SEGMENT AND GEOGRAPHICAL INFORMATION - Concentration Risk (Details)	3 Months Ended		6 Months Ended
	Jul. 03, 2026	Jul. 04, 2025	Jul. 03, 2026	Jul. 04, 2025
Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Top Ten Customers
Concentration Risk
Concentration risk (as a percent)	51.70%	52.50%	47.10%	52.60%
Revenue from Contract with Customer Benchmark \| Customer Concentration Risk \| Southern California Edison and Clark County School District
Concentration Risk
Concentration risk (as a percent)		26.30%		25.30%
Revenue from Contract with Customer Benchmark \| Geographic Concentration Risk \| California
Concentration Risk
Concentration risk (as a percent)	43.70%	44.60%	44.60%	42.40%
Revenue from Contract with Customer Benchmark \| Geographic Concentration Risk \| New York
Concentration Risk
Concentration risk (as a percent)	15.80%	18.40%	17.30%	20.00%
Revenue from Contract with Customer, Segment Benchmark \| Customer Concentration Risk \| Southern California Edison and Clark County School District \| Energy
Concentration Risk
Concentration risk (as a percent)		31.10%		30.20%
Revenue from Contract with Customer, Segment Benchmark \| Customer Concentration Risk \| Southern California Edison \| Energy
Concentration Risk
Concentration risk (as a percent)	11.20%		11.30%