Business Combinations (Details) (USD $)	12 Months Ended	0 Months Ended										12 Months Ended
	Dec. 31, 2013 2013 Acquisitions Acquisitions	Aug. 30, 2013 Dallas, Texas	Mar. 11, 2013 Dallas, Texas	Mar. 22, 2013 Bryan - College Station, Texas	Jun. 18, 2013 Atlanta, Georgia	Jul. 12, 2013 Monroeville, Pennsylvania	Jul. 29, 2013 Denver, Colorado	Sep. 20, 2013 Miami/West Palm Beach, Florida	Dec. 10, 2013 Austin, Texas	Nov. 13, 2013 Austin, Texas	Dec. 13, 2013 Tampa/Jupiter, Florida	Dec. 31, 2012 2012 Acquisitions	Dec. 31, 2013 Mortgages 2013 Acquisitions	Sep. 20, 2013 Fixed Rate Mortgages Miami/West Palm Beach, Florida	Dec. 10, 2013 Fixed Rate Mortgages Austin, Texas	Dec. 13, 2013 Variable Rate Mortgages Tampa/Jupiter, Florida
Business Acquisition
Number of businesses acquired	10
Acquisition-related expenses	$ 4,800,000											$ 3,000,000
Acquisition, assumed mortgage loans													53,400,000	18,000,000	4,800,000	29,900,000
Business Acquisition, Purchase Price Allocation, Real Estate [Abstract]
Land	16,192,000											13,479,000
Building and improvements	292,037,000											225,924,000
Below market leasehold interests	10,317,000											3,284,000
Above market leases	2,999,000											4,199,000
In place leases	52,845,000											27,136,000
Tenant relationships	25,119,000											22,100,000
Below market leases	(2,104,000)											(1,472,000)
Above market debt	(694,000)
Interest rate swap	(2,600,000)
Net assets acquired	394,111,000											294,650,000
Contingencies and other, net	3,715,000											287,000
Aggregate purchase price	$ 397,826,000	$ 27,700,000	$ 48,700,000	$ 39,800,000	$ 5,600,000	$ 15,100,000	$ 42,000,000	$ 62,900,000	$ 19,700,000	$ 9,600,000	$ 126,700,000	$ 294,937,000
Weighted average lives of acquired intangible assets	16 years											14 years 2 months 12 days
Weighted average lives of acquired intangible liabilities	5 years 7 months 6 days											7 years 7 months 6 days