INDEBTEDNESS (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		9 Months Ended				9 Months Ended						9 Months Ended						9 Months Ended									9 Months Ended												1 Months Ended		1 Months Ended					9 Months Ended																				9 Months Ended
	Oct. 01, 2011	Jun. 30, 2011 Senior credit facility	Oct. 01, 2011 Senior credit facility quarter D	Oct. 01, 2011 Senior credit facility Federal funds alternative base rate	Oct. 01, 2011 Senior credit facility LIBOR alternative base rate	Oct. 01, 2011 Senior credit facility Reserve adjusted LIBOR rate	Oct. 01, 2011 Domestic revolving credit facility	Jun. 30, 2011 Domestic revolving credit facility	Oct. 01, 2011 Domestic revolving credit facility Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Domestic revolving credit facility Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Domestic revolving credit facility Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Domestic revolving credit facility Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Domestic revolving credit facility Less than 1.00 to 1.0	Jun. 30, 2011 Global revolving credit facility	Oct. 01, 2011 Global revolving credit facility Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Global revolving credit facility Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Global revolving credit facility Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Global revolving credit facility Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Global revolving credit facility Less than 1.00 to 1.0	Oct. 01, 2011 Foreign credit instrument facility	Oct. 01, 2011 Foreign credit instrument facility Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Foreign credit instrument facility Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Foreign credit instrument facility Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Foreign credit instrument facility Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Foreign credit instrument facility Less than 1.00 to 1.0	Oct. 01, 2011 Participation foreign credit instrument facility	Jun. 30, 2011 Participation foreign credit instrument facility	Jun. 30, 2011 Bilateral foreign credit instrument facility	Oct. 01, 2011 Letters of credit under separate arrangements in China and South Africa	Oct. 01, 2011 Term Loans After Modification	Oct. 05, 2011 Term Loans After Modification	Oct. 05, 2011 Term Loans After Modification Alternate Base Rate Greater than or equal to 3.00 to 1.0	Oct. 05, 2011 Term Loans After Modification Alternate Base Rate Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 05, 2011 Term Loans After Modification Alternate Base Rate Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 05, 2011 Term Loans After Modification Alternate Base Rate Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 05, 2011 Term Loans After Modification Alternate Base Rate Less than 1.00 to 1.0	Oct. 05, 2011 Term Loans After Modification Reserve adjusted LIBOR rate Greater than or equal to 3.00 to 1.0	Oct. 05, 2011 Term Loans After Modification Reserve adjusted LIBOR rate Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 05, 2011 Term Loans After Modification Reserve adjusted LIBOR rate Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 05, 2011 Term Loans After Modification Reserve adjusted LIBOR rate Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 05, 2011 Term Loans After Modification Reserve adjusted LIBOR rate Less than 1.00 to 1.0	Oct. 31, 2011 Delayed draw incremental term loan after modification repayable in full M	Oct. 05, 2011 Delayed draw incremental term loan after modification repayable in full	Oct. 31, 2011 Delayed draw incremental term loan after modification repayable in quarterly installments	Oct. 05, 2011 Delayed draw incremental term loan after modification repayable in quarterly installments	Oct. 01, 2011 Additional bilateral foreign trade facility	Oct. 05, 2011 Foreign trade facilities after modification	Oct. 05, 2011 Bilateral foreign trade facility after modification	Oct. 01, 2011 Letter of credit Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Letter of credit Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Letter of credit Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Letter of credit Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Letter of credit Less than 1.00 to 1.0	Oct. 01, 2011 Foreign Credit Commitment Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Foreign Credit Commitment Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Foreign Credit Commitment Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Foreign Credit Commitment Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Foreign Credit Commitment Less than 1.00 to 1.0	Oct. 01, 2011 Alternate Base Rate Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Alternate Base Rate Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Alternate Base Rate Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Alternate Base Rate Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Alternate Base Rate Less than 1.00 to 1.0	Oct. 01, 2011 Reserve adjusted LIBOR rate Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Reserve adjusted LIBOR rate Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Reserve adjusted LIBOR rate Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Reserve adjusted LIBOR rate Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Reserve adjusted LIBOR rate Less than 1.00 to 1.0	Oct. 01, 2011 Greater than or equal to 3.00 to 1.0	Oct. 01, 2011 Between 2.00 to 1.0 and 3.00 to 1.0	Oct. 01, 2011 Between 1.50 to 1.0 and 2.00 to 1.0	Oct. 01, 2011 Between 1.00 to 1.0 and 1.50 to 1.0	Oct. 01, 2011 Less than 1.00 to 1.0
