Other Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid assets	$ 55,300,000	$ 50,700,000
Straight-line rent receivables	42,200,000	34,700,000
Additional long-lived assets, net	15,900,000	4,300,000
Above-market intangible assets, net	14,400,000	12,700,000
Deferred financing costs, net	11,700,000	10,600,000
Accounts receivable	7,000,000	6,100,000
Allowance for uncollectible accounts	(500,000)	(700,000)
Goodwill	3,500,000	3,500,000
Customer relationship intangible assets, net	2,000,000	2,000,000
Investment in unconsolidated LLC - cost method	0	1,300,000
Other	2,000,000	1,800,000
Other Assets	153,514,000	126,962,000
Other Assets (Textual) [Abstract]
Gain on sale of cost method investment in real estate	1,492,000	0	0
Cost method investments income loss from joint venture	$ 500,000	$ 400,000	$ 700,000