges1
	(Thousands of dollars)
	Balance at January 1, 2013		613,492			(186,539	)		(18,052	)		408,901
	Components of other comprehensive income (loss):
	Before reclassifications to income		(139,944	)		(237	)		0			(140,181	)
	Reclassifications to income		0			8,787	2		1,453	3		10,240
	Net other comprehensive income (loss)		(139,944	)		8,550			1,453			(129,941	)
	Balance at September 30, 2013		473,548			(177,989	)		(16,599	)		278,960

Business_Segments_Tables

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment Reporting Information by Business Segments	'
					Three Months Ended						Three Months Ended
					Sept. 30, 2013						Sept. 30, 20121
	(Millions of dollars)		Total Assets		External			Income			External			Income
			at Sept. 30,		Revenues			(Loss)			Revenues			(Loss)
			2013
	Exploration and production2
	United States		$	4,278.60		512			151.3			248.8			33.5
	Canada			4,286.40		316.4			77.3			232.8			29.3
	Malaysia			5,953.70		538			183.8			602.2			215.7
	Republic of the Congo			78.5		0			(10.8	)		0			(4.7	)
	Other			107.3		0			(137.4	)		0			(52.7	)
	Total			14,704.50		1,366.40			264.2			1,083.80			221.1
	Refining and marketing – U.K.			1,161.50		1,538.40			(12.9	)		1,571.40			25.5
	Total operating segments			15,866.00		2,904.80			251.3			2,655.20			246.6
	Corporate			1,625.10		53.1			0.8			(8.5	)		(34.9	)
	Assets/revenue/income from continuing operations			17,491.10		2,957.90			252.1			2,646.70			211.7
	Discontinued operations, net of tax			0		0			32.7			0			15
	Total		$	17,491.10		2,957.90			284.8			2,646.70			226.7
					Nine Months Ended						Nine Months Ended
					Sept. 30, 2013						Sept. 30, 20121
					External			Income			External			Income
	(Millions of dollars)				Revenues			(Loss)			Revenues			(Loss)
	Exploration and production2
	United States				$	1,365.10			368			671.6			83.1
	Canada					894			142.3			804.7			146.3
	Malaysia					1,652.70			602.5			1,777.50			662.9
	Republic of the Congo					69.5			(37.3	)		57.6			(8.4	)
	Other					(.6	)		(289.2	)		0.1			(123.9	)
	Total					3,980.70			786.3			3,311.50			760
	Refining and marketing – U.K.					4,295.50			(22.7	)		4,668.10			35.7
	Total operating segments					8,276.20			763.6			7,979.60			795.7
	Corporate					61.7			(78.7	)		5.4			(77.4	)
	Revenue/income from continuing operations					8,337.90			684.9			7,985.00			718.3
	Discontinued operations, net of tax					0			363.1			0			93.9
	Total				$	8,337.90			1,048.00			7,985.00			812.2
	1	Reclassified to conform to current presentation.
	2	Additional details about results of oil and gas operations are presented in the tables on pages 24 and 25.

Property_Plant_and_Equipment_A

Property, Plant and Equipment - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Total capitalized exploratory well costs	$421,000,000	$445,697,000	$571,776,000	$556,412,000
Exploratory well costs capitalized more than one year	384,600,000	'	'	'
Malaysia	'	'	'	'
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Exploratory well costs capitalized more than one year	262,100,000	'	'	'
United States	'	'	'	'
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Exploratory well costs capitalized more than one year	115,900,000	'	'	'
Brunei	'	'	'	'
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Exploratory well costs capitalized more than one year	$6,600,000	'	'	'

Net_Changes_in_Capitalized_Exp

Net Changes in Capitalized Exploratory Well Costs (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Extractive Industries [Abstract]	'	'
Beginning balance	$445,697	$556,412
Additions pending the determination of proved reserves	28,168	143,863
Reclassifications to proved properties based on the determination of proved reserves	-52,865	-76,633
Capitalized exploratory well costs charged to expense	0	-51,866
Ending balance	$421,000	$571,776

