Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,221	$ 2,398
Receivables, less reserve of $4 and $3	912	1,729
Inventories	313	357
Other current assets	144	109
Total current assets	2,590	4,593
Equity method investments	1,003	1,113
Property, plant and equipment, less accumulated depreciation, depletion and amortization of $23,260 and $21,884	27,061	29,040
Goodwill	115	459
Other noncurrent assets	1,542	778
Total assets	32,311	35,983
Current liabilities:
Accounts payable	1,313	2,545
Payroll and benefits payable	133	191
Accrued taxes	132	285
Other current liabilities	150	290
Long-term debt due within one year	1	1,068
Total current liabilities	1,729	4,379
Long-term debt	7,276	5,295
Deferred tax liabilities	2,441	2,486
Defined benefit postretirement plan obligations	403	598
Asset retirement obligations	1,601	1,917
Deferred credit and other liabilities	308	288
Total liabilities	$ 13,758	$ 14,963
Commitments and contingencies
Stockholders’ Equity
Preferred stock no shares issued or 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
Common stock, held in treasury, at cost – 93 million and 95 million shares	(3,554)	(3,642)
Additional paid-in capital	6,498	6,531
Retained earnings	14,974	17,638
Accumulated other comprehensive loss	(135)	(277)
Total stockholders equity	18,553	21,020
Total liabilities and stockholders equity	$ 32,311	$ 35,983