v3.8.0.1
Consolidated Statements of Cash Flows - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Operating activities      
Net loss $ (50.2) $ (65.6) $ (57.6)
Adjustments to reconcile net loss to cash used in operating activities:      
Depreciation and amortization 16.1 15.0 10.8
Share-based compensation 106.2 110.8 82.7
Non-cash interest expense 9.4 0.1 0.2
Non-cash research and development charge through issuance of common stock 0.0 0.0 36.5
Other non-cash expenses 7.9 2.2 0.8
Changes in operating assets and liabilities:      
Accounts receivable, net (31.8) (27.2) (31.7)
Inventory 0.4 (9.8) (19.2)
Prepaid and other assets (6.7) (3.9) (2.5)
Restricted cash 0.0 0.0 1.0
Accounts payable and accrued liabilities 21.1 21.1 17.8
Accrued payroll and related expenses 14.8 8.5 7.7
Deferred revenue 2.2 0.1 0.1
Deferred rent and other liabilities 2.6 4.9 2.4
Net cash provided by operating activities 92.0 56.2 49.0
Investing activities      
Purchase of available-for-sale marketable securities (171.8) (39.2) (45.2)
Proceeds from the maturity of available-for-sale marketable securities 93.4 38.7 27.5
Purchase of property and equipment (66.0) (55.7) (33.3)
Acquisitions, net of cash acquired 0.0 0.3 (0.5)
Net cash used in investing activities (144.4) (55.9) (51.5)
Financing activities      
Net proceeds from issuance of common stock 10.1 10.4 19.1
Proceeds from issuance of convertible debt, net of issuance costs 389.0 0.0 0.0
Proceeds from short-term borrowings 75.0 0.0 0.0
Repayment of short-term borrowings (75.0) 0.0 0.0
Repayment of long-term debt 0.0 (2.3) (2.3)
Net cash provided by financing activities 399.1 8.1 16.8
Effect of exchange rate changes on cash and cash equivalents 0.3 0.0 0.0
Increase in cash and cash equivalents 347.0 8.4 14.3
Cash and cash equivalents, beginning of period 94.5 86.1 71.8
Cash and cash equivalents, end of period 441.5 94.5 86.1
Supplemental disclosure of non-cash transactions      
Issuance of common stock in connection with acquisition 0.0 7.2 0.0
Acquisition-related holdback liability 0.0 1.8 0.0
Assets acquired and financing obligation under build-to-suit leasing arrangement 0.0 6.0 0.0
Acquisition of property and equipment included in accounts payable and accrued liabilities 6.3 10.5 2.9
Cash paid during the year for interest 2.4 0.1 0.3
Cash paid during the year for taxes $ 1.4 $ 0.1 $ 0.1