Aging_of_Capitalized_Explorato

Aging of Capitalized Exploratory Well Costs (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
	Well	Well
	Project	Project
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Amount	$421,000	$571,776	$445,697	$556,412
No. of Wells	38	47	'	'
No. of Projects	10	15	'	'
Zero to one year [Member]	'	'	'	'
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Amount	36,424	82,521	'	'
No. of Wells	2	8	'	'
No. of Projects	2	5	'	'
One to two years [Member]	'	'	'	'
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Amount	51,444	90,390	'	'
No. of Wells	6	7	'	'
No. of Projects	0	3	'	'
Two to three years [Member]	'	'	'	'
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Amount	35,504	114,532	'	'
No. of Wells	3	6	'	'
No. of Projects	3	1	'	'
Three years or more [Member]	'	'	'	'
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]	'	'	'	'
Amount	$297,628	$284,333	'	'
No. of Wells	27	26	'	'
No. of Projects	5	6	'	'

Inventories_Additional_Informa

Inventories - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Carrying value of inventories under LIFO method	$285.90	$571.20

Discontinued_Operations_Additi

Discontinued Operations - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended	6 Months Ended	9 Months Ended			1 Months Ended
	Jul. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012		Aug. 30, 2013
							Murphy USA Inc [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]	'	'	'	'	'		'
After tax gain on sale of assets	'	'	'	$216,200,000	'		'
Cash dividends paid prior to spin-off	'	'	'	650,000,000	0	[1]	650,000,000
United kingdom, corporation tax rate, tax relief on oil and gas decommissioning costs	50.00%	'	62.00%	'	'		'
United kingdom, increase in tax expense of discontinued operations	'	$5,500,000	'	'	$5,500,000		'
[1]	Reclassified to conform to current presentation.

Results_of_Operations_Associat

Results of Operations Associated with Discontinued Operations (Detail) (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Discontinued Operations And Disposal Groups [Abstract]	'	'		'	'
Revenues	$2,963,739	$4,507,328		$11,686,213	$13,353,927
Income before income taxes, including pretax gain on disposals of $130,568 during the nine-month periods in 2013	52,371	40,039		381,941	184,105
Income tax expense	19,677	25,038		18,809	90,202
Income from discontinued operations	$32,694	$15,001	[1]	$363,132	$93,903	[1]
[1]	Reclassified to conform to current presentation.

Results_of_Operations_Associat1

Results of Operations Associated with Discontinued Operations (Parenthetical) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Discontinued Operations And Disposal Groups [Abstract]	'
Gain on disposal	$130,568

Financing_Arrangements_and_Deb1

Financing Arrangements and Debt - Additional Information (Detail) (USD $)	1 Months Ended	9 Months Ended
	Jun. 30, 2013	Sep. 30, 2013
Debt Disclosure [Abstract]	'	'
Credit facility maximum borrowing capacity	'	$2,000,000,000
Credit facility, maturity date	'	30-Jun-17
Credit facility interest rate above LIBOR	'	1.25%
Line of credit facility fee	'	0.25%
Capital lease term	'25 years	'
Capital lease payment period	'15 years	'
Capital lease expiration date	'	30-Jun-28
Lease obligation	'	$354,818,000

Cash_Flow_Activities_Detail

Cash Flow Activities (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Net (increase) decrease in operating working capital other than cash and cash equivalents (from continuing operations):	'	'
(Increase) decrease in accounts receivable	($60,558)	$94,145
Increase in inventories	-92,916	-156,973
Increase in prepaid expenses	-53,554	-141,267
Decrease in deferred income tax assets	41,714	35,277
Increase (decrease) in accounts payable and accrued liabilities	199,301	-131,701
Increase in current income tax liabilities	189,994	48,385
Total	223,981	-252,134	[1]
Supplementary disclosures (including discontinued operations):	'	'
Cash income taxes paid	323,965	414,676
Interest paid, net of amounts capitalized	$16,063	$1,077
[1]	Reclassified to conform to current presentation.

