SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Foreign Currency Translation and Accumulated Other Comprehensive Loss) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss) Net of Tax [Abstract]
Material gains or losses from foreign currency exchange transactions	$ 0	$ 0	$ 0
Foreign currency translation adjustment	(10,958,000)	(8,290,000)
Net unrealized loss on investments, net of tax	(730,000)	(730,000)
Total accumulated other comprehensive loss	(11,688,000)	(9,020,000)
Reclassifications out of accumulated other comprehensive loss	0	0
Reclassification adjustment for realized gains on investments included in net income	$ 0	$ 0	$ (808,000)