| In millions, except per share items | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 | Dec-31-12 |
| | 10-K | 10-K | 10-K | 10-K | 10-K/A | 10-K | 10-K | 10-K |
| Revenue, net | 169.8 | 171.8 | 161.6 | 232.1 | 138.3 | 161.6 | 178.3 | 208.5 |
| Revenue, net growth | -1.2% | 6.3% | -30.4% | 67.9% | -14.4% | -9.4% | -14.5% | 2.7% |
| Operating expenses: | | | | | | | | |
| Cost of revenue | 100.2 | 104.8 | 102.1 | 91.3 | | | | |
| Selling, general and administrative expenses | 57.6 | 50.5 | 46.9 | 39.4 | 32.3 | 38.6 | 46.1 | 49.6 |
| Amortization of intangible assets | 3.5 | 3.4 | 3.6 | 1.8 | 2.5 | 3.5 | 5.0 | 7.2 |
| Impairment charges | 10.1 | | | | | | 2.8 | |
| Acquisition-related adjustment income | -0.3 | -1.6 | -2.3 | | | | | |
| Operating income (loss) from continuing operations | -11.3 | 7.4 | 6.7 | 3.3 | 5.1 | 2.5 | 4.7 | 7.3 |
| Operating margin | -6.6% | 4.3% | 4.1% | 1.4% | 3.7% | 1.6% | 2.6% | 3.5% |
| Interest expense, net | 1.8 | 1.7 | 1.5 | -0.2 | | | | |
| Other loss (income) | 0.0 | 0.0 | -0.2 | -0.1 | 1.2 | -0.1 | | |
| Income (loss) from continuing operations before income tax | -13.4 | 4.7 | 7.5 | 3.5 | 1.9 | 0.5 | 4.8 | 6.7 |
| Income tax expense | 0.9 | 1.3 | 3.0 | 1.2 | 0.4 | | | |
| Tax rate | | 28.3% | 39.4% | 35.8% | 19.3% | | | |
| Net income (loss) from continuing operations | -14.3 | 3.4 | 4.6 | 2.2 | 1.5 | -2.7 | 2.1 | 5.4 |
| |
| Discontinued operations: | | | | | | | | |
| Income from discontinued operations | 0.6 | 1.2 | -1.4 | -1.3 | -4.8 | -4.8 | -2.2 | |
| Net income from discontinued operations | 0.6 | 1.2 | -1.4 | -1.3 | -4.8 | -4.8 | -2.2 | |
| Net income (loss) | -13.7 | 4.6 | 3.2 | 0.9 | -3.2 | | | |
| |
| Basic income (loss) per common share (Note 2): | | | | | | | | |
| Basic income (loss) from continuing operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Basic income from discontinued operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| |
| Total basic income (loss) per share (in usd per share) | ($0.60) | $0.20 | $0.15 | $0.04 | ($0.12) | ($0.26) | ($0.01) | $0.21 |
| |
| Diluted income (loss) per common share (Note 2): | | | | | | | | |
| Diluted income (loss) from continuing operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Diluted income from discontinued operations (in usd per share) | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Total diluted income (loss) per common share (in usd per share) | ($0.60) | $0.20 | $0.15 | $0.04 | ($0.12) | ($0.26) | ($0.01) | $0.21 |
| |
| Weighted-average common shares outstanding (Note 2): | | | | | | | | |
| Basic (in shares) | 22.7 | 22.8 | 21.9 | 22.0 | 25.9 | 28.7 | 29.2 | 25.6 |
| Diluted (in shares) | 22.7 | 23.4 | 22.1 | 22.0 | 25.9 | 28.7 | 29.6 | 26.1 |
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| Revenue, Product and Service [Extensible List] | | | | | | | | |