Components_of_Net_Periodic_Ben

Components of Net Periodic Benefit Expense (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Benefits [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost	$7,252	$6,030	$21,949	$17,953
Interest cost	8,450	7,549	22,581	22,386
Expected return on plan assets	-8,257	-6,520	-21,526	-19,345
Amortization of prior service cost	262	313	841	938
Amortization of transitional asset	125	112	366	339
Recognized actuarial loss	4,591	3,846	12,882	11,460
Special termination benefits	849	0	849	6,170
Curtailments	1,366	0	1,366	0
Net periodic benefit expense	14,638	11,330	39,308	39,901
Other Postretirement Benefits [Member]	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'
Service cost	1,232	1,049	3,629	3,139
Interest cost	1,352	1,342	3,865	4,133
Expected return on plan assets	0	0	0	0
Amortization of prior service cost	-35	-42	-121	-131
Amortization of transitional asset	2	2	6	6
Recognized actuarial loss	391	453	1,321	1,394
Special termination benefits	0	0	0	0
Curtailments	-443	0	-443	0
Net periodic benefit expense	$2,499	$2,804	$8,257	$8,541

Employee_and_Retiree_Benefit_P2

Employee and Retiree Benefit Plans - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013
Compensation And Retirement Disclosure [Abstract]	'
Contributions to benefit plans	$41,200,000
Expected benefit plan contributions to be made during the year	7,300,000
Provisions of the March 2010 Health Care Reform	'In March 2010, the United States Congress enacted a health care reform law. Along with other provisions, the law (a) eliminates the tax free status of federal subsidies to companies with qualified retiree prescription drug plans that are actuarially equivalent to Medicare Part D plans beginning in 2013; (b) imposes a 40% excise tax on high-cost health plans as defined in the law beginning in 2018; (c) eliminated lifetime or annual coverage limits and required coverage for preventative health services beginning in September 2010; and (d) imposed a fee of $2 (subsequently adjusted for inflation) for each person covered by a health insurance policy beginning in September 2010.
Excise tax rate imposed on high-cost health plans beginning 2018	40.00%
Government imposed fee for each person covered by health insurance policy	$2

Incentive_Plans_Additional_Inf

Incentive Plans - Additional Information (Detail) (USD $)

9 Months Ended

9 Months Ended

1 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Feb. 05, 2013

Feb. 05, 2013

Sep. 30, 2013

Employee Stock Purchase Plan [Member]

Stock Options [Member]

Stock Options [Member]

Stock Options [Member]

Performance-Based Restricted Stock Units [Member]

Performance-Based Restricted Stock Units [Member]

Performance-Based Restricted Stock Units [Member]

Time Based Restricted Stock Units (RSU) [Member]

Time Based Restricted Stock Units (RSU) [Member]

Time Based Restricted Stock Units (RSU) [Member]

Time Based Restricted Stock Units (RSU) [Member]

Stock Appreciation Rights (SAR) [Member]

Restricted Stock-Cash (RSU-C) [Member]

2012 Long-Term Plan [Member]

Minimum [Member]

Maximum [Member]

Minimum [Member]

Maximum [Member]

Non-employee Director Plan [Member]

Non-employee Director Plan [Member]

Non-employee Director Plan [Member]

Former Chief Executive Officer [Member]

Minimum [Member]

Maximum [Member]

Compensation Related Costs Share Based Payments Disclosure [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Maximum number of shares available for issuance

'

'

980,000

'

'

'

'

'

'

'

'

'

'

'

'

8,700,000

Maximum number of shares available for issuance, annual rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.00%

Long term plan expiration year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'2022

Granted stock options

'

'

'

1,320,176

'

'

'

'

'

'

'

'

'

851,000

'

'

Granted stock options, exercise price

'

'

'

'

$60.02

$70.72

'

'

'

'

'

'

'

'

'

'

Stock-based compensation, fair value assumption model

'

'

'

'Black-Scholes valuation model

'

'

'Monte Carlo valuation model

'

'

'

'

'

'

'

'

'

Granted stock options, valuation per option

'

'

'

'

$15.81

$20.62

'

'

'

'

'

'

'

'

'

'

Granted restricted stock

'

'

'

'

'

'

496,076

'

'

38,184

'

'

25,000

'

93,200

'

Granted restricted stock, fair value

'

'

'

'

'

'

'

$39.50

$68.01

'

$60.30

$69.67

$69.67

'

'

'

Granted restricted stock, vesting scheme

'

'

'

'

'

'

'

'

'

'These shares vest on the third anniversary of the date of grant.

