Acquired Leases Intangibles (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Acquired lease intangible assets, net of amortization	$ 52,365		$ 44,805
Finite-Lived Intangible Assets, Amortization Expense	12,183		8,709		5,069
Weighted Average Accretion Period of Intangible Liabilities (in years)	12 years 6 months
Acquired lease intangible liability accretion	4,590		3,726		1,950
In-place leases, net
Finite-Lived Intangible Assets [Line Items]
Acquired lease intangible assets, net of amortization	40,145		33,049
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life (in years)	5 years 10 months 24 days
Finite-Lived Intangible Assets, Amortization Expense	10,365		7,441		4,307
Above-market leases, net
Finite-Lived Intangible Assets [Line Items]
Acquired lease intangible assets, net of amortization	10,549		10,074
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life (in years)	7 years 4 months 24 days	[1]
Finite-Lived Intangible Assets, Amortization Expense	1,795	[1]	1,246	[1]	739	[1]
Above-market ground leases, net
Finite-Lived Intangible Assets [Line Items]
Acquired lease intangible assets, net of amortization	1,671		1,682
Acquired Finite-lived Intangible Asset, Weighted Average Useful Life (in years)	82 years 2 months 12 days	[1]
Finite-Lived Intangible Assets, Amortization Expense	$ 23	[1]	$ 22	[1]	$ 23	[1]

[1] Amounts are recorded as a reduction to minimum rent.