Per Share Information - Narrative (Details) - shares		3 Months Ended		9 Months Ended
	Apr. 13, 2024	Sep. 29, 2024	Oct. 01, 2023	Sep. 29, 2024	Oct. 01, 2023	Dec. 31, 2023
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock outstanding (in shares)		88,517,521		88,517,521		1,000
Common stock issued (in shares)		88,517,521		88,517,521		1,000
Weighted average dilutive securities (in shares)		0	0	0	0
Centuri Holdings, Inc. | Southwest Gas Holdings
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Common stock outstanding (in shares)	1,000
Common stock issued (in shares)	1,000
Southwest Gas Holdings
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Sale of stock (in shares)	71,665,592
Common stock outstanding (in shares)	71,665,592