Goodwill and Other Intangible Assets - Activity in Goodwill by Reporting Segment (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Goodwill [Line Items]
Gross goodwill	$ 307.6	[1]	$ 307.6	[1]	$ 294.1	[1]
Impairment losses	0	[1]	0	[1]	0	[1]
Goodwill	307.6	[1]	307.6	[1]
Goodwill [Roll Forward]
Goodwill at the beginning of year	307.6	[1]	294.1	[1]
Purchase Accounting	0	[2]	13.5	[2]
Goodwill at the end of year	307.6	[1]	307.6	[1]
RESV [Member]
Goodwill [Line Items]
Gross goodwill	156.8	[1]	156.8	[1]	156.8	[1]
Impairment losses	0	[1]	0	[1]	0	[1]
Goodwill	156.8	[1]	156.8	[1]
Goodwill [Roll Forward]
Goodwill at the beginning of year	156.8	[1]	156.8	[1]
Purchase Accounting	0	[2]	0	[2]
Goodwill at the end of year	156.8	[1]	156.8	[1]
TECH [Member]
Goodwill [Line Items]
Gross goodwill	19.4	[1]	19.4	[1]	7.3	[1]
Impairment losses	0	[1]	0	[1]	0	[1]
Goodwill	19.4	[1]	19.4	[1]
Goodwill [Roll Forward]
Goodwill at the beginning of year	19.4	[1]	7.3	[1]
Purchase Accounting	0	[2]	12.1	[2]
Goodwill at the end of year	19.4	[1]	19.4	[1]
DMS [Member]
Goodwill [Line Items]
Gross goodwill	131.4	[1]	131.4	[1]	130.0	[1]
Impairment losses	0	[1]	0	[1]	0	[1]
Goodwill	131.4	[1]	131.4	[1]
Goodwill [Roll Forward]
Goodwill at the beginning of year	131.4	[1]	130.0	[1]
Purchase Accounting	0	[2]	1.4	[2]
Goodwill at the end of year	131.4	[1]	131.4	[1]
Ergotron, Inc [Member]
Goodwill [Line Items]
Goodwill			131.4
Goodwill [Roll Forward]
Goodwill at the beginning of year			130.0
Purchase Accounting			1.4
Goodwill at the end of year			$ 131.4

[1] The Residential Heating and Cooling ("RHC") and Custom & Engineered Solutions ("CES") reporting units did not have goodwill in any period presented.

[2] Purchase accounting adjustments during 2011 for TECH relate to the acquisition of TV One and for DMS relate to the acquisition of Ergotron. Due to revisions to the preliminary estimate of fair value for Ergotron, which primarily related to intangible assets, net of deferred tax consequences, as well as other deferred tax adjustments, the preliminary goodwill allocation increased by approximately $1.4 million from $130.0 million at December 31, 2010 to approximately $131.4 million at December 31, 2011. See Note 2, “Acquisitions and Other Investments”.