CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net income	$ 23.9	$ 6.6
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	29.7	18.8
Non-cash interest	33.6	24.3
Stock-based compensation	20.3	20.7
Loss on extinguishment of debt	0.0	6.4
Provision for credit losses	3.1	2.6
Other	0.3	1.9
Changes in operating assets and liabilities:
Accounts receivable	(19.9)	(6.8)
Inventories	(22.9)	(20.0)
Prepaid expenses and other assets	(16.8)	(4.0)
Accounts payable, accrued expenses and other current liabilities	36.1	(1.7)
Other liabilities	(2.4)	2.7
Net cash provided by operating activities	85.0	51.5
Cash flows from investing activities
Capital expenditures	(88.5)	(114.6)
Acquisition of intangible assets	(8.3)	(6.4)
Purchases of investments	(37.9)	(63.9)
Receipts from the maturity or sale of investments	200.0	165.3
Net cash provided by (used in) investing activities	65.3	(19.6)
Cash flows from financing activities
Proceeds from issuance of common stock, net of issuance costs	477.5	0.0
Proceeds from issuance of convertible notes, net of issuance costs	0.0	780.2
Repayment of convertible debt	0.0	(453.6)
Purchase of capped call options	0.0	(85.4)
Proceeds from exercise of stock options and issuance of common stock under employee stock purchase plan	24.8	42.9
Payment of withholding taxes in connection with vesting of restricted stock units	(26.9)	(8.2)
Net cash provided by financing activities	475.4	275.9
Effect of exchange rate changes on cash	(1.3)	(1.8)
Net increase in cash, cash equivalents and restricted cash	624.4	306.0
Cash, cash equivalents and restricted cash at beginning of period	213.7	113.9
Cash, cash equivalents and restricted cash at end of period	838.1	419.9
Supplemental noncash information:
Purchases of property and equipment included in accounts payable and accrued expenses	4.7	10.2
Lease liabilities arising from obtaining right-of-use assets	$ 2.1	$ 5.1