Discontinued Operations (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended									0 Months Ended	3 Months Ended		12 Months Ended	1 Months Ended	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2012 Goodwill in assets of discontinued operations [Member]	Dec. 31, 2011 Goodwill in assets of discontinued operations [Member]	Mar. 22, 2013 Service Experts [Member]	Mar. 31, 2013 Service Experts [Member]	Mar. 31, 2013 Service Experts [Member] Goodwill in assets of discontinued operations [Member]	Dec. 31, 2012 Service Experts [Member] Goodwill in assets of discontinued operations [Member]	Apr. 30, 2012 Hearth [Member]	Mar. 31, 2012 Hearth [Member]
Discontinued Operations (Textual) [Abstract]
Goodwill	$ 223.4				$ 223.8	[1]							$ 66.0
Goodwill impairment												0	20.5
Accumulated impairment charges							17.0	228.5	208.0
Net proceeds from sale of discontinued operations										10.4				10.1
Working capital adjustment included in net proceeds from sale of discontinued operations										3.8
Pre-tax charge for write-down of net assets to estimated fair market value															6.3
Sale of equipment	0		0.1
Severance expense											2.3
Stock-based compensation expense	$ 7.7	[2]	$ 4.3	[2]							$ 0.2

[1] The Goodwill balances presented in the table above are presented net of accumulated impairment charges of $17.0 million, all of which relate to impairments in periods prior to 2012.

[2] Stock-Based Compensation expense is recorded in our Corporate and other business segment.