Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Straight-line rent receivables	$ 69,500	$ 67,000
Prepaid assets	66,200	65,200
Additional long-lived assets, net	23,500	24,900
Above-market intangible assets, net	16,800	17,900
Accounts receivable	10,000	7,400
Allowance for uncollectible accounts	(300)	(300)
Ground lease modification, net	9,900	10,300
Equity investments in joint ventures	8,500	8,700
Goodwill	3,500	3,487
Project costs	2,200	2,000
Debt issuance costs, net (1)	2,200	3,500
Customer relationship intangible assets, net	1,700	1,700
Interest rate swap assets	229
Other	800	1,200
Other Assets	$ 214,697	$ 213,015