DESCRIPTION OF BUSINESS AND PRINCIPLES OF INTERIM STATEMENTS - Description of Business (Details) ft² in Millions	Mar. 31, 2019 a ft² USD ($) property	Dec. 31, 2018 property
Description of business
Number of real estate properties	0	4
Land
Description of business
Number of billboards under lease | $	18
Commercial
Description of business
Number of real estate properties	46
Number of states in which entity operates	14
Gross leasable space | ft²	2.3
Single-tenant
Description of business
Number of real estate properties	40
Multi-tenant
Description of business
Number of real estate properties	6
Undeveloped land | Daytona Beach, FL
Description of business
Acres | a	5,400