Intangible Assets and Liabilities - Annual Amortization of Intangible Assets, Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Assets
2017 (three months remaining)	$ 3,443
2018	12,257
2019	10,984
2020	8,904
2021	6,366
Thereafter	16,863
Intangible Assets, net	58,817	$ 72,478
Liabilities
2017 (three months remaining)	677
2018	2,512
2019	2,198
2020	1,650
2021	1,062
Thereafter	9,057
Acquired Lease Intangibles, Net	$ 17,156	$ 18,119