CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net (loss) income	$ (157.1)	$ 523.9
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:
Depreciation and amortization	33.4	25.4
Share-based compensation expense (benefit)	15.9	(29.2)
Impairment of investment in privately-held company		12.4
Deconsolidation of variable interest entity	2.0
Intangible asset impairment charges	8.8
Asset impairment charges	8.4
Other	(27.9)	4.4
Impairment write downs	8.4
Changes in operating assets and liabilities:
Accounts receivable	(7.8)	81.9
Inventories	10.5	4.2
Accounts payable and accrued expenses	(4.9)	21.9
Other assets and liabilities	(190.4)	48.1
Net cash (used in) provided by operating activities	(309.1)	693.0
Cash flows from investing activities:
Purchases of property, plant and equipment	(59.0)	(132.6)
Decrease in cash due to deconsolidation of variable interest entity	(12.5)
Deposits	(5.6)	(33.0)
Purchases of held-to-maturity and other investments		(63.4)
Sales/maturities of held-to-maturity investments	39.7	53.0
Purchases of available-for-sale investments	(974.7)	(618.5)
Sales/maturities of available-for-sale investments	618.5	175.2
Purchase of investments in privately-held companies	(8.0)	(5.0)
Acquisition, net of cash acquired		(124.1)
Net cash used in investing activities	(401.6)	(748.4)
Cash flows from financing activities:
Proceeds from line of credit	800.0	250.0
Repayment of line of credit	(50.0)	(250.0)
Payments of debt issuance costs	(0.7)	(13.2)
Proceeds from the exercise of stock options	(9.9)	(15.5)
Proceeds from the issuance of stock under employee stock purchase plan	4.1	3.9
Restricted stock units withheld for taxes	(2.1)
Net cash provided by financing activities	761.2	6.2
Effect of exchange rate changes on cash and cash equivalents		0.1
Net increase in cash and cash equivalents	50.5	(49.1)
Net increase in cash and cash equivalents	50.5	(49.1)
Cash and cash equivalents, beginning of period	669.2	705.1
Cash and cash equivalents, end of period	719.7	656.0
Supplemental cash flow information:
Cash paid for interest	31.7	6.9
Cash paid for income taxes	94.4	52.1
Non-cash investing and financing activities:
Non-cash additions to property, plant and equipment	$ 3.9	$ 18.2