Acquired In-Place Leases and Above/Below Market Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of acquired above and below market leases	$ 3.3	$ 3.5	$ 2.9
Weighted-average amortization period of below market leases	6 years 5 months
Acquired lease, below market renewal options	$ 15.3
Weighted-average amortization period of acquired leases prior to the commencement of renewal option	9 years 1 month
In-place leases
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted-average amortization period of acquired leases	7 years 11 months
Above market leases
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted-average amortization period of acquired leases	1 year 3 months