Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid assets	$ 65,200	$ 64,800
Equity investment in joint ventures	8,700	0
Straight-line rent receivables	67,000	64,600
Above-market intangible assets, net	17,900	19,100
Additional long-lived assets, net	24,900	14,500
Ground lease modification, net	10,300	10,800
Accounts receivable	7,400	8,100
Allowance for uncollectible accounts	(300)	(100)
Credit facility deferred financing costs	3,500	4,900
Goodwill	3,487	3,487
Customer relationship intangible assets, net	1,700	1,800
Other	3,200	3,700
Other Assets	$ 213,015	$ 195,666