Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014 Guarantee	Sep. 30, 2013
Commitments and Contingencies [Line Items]
Payments for capital improvements	$ 9,434	$ 38,067
Number of guarantees outstanding	2
Base Building Improvements [Member]
Commitments and Contingencies [Line Items]
Obligation for tenant improvements	1,384
Payment of the Base Building Improvement, Tenant Improvement Alloance, and Lease Commissions [Member]
Commitments and Contingencies [Line Items]
Obligation for tenant improvements	592
Byhalia Mississippi [Member]
Commitments and Contingencies [Line Items]
Payments for capital improvements	$ 15,300