Condensed Consolidated Statements of Cash Flows $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)
Operating Activities
Net income	$ 1,798	$ 3,139	$ 2,606
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation	550	1,099	1,098
Deferred and other income taxes		128	171
Other operating activities, net		(128)	(9)
Changes in current assets and liabilities:
Accounts receivable, net		(161)	207
Materials and supplies		(50)	83
Other current assets		(3)	(36)
Accounts payable and other current liabilities		73	(197)
Income and other taxes		122	469
Cash provided by operating activities		4,219	4,392
Investing Activities
Capital investments		(1,190)	(1,599)
Proceeds from asset sales		101	107
Maturities of short-term investments (Note 13)		48	75
Purchases of short-term investments (Note 13)		(24)	(75)
Other investing activities, net		(6)	75
Cash used in investing activities		(1,071)	(1,417)
Financing Activities
Share repurchase programs (Note 16)		(4,085)	(2,556)
Debt issued (Note 14)		2,896	4,004
Dividends paid		(1,350)	(1,319)
Debt repaid		(691)	(770)
Debt exchange		(268)
Net issuance/(repayment) of commercial paper (Note 14)		125	(1)
Other financing activities, net		(34)	(65)
Cash used in financing activities		(3,807)	(1,107)
Net change in cash, cash equivalents, and restricted cash		(659)	1,868
Cash, cash equivalents, restricted cash, beginning balance		1,818	856
Cash, cash equivalents, restricted cash, ending balance	1,159	1,159	2,724
Non-cash investing and financing activities:
Capital investments accrued but not yet paid		104	141
Common shares repurchased but not yet paid	32	32
Cash (paid for)/received from:
Income taxes, net of refunds		(712)	(158)
Interest, net of amounts capitalized		(535)	(489)
Reconciliation of cash, cash equivalents, and restricted cash to the Condensed Consolidated Statement of Financial Position
Cash and cash equivalents, at carry value	1,115	1,115	2,706
Cash, cash equivalents, restricted cash, ending balance	1,159	1,159	2,724
Accelerated Share Repurchase Agreement [Member]
Financing Activities
Share repurchase programs (Note 16)		(400)	(400)
Other Current Assets [Member]
Reconciliation of cash, cash equivalents, and restricted cash to the Condensed Consolidated Statement of Financial Position
Restricted Cash and Cash Equivalents	32	32	6
Other Noncurrent Assets [Member]
Reconciliation of cash, cash equivalents, and restricted cash to the Condensed Consolidated Statement of Financial Position
Restricted Cash and Cash Equivalents	$ 12	$ 12	$ 12