Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ 475,800,000	$ 514,800,000	$ (104,500,000)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	49,900,000	49,900,000	45,900,000
Share-based compensation expense	138,500,000	163,800,000	45,400,000
Impairments of investments in privately-held companies	2,300,000	9,100,000	0
Impairments of property, plant, and equipment	19,200,000	5,400,000	17,200,000
Intangible asset impairment charges	113,400,000	0	0
Realized gain on sale of equity securities	(92,600,000)	(3,400,000)	(2,600,000)
Other	65,900,000	(47,000,000.0)	(29,700,000)
Changes in operating assets and liabilities:
Accounts receivable	(41,300,000)	(6,000,000.0)	24,400,000
Inventories	(7,500,000)	10,300,000	12,900,000
Accounts payable and accrued expenses	(12,500,000)	38,600,000	(16,300,000)
Other assets and liabilities	(112,900,000)	20,200,000	(199,300,000)
Net cash provided by (used in) operating activities	598,200,000	755,700,000	(206,600,000)
Cash flows from investing activities:
Purchases of property, plant, and equipment	(120,800,000)	(59,300,000)	(83,700,000)
Proceeds from sale of property, plant, and equipment	0	2,400,000	0
Sales/maturities of held-to-maturity investments	0	0	39,700,000
Purchases of available-for-sale debt securities	(1,895,300,000)	(2,308,800,000)	(1,271,500,000)
Maturities of available-for-sale debt securities	1,370,100,000	1,523,400,000	799,200,000
Sales of available-for-sale debt securities	47,600,000	76,500,000	180,900,000
Sales of investments in equity securities	111,500,000	27,300,000	20,500,000
Purchases of investments in privately-held companies	0	0	(8,000,000.0)
Decrease in cash due to deconsolidation of variable interest entity	0	0	(12,500,000)
Net cash used in investing activities	(486,900,000)	(738,500,000)	(335,400,000)
Cash flows from financing activities:
Proceeds from line of credit	0	0	800,000,000.0
Repayment of line of credit	0	(50,000,000.0)	(200,000,000.0)
Payments of debt issuance costs	0	(1,700,000)	(700,000)
Proceeds from the exercise of stock options	50,000,000.0	33,800,000	9,900,000
Proceeds from the issuance of stock under employee stock purchase plan	5,600,000	4,700,000	4,100,000
Restricted stock units withheld for taxes	(10,800,000)	(3,700,000)	(2,100,000)
Net cash provided by (used in) financing activities	44,800,000	(16,900,000)	611,200,000
Net increase in cash and cash equivalents	156,100,000	300,000	69,200,000
Cash and cash equivalents, beginning of year	738,700,000	738,400,000	669,200,000
Cash and cash equivalents, end of year	894,800,000	738,700,000	738,400,000
Supplemental cash flow information:
Cash paid for interest	16,200,000	20,700,000	41,000,000.0
Cash paid for income taxes	153,300,000	92,800,000	120,200,000
Non-cash investing and financing activities:
Non-cash additions to property, plant, and equipment	$ 3,700,000	$ 3,500,000	$ 54,500,000