Accounting for the Impairment or Disposal of Long-Lived Assets (Tables)
 3 Months Ended
Mar. 31, 2015
Disposal Group, Including Discontinued Operation, Long Lived Assets [Abstract]  
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]
A summary of the results of operations for the properties classified as discontinued operations through the respective disposition dates is as follows (in thousands):
 
 
Three Months Ended March 31,
 
2015
 
2014
Revenues
$
—

 
$
4,748

Operating expenses
—

 
(2,495
)
Interest and other income
—

 
37

Interest expense
—

 
(557
)
Depreciation and amortization
—

 
—

Income before gain on property dispositions
—

 
1,733

Gain on property dispositions
—

 
46,115

Net income
$
—

 
$
47,848