Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,613	$ 563
Receivables, less reserve of $9 and $12	1,100	1,082
Notes receivable	0	748
Inventories	110	126
Other current assets	66	36
Current assets held for sale	13	11
Total current assets	2,902	2,566
Equity method investments	806	847
Property, plant and equipment, less accumulated depreciation, depletion and amortization of $21,872 and $21,564	16,931	17,665
Goodwill	98	115
Other noncurrent assets	849	764
Noncurrent assets held for sale	48	55
Total assets	21,634	22,012
Current liabilities:
Accounts payable	1,335	1,395
Payroll and benefits payable	85	108
Accrued taxes	128	177
Other current liabilities	359	288
Current liabilities held for sale	2	0
Total current liabilities	1,909	1,968
Long-term debt	5,495	5,494
Deferred tax liabilities	221	833
Defined benefit postretirement plan obligations	331	362
Asset retirement obligations	1,445	1,428
Deferred credit and other liabilities	197	217
Noncurrent liabilities held for sale	2	2
Total liabilities	9,600	10,304
Commitments and contingencies
Stockholders' Equity
Preferred stock - no shares issued or outstanding (no par value, 26 million shares authorized)	0	0
Issued – 937 million shares and 937 million shares (par value $1 per share, 1.1 billion shares authorized)	937	937
Held in treasury, at cost – 84 million and 87 million shares	(3,175)	(3,325)
Additional paid-in capital	7,237	7,379
Retained earnings	7,093	6,779
Accumulated other comprehensive loss	(58)	(62)
Total stockholders' equity	12,034	11,708
Total liabilities and stockholders' equity	$ 21,634	$ 22,012