| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 6-K | 6-K |
| Cash flows used in operating activities: | | | | | | | |
| Net loss | -108.2 | -181.0 | -102.7 | -88.4 | -53.1 | | |
| Adjustments to reconcile net loss to net cash used in operating activities | | | | | | | |
| Depreciation and amortization | | | | 0.0 | 0.0 | | |
| Share-based compensation expense | 32.3 | 31.2 | 17.5 | 7.4 | 6.9 | | |
| Other, net | -3.2 | 0.7 | 9.5 | 14.2 | -0.7 | | |
| Net changes in operating assets and liabilities | | | | | | | |
| Accounts receivable, net | 1.9 | -15.4 | -0.7 | -0.2 | -0.1 | | |
| Inventories, net | -9.1 | -5.6 | -13.9 | | | | |
| Prepaid expenses and other current assets | -2.4 | -5.3 | 2.6 | -1.8 | -5.0 | | |
| Non-current assets | -0.8 | 0.2 | | | | | |
| Accounts payable, accrued and other liabilities | 0.7 | 4.1 | 13.6 | 4.0 | -0.9 | | |
| Net cash used in operating activities | -79.5 | -157.7 | -69.9 | -63.6 | -51.6 | | |
| |
| Cash flows used in investing activities: | | | | | | | |
| Purchase of investments | -524.0 | -439.0 | -203.0 | | -36.1 | | |
| Proceeds from investments | 464.3 | 354.4 | 52.1 | 7.9 | 36.1 | | |
| Upfront lease payment | -0.7 | -11.8 | | | | | |
| Purchase of long-lived assets | -0.3 | -1.5 | -7.3 | -0.1 | -0.1 | | |
| Capitalized patent costs | | | | 0.0 | | | |
| Net cash provided by (used in) investing activities | -60.6 | -103.9 | -158.2 | 7.8 | -0.1 | | |
| |
| Cash flows from financing activities | | | | | | | |
| Proceeds from exercise of stock options and employee share purchase plan | 2.4 | 24.0 | 6.6 | 13.7 | 0.9 | | |
| Cash provided by financing activities | 2.4 | 221.1 | 194.4 | 243.9 | 4.0 | | |
| |
| Cash, cash equivalents and restricted cash, beginning of period | | | | | | | |
| Cash, cash equivalents and restricted cash, end of period | | | | | | | |
| Supplemental cash flow information | | | | | | | |
| Cash received for interest | 2.3 | 0.7 | 1.9 | 2.6 | 2.1 | | |
| Cash paid for income taxes | -2.0 | -0.3 | -0.3 | -0.1 | | | |
| |
| Reconciliation of cash, cash equivalents and restricted cash to the condensed consolidated balance sheets | | | | | | | |
| Cash, cash equivalents | | | | | | | |
| Restricted cash | | | | | | | |
| Total cash, cash equivalents and restricted cash | | | | | | | |