| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 8-K | 8-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K/A |
| NET REVENUE | | | | | | | | |
| Total net revenue | 158.2 | 130.3 | 80.1 | 45.5 | 31.9 | 23.4 | 13.3 | 11.6 |
| Total net revenue growth | 21.4% | 62.6% | 76.2% | 42.5% | 36.2% | 76.0% | 14.4% | 4.7% |
| COSTS OF REVENUE AND OPERATING EXPENSES | | | | | | | | |
| Costs of revenue - devices and supplies | | | 17.4 | 8.8 | 6.0 | 4.8 | 3.5 | |
| Sales and marketing | 67.1 | 54.3 | 34.1 | 14.9 | 6.5 | | | |
| General and administrative | 36.1 | 26.3 | 18.3 | 10.7 | 9.0 | | | |
| Total costs of revenue and operating expenses | 217.9 | 174.3 | 69.9 | 34.4 | 21.5 | 14.5 | 12.7 | |
| Income from operations | 22.9 | 22.4 | 10.2 | 11.1 | 10.4 | 8.9 | 0.6 | -2.5 |
| Operating margin | 14.5% | 17.2% | 12.8% | 24.3% | 32.5% | 38.2% | 4.8% | -21.3% |
| |
| Other income (expense) | | | | | | | | |
| Interest expense, net | -0.4 | -0.1 | 0.0 | 0.0 | | | | |
| Other income (expense), net | 0.7 | 0.1 | -0.1 | 0.9 | -0.2 | -1.5 | -0.6 | 0.0 |
| Income from operations before income taxes | | | 10.2 | 11.9 | 10.2 | 7.5 | 0.1 | |
| Income tax expense | 5.2 | 5.2 | 1.1 | 2.4 | 0.7 | 0.1 | 0.0 | -0.1 |
| Net income | 17.0 | 17.1 | 9.1 | 9.5 | 9.6 | 7.4 | 0.1 | -2.9 |
| |
| Net income per share: | | | | | | | | |
| Basic | $0.44 | $0.45 | $0.27 | $0.29 | $0.29 | $0.23 | | ($0.09) |
| Diluted | $0.44 | $0.44 | $0.26 | $0.28 | $0.28 | $0.22 | | ($0.09) |
| |
| Weighted average basic shares outstanding | 38.5 | 38.3 | 33.9 | 32.4 | 32.5 | 32.2 | 31.3 | 31.3 |
| Weighted average diluted shares outstanding | 39.1 | 39.2 | 34.9 | 34.0 | 34.0 | 33.2 | 31.3 | 31.3 |