Consolidated Statements of Equity (USD $) In Millions, unless otherwise specified	Total	Common Stock	Paid-In Capital	Retained Earnings	Accum. Other Comprehensive Income (Loss)	Common Stock In Treasury	SPX Corporation Shareholders' Equity	Noncontrolling Interests
Balance at Dec. 31, 2008	$ 2,024.8	$ 972.3	$ 1,393.9	$ 2,220.5	$ (179.9)	$ (2,416.0)	$ 1,990.8	$ 34.0
Increase (Decrease) in Shareholders' Equity
Net income (loss)	16.2			31.7			31.7	(15.5)
Other comprehensive income (loss)	(32.9)				(33.7)		(33.7)	0.8
Dividends declared ($1.00 per share)	(49.2)			(49.2)			(49.2)
Exercise of stock options and other incentive plan activity, including related tax benefit of $1.1, $3.2 and $1.7 in 2011, 2010 and 2009, respectively	25.2	5.0	20.2				25.2
Amortization of restricted stock and restricted stock unit grants (includes $0.1 recorded to discontinued operations)	27.7		27.7				27.7
Restricted stock and restricted stock unit vesting, net of tax withholdings	(6.7)	1.7	(14.3)			5.9	(6.7)
Treasury stock repurchased	(113.2)					(113.2)	(113.2)
Dividends attributable to noncontrolling interests	(0.4)							(0.4)
Liquidation of noncontrolling interest due to disposition of Filtran (See Note 4)	(5.1)							(5.1)
Purchase of subsidiary shares from noncontrolling interest	(3.0)		(1.8)				(1.8)	(1.2)
Other changes in noncontrolling interests	(1.9)							(1.9)
Balance at Dec. 31, 2009	1,881.5	979.0	1,425.7	2,203.0	(213.6)	(2,523.3)	1,870.8	10.7
Increase (Decrease) in Shareholders' Equity
Net income (loss)	202.8			205.6			205.6	(2.8)
Other comprehensive income (loss)	21.3				21.0		21.0	0.3
Dividends declared ($1.00 per share)	(50.0)			(50.0)			(50.0)
Exercise of stock options and other incentive plan activity, including related tax benefit of $1.1, $3.2 and $1.7 in 2011, 2010 and 2009, respectively	31.4	5.1	26.3				31.4
Amortization of restricted stock and restricted stock unit grants (includes $0.1 recorded to discontinued operations)	31.1		31.1				31.1
Restricted stock and restricted stock unit vesting, net of tax withholdings	(12.2)	2.6	(22.0)			7.2	(12.2)
Dividends attributable to noncontrolling interests	(2.6)							(2.6)
Other changes in noncontrolling interests	0.7							0.7
Balance at Dec. 31, 2010	2,104.0	986.7	1,461.1	2,358.6	(192.6)	(2,516.1)	2,097.7	6.3
Increase (Decrease) in Shareholders' Equity
Net income (loss)	185.6			180.6			180.6	5.0
Other comprehensive income (loss)	(54.0)				(53.9)		(53.9)	(0.1)
Dividends declared ($1.00 per share)	(50.9)			(50.9)			(50.9)
Exercise of stock options and other incentive plan activity, including related tax benefit of $1.1, $3.2 and $1.7 in 2011, 2010 and 2009, respectively	29.0	4.3	24.7				29.0
Amortization of restricted stock and restricted stock unit grants (includes $0.1 recorded to discontinued operations)	41.4		41.4				41.4
Restricted stock and restricted stock unit vesting, net of tax withholdings	(16.6)	2.6	(25.0)			5.8	(16.6)
Dividends attributable to noncontrolling interests	(4.1)							(4.1)
Other changes in noncontrolling interests	2.9							2.9
Balance at Dec. 31, 2011	$ 2,237.3	$ 993.6	$ 1,502.2	$ 2,488.3	$ (246.5)	$ (2,510.3)	$ 2,227.3	$ 10.0