| Schedule of Segment Reporting Information, by Segment, Revenue and Net Operating Income [Table Text Block] |
The operating information by reportable segment is as follows (in thousands): | | | | | | | | | | | | | | For the Three Months | | | | Ended March 31, | | | | 2015 | | 2014 | Operating revenue | | | | | | Carolinas | | $ | 9,844 |
| | $ | 8,316 |
| | Chicago/Milwaukee | | 9,793 |
| | 8,570 |
| | Houston | | 12,324 |
| | 11,867 |
| | Lehigh/Central PA | | 33,554 |
| | 29,623 |
| | Minnesota | | 12,672 |
| | 13,750 |
| | Orlando | | 5,264 |
| | 7,995 |
| | Philadelphia | | 9,982 |
| | 9,408 |
| | Richmond/Hampton Roads | | 10,490 |
| | 10,068 |
| | South Florida | | 12,206 |
| | 12,309 |
| | Southeastern PA | | 39,238 |
| | 38,437 |
| | Tampa | | 13,462 |
| | 13,173 |
| | United Kingdom | | 3,725 |
| | 4,102 |
| | Other | | 34,398 |
| | 35,039 |
| Segment-level operating revenue | | 206,952 |
| | 202,657 |
| | | | | | | Reconciliation to total operating revenues | | | | | | Discontinued operations | | — |
| | (4,748 | ) | | Other | | (51 | ) | | (279 | ) | Total operating revenue | | $ | 206,901 |
| | $ | 197,630 |
| | | | | | | Net operating income | | | | | | | Carolinas | | $ | 6,617 |
| | $ | 5,742 |
| | Chicago/Milwaukee | | 6,743 |
| | 5,163 |
| | Houston | | 7,221 |
| | 7,053 |
| | Lehigh/Central PA | | 22,971 |
| | 19,240 |
| | Minnesota | | 5,985 |
| | 6,619 |
| | Orlando | | 3,571 |
| | 5,492 |
| | Philadelphia | | 7,022 |
| | 6,721 |
| | Richmond/Hampton Roads | | 6,229 |
| | 5,920 |
| | South Florida | | 6,829 |
| | 7,527 |
| | Southeastern PA | | 20,988 |
| | 19,600 |
| | Tampa | | 8,702 |
| | 8,441 |
| | United Kingdom | | 2,516 |
| | 2,850 |
| | Other | | 22,176 |
| | 21,731 |
| Segment-level net operating income | | 127,570 |
| | 122,099 |
| | | | | | | Reconciliation to income from continuing operations | | | | | | Interest expense (1) | | (34,670 | ) | | (39,764 | ) | | Depreciation/amortization expense (1) (2) | | (43,514 | ) | | (44,536 | ) | | Impairment - real estate assets | | (15,739 | ) | | — |
| | Gain on property dispositions | | 2,271 |
| | — |
| | Equity in earnings of unconsolidated joint ventures | | 6,906 |
| | 4,159 |
| | General and administrative expense (1) (2) | | (12,574 | ) | | (12,401 | ) | | Discontinued operations excluding interest and gain on property dispositions | | — |
| | (2,290 | ) | | Income taxes (2) | | (707 | ) | | (483 | ) | | Other | | 2,319 |
| | (526 | ) | Income from continuing operations | | $ | 31,862 |
| | $ | 26,258 |
|
| | (1) | Includes activity on discontinued operations. |
| | (2) | Excludes costs which are included in determining segment-level net operating income. |
|