INDEBTEDNESS - Summary of Debt Activity (Details) - USD ($)	3 Months Ended
	Mar. 30, 2024	Dec. 31, 2023	Apr. 21, 2023
Debt
Balance at the beginning of the period	$ 558,300,000
Borrowings	622,200,000
Repayments	(326,500,000)
Other	400,000
Balance at the end of the period	854,400,000
Less: short-term debt	317,000,000.0	$ 17,900,000
Less: current maturities of long-term debt	20,800,000	17,300,000
Long-term debt	516,600,000	523,100,000
Trade receivables financing arrangement
Debt
Balance at the beginning of the period	16,000,000.0
Borrowings	65,000,000.0
Repayments	(47,000,000.0)
Other	0
Balance at the end of the period	34,000,000.0
Maximum borrowing capacity under financing arrangement	60,000,000.0
Available borrowing capacity	5,000,000.0
Other indebtedness
Debt
Balance at the beginning of the period	2,400,000
Borrowings	0
Repayments	(300,000)
Other	300,000
Balance at the end of the period	2,400,000
Purchase card programs	1,600,000	1,900,000
Finance lease, liability	800,000	500,000
Revolving Credit Facility | Current Revolving SPX Facilities
Debt
Balance at the beginning of the period	0
Borrowings	557,200,000
Repayments	(275,800,000)
Other	0
Balance at the end of the period	$ 281,400,000
Revolving Credit Facility | Current Revolving SPX Facilities | Option Four | Maximum
Debt
Maturity increments	12 months
Term loan | Current SPX Term Loan Facilities
Debt
Balance at the beginning of the period	$ 539,900,000
Borrowings	0
Repayments	(3,400,000)
Other	100,000
Balance at the end of the period	536,600,000
Face amount of debt			$ 545,000,000.0
Unamortized debt issuance costs	$ 1,600,000	$ 1,700,000
Term loan | Current SPX Term Loan Facilities | First Three Quarters of 2024
Debt
Periodic payment (as a percent of principal)	0.625%
Term loan | Current SPX Term Loan Facilities | During Fourth Quarter of 2024
Debt
Periodic payment (as a percent of principal)	1.25%