Real Estate Investments and Related Intangibles - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Assumed intangible liabilities:
Below market lease, weighted average useful life	18 years 7 months
Acquisitions 2018 [Member]
Real estate investments, at cost:
Land	$ 27,049
Buildings, fixtures and improvements	96,044
Total tangible assets	123,093
Assumed intangible liabilities:
Total purchase price of assets acquired	139,882
Acquisitions 2018 [Member] | In-place leases and other intangible assets [Member]
Acquired intangible assets:
Acquired intangible assets	$ 14,037
Assumed intangible liabilities:
Weighted-Average Useful Life	14 years 11 months 8 days
Acquisitions 2018 [Member] | Above-market leases [Member]
Acquired intangible assets:
Acquired intangible assets	$ 2,752
Assumed intangible liabilities:
Weighted-Average Useful Life	10 years 9 months 5 days
Acquisitions 2018 [Member] | Below-market leases [Member]
Assumed intangible liabilities:
Below-market leases	$ 0
2017 Acquisitions [Member]
Real estate investments, at cost:
Land		$ 24,107
Buildings, fixtures and improvements		59,261
Total tangible assets		83,368
Assumed intangible liabilities:
Total purchase price of assets acquired		101,914
2017 Acquisitions [Member] | In-place leases and other intangible assets [Member]
Acquired intangible assets:
Acquired intangible assets		$ 15,916
Assumed intangible liabilities:
Weighted-Average Useful Life		10 years 9 months 11 days
2017 Acquisitions [Member] | Above-market leases [Member]
Acquired intangible assets:
Acquired intangible assets		$ 2,815
Assumed intangible liabilities:
Weighted-Average Useful Life		20 years 8 days
2017 Acquisitions [Member] | Below-market leases [Member]
Assumed intangible liabilities:
Below-market leases		$ (185)
Below market lease, weighted average useful life		20 years 8 days