Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 773	$ 1,399
Reconciliation of net income to net cash provided by operating activities:
Depreciation	574	567
Deferred income taxes	56	133
Gains and losses on properties	(11)	(7)
Loss on asset disposal	385	0
Changes in assets and liabilities affecting operations:
Accounts receivable	98	(30)
Materials and supplies	(13)	(49)
Other current assets	30	55
Current liabilities other than debt	0	(30)
Other – net	(134)	(86)
Net cash provided by operating activities	1,758	1,952
Cash flows from investing activities:
Property additions	(735)	(979)
Property sales and other transactions	258	214
Investment purchases	(5)	(12)
Investment sales and other transactions	(58)	(75)
Net cash used in investing activities	(540)	(852)
Cash flows from financing activities:
Dividends	(482)	(458)
Common stock transactions	26	18
Purchase and retirement of common stock	(669)	(1,050)
Proceeds from borrowings	784	1,054
Debt repayments	(314)	(750)
Net cash used in financing activities	(655)	(1,186)
Net increase (decrease) in cash, cash equivalents, and restricted cash	563	(86)
Cash, cash equivalents, and restricted cash:
At beginning of year	580	446
At end of period	1,143	360
Supplemental disclosures of cash flow information:
Interest (net of amounts capitalized)	287	271
Income taxes (net of refunds)	$ 1	$ 215