Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flow from operating activities:
Net income	$ 404.6	$ 1,392.6
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation, amortization and impairments	146.9	119.9
Acquired in-process research and development	0.0	75.0
Share-based compensation	70.0	67.7
Contingent consideration	(33.8)	(4.6)
Deferred income taxes	(15.0)	36.9
(Gain) loss on strategic investments	437.6	62.0
Our share of Samsung Bioepis gains (losses)	18.2	16.8
Other	71.7	28.9
Changes in operating assets and liabilities, net:
Accounts receivable	37.2	(238.4)
Due from anti-CD20 therapeutic programs	43.8	78.6
Inventory	(112.5)	(62.2)
Accrued expense and other current liabilities	(283.6)	(347.4)
Income tax assets and liabilities	64.8	223.0
Other changes in operating assets and liabilities, net	(80.9)	18.5
Net cash flow provided by operating activities	769.0	1,467.3
Cash flows from investing activities:
Proceeds from sales and maturities of marketable securities	819.2	2,389.3
Purchases of marketable securities	(913.3)	(1,684.7)
Proceeds from divestiture of Hillerød, Denmark manufacturing operations	28.1	0.0
Purchases of property, plant and equipment	(92.6)	(149.7)
Acquired in-process research and development	0.0	(75.0)
Acquisitions of intangible assets	0.0	(37.0)
Proceeds from sales of strategic investments	91.2	0.5
Other	2.7	(0.5)
Net cash flow (used in) provided by investing activities	(64.7)	442.9
Cash flows from financing activities:
Purchases of treasury stock	(600.0)	(2,220.2)
Payments related to issuance of stock for share-based compensation arrangements, net	(27.1)	(29.6)
Repayments of borrowings and premiums paid on debt exchange	(169.3)	0.0
Other	11.4	4.5
Net cash flow used in financing activities	(785.0)	(2,245.3)
Net increase (decrease) in cash and cash equivalents	(80.7)	(335.1)
Effect of exchange rate changes on cash and cash equivalents	33.0	(12.7)
Cash and cash equivalents, beginning of the period	1,331.2	2,913.7
Cash and cash equivalents, end of the period	$ 1,217.5	$ 2,591.3