SPECIAL CHARGES, NET - Analysis of Restructuring Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
Apr. 02, 2022	Apr. 03, 2021
Restructuring liabilities
Balance at beginning of year	$ 0.3	$ 0.8
Special charges	0.0	0.2
Utilization — cash	(0.1)	(0.4)
Currency translation adjustment and other	0.0	0.0
Balance at end of period	$ 0.2	$ 0.6

Reserve increase representing the amount charged against earnings in the period for a specified incurred and estimated type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan. Also includes the amount charged against earnings in the period for integration expenses.

No definition available.

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Namespace Prefix:	spxc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration