Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income	$ 306.6	$ 240.9
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15.0	13.3
Share-based compensation expense (benefit)	25.6	(12.4)
Other	(10.5)	5.8
Changes in operating assets and liabilities:
Accounts receivable	(28.3)	85.9
Inventories	(9.3)	(2.5)
Accounts payable and accrued expenses	1.9	2.8
Other assets and liabilities	75.5	41.0
Net cash provided by operating activities	376.5	374.8
Cash flows from investing activities:
Purchases of property, plant, and equipment	(38.2)	(41.3)
Deposits	(4.3)	0.0
Purchases of available-for-sale debt securities	(529.3)	(889.5)
Maturities of available-for-sale debt securities	475.3	709.7
Sales of available-for-sale debt securities	831.8	0.0
Net cash provided by (used in) investing activities	735.3	(221.1)
Cash flows from financing activities:
Payments to repurchase common stock	(1,000.0)	0.0
Repayment of line of credit	(100.0)	0.0
Payments of debt issuance costs	(2.7)	(2.7)
Proceeds from the exercise of stock options	42.2	61.4
Proceeds from the issuance of stock under ESPP	3.9	3.4
RSUs withheld for taxes	(11.4)	(13.5)
Net cash (used in) provided by financing activities	(1,068.0)	48.6
Net increase in cash and cash equivalents	43.8	202.3
Cash and cash equivalents, beginning of period	1,207.7	961.2
Cash and cash equivalents, end of period	1,251.5	1,163.5
Supplemental cash flow information:
Cash paid for interest	12.6	13.1
Cash paid for income taxes	4.7	0.0
Non-cash investing and financing activities:
Non-cash additions to property, plant, and equipment	23.6	18.4
Measurement period adjustment to purchase price	1.4	0.0
Excise tax on net share repurchase	$ 6.9	$ 0.0