| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Revenues: | | | | | | | | |
| Revenue from Contract with Customer, Product and Service [Extensible Enumeration] | | | | | | | | |
| Total revenues | 20.4 | 20.8 | 23.4 | 28.4 | 24.7 | 26.4 | 25.8 | 30.9 |
| Total revenues growth | -17.4% | -21.2% | -9.1% | -7.8% | 17.4% | 16.8% | 6.7% | 58.5% |
| Operating expenses: | | | | | | | | |
| Payroll and benefits | 3.6 | 4.7 | 3.1 | 2.3 | 2.5 | 2.6 | 3.3 | 2.6 |
| Legal and professional fees | 1.9 | 4.5 | 2.1 | 3.7 | 1.6 | 2.2 | 1.9 | 1.1 |
| General and administrative | 3.3 | 2.8 | 2.5 | 1.8 | 1.9 | 1.9 | 1.8 | 1.7 |
| Depreciation, amortization, depletion and accretion | 2.4 | 2.1 | 1.7 | 1.7 | 1.6 | 1.5 | 1.8 | 2.1 |
| Other | | | | | 0.0 | | | |
| Total operating expenses | 26.5 | 28.6 | 26.8 | 31.1 | 27.5 | 29.7 | 25.0 | 27.6 |
| Operating loss | -6.1 | -7.8 | -3.4 | -2.6 | -2.7 | -3.3 | 0.8 | 3.3 |
| Operating margin | -29.8% | -37.6% | -14.4% | -9.2% | -11.1% | -12.6% | 3.0% | 10.7% |
| |
| Other income (expense): | | | | | | | | |
| Earnings from equity method investments | 0.5 | 0.6 | 0.3 | | 2.4 | 0.8 | 6.8 | 22.2 |
| Interest expense | -0.8 | -0.5 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 |
| Other | 0.6 | 0.2 | 0.2 | 0.3 | 0.1 | -0.4 | 0.0 | 0.1 |
| Total other income | 0.8 | 0.3 | 0.4 | 0.5 | 2.4 | -0.1 | 6.7 | 25.5 |
| Income tax benefit | | 0.0 | | | | | -1.7 | -4.6 |
| Net loss | -5.9 | -7.5 | -3.2 | -2.4 | -0.3 | -3.0 | 5.8 | 24.3 |
| |
| Loss per common share (Note 1): | | | | | | | | |
| Basic (in dollars per share) | ($0.21) | ($0.32) | ($0.17) | ($0.13) | ($0.02) | ($0.17) | $0.32 | $1.33 |
| Diluted (in dollars per share) | ($0.21) | ($0.32) | ($0.17) | ($0.13) | ($0.02) | ($0.17) | $0.31 | $1.31 |
| |
| Weighted-average number of common shares outstanding: | | | | | | | | |
| Basic (in shares) | 27.4 | 23.8 | 18.5 | 18.5 | 18.5 | 18.3 | 18.3 | 18.3 |
| Diluted (in shares) | 27.4 | 23.8 | 18.5 | 18.5 | 18.5 | 18.3 | 18.5 | 18.5 |