Consolidated Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net income	$ 767.7	$ 595.2
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	39.5	38.1
Share-based compensation expense	22.5	42.0
Impairment of investment in privately-held company	0.0	1.7
Impairments of property, plant, and equipment	3.6	7.0
Realized gain on sale of equity securities	0.0	(0.9)
Other	0.1	44.6
Changes in operating assets and liabilities:
Accounts receivable	(38.2)	(33.0)
Inventories	(6.6)	0.5
Accounts payable and accrued expenses	80.2	35.4
Other assets and liabilities	(41.5)	(56.3)
Net cash provided by operating activities	827.3	674.3
Cash flows from investing activities:
Purchases of property, plant, and equipment	(151.7)	(99.3)
Deposits	(14.3)	0.0
Purchases of available-for-sale debt securities	(2,206.3)	(1,278.1)
Maturities of available-for-sale debt securities	1,610.6	752.9
Sales of investments in equity securities	0.0	3.8
Purchase of investment in privately-held company	0.0	(1.5)
Net cash used in investing activities	(761.7)	(622.2)
Cash flows from financing activities:
Proceeds from line of credit	0.0	800.0
Repayment of line of credit	0.0	(800.0)
Payments of debt issuance costs	(2.7)	(7.5)
Proceeds from the exercise of stock options	90.7	32.9
Proceeds from the issuance of stock under ESPP	6.6	5.9
RSUs withheld for taxes	(13.7)	(11.4)
Net cash provided by financing activities	80.9	19.9
Net increase in cash and cash equivalents	146.5	72.0
Cash and cash equivalents, beginning of period	961.2	894.8
Cash and cash equivalents, end of period	1,107.7	966.8
Supplemental cash flow information:
Cash paid for interest	41.8	17.8
Cash paid for income taxes	235.9	189.1
Non-cash investing and financing activities:
Non-cash additions to property, plant, and equipment	34.8	13.8
Receivable from maturity of available-for-sale debt securities	$ 60.0	$ 0.0