| 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 |
| REVENUE | | | | | | | | |
| Revenues | | | | | | | | |
| Total revenue | 425.1 | 330.1 | 387.6 | 414.2 | 407.0 | 326.0 | 322.9 | 315.7 |
| Total revenue growth | 28.8% | -14.8% | -6.4% | 1.7% | 24.9% | 0.9% | 2.3% | -13.0% |
| EXPENSES | | | | | | | | |
| Depreciation and amortization | 92.3 | 96.0 | 94.1 | 99.4 | 82.3 | 56.1 | 57.3 | 53.7 |
| Real estate taxes | 63.8 | 60.0 | 60.2 | 63.7 | 59.7 | 51.4 | 49.3 | 49.8 |
| Property operating | 68.5 | 56.1 | 64.1 | 78.4 | 54.3 | 45.3 | 50.6 | 52.0 |
| General and administrative | 39.2 | 48.7 | 38.2 | 35.0 | 30.7 | 28.8 | 32.0 | 17.8 |
| Real estate impairment loss | | | | | | | | |
| Total expenses | 559.7 | 578.3 | 609.0 | 632.8 | 370.2 | 299.7 | 358.9 | 314.0 |
| Gain on sale of real estate | 18.6 | 39.8 | 68.6 | 52.6 | | 15.6 | | |
| Interest income | 0.4 | 2.6 | 9.8 | 8.3 | 2.2 | 0.7 | 0.2 | 0.0 |
| Interest and debt expense | -57.9 | -71.0 | -66.6 | -64.9 | -56.2 | -51.9 | -55.6 | -55.0 |
| Income (loss) before income taxes | 109.0 | 58.8 | 117.5 | 120.5 | 72.7 | 97.4 | 42.6 | 67.5 |
| Income tax expense | -1.1 | 39.0 | -1.3 | -3.5 | 0.3 | -0.8 | -1.3 | -1.7 |
| Net income (loss) | 107.8 | 97.8 | 116.2 | 117.0 | 72.9 | 96.6 | 41.3 | 65.8 |
| |
| Less net (income) loss attributable to NCI in: | | | | | | | | |
| Operating partnership | -4.3 | -4.2 | -6.7 | -11.8 | -5.8 | -5.8 | -2.5 | |
| Net income (loss) attributable to common shareholders | 102.7 | 93.6 | 109.5 | 105.2 | 67.1 | 90.8 | 38.8 | 65.8 |
| |
| Earnings per common share - Basic (in dollars per share) | $0.88 | $0.79 | $0.91 | $0.92 | $0.62 | $0.91 | $0.39 | $0.66 |
| Earnings per common share - Diluted (in dollars per share) | $0.88 | $0.79 | $0.91 | $0.92 | $0.61 | $0.91 | $0.39 | $0.66 |
| |
| Weighted average shares outstanding - Basic (in shares) | 117.0 | 117.7 | 119.8 | 113.9 | 107.1 | 99.4 | 99.3 | 99.2 |
| Weighted average shares outstanding - Diluted (in shares) | 121.4 | 117.9 | 119.9 | 114.1 | 118.4 | 99.8 | 99.3 | 99.2 |
| Net income (loss) | 107.8 | 97.8 | 116.2 | 117.0 | 72.9 | 96.6 | 41.3 | 65.8 |
| |
| Comprehensive income (loss) | | | | | | | | |
| Less net (income) loss attributable to NCI in Operating partnership | -4.3 | -4.2 | -6.7 | -11.8 | -5.8 | -5.8 | -2.5 | |