Statement of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Cash flows from operating activities:
Net income (loss)	$ 2,404.3	$ 77.6	$ 443.3
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation and amortization	376.8	405.3	496.7
Impairment of assets	0.0	13.5	118.8
Change in fair value of contingent consideration	11.6	116.5	41.0
Payments of contingent consideration	(100.0)	0.0	(18.0)
Share-based compensation expense	237.0	203.0	243.1
Non-cash expense for acquired IPR&D	0.0	64.6	0.0
Deferred tax (benefit) expense	(455.4)	32.9	(45.9)
Unrealized foreign currency (gain) loss	(2.1)	4.8	(9.4)
Unrealized (gain) loss on forward contracts	(16.5)	(15.8)	11.1
Unrealized gain on strategic equity investments	(26.9)	(40.2)	0.0
Gain on sale of strategic equity investments	(32.8)	0.0	0.0
Gain on modification of purchase option	(32.0)	0.0	0.0
Other	(2.7)	(2.0)	5.4
Changes in operating assets and liabilities, excluding the effect of acquisitions:
Accounts receivable	(319.2)	(208.8)	(55.2)
Inventories	(156.9)	(14.7)	(88.2)
Prepaid expenses, right of use operating assets and other assets	(31.0)	(155.6)	(137.2)
Accounts payable, accrued expenses, lease liabilities and other liabilities	230.7	(55.1)	110.1
Net cash provided by operating activities	2,084.9	426.0	1,115.6
Cash flows from investing activities:
Purchases of available-for-sale debt securities	(80.2)	(782.7)	(1,648.8)
Proceeds from maturity or sale of available-for-sale debt securities	222.2	1,473.5	1,089.9
Purchases of mutual funds related to nonqualified deferred compensation plan	(17.6)	(12.1)	(9.9)
Proceeds from sale of mutual funds related to nonqualified deferred compensation plan	14.7	12.3	7.7
Purchases of property, plant and equipment	(154.7)	(213.0)	(357.3)
Purchases of strategic equity investments	(73.3)	(10.3)	0.0
Proceeds from sale of strategic equity investments	114.7	0.0	0.0
Purchases of intangible assets	(16.0)	0.0	0.0
Other	(0.1)	2.8	0.1
Net cash provided by (used in) investing activities	9.7	470.5	(918.3)
Cash flows from financing activities:
Proceeds from revolving credit facility	0.0	250.0	0.0
Payments on revolving credit facility	(250.0)
Payments on term loan	(98.0)	(293.8)	(175.0)
Repurchase of common stock	(416.0)	(85.0)	(463.6)
Net proceeds from issuance of stock under share-based compensation arrangements	29.9	47.3	85.9
Payments of contingent consideration	0.0	0.0	(7.0)
Repayment of development-related grants	0.0	0.0	(26.0)
Other	(5.0)	(20.9)	(10.9)
Net cash used in financing activities	(739.1)	(102.4)	(596.6)
Effect of exchange rate changes on cash and cash equivalents and restricted cash	0.8	(11.2)	17.7
Net change in cash and cash equivalents and restricted cash	1,356.3	782.9	(381.6)
Cash and cash equivalents and restricted cash at beginning of period	1,367.3	584.4	966.0
Cash and cash equivalents and restricted cash at end of period	2,723.6	1,367.3	584.4
Supplemental disclosures
Cash paid for interest (net of amounts capitalized)	72.6	90.9	95.3
Cash paid for income taxes	187.9	163.9	162.1
Other Significant Noncash Transaction, Value of Consideration Given	75.0	0.0	0.0
Supplemental cash flow disclosures from investing and financing activities:
Operating ROU lease assets obtained in exchange for operating lease liabilities	27.5	0.0	0.0
Capitalization of construction costs related to facility lease obligations	0.0	44.8	121.8
Accounts payable and accrued expenses for purchases of property, plant and equipment and intangible assets	13.3	21.4	34.7
Cash and cash equivalents	2,685.5	1,365.5	584.4
Restricted cash included in other current assets	37.8	0.1	0.0
Restricted cash included in other noncurrent assets	$ 0.3	$ 1.7	$ 0.0