Significant Accounting Policies - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) property	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Significant Accounting Policies Statement [Line Items]
Amortization of above and below-market leases	$ 1,300,000	$ 1,300,000	$ 4,100,000	$ 3,200,000
Remaining weighted average lease term related to these intangible assets and liabilities			8 years 1 month 6 days
Straight-line rent and accounts receivables, net of allowances	28,100,000		$ 28,100,000		$ 27,400,000
Straight-line rent and accounts receivable, allowances	(1,300,000)		(1,300,000)		(200,000)
Deferred financing cost accumulated amortization	9,100,000		$ 9,100,000		$ 8,300,000
Performance measurement period			3 years
Number of reportable segments | property			1
COVID-19
Significant Accounting Policies Statement [Line Items]
Decrease in straight-line rent and accounts receivable, net of allowances COVID-19	200,000		$ 1,100,000
Senior Secured Loan Receivable
Significant Accounting Policies Statement [Line Items]
Impairment charges	0	0	0	0
Real estate investment
Significant Accounting Policies Statement [Line Items]
Property impairment charges	$ 0	$ 0	$ 0	$ 0