SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Property and Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 97,194	$ 68,992
Land
Property, Plant and Equipment [Line Items]
Total property and equipment	8,396	8,396
Buildings
Property, Plant and Equipment [Line Items]
Total property and equipment	69,214	48,677
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	5,733	4,645
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	13,851	7,274
Airplane
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 0	$ 0