Business Segment Information (Summary of Operations by Reportable Segments) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Net revenues		$ 14,782.0		$ 14,001.1	$ 13,009.1
Depreciation and amortization		402.7		436.8	421.5
Capital expenditures		242.9		179.5	204.1
Loss on sale/asset impairment		(646.9)		0	0
Operating income (loss)		860.3		1,261.4	885.2
Operating income (loss) as a percentage of revenues		5.80%		9.00%	6.80%
Climate Solutions [Member]
Net revenues		8,284.6		7,800.8	7,211.2
Segment Operating Income		824.6		598.3	431.3
Segment Operating Income As a Percentage Of Revenues		10.00%		7.70%	6.00%
Depreciation and amortization		171.4		206.0	208.3
Capital expenditures		81.6		67.0	93.5
Residential Solutions [Member]
Net revenues		2,012.7		2,121.7	2,001.5
Segment Operating Income		62.1		191.3	130.6
Segment Operating Income As a Percentage Of Revenues		3.10%		9.00%	6.50%
Depreciation and amortization		110.1		107.4	108.4
Capital expenditures		27.7		35.9	43.5
Industrial Technologies [Member]
Net revenues		2,852.9		2,485.2	2,170.0
Segment Operating Income		415.5		310.4	178.5
Segment Operating Income As a Percentage Of Revenues		14.60%		12.50%	8.20%
Depreciation and amortization		40.3		41.5	42.9
Capital expenditures		57.2		31.3	23.0
Security Technologies [Member]
Net revenues		1,631.8		1,593.4	1,626.4
Segment Operating Income		331.6		328.3	328.6
Segment Operating Income As a Percentage Of Revenues		20.30%		20.60%	20.20%
Depreciation and amortization		37.2		38.7	39.0
Capital expenditures		22.8		14.6	25.9
Reportable Segments [Member]
Segment Operating Income		1,633.8		1,428.3	1,069.0
Depreciation and amortization		359.0		393.6	398.6
Capital expenditures		189.3		148.8	185.9
Unallocated Amount to Segment [Member]
Depreciation and amortization		43.7		43.2	22.9
Capital expenditures		53.6		30.7	18.2
Operating Expenses		(126.6)		(166.9)	(183.8)
Hussmann Divestiture [Member]
Net revenues		818.5	[1]	1,106.1	1,008.9
Segment Operating Income		58.6	[1]	84.4	19.4
Loss on sale/asset impairment	$ (260.0)	$ (646.9)	[1],[2],[3]	$ 0	$ 0

[1] Results represent the operating results of Hussmann Business and Branches through their respective divestiture transaction dates.

[2] Included in Loss on sale/asset impairment for the year ended December 31, 2011 are transaction costs of $12.2 million

[3] During the year ended December 31, 2011, the Company recorded a pre-tax loss on sale and impairment charges related to the Hussmann divestiture of $646.9 million. These charges have been excluded from Segment operating income within the Climate Solutions segment as management excludes these charges from Operating income when making operating decisions about the business