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Fair Value (Details) € in Millions, $ in Millions		3 Months Ended			12 Months Ended
Fair Value (Details) € in Millions, $ in Millions	Dec. 30, 2016 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2016 USD ($)	Apr. 02, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2018 EUR (€)	Jan. 01, 2018 USD ($)	Dec. 30, 2016 EUR (€)
Assets and liabilities measured at fair value on a recurring basis
Gain (loss) on sale of business, net of tax					$ 3.0	$ 5.3	$ (81.3)
Equity security, cost						$ 0.7
Equity security, fair value									$ 16.6
SPX Heat Transfer Business
Assets and liabilities measured at fair value on a recurring basis
Impairment charge			$ 23.9
SPX Heat Transfer Business \| Trademarks
Assets and liabilities measured at fair value on a recurring basis
Impairment charge related to trademarks			$ 2.2	$ 4.0			$ 30.1
Balcke Durr
Assets and liabilities measured at fair value on a recurring basis
Gain (loss) on sale of business, net of tax		$ 3.8
Discontinued Operations, Disposed of by Sale \| Balcke Durr
Assets and liabilities measured at fair value on a recurring basis
Gain (loss) on sale of business, net of tax		$ 3.8
Discontinued Operations, Disposed of by Sale \| SPXC \| Indemnification Agreement \| mutares AG \| Balcke Durr
Assets and liabilities measured at fair value on a recurring basis
Amount of guarantees \| €								€ 5.0		€ 5.0
Discontinued Operations, Disposed of by Sale \| Subsidiary of mutares AG (the Buyer) \| Balcke Durr
Assets and liabilities measured at fair value on a recurring basis
Amount of guarantees \| €								31.7		79.0
Gain (loss) on sale of business, net of tax	$ (78.6)
Discontinued Operations, Disposed of by Sale \| Subsidiary of mutares AG (the Buyer) \| Balcke-Durr GmbH \| Balcke Durr
Assets and liabilities measured at fair value on a recurring basis
Cash collateral \| €								3.0		4.0
Discontinued Operations, Disposed of by Sale \| Subsidiary of mutares AG (the Buyer) \| Bank and Surety Bonds \| Balcke Durr
Assets and liabilities measured at fair value on a recurring basis
Amount of guarantees \| €								€ 21.8		€ 79.0
Discontinued Operations, Disposed of by Sale \| Subsidiary of mutares AG (the Buyer) \| Guarantees and Bonds \| Balcke Durr
Assets and liabilities measured at fair value on a recurring basis
Gain (loss) on sale of business, net of tax	$ (5.1)
Accounting Standards Update 2016-01
Assets and liabilities measured at fair value on a recurring basis
Impact of adoption of ASU Adoption									$ 12.0