Fair Value Measurements - Fair Value Disclosures (Details) $ in Thousands	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgages payable, net	$ 92,967	$ 94,155
Unsecured notes payable, net	796,568	796,247
Unsecured term loans, net	716,992	716,523
Unsecured revolving line of credit	135,000	18,000
Fair Value, Level 1
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unsecured notes payable, net	243,380	255,965
Fair Value, Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgages payable, net	94,982	98,082
Unsecured notes payable, net	543,339	566,918
Unsecured term loans, net	704,148	720,000
Unsecured revolving line of credit	133,299	18,000
Fair Value, Total
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgages payable, net	94,982	98,082
Unsecured notes payable, net	786,719	822,883
Unsecured term loans, net	704,148	720,000
Unsecured revolving line of credit	133,299	18,000
Unsecured notes payable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Unsecured notes payable, net	$ 800,000	$ 800,000
Discount rate | Unsecured revolving line of credit
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Input for measuring debt	0.0175	0.0105
Minimum | Discount rate | Mortgages payable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Input for measuring debt	0.036	0.032
Maximum | Discount rate | Mortgages payable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Input for measuring debt	0.042	0.036
Weighted average | Discount rate | Unsecured notes payable
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Input for measuring debt	0.0469	0.0379
Weighted average | Discount rate | Unsecured term loans
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Input for measuring debt	0.0195	0.0126