EARNINGS PER SHARE - Schedule of Basic to Diluted Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2023	Jul. 02, 2022	Jul. 01, 2023	Jul. 02, 2022
Reconciliation of basic to diluted loss per share
Net income attributable to Summit Inc.	$ 83,637	$ 190,113	$ 52,833	$ 155,821
Diluted net income attributable to Summit Inc.	$ 83,637	$ 190,113	$ 52,833	$ 155,821
LP Units
Reconciliation of basic to diluted loss per share
Anti dilutive shares excluded from calculation of earnings per share (in shares)	1,310,004	1,314,006	1,310,630	1,314,006
Common Class A And Restricted Stock
Reconciliation of basic to diluted loss per share
Weighted average shares of Class A stock outstanding (in shares)	118,931,914	120,222,094	118,805,785	120,569,387
Weighted average basic shares outstanding (in shares)	118,931,914	120,222,094	118,805,785	120,569,387
Basic earning per share (in usd per share)	$ 0.70	$ 1.58	$ 0.44	$ 1.29
Common Class A
Reconciliation of basic to diluted loss per share
Weighted average shares of Class A stock outstanding (in shares)	118,848,214	120,078,273	118,706,385	120,417,414
Weighted average basic shares outstanding (in shares)	118,848,214	120,078,273	118,706,385	120,417,414
Basic earning per share (in usd per share)	$ 0.70	$ 1.58	$ 0.44	$ 1.29
Add: warrants (in shares)	13,194	10,413	12,978	12,844
Weighted average dilutive shares outstanding (in shares)	119,393,709	120,660,721	119,431,604	121,374,168
Diluted earning per share (in usd per share)	$ 0.70	$ 1.58	$ 0.44	$ 1.28
Common Class A | Time-vesting stock options
Reconciliation of basic to diluted loss per share
Add: share-based payment arrangements (in shares)	100,895	76,161	99,102	101,094
Common Class A | Add: restricted stock units
Reconciliation of basic to diluted loss per share
Add: share-based payment arrangements (in shares)	193,011	257,454	340,958	533,242
Common Class A | Add: performance stock units
Reconciliation of basic to diluted loss per share
Add: share-based payment arrangements (in shares)	154,695	94,599	172,781	157,601
Restricted Stock
Reconciliation of basic to diluted loss per share
Add: Nonvested restricted stock awards of retirement eligible shares (in shares)	83,700	143,821	99,400	151,973