INDEBTEDNESS - Senior Credit Facilities (Details)		3 Months Ended	9 Months Ended
	Sep. 09, 2025 USD ($)	Sep. 27, 2025 USD ($)	Sep. 27, 2025 USD ($)
Line of Credit Facility [Line Items]
Borrowings			$ 1,258,600,000
Loss on amendment/refinancing of senior credit agreement		$ 1,000,000.0
Transaction cost		500,000
Senior Credit Facilities | Term loans | Federal Funds Effective Swap Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	0.50%
Senior Credit Facilities | Term loans | SOFR
Line of Credit Facility [Line Items]
Basis spread on variable rate (as a percent)	1.00%
Senior Credit Facilities | Term loans | One-Month SOFR
Line of Credit Facility [Line Items]
Duration of interest period	1 month
Senior Credit Facilities | Term loans | Three-Month SOFR
Line of Credit Facility [Line Items]
Duration of interest period	3 months
Senior Credit Facilities | Term loans | Six-Month SOFR
Line of Credit Facility [Line Items]
Duration of interest period	6 months
Foreign Credit Instrument Facilities
Line of Credit Facility [Line Items]
Letters of credit issued, amount outstanding		12,200,000	12,200,000
Senior Credit Facility | Revolving loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement	$ 1,500,000,000
Senior Credit Facility | Revolving Credit Facility and Current SPX Term Loan Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement	2,025,000,000
Senior Credit Facility | Revolving Credit Facility and Current SPX Term Loan Facility | Additional Commitments
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement	$ 500,000,000.0
Senior Credit Facility | Revolving Credit Facility and Current SPX Term Loan Facility | Maximum
Line of Credit Facility [Line Items]
EBITDA coverage ratio	3.00
Senior Credit Facility | Current SPX Term Loan Facility
Line of Credit Facility [Line Items]
Face amount of debt	$ 500,000,000.0
Borrowings			500,000,000.0
Revolving loans | Revolving loans
Line of Credit Facility [Line Items]
Amount of available borrowing capacity		1,489,000,000	1,489,000,000
Revolving loans | Revolving loans | United States
Line of Credit Facility [Line Items]
Borrowings			0.0
Term loans | Third Amendment
Line of Credit Facility [Line Items]
Payments of debt issuance costs		4,200,000
Financial Letter of Credit Fee | Senior Credit Facilities
Line of Credit Facility [Line Items]
Fronting fees percentage	0.125%
Financial Letter of Credit Fee | Financial Letters Of Credit | Revolving loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement	$ 200,000,000.0
Financial Letter of Credit Fee | Non - Financial Letters Of Credit | Revolving loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement	50,000,000.0
Financial Letter of Credit Fee | Non-U.S. Exposure | Revolving loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement	250,000,000.0
Financial Letter of Credit Fee | Bilateral Foreign Credit Instrument Facility | Revolving loans
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement	$ 25,000,000.0
Financial Letter of Credit Fee | Domestic Revolving Loan Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity under financing arrangement		$ 11,000,000.0	$ 11,000,000.0
Line of Credit | Senior Credit Facilities
Line of Credit Facility [Line Items]
Weighted-average interest rate of senior credit facilities		5.50%	5.50%
Maximum period within which net proceeds should be reinvested	365 days
Period after end of 365 day period if committed to be reinvested	180 days
Percentage of capital stock	100.00%
Percentage of capital stock of material first tier foreign subsidiaries	65.00%
Percentage of non-voting capital stock	100.00%
Line of Credit | Senior Credit Facilities | Four Fiscal Quarters After Certain Permitted Acquisitions
Line of Credit Facility [Line Items]
Coverage ratio	4.25
Line of Credit | Senior Credit Facilities | Maximum | Last Day Of Any Fiscal Quarter
Line of Credit Facility [Line Items]
Leverage ratio	3.75
Line of Credit | Senior Credit Facilities | Minimum | Last Day Of Any Fiscal Quarter
Line of Credit Facility [Line Items]
Interest coverage ratio	3.00
Foreign credit instrument facility
Line of Credit Facility [Line Items]
Amount of available borrowing capacity		$ 12,800,000	$ 12,800,000
Foreign credit instrument facility | Senior Credit Facilities
Line of Credit Facility [Line Items]
Fronting fees percentage	0.25%