Debt - Narrative (Details)		3 Months Ended	6 Months Ended		12 Months Ended
	Dec. 21, 2018 USD ($) option	Jun. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Debt, net		$ 655,261,000	$ 655,261,000		$ 572,850,000
Repayment of mortgages payable		26,349,000	67,349,000	$ 12,491,000
Mortgages Payable
Debt Instrument [Line Items]
Total mortgages payable, net		107,282,000	107,282,000		175,321,000
Line of Credit
Debt Instrument [Line Items]
Total mortgages payable, net		547,979,000	547,979,000
Revolving Credit Facility | Revolving Credit Facility, Amended and Restated
Debt Instrument [Line Items]
Debt, net		150,000,000	150,000,000		$ 0
Debt instrument, face amount	$ 350,000,000
Proceeds from lines of credit			$ 150,000,000
Interest rate (percent)			1.22%
Debt instrument, term	4 years
Number of extension options | option	2
Extension option on line of credit, period	6 months
Unused commitment fee (percent)			0.15%		0.15%
Remaining borrowing capacity		$ 200,000,000	$ 200,000,000
Revolving Credit Facility | Revolving Credit Facility, Amended and Restated | One-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (percent)			1.05%