Real Estate Intangibles - Schedule of Future Estimated Aggregate Amortization of Intangible Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Assets
2019	$ 80,093
2020	60,916
2021	30,530
2022	24,734
2023	20,582
Thereafter	107,773
Net book value	324,628	$ 383,823
Liabilities
2019	5,233
2020	6,506
2021	5,870
2022	5,273
2023	3,395
Thereafter	12,124
Net book value	$ 38,401	$ 45,950