SIGNIFICANT ACCOUNTING POLICIES SIGNIFICANT ACCOUNTING POLICIES (Details 2) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 28, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Class of Stock [Line Items]
Preferred stock redemption period		5 years
Preferred stock conversion ratio		1
Preferred stock redemption price (percentage)		150.00%
Redeemable Convertible Preferred Stock [Roll Forward]
Beginning Balance	$ 34,859	$ 32,143	$ 29,638
Deemed Dividend on Redeemable Convertible Preferred Stock		(2,716)	(2,505)
Ending Balance		$ 34,859	$ 32,143
Subsequent Event [Member]
Class of Stock [Line Items]
Preferred stock redemption price (percentage)	145.00%