Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 3,702.9	$ 4,448.8
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation, amortization and impairments	366.8	567.6
Acquired in-process research and development	75.0	0.0
Share-based compensation	149.3	143.9
Contingent consideration	(23.5)	(66.3)
Loss on divestiture of Hillerød, Denmark manufacturing operations	0.0	95.5
Deferred income taxes	211.9	28.4
Unrealized (gain) loss on strategic investments	41.8	(189.8)
Loss on equity method investment	14.7	63.5
Other	110.1	87.4
Changes in operating assets and liabilities, net:
Accounts receivable	(135.7)	(2.4)
Due from anti-CD20 therapeutic programs	63.0	(55.4)
Inventory	(270.6)	47.3
Accrued expenses and other current liabilities	372.9	(109.1)
Income tax assets and liabilities	15.3	64.6
Other changes in operating assets and liabilities, net	(97.0)	(5.6)
Net cash flows provided by operating activities	4,596.9	5,118.4
Cash flows from investing activities:
Proceeds from sales and maturities of marketable securities	5,240.7	3,867.6
Purchases of marketable securities	(4,649.1)	(4,052.1)
Contingent consideration paid related to Fumapharm AG acquisition	0.0	(300.0)
Acquisition of Nightstar Therapeutics plc, net of cash acquired	0.0	(744.4)
Proceeds from divestiture of Hillerød, Denmark manufacturing operations	0.0	923.7
Purchases of property, plant and equipment	(338.8)	(404.1)
Acquired in-process research and development	(75.0)	0.0
Acquisitions of intangible assets	(37.0)	0.0
Proceeds from sales of strategic investments	0.5	476.0
Other	(18.0)	(4.6)
Net cash flows provided by (used in) investing activities	(442.2)	(237.9)
Cash flows from financing activities:
Purchases of treasury stock	(6,279.1)	(3,775.2)
Payments related to issuance of stock for share-based compensation arrangements, net	(11.8)	(16.9)
Proceeds from borrowings	2,967.3	0.0
Repayment of borrowings	(1,500.0)	0.0
Net distribution to noncontrolling interest	(70.9)	4.3
Other	22.9	43.8
Net cash flows used in financing activities	(4,871.6)	(3,744.0)
Net increase (decrease) in cash and cash equivalents	(716.9)	1,136.5
Effect of exchange rate changes on cash and cash equivalents	(28.0)	17.2
Cash and cash equivalents, beginning of the period	2,913.7	1,224.6
Cash and cash equivalents, end of the period	2,224.8	2,343.9
Sangamo
Cash flows from investing activities:
Purchase of Sangamo Therapeutics, Inc. stock	(141.8)	0.0
Denali Therapeutics
Cash flows from investing activities:
Purchase of Sangamo Therapeutics, Inc. stock	$ (423.7)	$ 0.0