'

'

'Vest on January 2, 2014

'

'

'

Proceeds from exercise of stock options and employee stock purchase plans

$2,778,000

$11,138,000

[1]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Income tax benefits realized for the tax deductions from option exercises

$6,300,000

$3,300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Reclassified to conform to current presentation.

ShareBased_Plans_Amounts_Recog

Share-Based Plans, Amounts Recognized (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'	'
Compensation charged against income before tax benefit	$51,085	$33,952
Related income tax benefit recognized in income	$9,494	$8,007

WeightedAverage_Shares_Outstan

Weighted-Average Shares Outstanding for Computation of Basic and Diluted Income Per Common Share (Detail)	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]	'	'		'	'
Basic method	186,938,328	194,290,277	[1]	188,914,000	194,126,104	[1]
Dilutive stock options and restricted stock units	1,399,183	767,675		1,331,166	748,468
Diluted method	188,337,511	195,057,952	[1]	190,245,166	194,874,572	[1]
[1]	Reclassified to conform to current presentation.

Anti_Dilutive_Securities_Not_I

Anti Dilutive Securities Not Included in Computation of Diluted EPS (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]	'	'	'	'
Antidilutive stock options excluded from diluted shares	1,165,464	3,538,507	941,155	3,276,850
Weighted average price of these options	$54.56	$63.83	$54.40	$65.01

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Income Tax Examination [Line Items]	'	'
U.S. Federal statutory income tax rate	'	35.00%
Tax benefit recognized	$13.70	'
United States	'	'
Income Tax Examination [Line Items]	'	'
Earliest year remaining open for audit and/or settlement in major taxing jurisdictions	'	'2010
Canada	'	'
Income Tax Examination [Line Items]	'	'
Earliest year remaining open for audit and/or settlement in major taxing jurisdictions	'	'2007
United Kingdom	'	'
Income Tax Examination [Line Items]	'	'
Earliest year remaining open for audit and/or settlement in major taxing jurisdictions	'	'2011
Malaysia	'	'
Income Tax Examination [Line Items]	'	'
Earliest year remaining open for audit and/or settlement in major taxing jurisdictions	'	'2006

Effective_Income_Tax_Rates_Det

Effective Income Tax Rates (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]	'	'	'	'
Effective income tax rate	43.90%	43.90%	45.30%	41.20%

WTI_Open_Contracts_Detail

WTI Open Contracts (Detail)	Sep. 30, 2013
	bbl
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'
Number of barrels	2,900
Natural gas deliveries contract average price per thousand cubic feet	55.05
October to December 2013 [Member]	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'
Number of barrels	10,000
Natural gas deliveries contract average price per thousand cubic feet	101.55
January to March 2014 [Member]	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'
Number of barrels	20,000
Natural gas deliveries contract average price per thousand cubic feet	98.47
April to June 2014 [Member]	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'
Number of barrels	20,000
Natural gas deliveries contract average price per thousand cubic feet	96.48
July to September 2014 [Member]	'
Derivative Instruments and Hedging Activities Disclosures [Line Items]	'
Number of barrels	6,000
Natural gas deliveries contract average price per thousand cubic feet	95.27

Financial_Instruments_and_Risk2

Financial Instruments and Risk Management - Additional Information (Detail) (USD $)

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

bbl

Scenario, Forecast [Member]

Commodity derivative contracts [Member]

Commodity derivative contracts [Member]

Commodity derivative contracts [Member]

Foreign exchange derivative contract [Member]

Foreign exchange derivative contract [Member]

Foreign exchange derivative contract [Member]

Foreign exchange derivative contract [Member]

