Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2021	Feb. 18, 2022	Jul. 03, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-6948
Entity Registrant Name	SPX Corp
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	38-1016240
Entity Address, Address Line One	6325 Ardrey Kell Road Suite 400
Entity Address, City or Town	Charlotte
Entity Address, State or Province	NC
Entity Address, Postal Zip Code	28277
City Area Code	980
Local Phone Number	474-3700
Title of 12(b) Security	Common Stock, Par Value $0.01
Trading Symbol	SPXC
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2,744,821,519
Entity Common Stock, Shares Outstanding		45,491,812
Documents Incorporated by Reference	Documents incorporated by reference: Portions of the Registrant’s proxy statement for its Annual Meeting to be held on May 10, 2022 are incorporated by reference into Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0000088205
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY