Subsequent Events (Details) $ / shares in Units, $ in Thousands				3 Months Ended								12 Months Ended
	Feb. 05, 2021 $ / shares	Jan. 13, 2021 USD ($) ft² property	Jan. 04, 2021 USD ($)	Dec. 31, 2020 $ / shares	Sep. 30, 2020 $ / shares	Jun. 30, 2020 $ / shares	Mar. 31, 2020 $ / shares	Dec. 31, 2019 $ / shares	Sep. 30, 2019 $ / shares	Jun. 30, 2019 $ / shares	Mar. 31, 2019 $ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Feb. 09, 2021 property	Feb. 09, 2021	Feb. 09, 2021 tenant
Subsequent Event [Line Items]
Repayment on mortgage loans payable | $												$ 33,077	$ 1,514	$ 19,201
Dividend, common stock, declared (in dollars per share) | $ / shares				$ 0.29	$ 0.29	$ 0.27	$ 0.27	$ 0.27	$ 0.27	$ 0.24	$ 0.24
Subsequent event
Subsequent Event [Line Items]
Dividend, common stock, declared (in dollars per share) | $ / shares	$ 0.29
Subsequent event | Asset Acquisitions 2021 | Buildings
Subsequent Event [Line Items]
Number of properties acquired		1
Area of real estate property acquired | ft²		16,000
Asset acquisitions, assets acquired and liabilities assumed, net | $		$ 10,600
Subsequent event | COVID-19
Subsequent Event [Line Items]
Number of deferrals granted															62		62
Deferrals granted, percentage of annualized rent																2.80%
Number of tenants which completed rent deferral period and fully repaid deferral															17
Rent deferrals completed and fully paid as a percentage of annualized base rent																0.30%
Rent deferrals completed and fully repaid as a percentage of total deferrals																11.00%
Number of tenants currently in deferral and are fulfilling the deferral agreement															31
Number of tenants currently in deferral and fulfilling the deferral agreement as a percentage of annualized base rent																2.10%
Number of tenants currently in deferral and fulfilling deferral agreement as a percentage of total deferrals.																73.60%
Number of tenants that have defaulted on rent deferral payments															14
Number of tenants that have defaulted on rent deferral repayments as a percentage of annualized base rent.																0.40%
Number of tenants that have defaulted on rent deferral repayments as a percentage of total deferrals																15.40%
Subsequent event | Mortgage loans payable
Subsequent Event [Line Items]
Repayment on mortgage loans payable | $			$ 11,300
Debt instrument, interest rate			5.50%