| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-05-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 8-K | 10-K | 10-K | S-1/A |
| Revenue | | | | | | | | |
| Revenue | 518.1 | 525.6 | 532.6 | 420.3 | 133.8 | 325.9 | 263.9 | 173.5 |
| Revenue growth | -1.4% | -1.3% | 26.7% | 29.0% | | 23.5% | 52.1% | |
| Interest and other | 14.1 | 17.1 | 6.1 | 0.5 | 2.7 | 5.2 | 7.3 | |
| Total revenue | 518.1 | 525.6 | 532.6 | 420.3 | 133.8 | 325.9 | 263.9 | 173.5 |
| Total revenue growth | -1.4% | -1.3% | 26.7% | 29.0% | | 23.5% | 52.1% | |
| Costs and expenses | | | | | | | | |
| Cost of revenue | 198.9 | 309.3 | 249.9 | | | | | |
| Compensation and benefits | 90.1 | 86.7 | 84.1 | 62.4 | | 54.7 | 39.8 | |
| Property, office and technology | 18.0 | 16.6 | 16.7 | 12.7 | 4.2 | 10.1 | 8.0 | |
| Depreciation and amortization | 14.0 | 11.3 | 7.3 | 4.5 | | 4.0 | 3.7 | 2.4 |
| Sales, general and administrative | 37.5 | 42.5 | 33.4 | 19.8 | | | | |
| Financial guarantee expense (benefit) | -15.2 | 5.0 | 20.7 | | | | | |
| Related party | 1.8 | 1.7 | 2.4 | 2.2 | 0.6 | 4.8 | | |
| Merger Related Costs | 11.7 | | | | | | | |
| Total costs and expenses | 356.9 | 473.1 | 414.4 | 264.6 | 123.3 | 180.3 | 144.1 | 80.4 |
| Operating profit | 161.2 | 52.5 | 118.3 | 155.7 | 10.6 | 145.6 | 119.8 | 93.1 |
| Operating margin | 31.1% | 10.0% | 22.2% | 37.1% | 7.9% | 44.7% | 45.4% | 53.7% |
| |
| Other income (expense), net | | | | | | | | |
| Interest and dividend income | 0.6 | 1.2 | 3.1 | | | | | 1.9 |
| Interest expense | -26.3 | -25.0 | -23.9 | -23.6 | -5.7 | -7.5 | | |
| Other (losses) gains, net | -3.8 | 1.6 | -8.6 | 0.9 | | -4.6 | -2.6 | |
| Total other income (expense), net | -29.5 | -22.3 | -29.4 | -22.2 | | -6.9 | 4.7 | |
| Income before income tax expense | 131.7 | 30.3 | 88.8 | 133.5 | | 138.7 | 124.5 | |
| Income tax expense (benefit) | 13.9 | 1.6 | -7.1 | 5.5 | -3.6 | | | |
| Net income | 117.8 | 28.7 | 96.0 | 128.0 | | 138.7 | 124.5 | |
| Less: Net income attributable to noncontrolling interests | 75.7 | 18.7 | 64.0 | 103.7 | | | | |
| Net income attributable to GreenSky, Inc. | 42.1 | 10.0 | 32.0 | 24.3 | 5.3 | | | 93.8 |
| |
| Earnings per share of Class A common stock: | | | | | | | | |
| Basic (in dollars per share) | $0.55 | $0.15 | $0.52 | $0.43 | | | | $5.72 |
| Diluted (in dollars per share) | $0.55 | $0.14 | $0.49 | $0.41 | | | | $5.54 |