Acquisitions (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended		0 Months Ended											12 Months Ended
	Aug. 22, 2011	Dec. 31, 2011	Dec. 31, 2010	Aug. 22, 2011 Electrical Products Company Of A.O.Smith Corporation [Member]	Dec. 31, 2011 Electrical Products Company Of A.O.Smith Corporation [Member]	Jun. 01, 2011 Australian Fan And Motor Company [Member]	Dec. 31, 2011 Ramu, Inc. [Member]	May 01, 2011 Ramu, Inc. [Member]	Jan. 01, 2011 Unico, Inc. [Member]	Dec. 23, 2010 Unico, Inc. [Member]	Dec. 31, 2011 Elco Group B.V. [Member]	Nov. 01, 2010 Elco Group B.V. [Member]	Sep. 01, 2010 Rotor B.V. [Member]	Apr. 06, 2010 CMG Engineering Group Pty, Ltd. [Member]	Dec. 31, 2011 Customer Relationships [Member]	Dec. 31, 2011 Technology [Member]
Business Acquisition [Line Items]
Acquisition related expenses		$ 16,100,000	$ 6,600,000
Acquisitions purchase price						5,700,000		5,300,000		105,100,000		26,900,000	36,400,000	82,600,000
Business acquisition recorded liability							13,700,000		9,800,000
Percentage of interest acquired												55.00%
Cash included in purchase price					756,100,000							4,600,000		76,500,000
Amount payable to an entity related to acquisition												22,300,000
Acquisition to be paid in semi-annual payments		11,100,000									11,100,000
Acquisitions no of installments payment												4
Acquisition purchase price paid in shares					2,834,026									6,100,000
Sales of acquired entity				246,200,000
Intangible assets	$ 155,100,000														$ 87,700,000	$ 67,400,000
Intangible assets, useful lives, minimum (years)	8														3
Intangible assets, useful lives, maximum (years)	15														14
Percentage of goodwill estimated to be deductible for tax purposes		74.00%