Intangible Assets and Liabilities - Annual Amortization of Intangible Assets, Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Assets
2019 (three months remaining)	$ 10,057
2020	28,185
2021	18,289
2022	12,153
2023	9,236
Thereafter	17,878
Intangible assets, net	95,798	$ 131,348
Liabilities
2019 (three months remaining)	1,696
2020	5,299
2021	3,890
2022	2,270
2023	1,722
Thereafter	9,173
Acquired lease intangibles, net	$ 24,050	$ 31,783