Foreign exchange derivative contract [Member]

Interest Rate Swap [Member]

Income from continuing operations [Member]

Income from discontinued operations [Member]

Income from discontinued operations [Member]

Currency, Malaysian ringgit [Member]

Currency, Malaysian ringgit [Member]

Currency, U.S. Dollar

Derivative Instruments and Hedging Activities Disclosures [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Crude oil swap contracts to hedge

1,500

'

'

'

'

'

'

'

'

'

'

'

Estimated netback price of contracts

55.05

'

'

'

'

'

'

'

'

'

'

'

Increase (decrease) in income before taxes due to the impact of marking to market of derivative contracts

'

'

'

$1,600,000

'

'

($4,100,000)

$3,100,000

'

'

'

'

Amount of Gain (Loss) Recognized in Income on Derivative

'

'

'

'

1,600,000

38,000,000

'

'

'

'

'

'

Short-term derivative instruments

'

'

'

'

'

'

'

'

76,000,000

97,600,000

28,000,000

'

Maturities of notes payable

0

350,000,000

[1]

'

'

'

'

'

'

'

'

'

'

Deferred loss charged to income

2,300,000

1,100,000

'

'

'

'

'

'

'

'

'

'

Loss deferred for fair value of interest rate derivative contracts, net of tax

'

'

'

'

'

'

'

'

'

'

'

25,600,000

Loss deferred for fair value of interest rate derivative contracts

'

'

'

'

'

'

'

'

'

'

'

9,000,000

Interest expense due to deferred loss on interest rate swaps expected during the remaining three months of 2013

'

'

$700,000

'

'

'

'

'

'

'

'

'

[1]

Reclassified to conform to current presentation.

Fair_Value_of_Derivative_Instr

Fair Value of Derivative Instruments Not Designated as Hedging Instruments (Detail) (Nondesignated [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Commodity derivative contracts [Member] | Accounts Payable [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Liability Derivatives	($1,138)	($102)
Commodity derivative contracts [Member] | Accounts Receivable [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Asset Derivatives	1,385	3,043
Foreign exchange derivative contract [Member] | Accounts Payable [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Liability Derivatives	($4,096)	($1,031)

Recognized_Gains_and_Losses_fo

Recognized Gains and Losses for Derivative Instruments Not Designated as Hedging Instruments (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Commodity derivative contracts [Member] | Income from discontinued operations [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain (Loss) Recognized in Income on Derivative	'	'	$1,600	$38,000
Nondesignated [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain (Loss) Recognized in Income on Derivative	-882	-33,656	-6,404	-22,196
Nondesignated [Member] | Commodity derivative contracts [Member] | Sales and other operating revenues [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain (Loss) Recognized in Income on Derivative	-1,305	0	-1,305	0
Nondesignated [Member] | Commodity derivative contracts [Member] | Income from discontinued operations [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain (Loss) Recognized in Income on Derivative	2,980	-40,241	1,604	-37,978
Nondesignated [Member] | Foreign exchange derivative contract [Member] | Interest and other income [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Amount of Gain (Loss) Recognized in Income on Derivative	($2,557)	$6,585	($6,703)	$15,782

Carrying_Value_of_Assets_and_L

Carrying Value of Assets and Liabilities Recorded at Fair Value on Recurring Basis (Detail) (Fair Value, Measurements, Recurring [Member], USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	($17,453)	($11,426)
Commodity derivative contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative assets	1,385	3,043
Derivative liabilities	-1,138	-102
Nonqualified Employee Savings Plans [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	-12,219	-10,293
Foreign exchange derivative contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	-4,096	-1,031
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	-12,219	-10,293
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commodity derivative contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative assets	0	0
Derivative liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Nonqualified Employee Savings Plans [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	-12,219	-10,293
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Foreign exchange derivative contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	-5,234	-1,133
Significant Other Observable Inputs (Level 2) [Member] | Commodity derivative contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative assets	1,385	3,043
Derivative liabilities	-1,138	-102
Significant Other Observable Inputs (Level 2) [Member] | Nonqualified Employee Savings Plans [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member] | Foreign exchange derivative contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	-4,096	-1,031
Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Commodity derivative contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative assets	0	0
Derivative liabilities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Nonqualified Employee Savings Plans [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Foreign exchange derivative contract [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]	'	'
Derivative liabilities	$0	$0

