Lease Intangibles - Scheduled Amortization of Acquired Lease Intangible Assets and Assumed Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Acquired Lease Intangibles [Abstract]
Net Increase In Lease Revenues, Total	$ 86,256	$ 94,467
Amortizable Intangible Assets, Net Carrying Amount	(110,634)	(115,939)
In-place lease intangible assets
Acquired Lease Intangibles [Abstract]
2019 (Remainder), Net Increase In Lease Revenues	6,418
2020, Net Increase In Lease Revenues	8,217
2021, Net Increase In Lease Revenues	7,739
2022, Net Increase In Lease Revenues	7,380
2023, Net Increase In Lease Revenues	7,406
Thereafter, Net Increase In Lease Revenues	44,177
Net Increase In Lease Revenues, Total	81,337
2019 (Remainder), Increase to Amortization	(20,111)
2020, Increase to Amortization	(20,671)
2021, Increase to Amortization	(15,351)
2022, Increase to Amortization	(10,627)
2023, Increase to Amortization	(8,481)
Thereafter, Increase to Amortization	(30,474)
Amortizable Intangible Assets, Net Carrying Amount	(105,715)	$ (110,049)
2019 (Remainder), Reduction of Rent Expense	44
2020, Reduction of Rent Expense	58
2021, Reduction of Rent Expense	58
2022, Reduction of Rent Expense	58
2023, Reduction of Rent Expense	58
Thereafter, Reduction of Rent Expense	287
Reduction of Rent Expense, Total	563
2019 (Remainder), Net Income (Expense)	(13,649)
2020, Net Income (Expense)	(12,396)
2021, Net Income (Expense)	(7,554)
2022, Net Income (Expense)	(3,189)
2023, Net Income (Expense)	(1,017)
Thereafter, Net Income (Expense)	13,990
Total, Net Income (Expense)	$ (23,815)