Other Assets, Net - Schedule of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	$ 162,524	$ 15,971
Total accumulated amortization	19,524	12,908
Identified intangible assets, net	143,000	3,063
In-place leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	72,081	12,777
Total accumulated amortization	15,187	10,871
Above-market real estate leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	12,473	773
Total accumulated amortization	1,082	612
Below-market ground leases
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	2,874	2,215
Total accumulated amortization	1,344	1,278
Option to enter into ground lease
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	17,090	0
Management and leasing contracts
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	57,800	0
Total accumulated amortization	1,753	0
Other
Finite-Lived Intangible Assets [Line Items]
Total identified intangibles assets	206	206
Other
Finite-Lived Intangible Assets [Line Items]
Total accumulated amortization	$ 158	$ 147