Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Revenues	$ 1,219.5	$ 1,128.1	$ 1,123.6
Costs and expenses:
Cost of products sold	787.7	732.6	721.6
Selling, general and administrative	309.6	272.5	275.8
Intangible amortization	21.6	14.0	8.9
Impairment of goodwill and intangible assets	5.7	0.7	0.0
Special charges, net	1.0	2.4	1.5
Other operating expenses, net	20.2	9.0	1.8
Operating income	73.7	96.9	114.0
Other income (expense), net	9.0	(0.1)	(5.2)
Interest expense	(13.3)	(18.4)	(21.0)
Interest income	0.5	0.2	1.6
Loss on amendment/refinancing of senior credit agreement	0.0	0.0	(0.6)
Income from continuing operations before income taxes	69.9	78.6	88.8
Income tax provision	(10.9)	(4.8)	(12.5)
Income from continuing operations	59.0	73.8	76.3
Income (loss) from discontinued operations, net of tax	5.7	28.9	(6.6)
Gain (loss) on disposition of discontinued operations, net of tax	360.7	(3.7)	(4.4)
Gain (loss) from discontinued operations, net of tax	366.4	25.2	(11.0)
Net income	425.4	99.0	65.3
Less: Net loss attributable to noncontrolling interests	0.0	0.0	0.0
Net income attributable to SPX Corporation common stockholders	425.4	99.0	65.3
Adjustment related to redeemable noncontrolling interest (Note 15)	0.0	0.0	5.6
Net income attributable to SPX Corporation common stockholders after adjustment related to redeemable noncontrolling interest	425.4	99.0	70.9
Amounts attributable to SPX Corporation common stockholders after adjustment related to redeemable noncontrolling interest:
Income from continuing operations, net of tax	59.0	73.8	76.3
Gain (loss) from discontinued operations, net of tax	366.4	25.2	(5.4)
Net income attributable to SPX Corporation common stockholders after adjustment related to redeemable noncontrolling interest	$ 425.4	$ 99.0	$ 70.9
Basic income (loss) per share of common stock:
Income from continuing operations attributable to SPX Corporation common shareholders after adjustment related to redeemable noncontrolling interest (in dollars per share)	$ 1.30	$ 1.65	$ 1.74
Income (loss) from discontinued operations attributable to SPX Corporation common shareholders (in dollars per share)	8.09	0.57	(0.13)
Net income per share attributable to SPX Corporation common shareholders after adjustment related to redeemable noncontrolling interest (in dollars per share)	$ 9.39	$ 2.22	$ 1.61
Weighted-average number of shares outstanding — basic (in shares)	45,289	44,628	43,942
Diluted income (loss) per share of common stock:
Income from continuing operations attributable to SPX Corporation common shareholders after adjustment related to redeemable noncontrolling interest (in dollars per share)	$ 1.27	$ 1.61	$ 1.70
Gain (loss) from discontinued operations, net of tax (in dollars per share)	7.88	0.55	(0.12)
Net income per share attributable to SPX Corporation common shareholders after adjustment related to redeemable noncontrolling interest (in dollars per share)	$ 9.15	$ 2.16	$ 1.58
Weighted-average number of shares outstanding — diluted (in shares)	46,495	45,766	44,957