Organization and Basis of Presentation - Subsequent Events (Details) - Subsequent Event - USD ($) $ in Millions	Nov. 04, 2020	Oct. 31, 2020
410 Tenth Avenue
Subsequent Event [Line Items]
Gross asset valuation		$ 952.5
Ownership Interest		70.90%
Ownership percentage retained by investee		5.00%
Third Quarter 2020
Subsequent Event [Line Items]
Gross tenant billings collected, percent	92.70%
Third Quarter 2020 | Office
Subsequent Event [Line Items]
Gross tenant billings collected, percent	96.90%
Third Quarter 2020 | Retail
Subsequent Event [Line Items]
Gross tenant billings collected, percent	70.20%
October 2020 Period
Subsequent Event [Line Items]
Gross tenant billings collected, percent	93.00%
October 2020 Period | Office
Subsequent Event [Line Items]
Gross tenant billings collected, percent	96.40%
October 2020 Period | Retail
Subsequent Event [Line Items]
Gross tenant billings collected, percent	72.60%