CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 5,910	$ 5,238
Marketable securities	406	503
Accounts receivable	10,888	9,645
Less: Allowance for credit losses	(138)	(93)
Accounts receivable, net	10,750	9,552
Assets held for sale	1,197	0
Other current assets	1,953	1,810
Total Current Assets	20,216	17,103
Property, Plant and Equipment, Net	32,254	30,482
Operating Lease, Right-of-Use Asset	3,073	2,856
Goodwill	3,367	3,813
Intangible Assets, Net	2,274	2,167
Investments and Restricted Cash	25	24
Deferred Income Tax Assets	527	330
Other Non-Current Assets	672	1,082
Total Assets	62,408	57,857
Current Liabilities:
Current maturities of long-term debt, commercial paper and finance leases	2,623	3,420
Operating Lease, Liability, Current	560	538
Accounts payable	6,455	5,555
Accrued wages and withholdings	3,569	2,552
Self-insurance reserves	1,085	914
Accrued group welfare and retirement plan contributions	927	793
Liabilities to be disposed of	347	0
Other current liabilities	1,450	1,641
Total Current Liabilities	17,016	15,413
Long-Term Debt and Finance Leases	22,031	21,818
Operating Lease, Liability, Noncurrent	2,540	2,391
Pension and Postretirement Benefit Obligations	15,817	10,601
Deferred Income Tax Liabilities, Net	488	1,632
Other Non-Current Liabilities	3,847	2,719
Shareowners' Equity:
Additional paid-in capital	865	150
Retained earnings	6,896	9,105
Accumulated other comprehensive loss	(7,113)	(5,997)
Deferred compensation obligations	20	26
Less: Treasury stock (0.4 shares in 2020 and 2019)	(20)	(26)
Total Equity for Controlling Interests	657	3,267
Noncontrolling Interests	12	16
Total Shareowners’ Equity	669	3,283
Total Liabilities and Shareowners’ Equity	$ 62,408	$ 57,857
Treasury stock, shares	400,000	400,000
Common Class A [Member]
Shareowners' Equity:
Common stock	$ 2	$ 2
Common Class A [Member] | Common Stock
Shareowners' Equity:
Total Equity for Controlling Interests	$ 2	$ 2
Common stock, shares issued	147,000,000	156,000,000
Common Class B [Member]
Shareowners' Equity:
Common stock	$ 7	$ 7
Common Class B [Member] | Common Stock
Shareowners' Equity:
Total Equity for Controlling Interests	$ 7	$ 7
Common stock, shares issued	718,000,000	701,000,000