Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 7,842	$ 8,394	$ 1,979
Depreciation, amortization and other	2,206	1,946	1,955
Stock-based compensation expense	308	311	329
Deferred income taxes	(289)	(363)	(1,330)
Other items, net	186	(386)	(334)
Changes in operating assets and liabilities, net of acquisitions:
Trade receivables, net	(504)	(378)	(58)
Inventories	(66)	(3)	133
Other assets	10	35	(24)
Accounts payable	164	(143)	424
Accrued income taxes, net	(585)	(361)	523
Long-term tax liabilities	(146)	258	6,681
Other liabilities	396	1,214	231
Net cash provided by operating activities	9,150	11,296	11,177
Cash flows from investing activities:
Purchases of marketable securities	(9,394)	(18,741)	(33,607)
Proceeds from sales of marketable securities	8,842	28,356	24,240
Proceeds from maturities of marketable securities	20,548	5,412	6,174
Purchases of property, plant and equipment	(618)	(738)	(664)
Cash paid for acquisitions, net of cash acquired	(13,617)	195	(19)
Other	(52)	(145)	(148)
Net cash provided by (used in) investing activities	5,709	14,339	(4,024)
Cash flows from financing activities:
Net proceeds from issuance of debt	0	0	4,476
Repayment of debt	(4,514)	(1,121)	(4,405)
Repurchases of common stock	(7,702)	(17,794)	(3,160)
Dividends paid	(3,509)	(3,507)	(3,365)
Withholding taxes arising from shares withheld for share-based payments	(137)	(126)	(191)
Other	95	58	51
Net cash used in financing activities	(15,767)	(22,490)	(6,594)
(Decrease) increase in cash and cash equivalents	(908)	3,145	559
Cash and cash equivalents at beginning of year	6,945	3,800	3,241
Cash and cash equivalents at end of year	$ 6,037	$ 6,945	$ 3,800