Offsetting_of_Assets_and_Liabi

Offsetting of Assets and Liabilities Related to Derivative Contracts (Detail) (Commodity derivatives [Member], USD $)	Dec. 31, 2012
In Thousands, unless otherwise specified
Commodity derivatives [Member]	'
Derivative Financial Instruments [Line Items]	'
Gross Amounts of Recognized Assets	$3,111
Gross Amounts Offset in the Consolidated Balance Sheet	-2,169
Net Amounts of Assets Presented in the Consolidated Balance Sheet	942
Gross Amounts of Recognized Liabilities	2,271
Gross Amounts Offset in the Consolidated Balance Sheet	-2,169
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	$102

Components_of_Accumulated_Othe

Components of Accumulated Other Comprehensive Income (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Beginning Balance	$408,901	[1]
Before reclassifications to income	-140,181	[1]
Reclassifications to income	10,240	[1]
Net other comprehensive income (loss)	-129,941	[1]
Ending Balance	278,960	[1]
Foreign Currency Translation Gains (Losses) [Member]	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Beginning Balance	613,492	[1]
Before reclassifications to income	-139,944	[1]
Reclassifications to income	0	[1]
Net other comprehensive income (loss)	-139,944	[1]
Ending Balance	473,548	[1]
Retirement and Postretirement Benefit Plan Adjustments [Member]	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Beginning Balance	-186,539	[1]
Before reclassifications to income	-237	[1]
Reclassifications to income	8,787	[1],[2]
Net other comprehensive income (loss)	8,550	[1]
Ending Balance	-177,989	[1]
Deferred Loss On Interest Rate Derivative Hedges [Member]	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'
Beginning Balance	-18,052	[1]
Before reclassifications to income	0	[1]
Reclassifications to income	1,453	[1],[3]
Net other comprehensive income (loss)	1,453	[1]
Ending Balance	($16,599)	[1]
[1]	All amounts are presented net of income taxes.
[2]	Reclassifications before taxes of $15,610 for the nine-month period ended September 30, 2013 are included in the computation of net periodic benefit expense. See Note G for additional information. Related income taxes of $6,823 for the nine-month period ended September 30, 2013 are included in Income tax expense.
[3]	Reclassifications before taxes of $2,223 for the nine-month period ended September 30, 2013 are included in Interest expense. Related income taxes of $770 for the nine-month period ended September 30, 2013 are included in Income tax expense.

Components_of_Accumulated_Othe1

Components of Accumulated Other Comprehensive Income (Parenthetical) (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]	'
Reclassifications before taxes	$15,610
Reclassifications income tax	6,823
Reclassifications before taxes	2,223
Reclassifications income tax	$770

Environmental_and_Other_Contin1

Environmental and Other Contingencies - Additional Information (Detail) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified	Location
Commitments and Contingencies Disclosure [Line Items]	'
Superfund site company is considered to be Potentially Responsible Party (PRP)	1
Letter of Credit [Member]	'
Commitments and Contingencies Disclosure [Line Items]	'
Contingent liabilities	22.8

Commitments_Additional_Informa

Commitments - Additional Information (Detail)	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	bbl	October through December 2013 Deliveries [Member]	2014 Deliveries [Member]
		MMcf	MMcf
Commitments and Contingencies Disclosure [Line Items]	'	'	'
Natural gas deliveries contract, cubic feet per day	'	77	50
Number of barrels	2,900	'	'
Netback values	50.89	'	'
Natural gas deliveries contract, average price per thousand cubic feet, in Canadian dollars	55.05	3.76	4.01

