CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010
OPERATING ACTIVITIES
Net income	$ 986,630		$ 624,012	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
(Income) loss from discontinued operations	(132,431)		6,066	[1]
Depreciation, depletion and amortization	793,445		828,918	[1]
Amortization of deferred major repair costs	17,357		10,047	[1]
Expenditures for asset retirements	(18,399)		(34,376)	[1]
Dry hole costs	118,585		35,045	[1]
Amortization of undeveloped leases	90,623		76,816	[1]
Accretion of asset retirement obligations	28,494		23,561	[1]
Deferred and noncurrent income tax charges	125,461		38,939	[1]
Pretax gain from disposition of assets	(23,192)		(997)	[1]
Net (increase) decrease in noncash operating working capital	(309,436)		417,237	[1]
Other operating activities, net	36,121		123,663	[1]
Net cash provided by continuing operations	1,713,258		2,148,931	[1]
Net cash provided by discontinued operations	163,489		51,950	[1]
Net cash provided by operating activities	1,876,747		2,200,881	[1]
INVESTING ACTIVITIES
Property additions and dry hole costs	(1,853,939)		(1,532,446)	[1]
Proceeds from sales of assets	27,629		2,195	[1]
Purchase of investment securities	(1,233,321)	[2]	(1,862,609)	[1],[2]
Proceeds from maturity of investment securities	1,356,175	[2]	2,011,386	[1],[2]
Expenditures for major repairs	(2,826)		(58,453)	[1]
Investing activities of discontinued operations, including proceeds from sale of Superior refinery and associated inventories	354,238		(116,757)	[1]
Other - net	7,150		(31,225)	[1]
Net cash required by investing activities	(1,344,894)		(1,587,909)	[1]
FINANCING ACTIVITIES
Borrowings (repayments) of notes payable	384,970		(247,028)	[1]
Repayment of nonrecourse debt of a subsidiary	0		(82,000)	[1]
Proceeds from exercise of stock options and employee stock purchase plans	8,245		26,100	[1]
Excess tax benefits related to exercise of stock options	4,119		9,585	[1]
Withholding tax on stock-based incentive awards	(8,014)		(5,170)	[1]
Issue cost of debt facility	(8,619)		0	[1]
Cash dividends paid	(159,529)		(148,439)	[1]
Net cash provided (required) by financing activities	221,172		(446,952)	[1]
Effect of exchange rate changes on cash and cash equivalents	(9,869)		(4,772)	[1]
Net increase in cash and cash equivalents	743,156		161,248	[1]
Cash and cash equivalents, beginning	535,825		301,144	[1]
Cash and cash equivalents, ending	$ 1,278,981		$ 462,392	[1]

[1] Reclassified to conform to current presentation

[2] Investments are Canadian government securities with maturities greater than 90 days at the date of acquisition.