Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015 Guarantee	Mar. 31, 2014	Dec. 31, 2014
Commitments and Contingencies [Line Items]
Payments for capital improvements	$ 1,717	$ 3,051
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	138
Byhalia Mississippi [Member]
Commitments and Contingencies [Line Items]
Payments for capital improvements			$ 15,300