| In millions, except per share items | Sep-30-22 | Sep-30-21 | Sep-30-20 | Sep-30-19 | Sep-30-18 | Sep-30-17 | Sep-30-16 | Sep-30-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net sales | 83.9 | 99.6 | 113.6 | 112.5 | 111.2 | 121.5 | 119.1 | 109.3 |
| Net sales growth | -15.8% | -12.3% | 1.0% | 1.1% | -8.4% | 2.0% | 9.0% | -8.7% |
| Cost of goods sold | 85.8 | 88.4 | 93.6 | 101.8 | 101.1 | 108.1 | | |
| Gross profit | -1.9 | 11.2 | 20.0 | 10.6 | 10.1 | 13.4 | 12.1 | 15.7 |
| Gross margin | -2.2% | 11.3% | 17.6% | 9.5% | 9.1% | 11.0% | 10.1% | 14.4% |
| Selling, general and administrative expenses | 11.9 | 13.5 | 14.0 | 15.3 | 15.2 | 17.8 | 17.4 | 19.2 |
| Amortization of intangible assets | 0.3 | 1.0 | 1.5 | 1.6 | 1.7 | 2.2 | 2.6 | 2.2 |
| Gain on disposal of operating assets | | | | | | | | |
| Operating income (loss) | -14.1 | -1.1 | 10.1 | -7.0 | -5.9 | -11.5 | -12.1 | -5.7 |
| Operating margin | -16.8% | -1.1% | 8.9% | -6.3% | -5.3% | -9.5% | -10.1% | -5.3% |
| Interest expense, net | -0.6 | -0.6 | -0.9 | -1.1 | -2.1 | -2.2 | -1.7 | -0.6 |
| Gain on debt extinguishment | -5.1 | -0.3 | | | | | | |
| Foreign currency exchange loss (gain), net | 0.0 | 0.0 | 0.1 | 0.0 | -0.1 | 0.0 | 0.0 | 0.2 |
| Other expense (income), net | 0.1 | 0.5 | 0.2 | 0.1 | -0.4 | -0.6 | -0.4 | -0.5 |
| Loss before income tax benefit | -9.7 | -2.0 | 9.0 | | | | | |
| Income tax expense (benefit) | 0.0 | -1.2 | -0.2 | -0.7 | -0.4 | 1.1 | -2.0 | -2.4 |
| Net loss | -9.6 | -0.7 | 9.2 | -7.5 | -7.2 | -14.2 | -11.3 | -2.9 |
| |
| Net loss per share | | | | | | | | |
| Basic (in dollars per share) | ($1.65) | ($0.13) | $1.62 | ($1.35) | ($1.30) | ($2.59) | ($2.07) | ($0.53) |
| Diluted (in dollars per share) | ($1.65) | ($0.13) | $1.59 | ($1.35) | ($1.30) | ($2.59) | ($2.07) | ($0.53) |
| |
| Weighted-average number of common shares (basic) (in shares) | 5.8 | 5.8 | 5.7 | 5.6 | 5.5 | 5.5 | 5.5 | 5.4 |
| Weighted-average number of common shares (diluted) (in shares) | 5.8 | 5.8 | 5.8 | 5.6 | 5.5 | 5.5 | 5.5 | 5.4 |