Segment and Geographical Information - Reconciliation of Other Significant Reconciling Items from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2021	Sep. 27, 2020	Oct. 03, 2021	Sep. 27, 2020
Segment Reporting Information [Line Items]
Segment gross profit as reviewed by CODM	$ 59,650	$ 37,140	$ 170,555	$ 91,976
Residential, Light Commercial
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	281,635	197,710	773,691	590,140
Segment gross profit as reviewed by CODM	63,108	34,779	173,239	94,501
Adjusted EBITDA	30,825	15,521	83,771	31,346
Commercial and Industrial Solutions
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	40,324	74,334	154,763	175,265
Segment gross profit as reviewed by CODM	(2,387)	5,120	2,527	14,533
Adjusted EBITDA	(8,133)	1,228	(13,125)	(1,244)
Others
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	1,677	10,056	9,871	55,615
Segment gross profit as reviewed by CODM	(19)	(3,168)	5,013	(18,906)
Adjusted EBITDA	(649)	(3,192)	3,615	(19,278)
Operating Segments
Segment Reporting Information [Line Items]
Segment gross profit as reviewed by CODM	60,702	36,731	180,779	90,128
Intersegment revenue
Segment Reporting Information [Line Items]
Segment gross profit as reviewed by CODM	(83)	1,752	785	11,604
Intersegment revenue | Residential, Light Commercial
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	0	0	0	0
Intersegment revenue | Commercial and Industrial Solutions
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	0	0	0	0
Intersegment revenue | Others
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	0	7,293	(11)	32,815
Dev Co | Operating Segments | Residential, Light Commercial
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	274,747	190,480	753,429	571,236
Dev Co | Operating Segments | Commercial and Industrial Solutions
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	36,596	73,790	139,486	167,544
Dev Co | Operating Segments | Others
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	980	2,688	7,320	2,954
Power Co | Operating Segments | Residential, Light Commercial
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	6,888	7,230	20,262	18,904
Power Co | Operating Segments | Commercial and Industrial Solutions
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	3,728	544	15,277	7,721
Power Co | Operating Segments | Others
Segment Reporting Information [Line Items]
Total segment revenues as reviewed by CODM	$ 697	$ 75	$ 2,562	$ 19,846