Real Estate Investments and Related Intangibles - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Acquisitions, 2020 [Member]
Real estate investments, at cost:
Land	$ 55,618
Buildings, fixtures and improvements	219,875
Total tangible assets	275,493
Acquired intangible assets:
Total purchase price of assets acquired	342,494
Acquisitions, 2020 [Member] | In-place leases and other intangible assets [Member]
Acquired intangible assets:
Acquired intangible assets	$ 37,919
Weighted-average useful life	16 years
Acquisitions, 2020 [Member] | Above-market leases [Member]
Acquired intangible assets:
Acquired intangible assets	$ 29,665
Weighted-average useful life	19 years 6 months
Acquisitions, 2020 [Member] | Below Market Lease [Member]
Acquired intangible assets:
Assumed intangible liabilities, Below-market leases	$ (583)
Weighted-average useful life	14 years
Acquisitions, 2019 [Member]
Real estate investments, at cost:
Land		$ 83,476
Buildings, fixtures and improvements		268,470
Total tangible assets		351,946
Acquired intangible assets:
Total purchase price of assets acquired		403,573
Acquisitions, 2019 [Member] | In-place leases and other intangible assets [Member]
Acquired intangible assets:
Acquired intangible assets		$ 51,627
Weighted-average useful life		16 years 6 months
Acquisitions, 2019 [Member] | Above-market leases [Member]
Acquired intangible assets:
Acquired intangible assets		$ 0
Acquisitions, 2019 [Member] | Below Market Lease [Member]
Acquired intangible assets:
Assumed intangible liabilities, Below-market leases		$ 0
Acquisitions 2018 [Member]
Real estate investments, at cost:
Land			$ 86,285
Buildings, fixtures and improvements			350,942
Total tangible assets			437,227
Acquired intangible assets:
Total purchase price of assets acquired			502,652
Acquisitions 2018 [Member] | In-place leases and other intangible assets [Member]
Acquired intangible assets:
Acquired intangible assets			$ 62,791
Weighted-average useful life			16 years 3 months 18 days
Acquisitions 2018 [Member] | Above-market leases [Member]
Acquired intangible assets:
Acquired intangible assets			$ 2,750
Weighted-average useful life			10 years 9 months 18 days
Acquisitions 2018 [Member] | Below Market Lease [Member]
Acquired intangible assets:
Assumed intangible liabilities, Below-market leases			$ (116)
Weighted-average useful life			9 years 10 months 24 days