Guarantor Financial Statements (Condensed Consolidating Balance Sheet) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Current Assets:
Unrestricted cash and cash equivalents	$ 144.7		$ 58.2		$ 57.7		$ 89.6
Restricted cash	0.2		0.1
Accounts receivable, less allowances	257.4		273.9
Intercompany receivables (payables)	0		0
Inventories, net	258.4		304.2
Prepaid expenses	14.4		22.0
Other current assets	20.0		23.6
Prepaid income taxes	29.3		38.7
Total current assets	724.4		720.7
Property and Equipment, at Cost:
Total property and equipment, net	199.5		211.2
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	0		0
Goodwill	307.6	[1]	307.6	[1]	294.1	[1]
Intangible assets, less accumulated amortization	614.9		659.2
Deferred tax asset	0		0
Other assets	41.7		43.2
Total other long-term assets	964.2		1,010.0
Total Assets	1,888.1		1,941.9
Current Liabilities:
Short-term bank obligations	0.7		1.3
Current maturities of long-term debt	2.4		32.1
Accounts payable	174.4		160.8
Accrued expenses and taxes, net	198.9		209.0
Current deferred taxes	0
Intercompany payables	0		0
Total current liabilities	376.4		403.2
Other Liabilities:
Deferred income taxes	132.7		137.4
Other long-term liabilities	186.9		209.8
Long-term intercompany payables	0		0
Total other long-term liabilities	319.6		347.2
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	1,097.9		1,111.1
Stockholders' investment (deficit)	94.2		80.4		158.8		170.1
Total Liabilities and Stockholders' Investment	1,888.1		1,941.9
Nortek [Member]
Current Assets:
Unrestricted cash and cash equivalents	94.9		17.8		16.0		43.6
Restricted cash	0		0
Accounts receivable, less allowances	0		0
Intercompany receivables (payables)	1.0		0.7
Inventories, net	0		0
Prepaid expenses	1.2		5.5
Other current assets	0		0.1
Prepaid income taxes	18.3		17.0
Total current assets	115.4		41.1
Property and Equipment, at Cost:
Total property and equipment, net	3.0		0.5
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	1,107.8		1,192.1
Goodwill	0		0
Intangible assets, less accumulated amortization	0		0
Deferred tax asset	10.9		21.6
Other assets	25.4		25.1
Total other long-term assets	1,144.1		1,238.8
Total Assets	1,262.5		1,280.4
Current Liabilities:
Short-term bank obligations	0		0
Current maturities of long-term debt	0.3		28.5
Accounts payable	4.1		2.1
Accrued expenses and taxes, net	31.1		36.2
Current deferred taxes	0
Intercompany payables	0		0
Total current liabilities	35.5		66.8
Other Liabilities:
Deferred income taxes	0		0
Other long-term liabilities	47.7		53.7
Long-term intercompany payables	0		0
Total other long-term liabilities	47.7		53.7
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	1,085.1		1,079.5
Stockholders' investment (deficit)	94.2		80.4
Total Liabilities and Stockholders' Investment	1,262.5		1,280.4
Guarantor Subsidiaries [Member]
Current Assets:
Unrestricted cash and cash equivalents	13.1		9.3		21.3		11.4
Restricted cash	0		0
Accounts receivable, less allowances	191.7		206.8
Intercompany receivables (payables)	0		0
Inventories, net	192.4		231.6
Prepaid expenses	8.7		11.8
Other current assets	10.7		15.1
Prepaid income taxes	12.6		19.7
Total current assets	429.2		494.3
Property and Equipment, at Cost:
Total property and equipment, net	128.7		140.0
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	321.2		169.3
Goodwill	292.7		292.6
Intangible assets, less accumulated amortization	591.6		621.9
Deferred tax asset	0		0
Other assets	15.7		17.5
Total other long-term assets	1,221.2		1,101.3
Total Assets	1,779.1		1,735.6
Current Liabilities:
Short-term bank obligations	0		0
Current maturities of long-term debt	2.1		2.0
Accounts payable	76.7		72.6
Accrued expenses and taxes, net	119.4		133.2
Current deferred taxes	0
Intercompany payables	43.3		23.9
Total current liabilities	241.5		231.7
Other Liabilities:
Deferred income taxes	137.3		148.5
Other long-term liabilities	110.3		122.4
Long-term intercompany payables	0		0
Total other long-term liabilities	247.6		270.9
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	12.8		14.6
Stockholders' investment (deficit)	1,277.2		1,218.4
Total Liabilities and Stockholders' Investment	1,779.1		1,735.6
Non-Guarantor Subsidiaries [Member]
Current Assets:
Unrestricted cash and cash equivalents	36.7		31.1		20.4		34.6
Restricted cash	0.2		0.1
Accounts receivable, less allowances	65.7		67.1
Intercompany receivables (payables)	42.3		23.2
Inventories, net	71.6		76.7
Prepaid expenses	4.5		4.7
Other current assets	10.4		9.0
Prepaid income taxes	0		2.0
Total current assets	231.4		213.9
Property and Equipment, at Cost:
Total property and equipment, net	67.8		70.7
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	0		0
Goodwill	14.9		15.0
Intangible assets, less accumulated amortization	34.5		37.3
Deferred tax asset	0		0
Other assets	0.6		0.6
Total other long-term assets	50.0		52.9
Total Assets	349.2		337.5
Current Liabilities:
Short-term bank obligations	0.7		1.3
Current maturities of long-term debt	0		1.6
Accounts payable	93.6		86.1
Accrued expenses and taxes, net	48.8		39.6
Current deferred taxes	1.6
Intercompany payables	0		0
Total current liabilities	144.7		128.6
Other Liabilities:
Deferred income taxes	8.7		12.3
Other long-term liabilities	28.9		33.7
Long-term intercompany payables	44.0		42.0
Total other long-term liabilities	81.6		88.0
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	0		17.0
Stockholders' investment (deficit)	122.9		103.9
Total Liabilities and Stockholders' Investment	349.2		337.5
Eliminations [Member]
Current Assets:
Unrestricted cash and cash equivalents	0		0
Restricted cash	0		0
Accounts receivable, less allowances	0		0
Intercompany receivables (payables)	(43.3)		(23.9)
Inventories, net	(5.6)		(4.1)
Prepaid expenses	0		0
Other current assets	(1.1)		(0.6)
Prepaid income taxes	(1.6)		0
Total current assets	(51.6)		(28.6)
Property and Equipment, at Cost:
Total property and equipment, net	0		0
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	(1,429.0)		(1,361.4)
Goodwill	0		0
Intangible assets, less accumulated amortization	(11.2)		0
Deferred tax asset	(10.9)		(21.6)
Other assets	0		0
Total other long-term assets	(1,451.1)		(1,383.0)
Total Assets	(1,502.7)		(1,411.6)
Current Liabilities:
Short-term bank obligations	0		0
Current maturities of long-term debt	0		0
Accounts payable	0		0
Accrued expenses and taxes, net	(0.4)		0
Current deferred taxes	(1.6)
Intercompany payables	(43.3)		(23.9)
Total current liabilities	(45.3)		(23.9)
Other Liabilities:
Deferred income taxes	(13.3)		(23.4)
Other long-term liabilities	0		0
Long-term intercompany payables	(44.0)		(42.0)
Total other long-term liabilities	(57.3)		(65.4)
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	0		0
Stockholders' investment (deficit)	(1,400.1)		(1,322.3)
Total Liabilities and Stockholders' Investment	$ (1,502.7)		$ (1,411.6)

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