Acquired Leases Intangibles (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Document Fiscal Year Focus	2016
Acquired lease intangible assets, net of amortization	$ 118,831	$ 105,380
Finite-Lived Intangible Assets, Gross	175,526	151,019
Finite-Lived Intangible Liabilities, Accumulated Accretion	(23,538)	(17,555)
Accumulated amortization	(56,695)	(45,639)
Finite-Lived Intangible Assets, Amortization Expense	14,386	11,442	$ 12,183
Acquired lease intangible liability accretion	6,994	4,155	4,590
In-place leases, net
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	96,178	77,691
Finite-Lived Intangible Assets, Amortization Expense	11,533	9,141	10,365
Above-market leases, net
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	14,684	14,841
Finite-Lived Intangible Assets, Amortization Expense	1,742	1,950	1,795
Above-market ground leases, net
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	64,664	58,487
Finite-Lived Intangible Assets, Amortization Expense	1,111	351	23
Partnership Interest [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired lease intangible assets, net of amortization	118,831	105,380
Off-market Lease, Unfavorable	54,180	42,034
Accumulated amortization	56,694	45,639
Off-Market Lease, Unfavorable [Member]
Finite-Lived Intangible Assets [Line Items]
Finite Lived Intangible Liabilities, Gross	71,996	53,868
Acquired lease intangible liability accretion	6,827	3,940	4,437
Above-market leases, net
Finite-Lived Intangible Assets [Line Items]
Finite Lived Intangible Liabilities, Gross	5,722	5,722
Acquired lease intangible liability accretion	$ 167	$ 215	$ 153