Customer Contract Terms

No definition available.

Name:	spxc_CustomerContractTerms
Namespace Prefix:	spxc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Increase (Decrease) in Contract with Customers, Net

+ References

No definition available.

+ Details

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

- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

+ Details

Name:	us-gaap_ContractWithCustomerLiabilityRevenueRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130556-203045

+ Details

Name:	us-gaap_RevenueRemainingPerformanceObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of remaining performance obligation to total remaining performance obligation not recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130556-203045

+ Details

Name:	us-gaap_RevenueRemainingPerformanceObligationPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of cost incurred on construction contract for unapproved change order, claim, or similar item subject to uncertainty.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 910
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6471471&loc=d3e48698-109348

+ Details

Name:	us-gaap_UnapprovedChangeOrdersAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=spxc_EngineeredSolutionsReportableSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=spxc_SouthAfricanProjectsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=spxc_HVACReportableSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=spxc_DetectionandMeasurementReportableSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=spxc_PowerTransformersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=spxc_ProcessCoolingProjectsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_ZA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=spxc_LargePowerProjectsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

REVENUES FROM CONTRACTS - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 29, 2018	Sep. 29, 2018	Dec. 31, 2019	Dec. 31, 2018
Revenue from External Customer [Line Items]
Revenue, remaining performance obligation	$ 53.9	$ 53.9
Increase (decrease) in contract with customers, net		55.2
Contract with customer, revenue recognized	6.8	$ 56.7
Engineered Solutions segment \| South African projects
Revenue from External Customer [Line Items]
Customer contract terms		10 years
Minimum \| HVAC segment
Revenue from External Customer [Line Items]
Customer contract terms		1 month
Minimum \| Detection and Measurement segment
Revenue from External Customer [Line Items]
Customer contract terms		1 month
Minimum \| Engineered Solutions segment \| Power transformers
Revenue from External Customer [Line Items]
Customer contract terms		6 months
Minimum \| Engineered Solutions segment \| Process cooling equipment and services, and heat exchangers
Revenue from External Customer [Line Items]
Customer contract terms		6 months
Maximum \| HVAC segment
Revenue from External Customer [Line Items]
Customer contract terms		3 months
Maximum \| Detection and Measurement segment
Revenue from External Customer [Line Items]
Customer contract terms		18 months
Maximum \| Engineered Solutions segment \| Power transformers
Revenue from External Customer [Line Items]
Customer contract terms		1 year
Maximum \| Engineered Solutions segment \| Process cooling equipment and services, and heat exchangers
Revenue from External Customer [Line Items]
Customer contract terms		1 year 6 months
SOUTH AFRICA \| Large Power Projects
Revenue from External Customer [Line Items]
Revenue recognized	$ 38.4	$ 38.4
Scenario, Forecast
Revenue from External Customer [Line Items]
Revenue remaining performance obligation percentage			91.00%	70.00%