Credit Facilities
Maximum borrowing capacity under financing arrangement		$ 1,800.0						$ 300.0						$ 300.0													$ 1,100.0	$ 100.0			$ 800.0												$ 300.0		$ 500.0	$ 100.0	$ 1,000.0	$ 200.0
Final maturity date under financing agreement		Jun. 30, 2016
Reduction in foreign credit commitments																																															100.0
Repayment term (in months)																																										18
Percentage of initial principal amount which the entity will repay in 2011																																												0.00%
Percentage of initial principal amount which the entity will repay in 2012																																												0.00%
Percentage of initial principal amount which the entity will repay in 2013																																												5.00%
Percentage of initial principal amount which the entity will repay in 2014																																												15.00%
Percentage of initial principal amount which the entity will repay in 2015																																												20.00%
Percentage of initial principal amount which the entity will repay at the end of the first fiscal quarter of 2016																																												5.00%
Additional commitments SPX may seek to add			1,000.0
Letters of credit issued, amount outstanding							83.8													654.5									2.9
Basis spread on variable rate (as a percent)				0.50%	1.00%																											1.25%	1.125%	1.00%	0.75%	0.50%	2.25%	2.125%	2.00%	1.75%	1.50%																		1.00%	0.875%	0.75%	0.50%	0.25%	2.00%	1.875%	1.75%	1.50%	1.25%
Description of variable rate					one-month LIBOR rate
Interest period which may be elected, shortest (in months)						1M
Interest period which may be elected, second shortest (in months)						2M
Interest period which may be elected, second longest (in months)						3M
Interest period which may be elected, longest (in months)						6M
Threshold amount of cash and cash equivalents above which amounts are netted against consolidated net debt for calculation of debt compliance	50.0
Consolidated leverage ratio, numerator																																																																					3.00				1.00
Consolidated leverage ratio, numerator, low end of range																																																																						2.00	1.50	1.00
Consolidated leverage ratio, denominator																																																																					1.0	1.0	1.0	1.0	1.0
Consolidated leverage ratio, numerator, high end of range																																																																						3.00	2.00	1.50
Commitment fee (as a percent)									0.40%	0.35%	0.30%	0.275%	0.25%		0.40%	0.35%	0.30%	0.275%	0.25%		1.25%	1.125%	1.00%	0.875%	0.75%					0.50%																			2.00%	1.875%	1.75%	1.50%	1.25%	0.40%	0.35%	0.30%	0.275%	0.25%
Commitment fee on the daily unused amount of the commitment (as a percent)																														0.275%
Weighted-average interest rate of senior credit facilities (as a percent)			2.30%
Fronting fees (as a percent)			0.125%																							0.20%
Security interest granted in capital stock of domestic subsidiaries or subsidiary guarantors (as a percent)			100.00%
Security interest granted in material first tier foreign subsidiaries (as a percent)			65.00%
Number of trailing fiscal quarters used in calculating the Consolidated Leverage Coverage Ratio under senior credit facilities' covenants (in number of quarters)			4
Number of trailing fiscal quarters used in calculating the Consolidated Interest Coverage Ratio under senior credit facilities' covenants (in number of quarters)			4
Prepayment reinvestment exclusion period (in days)			360
Consolidated Interest Coverage Ratio under senior credit facilities' covenants			at least 3.50:1.00
Consolidated Interest Coverage Ratio numerator, minimum			3.5
Consolidated Interest Coverage Ratio denominator			1.0
Consolidated Leverage Ratio under senior credit facilities' covenants			no more than 3.25:1.00
Consolidated Leverage Ratio numerator, upper limit			3.25
Consolidated Leverage Ratio under senior credit facilities' covenants after certain permitted acquisitions			3.50 to 1.00
Consolidated Leverage Ratio after certain permitted acquisitions, numerator, upper limit			3.5
Maximum consolidated Leverage Ratio necessary for unlimited amount of capital stock repurchases and dividend payments under senior credit facilities' covenants			less than 2.50:1.00
Consolidated Leverage Ratio breakpoint for determining restrictions on capital stock repurchases and dividend payments under senior credit facilities' covenants, numerator			2.5
Consolidated Leverage Ratio restricting amount of capital stock repurchases and dividend payments under senior credit facilities' covenants			greater than or equal to 2.50:1.00
Maximum amount of capital stock repurchases and dividend declarations allowable (before adjustment) under senior credit facilities' covenants in any fiscal year if Consolidated Leverage Ratio is greater than or equal to 2.50 to 1.00			100.0
Consolidated leverage ratio greater than 2.50 to 1.00 - capital stock repurchases and dividend declarations used in calculation			$ 300.0
Percentage of cumulative consolidated net income during the period from July 1, 2011 to the end of the most recent fiscal quarter used (as a percent)			50.00%
Percentage of consolidated net deficit removed from calculation of amounts available for stock repurchases and dividends (as a percent)			(100.00%)