Leases (Tables)

12 Months Ended

Dec. 31, 2012

Leases [Abstract]

Schedule of Future Minimum Rental Payments Receivable for Operating Leases [Table Text Block]

Minimum future rental receipts under the non-cancelable portion of tenant leases, assuming no new or re-negotiated leases, for the next five years and thereafter are as follows:

Year ending December 31,	Total
2013	$	335,434
2014	319,112
2015	276,155
2016	245,100
2017	222,542
Thereafter	1,111,022
	$	2,509,365

Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]

Minimum future rental payments under non-cancelable leasehold interests, excluding leases held through industrial revenue bonds and lease payments in the future that are based upon fair market value, for the next five years and thereafter are as follows:

Year ending December 31,	Total
2013	$	2,572
2014	2,328
2015	2,300
2016	1,971
2017	1,924
Thereafter	15,885
	$	26,980