Fair Value Measurements - Fair Value of Financial Instruments Presented at Carrying Values (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Carrying Value
Debt Instrument [Line Items]
Mortgages payable	$ 107,891	$ 176,051
Estimated Fair Value
Debt Instrument [Line Items]
Mortgages payable	107,682	178,937
Unsecured Debt | Unsecured Term Loan | Carrying Value
Debt Instrument [Line Items]
Term loans	400,000	400,000
Unsecured Debt | Unsecured Term Loan | Estimated Fair Value
Debt Instrument [Line Items]
Term loans	400,017	400,020
Revolving Credit Facility | Revolving Credit Facility, Amended and Restated | Carrying Value
Debt Instrument [Line Items]
Term loans	150,000	0
Revolving Credit Facility | Revolving Credit Facility, Amended and Restated | Estimated Fair Value
Debt Instrument [Line Items]
Term loans	$ 150,260	$ 0