| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-15 | Dec-31-14 | Dec-31-13 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net sales | 456.3 | 417.6 | 546.1 | 496.0 | 416.6 | 362.4 | 347.6 | 237.8 |
| Net sales growth | 9.2% | -23.5% | 10.1% | 19.1% | | 4.3% | 46.1% | 17.5% |
| Cost of sales | 415.0 | 359.2 | 446.2 | 437.3 | 365.6 | 311.1 | 283.5 | |
| Gross profit | 41.3 | 58.4 | 99.9 | 58.8 | 51.0 | 51.2 | 64.0 | 44.5 |
| Gross margin | 9.0% | 14.0% | 18.3% | 11.8% | 12.2% | | | |
| |
| Operating expenses: | | | | | | | | |
| Research, development and engineering expenses | 22.4 | 25.4 | 24.9 | 28.6 | 19.9 | 23.6 | 19.3 | 10.4 |
| Selling, general and administrative expenses | 57.9 | 51.7 | 54.1 | 59.6 | 44.3 | 28.8 | 23.1 | 7.5 |
| Amortization of intangible assets | 2.5 | 3.1 | 3.6 | 5.0 | 4.8 | 4.6 | 1.0 | |
| Total operating expenses | 82.8 | 80.2 | 82.7 | 95.5 | 69.0 | 137.3 | 83.7 | 29.6 |
| Operating income | -41.6 | -21.7 | 17.2 | -36.7 | -18.0 | -17.4 | 24.1 | 15.0 |
| Operating margin | -9.1% | -5.2% | 3.2% | -7.4% | -4.3% | | | |
| Interest expense | -7.3 | -5.7 | -7.9 | -7.6 | -10.8 | -4.3 | -1.3 | -0.7 |
| Income (Loss) before income taxes | -48.9 | -26.7 | 8.7 | -54.6 | -47.2 | -12.6 | 29.2 | |
| Income tax expense (benefit) | -0.4 | -3.7 | 0.4 | 0.2 | 0.4 | -9.7 | 7.7 | 4.8 |
| Net income (loss) | -48.5 | -23.0 | 8.2 | -54.7 | -47.6 | -2.9 | 21.5 | -18.8 |
| |
| Weighted-average common shares outstanding: | | | | | | | | |
| Basic (in shares) | 22.9 | 22.9 | 21.5 | 18.6 | 13.8 | 10.8 | 10.7 | 9.8 |
| Diluted (in shares) | 22.9 | 22.9 | 21.5 | 18.6 | 13.8 | 11.0 | 11.1 | 9.8 |
| |
| Earnings (Loss) per common share: | | | | | | | | |
| Basic (in dollars per share) | ($2.12) | ($1.00) | $0.38 | ($2.94) | ($6.20) | ($0.27) | $2.01 | |
| Diluted (in dollars per share) | ($2.12) | ($1.00) | $0.38 | ($2.94) | ($6.20) | ($1.11) | $1.38 | |