CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current assets
Cash and cash equivalents	$ 513,873	$ 535,825	[1]
Canadian government securities with maturities greater than 90 days at the date of acquisition	532,093	616,558
Accounts receivable, less allowance for doubtful accounts of $7,892 in 2011 and $7,954 in 2010	1,554,184	1,467,311
Inventories, at lower of cost or market
Crude oil and blend stocks	189,320	147,256
Finished products	254,880	388,162
Materials and supplies	222,438	226,795
Prepaid expenses	93,397	88,241
Deferred income taxes	87,486	80,545
Total current assets	3,447,671	3,550,693
Property, plant and equipment, at cost less accumulated depreciation, depletion and amortization of $6,861,494 in 2011 and $6,040,996 in 2010	10,475,149	10,367,847
Goodwill	41,863	42,850
Deferred charges and other assets	173,455	271,853
Total assets	14,138,138	14,233,243
Current liabilities
Current maturities of long-term debt	350,005	41
Accounts payable	1,941,008	2,237,920
Income taxes payable	201,784	358,764
Other taxes payable	169,535	206,951
Other accrued liabilities	140,024	109,918
Deferred income taxes	22,572	17,316
Total current liabilities	2,824,928	2,930,910
Long-term debt	249,553	939,350
Deferred income taxes	1,230,111	1,212,213
Asset retirement obligations	615,545	555,248
Deferred credits and other liabilities	439,604	395,972
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 at December 31, 2011 and 2010, issued 193,909,200 shares at December 31, 2011 and 193,293,526 shares at December 31, 2010	193,909	193,294
Capital in excess of par value	817,974	767,762
Retained earnings	7,460,942	6,800,992
Accumulated other comprehensive income	310,420	449,428
Treasury stock	(4,848)	(11,926)
Total stockholders' equity	8,778,397	8,199,550
Total liabilities and stockholders' equity	$ 14,138,138	$ 14,233,243

[1] Reclassified to conform to current presentation.