CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
CURRENT ASSETS
Cash and cash equivalents	$ 486	$ 406
Accounts receivable, less allowance of $162 and $191	1,883	1,962
Other	924	808
Total current assets	3,293	3,176
Property, plant and equipment, net of accumulated depreciation of $32,214 and $31,596	26,091	26,338
GOODWILL AND OTHER ASSETS
Goodwill	18,854	18,870
Other intangible assets, net	7,884	8,219
Other, net	2,706	2,791
Total goodwill and other assets	29,444	29,880
TOTAL ASSETS	58,828	59,394
CURRENT LIABILITIES
Current maturities of long-term debt	3,841	2,427
Accounts payable	1,017	1,134
Accrued expenses and other liabilities
Salaries and benefits	846	1,008
Income and other taxes	346	314
Current operating lease liabilities	387	379
Interest	285	291
Other	307	328
Current portion of deferred revenue	758	753
Total current liabilities	7,787	6,634
LONG-TERM DEBT	27,599	29,410
DEFERRED CREDITS AND OTHER LIABILITIES
Deferred income taxes, net	3,471	3,342
Benefit plan obligations, net	4,435	4,556
Other	4,233	4,290
Total deferred credits and other liabilities	12,139	12,188
COMMITMENTS AND CONTINGENCIES (Note 12)
STOCKHOLDERS' EQUITY
Preferred stock—non-redeemable, $25.00 par value, authorized 2,000 and 2,000 shares, issued and outstanding 7 and 7 shares	0	0
Common stock, $1.00 par value, authorized 2,200,000 and 2,200,000 shares, issued and outstanding 1,105,533 and 1,096,921 shares	1,106	1,097
Additional paid-in capital	20,598	20,909
Accumulated other comprehensive loss	(2,845)	(2,813)
Accumulated deficit	(7,556)	(8,031)
Total stockholders' equity	11,303	11,162
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 58,828	$ 59,394