Indebtedness - Summary of Indebtedness at Estimated Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Mortgage Loans Payable, Net	$ 179,287	$ 304,508
Senior Unsecured Notes, Net	756,351	546,607
Unsecured Term Loans	460,902	461,317
Unsecured Credit Facility	158,141	0
Total	1,554,681	1,312,432
Carrying Amount (A)
Debt Instrument [Line Items]
Mortgage Loans Payable, Net	174,360	297,716
Senior Unsecured Notes, Net	698,500	548,494
Unsecured Term Loans	460,000	460,000
Unsecured Credit Facility	158,000	0
Total	$ 1,490,860	$ 1,306,210