Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 246	$ 684
Receivables	2,443	2,418
Inventories	368	361
Other current assets	224	299
Total current assets	3,281	3,762
Equity method investments	1,244	1,279
Property, plant and equipment, less accumulated depreciation, depletion and amortization of $20,639 and $19,266	27,457	28,272
Goodwill	499	525
Other noncurrent assets	2,567	1,468
Total assets	35,048	35,306
Current liabilities:
Commercial paper	0	200
Accounts payable	2,152	2,324
Payroll and benefits payable	137	217
Accrued taxes	1,397	1,983
Other current liabilities	254	173
Long-term debt due within one year	68	184
Total current liabilities	4,008	5,081
Long-term debt	6,428	6,512
Deferred tax liabilities, noncurrent	2,406	2,432
Defined benefit postretirement plan obligations	739	856
Asset retirement obligations	2,039	1,749
Deferred credits and other liabilities, noncurrent	407	393
Total liabilities	16,027	17,023
Commitments and contingencies
Stockholders' Equity
Preferred stock - no shares issued and outstanding (no par value, 26 million shares authorized)	0	0
Common stock issued - 770 million and 770 million shares (par value $1 per share, 1.1 billion shares authorized)	770	770
Common stock, securities exchangeable into common stock - no shares issued or outstanding (no par value, 29 million shares authorized)	0	0
Held in treasury, at cost - 61 million and 63 million shares	(2,477)	(2,560)
Additional paid-in capital	6,614	6,616
Retained earnings	14,458	13,890
Accumulated other comprehensive loss	(344)	(433)
Total equity	19,021	18,283
Total liabilities and stockholders' equity	$ 35,048	$ 35,306