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STOCK-BASED COMPENSATION - Schedule of Weighted Average Assumptions (Details) - Employee Stock Purchase Plan
12 Months Ended
Dec. 31, 2017
Jan. 01, 2017
Jan. 03, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected life (months) 6 years 1 month 6 days 6 years 1 month 6 days 6 years
Risk-free interest rate 1.22% 0.97% 0.21%
Volatility 53.00% 59.00% 55.00%
Dividend yield 0.00% 0.00% 0.00%