Guarantor Financial Statements (Condensed Consolidating Balance Sheet) (Details) (USD $) In Millions, unless otherwise specified	Mar. 30, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Current Assets:
Unrestricted cash and cash equivalents	$ 201.4	$ 144.7	$ 72.4	$ 58.2
Restricted cash	0.2	0.2
Accounts receivable, less allowances	289.9	257.4
Intercompany receivables (payables)	0	0
Inventories, net	271.8	258.4
Prepaid expenses	18.4	14.4
Other current assets	13.8	20.0
Prepaid income taxes	35.5	29.3
Total current assets	831.0	724.4
Property and Equipment, at Cost:
Total property and equipment, net	198.7	199.5
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	0	0
Goodwill	309.3	307.6
Intangible assets, less accumulated amortization	604.3	614.9
Deferred tax asset	0	0
Other assets	39.7	41.7
Total other long-term assets	953.3	964.2
Total Assets	1,983.0	1,888.1
Current Liabilities:
Short-term bank obligations	0.6	0.7
Current maturities of long-term debt	2.5	2.4
Accounts payable	184.2	174.4
Accrued expenses and taxes, net	218.1	198.9
Current deferred taxes	0	0
Intercompany payables	0	0
Total current liabilities	405.4	376.4
Other Liabilities:
Deferred income taxes	134.5	132.7
Other	184.2	186.9
Long-term intercompany payables	0	0
Total other liabilities	318.7	319.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	1,181.8	1,097.9
Stockholders' investment (deficit)	77.1	94.2
Total Liabilities and Stockholders' Investment (Deficit)	1,983.0	1,888.1
Nortek [Member]
Current Assets:
Unrestricted cash and cash equivalents	166.0	94.9	34.6	17.8
Restricted cash	0	0
Accounts receivable, less allowances	0	0
Intercompany receivables (payables)	2.2	1.0
Inventories, net	0	0
Prepaid expenses	2.3	1.2
Other current assets	0	0
Prepaid income taxes	24.0	18.3
Total current assets	194.5	115.4
Property and Equipment, at Cost:
Total property and equipment, net	4.4	3.0
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	1,120.6	1,107.8
Goodwill	0	0
Intangible assets, less accumulated amortization	0	0
Deferred tax asset	7.2	10.9
Other assets	23.3	25.4
Total other long-term assets	1,151.1	1,144.1
Total Assets	1,350.0	1,262.5
Current Liabilities:
Short-term bank obligations	0	0
Current maturities of long-term debt	0.3	0.3
Accounts payable	3.2	4.1
Accrued expenses and taxes, net	54.9	31.1
Current deferred taxes	0	0
Intercompany payables	0	0
Total current liabilities	58.4	35.5
Other Liabilities:
Deferred income taxes	0	0
Other	45.0	47.7
Long-term intercompany payables	0	0
Total other liabilities	45.0	47.7
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	1,169.5	1,085.1
Stockholders' investment (deficit)	77.1	94.2
Total Liabilities and Stockholders' Investment (Deficit)	1,350.0	1,262.5
Guarantor Subsidiaries [Member]
Current Assets:
Unrestricted cash and cash equivalents	5.9	13.1	2.7	9.3
Restricted cash	0	0
Accounts receivable, less allowances	228.2	191.7
Intercompany receivables (payables)	0	0
Inventories, net	203.0	192.4
Prepaid expenses	11.0	8.7
Other current assets	4.8	10.7
Prepaid income taxes	13.1	12.6
Total current assets	466.0	429.2
Property and Equipment, at Cost:
Total property and equipment, net	127.1	128.7
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	307.7	321.2
Goodwill	292.7	292.7
Intangible assets, less accumulated amortization	581.5	591.6
Deferred tax asset	0	0
Other assets	15.6	15.7
Total other long-term assets	1,197.5	1,221.2
Total Assets	1,790.6	1,779.1
Current Liabilities:
Short-term bank obligations	0	0
Current maturities of long-term debt	2.2	2.1
Accounts payable	92.2	76.7
Accrued expenses and taxes, net	119.5	119.4
Current deferred taxes	0	0
Intercompany payables	36.3	43.3
Total current liabilities	250.2	241.5
Other Liabilities:
Deferred income taxes	135.5	137.3
Other	113.8	110.3
Long-term intercompany payables	0	0
Total other liabilities	249.3	247.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	12.3	12.8
Stockholders' investment (deficit)	1,278.8	1,277.2
Total Liabilities and Stockholders' Investment (Deficit)	1,790.6	1,779.1
Non-Guarantor Subsidiaries [Member]
Current Assets:
Unrestricted cash and cash equivalents	29.5	36.7	35.1	31.1
Restricted cash	0.2	0.2
Accounts receivable, less allowances	61.7	65.7
Intercompany receivables (payables)	34.1	42.3
Inventories, net	75.2	71.6
Prepaid expenses	5.1	4.5
Other current assets	9.7	10.4
Prepaid income taxes	0	0
Total current assets	215.5	231.4
Property and Equipment, at Cost:
Total property and equipment, net	67.2	67.8
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	0	0
Goodwill	16.6	14.9
Intangible assets, less accumulated amortization	33.8	34.5
Deferred tax asset	0	0
Other assets	0.8	0.6
Total other long-term assets	51.2	50.0
Total Assets	333.9	349.2
Current Liabilities:
Short-term bank obligations	0.6	0.7
Current maturities of long-term debt	0	0
Accounts payable	88.8	93.6
Accrued expenses and taxes, net	44.4	48.8
Current deferred taxes	1.6	1.6
Intercompany payables	0	0
Total current liabilities	135.4	144.7
Other Liabilities:
Deferred income taxes	8.7	8.7
Other	25.4	28.9
Long-term intercompany payables	43.6	44.0
Total other liabilities	77.7	81.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	0	0
Stockholders' investment (deficit)	120.8	122.9
Total Liabilities and Stockholders' Investment (Deficit)	333.9	349.2
Eliminations [Member]
Current Assets:
Unrestricted cash and cash equivalents	0	0
Restricted cash	0	0
Accounts receivable, less allowances	0	0
Intercompany receivables (payables)	(36.3)	(43.3)
Inventories, net	(6.4)	(5.6)
Prepaid expenses	0	0
Other current assets	(0.7)	(1.1)
Prepaid income taxes	(1.6)	(1.6)
Total current assets	(45.0)	(51.6)
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	(1,428.3)	(1,429.0)
Goodwill	0	0
Intangible assets, less accumulated amortization	(11.0)	(11.2)
Deferred tax asset	(7.2)	(10.9)
Other assets	0	0
Total other long-term assets	(1,446.5)	(1,451.1)
Total Assets	(1,491.5)	(1,502.7)
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	(0.7)	(0.4)
Current deferred taxes	(1.6)	(1.6)
Intercompany payables	(36.3)	(43.3)
Total current liabilities	(38.6)	(45.3)
Other Liabilities:
Deferred income taxes	(9.7)	(13.3)
Other	0	0
Long-term intercompany payables	(43.6)	(44.0)
Total other liabilities	(53.3)	(57.3)
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	0	0
Stockholders' investment (deficit)	(1,399.6)	(1,400.1)
Total Liabilities and Stockholders' Investment (Deficit)	$ (1,491.5)	$ (1,502.7)