INTANGIBLE ASSETS (Narrative) (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 17, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Intangible Assets Net Excluding Goodwill [Abstract]
South Beach Diet acquisition, initial cash outlay	$ 15,000	$ 0	$ 0	$ 15,000
Finite-lived intangible asset, useful life		15 years
Amortization expense		$ 1,000	$ 1,000
Domain names		$ 84