Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 1,667	$ 563
Receivables, less reserve of $8 and $12	1,176	1,082
Notes receivable	0	748
Inventories	117	126
Other current assets	92	36
Current assets held for sale	35	11
Total current assets	3,087	2,566
Equity method investments	788	847
Property, plant and equipment, less accumulated depreciation, depletion and amortization of $22,336 and $21,564	16,881	17,665
Goodwill	98	115
Other noncurrent assets	860	764
Noncurrent assets held for sale	157	55
Total assets	21,871	22,012
Current liabilities:
Accounts payable	1,428	1,395
Payroll and benefits payable	109	108
Accrued taxes	99	177
Other current liabilities	405	288
Current liabilities held for sale	3	0
Total current liabilities	2,044	1,968
Long-term debt	5,497	5,494
Deferred tax liabilities	237	833
Defined benefit postretirement plan obligations	311	362
Asset retirement obligations	1,364	1,428
Deferred credit and other liabilities	194	217
Noncurrent liabilities held for sale	92	2
Total liabilities	9,739	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, 1.925 billion shares authorized at June 30, 2018 and 1.1 billion shares authorized at December 31, 2017)	937	937
Held in treasury, at cost – 83 million and 87 million shares	(3,137)	(3,325)
Additional paid-in capital	7,227	7,379
Retained earnings	7,146	6,779
Accumulated other comprehensive loss	(41)	(62)
Total stockholders' equity	12,132	11,708
Total liabilities and stockholders' equity	$ 21,871	$ 22,012