Segment Reporting - Segment Assets (Details) - USD ($) $ in Thousands		Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information, Additional Information
Assets	[1]	$ 2,173,769	$ 2,234,803
Operating Segments | Net Lease
Segment Reporting Information, Additional Information
Assets		1,513,872	1,517,659
Operating Segments | Self Storage
Segment Reporting Information, Additional Information
Assets		365,196	369,883
Operating Segments | Other Operating Properties
Segment Reporting Information, Additional Information
Assets		223,107	213,692
Corporate
Segment Reporting Information, Additional Information
Assets		43,426	105,407
All Other
Segment Reporting Information, Additional Information
Assets		$ 28,168	$ 28,162

[1] See Note 2 for details related to variable interest entities (“VIEs”).