Segment_Reporting_Information_

Segment Reporting Information by Business Segments (Detail) (USD $)	3 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012		Dec. 31, 2012
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	$17,491,086	'		$17,491,086		'		$17,522,643
External Revenues	2,957,857	2,646,728	[1]	8,337,890	[1]	7,984,987	[1]	'
Income (Loss)	284,809	226,681	[1]	1,048,052	[1]	812,189	[1]	'
Operating Segments [Member]	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	15,866,000	'		15,866,000		'		'
External Revenues	2,904,800	2,655,200	[1]	8,276,200	[1]	7,979,600	[1]	'
Income (Loss)	251,300	246,600	[1]	763,600	[1]	795,700	[1]	'
Corporate, Non-Segment [Member]	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	1,625,100	'		1,625,100		'		'
External Revenues	53,100	-8,500	[1]	61,700	[1]	5,400	[1]	'
Income (Loss)	800	-34,900	[1]	-78,700	[1]	-77,400	[1]	'
Exploration and production [Member] | Operating Segments [Member]	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	14,704,500	'		14,704,500		'		'
External Revenues	1,366,400	1,083,800	[1],[2]	3,980,700	[1],[2]	3,311,500	[1],[2]	'
Income (Loss)	264,200	221,100	[1],[2]	786,300	[1],[2]	760,000	[1],[2]	'
Exploration and production [Member] | Operating Segments [Member] | United States	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	4,278,600	'		4,278,600		'		'
External Revenues	512,000	248,800	[1],[2]	1,365,100	[1],[2]	671,600	[1],[2]	'
Income (Loss)	151,300	33,500	[1],[2]	368,000	[1],[2]	83,100	[1],[2]	'
Exploration and production [Member] | Operating Segments [Member] | Canada	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	4,286,400	'		4,286,400		'		'
External Revenues	316,400	232,800	[1],[2]	894,000	[1],[2]	804,700	[1],[2]	'
Income (Loss)	77,300	29,300	[1],[2]	142,300	[1],[2]	146,300	[1],[2]	'
Exploration and production [Member] | Operating Segments [Member] | Malaysia	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	5,953,700	'		5,953,700		'		'
External Revenues	538,000	602,200	[1],[2]	1,652,700	[1],[2]	1,777,500	[1],[2]	'
Income (Loss)	183,800	215,700	[1],[2]	602,500	[1],[2]	662,900	[1],[2]	'
Exploration and production [Member] | Operating Segments [Member] | Republic of the Congo	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	78,500	'		78,500		'		'
External Revenues	0	0	[1],[2]	69,500	[1],[2]	57,600	[1],[2]	'
Income (Loss)	-10,800	-4,700	[1],[2]	-37,300	[1],[2]	-8,400	[1],[2]	'
Exploration and production [Member] | Operating Segments [Member] | Other Regions [Member]	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	107,300	'		107,300		'		'
External Revenues	0	0	[1],[2]	-600	[1],[2]	100	[1],[2]	'
Income (Loss)	-137,400	-52,700	[1],[2]	-289,200	[1],[2]	-123,900	[1],[2]	'
Refining and Marketing [Member] | Operating Segments [Member] | United Kingdom	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	1,161,500	'		1,161,500		'		'
External Revenues	1,538,400	1,571,400	[1]	4,295,500	[1]	4,668,100	[1]	'
Income (Loss)	-12,900	25,500	[1]	-22,700	[1]	35,700	[1]	'
Continuing Operations [Member]	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	17,491,100	'		17,491,100		'		'
External Revenues	2,957,900	2,646,700	[1]	8,337,900	[1]	7,985,000	[1]	'
Income (Loss)	252,100	211,700	[1]	684,900	[1]	718,300	[1]	'
Discontinued Operations [Member]	'	'		'		'		'
Segment Reporting Disclosure [Line Items]	'	'		'		'		'
Total Assets	0	'		0		'		'
External Revenues	0	0	[1]	0	[1]	0	[1]	'
Income (Loss)	$32,700	$15,000	[1]	$363,100	[1]	$93,900	[1]	'
[1]	Reclassified to conform to current presentation.
[2]	Additional details about results of oil and gas operations are presented in the tables on pages 24 and 25.