Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014 Guarantee	Jun. 30, 2013
Commitments and Contingencies [Line Items]
Payments for capital improvements	$ 5,403	$ 33,532
Number of guarantees outstanding	2
Base Building Improvements [Member]
Commitments and Contingencies [Line Items]
Obligation for tenant improvements	41
Payment of the Base Building Improvement, Tenant Improvement Alloance, and Lease Commissions [Member]
Commitments and Contingencies [Line Items]
Obligation for tenant improvements	1,499
Byhalia Mississippi [Member]
Commitments and Contingencies [Line Items]
Payments for capital improvements	$ 15,300