| In millions, except per share items | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 | Dec-31-12 | Dec-31-11 | Dec-31-10 | Dec-31-09 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Revenues: | | | | | | | | |
| Base rent | 345.0 | 298.6 | 285.7 | 265.7 | 236.8 | 206.0 | 154.9 | 117.3 |
| Recoveries from tenants | 169.7 | 139.5 | 124.9 | 104.3 | 91.0 | 79.1 | 78.4 | 69.0 |
| Other revenues | 14.0 | 14.3 | 7.0 | 5.1 | 4.6 | 2.3 | 9.2 | 14.0 |
| Total revenues | 528.7 | 452.4 | 417.6 | 375.1 | 332.4 | 287.4 | 242.5 | 200.3 |
| Total revenues growth | 16.9% | 8.3% | 11.3% | 12.8% | 15.7% | 18.5% | 21.1% | 15.3% |
| Expenses: | | | | | | | | |
| Property operating costs | 154.1 | 130.1 | 117.3 | 103.5 | 94.6 | 80.4 | 67.0 | 62.9 |
| Real estate taxes and insurance | 20.2 | 21.3 | 14.2 | 14.4 | 12.7 | 6.4 | 5.3 | 5.3 |
| Depreciation and amortization | 107.8 | 104.0 | 96.8 | 93.1 | 89.2 | 75.1 | 62.5 | 56.7 |
| General and administrative | 23.0 | 18.1 | 17.2 | 16.3 | 17.0 | 16.0 | 14.7 | 13.4 |
| Other expenses | 11.8 | 16.9 | 9.2 | 3.7 | 6.9 | 1.1 | 7.1 | 11.5 |
| Total expenses | 316.8 | 412.8 | 254.7 | 230.9 | 220.5 | 178.9 | 156.7 | 149.7 |
| Operating income | 211.9 | 39.6 | 162.9 | 144.2 | 111.9 | 108.5 | 85.9 | 50.5 |
| Operating margin | 40.1% | 8.7% | 39.0% | 38.5% | 33.7% | 37.8% | 35.4% | 25.2% |
| |
| Interest: | | | | | | | | |
| Expense incurred | -48.3 | -40.5 | -33.6 | -46.4 | -47.8 | -27.1 | -36.7 | -25.5 |
| Amortization of deferred financing costs | -3.7 | -3.2 | -3.0 | -3.3 | -3.5 | -2.4 | 4.0 | |
| Gain on sale of real estate | 22.8 | | | | | | | |
| Net income | 181.4 | -4.1 | 124.6 | 53.6 | 60.8 | 79.5 | 43.7 | 2.9 |
| Net income attributable to redeemable noncontrolling interests – operating partnership | -24.2 | 6.0 | -18.7 | -5.2 | -7.8 | | | |
| Net income attributable to controlling interests | 157.2 | 1.9 | 105.9 | 48.4 | 53.0 | 65.0 | 30.4 | 1.8 |
| Preferred stock dividends | -20.7 | -27.2 | -27.2 | -27.2 | -27.1 | -20.9 | -3.2 | |
| Other Preferred Stock Dividends and Adjustments | -12.5 | | | | | | | |
| Net income attributable to common shares | 124.0 | -25.3 | 78.7 | 21.1 | 26.0 | 44.1 | 27.3 | 1.8 |
| Net income attributable to common units | 148.2 | -31.3 | 97.4 | | | | | |
| |
| Earnings per share – basic: | | | | | | | | |
| Net income attributable to common shares | $1.69 | ($0.40) | $1.19 | $0.32 | $0.41 | $0.71 | $0.51 | $0.04 |
| |
| Weighted average common shares outstanding | 73.0 | 65.2 | 65.5 | 64.6 | 62.9 | 61.2 | 52.8 | 39.9 |
| |
| Earnings per share – diluted: | | | | | | | | |
| Net income attributable to common shares | $1.67 | ($0.40) | $1.18 | $0.32 | $0.41 | $0.71 | $0.51 | $0.04 |
| Weighted average common shares outstanding | 73.8 | 65.2 | 66.1 | 65.5 | 63.8 | 62.3 | 54.1 | 40.6 |
| |
| Dividends declared per common share | | | | | | | $0.44 | |
| |
| Earnings per unit – basic: | | | | | | | | |
| Net income attributable to common units | 0.0 | 0.0 | 0.0 | | | | | |
| |
| Weighted average common units outstanding | | | | | | | | |
| Earnings per unit – diluted: | | | | | | | | |
| Net income attributable to common units | 0.0 | 0.0 | 0.0 | | | | | |
| |
| Weighted average limited partnership units outstanding, diluted | | | | | | | | |
| Distributions declared per unit | | | | | | | | |