| 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 | 10-K | S-1/A |
| Cash flows from operating activities: | | | | | | | |
| Adjustments to reconcile net loss to net cash flows used in operating activities | | | | | | | |
| In kind contribution of services | 0.1 | 0.1 | | | | | |
| Changes in operating assets and liabilities and other, net | 0.0 | 0.0 | | | | | |
| Net cash flows used in operating activities | -0.1 | -0.1 | -0.1 | 0.0 | -0.3 | | |
| |
| Cash flows from financing activities: | | | | | | | |
| Proceeds from notes payable | 0.1 | 0.1 | 0.1 | 0.1 | | | |
| Net cash flows provided by financing activities | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | | |
| |
| Supplemental disclosure of cash flow information: | | | | | | | |
| Income taxes paid | | | | | | | |
| Interest paid | | | | | | | |