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Real Estate Investments (Tables) | 6 Months Ended
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Jun. 30, 2014
Real Estate [Abstract] |
Gross Carrying Value Of Company's Properties [Table Text Block] | As of June 30, 2014 and December 31, 2013, the gross carrying value of the Company’s Properties was as follows (in thousands):
| June 30, 2014 |  | December 31, 2013
Land | $ | 688,775 |  |  | $ | 680,513 |
Building and improvements | 3,479,850 |  |  | 3,504,060 |
Tenant improvements | 521,267 |  |  | 484,716 |
| $ | 4,689,892 |  |  | $ | 4,669,289 |

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