| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Current assets: | | | | | | | | |
| Cash and cash equivalents | 5.6 | 8.6 | 8.5 | 38.1 | 0.4 | 0.7 | 0.4 | 0.3 |
| Restricted cash | 0.6 | 0.7 | 0.6 | | 0.6 | 0.6 | 0.6 | 0.6 |
| Short-term investment securities | 19.4 | 19.8 | 23.5 | 38.1 | | | | |
| Accounts receivable, less provision for doubtful accounts of $65 at March 31, 2022 and $69 at December 31, 2021 | 8.3 | 10.1 | 9.0 | 11.3 | 9.1 | 7.3 | 8.3 | 7.7 |
| Inventories | 24.5 | 19.5 | 16.4 | 18.2 | 13.7 | 12.3 | 13.6 | 10.0 |
| Other current assets | 4.6 | 1.5 | 2.0 | 2.1 | 1.5 | 1.0 | 0.9 | 1.0 |
| Total current assets | 74.4 | 69.3 | 70.3 | 84.5 | 28.3 | 22.0 | 24.9 | 19.6 |
| Property, plant and equipment | 48.2 | 45.7 | 41.1 | 36.7 | 40.1 | 40.2 | 38.4 | 35.1 |
| Less: Accumulated depreciation | 34.4 | 31.5 | 27.5 | 25.3 | 32.9 | 33.5 | 31.7 | 30.9 |
| Net property, plant and equipment | 13.8 | 14.2 | 13.6 | 11.4 | 7.2 | 6.6 | 6.7 | 4.2 |
| Goodwill | 13.9 | 13.7 | 9.6 | 10.8 | 10.8 | 10.6 | 9.6 | 9.2 |
| Intangible assets, net | 9.0 | 10.8 | | 2.6 | 2.7 | 2.9 | | |
| Investment in partnerships | 0.5 | 0.6 | 1.2 | 2.1 | 1.6 | 0.1 | 0.2 | 0.4 |
| Long-term investment securities | 4.6 | 5.1 | 8.6 | | | | | |
| Other assets, net | 1.2 | 1.0 | 0.5 | 3.4 | 3.8 | 1.6 | 0.5 | 0.5 |
| Total assets | 122.5 | 121.3 | 113.6 | 115.2 | 54.5 | 43.8 | 41.9 | 34.0 |
| |
| Current liabilities: | | | | | | | | |
| Accounts payable | 9.4 | 8.7 | 9.9 | 12.9 | 10.4 | 6.7 | 7.8 | 6.0 |
| Accrued salaries, wages and commissions | 5.2 | 3.6 | 2.3 | 4.4 | 3.1 | 2.4 | 2.5 | 2.5 |
| Other accrued liabilities | 3.8 | 4.2 | | | | 1.9 | 1.3 | 1.4 |
| Total current liabilities | 20.2 | 18.7 | 16.9 | 21.6 | 19.3 | 13.5 | 13.6 | 11.8 |
| Deferred tax liabilities, net | 0.9 | 1.0 | | | | | | |
| Other long-term liabilities | 3.1 | 4.4 | 2.2 | 0.5 | 3.2 | 0.7 | 0.1 | 0.1 |
| Total liabilities | 28.7 | 30.1 | 23.1 | 23.3 | 33.0 | 24.7 | 23.0 | 17.9 |
| |
| Commitments and contingencies (Note 11) | | | | | | | | |
| Shareholders’ equity: | | | | | | | | |
| Common stock | 9.2 | 9.0 | 8.8 | 8.7 | 6.9 | 6.8 | 6.0 | 5.8 |
| Additional paid-in capital | 91.8 | 89.7 | 86.8 | 85.0 | 21.6 | 21.4 | 17.7 | 16.9 |
| Accumulated deficit | -6.9 | -6.8 | -4.3 | -0.5 | -6.1 | -8.6 | -4.0 | -6.3 |
| Accumulated other comprehensive loss | -0.4 | -0.7 | -0.5 | -0.9 | -0.7 | -1.0 | -0.7 | -0.4 |
| Total shareholders' equity | 93.7 | 91.2 | 90.7 | 92.2 | 21.7 | 18.6 | 18.9 | 16.1 |
| Non-controlling interest | 0.1 | 0.0 | -0.3 | -0.3 | -0.3 | 0.5 | 0.0 | |
| Total equity | 93.8 | 91.2 | 90.5 | 92.0 | 21.4 | 19.0 | 18.9 | 16.1 |
| Total liabilities and equity | 122.5 | 121.3 | 113.6 | 115.2 | 54.5 | 43.8 | 41.9 | 34.0 |