Acquired In-Place Leases and Above/Below Market Leases Increases (Decreases) in Net Income as Result of Amortization of In-Place Leases Above Market Leases and Below Market Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of leases	$ (558)	$ (1,848)	$ (3,142)
Amortization of below market leases	4,719	4,686	5,057
In-place leases
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of leases	(4,029)	(4,767)	(5,903)
Above market leases
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of leases	$ (1,248)	$ (1,767)	$ (2,296)