Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities:
Net income (loss)	$ (1,455)	$ 2,675
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation expense	209	186
Amortization expense	844	868
Stock-based compensation expense	482	479
Acquired in-process research and development expenses	5,792	4,251
Deferred income taxes	(12)	(796)
Net unrealized (gain) loss from equity securities	1,046	(312)
Other	210	199
Changes in operating assets and liabilities:
Accounts receivable, net	(334)	33
Inventories	(48)	(35)
Prepaid expenses and other	22	(225)
Accounts payable	(134)	(142)
Income taxes payable	(428)	107
Accrued liabilities and other	58	(724)
Net cash provided by operating activities	6,252	6,564
Investing Activities:
Purchases of marketable debt securities	(19,809)	(24,057)
Proceeds from sales of marketable debt securities	12,367	4,522
Proceeds from maturities of marketable debt securities	8,528	17,639
Acquisitions, including in-process research and development, net of cash acquired	(5,804)	(4,251)
Purchases of equity securities	(388)	(1,251)
Capital expenditures	(469)	(622)
Other	(63)	(228)
Net cash used in investing activities	(5,638)	(8,248)
Financing Activities:
Proceeds from debt financing, net of issuance costs	7,189	0
Proceeds from issuances of common stock	248	182
Repurchases of common stock	(1,583)	(1,644)
Repayments of debt and other obligations	(2,500)	(2,750)
Payments of dividends	(2,591)	(2,421)
Other	(124)	(105)
Net cash provided by (used in) financing activities	639	(6,738)
Effect of exchange rate changes on cash and cash equivalents	2	(44)
Net change in cash and cash equivalents	1,255	(8,466)
Cash and cash equivalents at beginning of period	11,631	17,940
Cash and cash equivalents at end of period	$ 12,886	$ 9,474