Guarantor Financial Statements (Condensed Consolidating Balance Sheet) (Details) (USD $) In Millions, unless otherwise specified	Sep. 28, 2013	Dec. 31, 2012	Sep. 29, 2012	Dec. 31, 2011
Current Assets:
Unrestricted cash and cash equivalents	$ 86.6	$ 144.7	$ 130.7	$ 58.2
Restricted cash	0.2	0.2
Accounts receivable, less allowances	325.7	257.4
Intercompany receivables	0	0
Inventories, net	289.5	258.4
Prepaid expenses	19.4	14.4
Other current assets	18.3	20.0
Prepaid income taxes	27.4	29.3
Total current assets	767.1	724.4
Property and Equipment, at Cost:
Total property and equipment, net	220.7	199.5
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	0	0
Goodwill	376.9	307.6
Intangible assets, less accumulated amortization	662.0	614.9
Deferred tax asset	0	0
Other assets	38.1	41.7
Total other long-term assets	1,077.0	964.2
Total Assets	2,064.8	1,888.1
Current Liabilities:
Short-term bank obligations	0.7	0.7
Current maturities of long-term debt	17.7	2.4
Accounts payable	232.7	174.4
Accrued expenses and taxes, net	252.8	198.9
Current deferred taxes	0	0
Intercompany payables	0	0
Total current liabilities	503.9	376.4
Other Liabilities:
Deferred income taxes	155.0	132.7
Other	194.3	186.9
Long-term intercompany payables	0	0
Total other liabilities	349.3	319.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	1,110.0	1,097.9
Stockholders' investment (deficit)	101.6	94.2
Total Liabilities and Stockholders' Investment (Deficit)	2,064.8	1,888.1
Nortek [Member]
Current Assets:
Unrestricted cash and cash equivalents	38.3	94.9	85.6	17.8
Restricted cash	0	0
Accounts receivable, less allowances	0	0
Intercompany receivables	1.7	1.0
Inventories, net	0	0
Prepaid expenses	2.9	1.2
Other current assets	0.4	0
Prepaid income taxes	12.5	18.3
Total current assets	55.8	115.4
Property and Equipment, at Cost:
Total property and equipment, net	6.5	3.0
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	1,221.7	1,107.8
Goodwill	0	0
Intangible assets, less accumulated amortization	0	0
Deferred tax asset	10.3	10.9
Other assets	21.1	25.4
Total other long-term assets	1,253.1	1,144.1
Total Assets	1,315.4	1,262.5
Current Liabilities:
Short-term bank obligations	0	0
Current maturities of long-term debt	15.3	0.3
Accounts payable	2.7	4.1
Accrued expenses and taxes, net	51.4	31.1
Current deferred taxes	0	0
Intercompany payables	0	0
Total current liabilities	69.4	35.5
Other Liabilities:
Deferred income taxes	0	0
Other	45.7	47.7
Long-term intercompany payables	0	0
Total other liabilities	45.7	47.7
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	1,098.7	1,085.1
Stockholders' investment (deficit)	101.6	94.2
Total Liabilities and Stockholders' Investment (Deficit)	1,315.4	1,262.5
Guarantor Subsidiaries [Member]
Current Assets:
Unrestricted cash and cash equivalents	17.5	13.1	12.4	9.3
Restricted cash	0	0
Accounts receivable, less allowances	261.0	191.7
Intercompany receivables	0	0
Inventories, net	218.6	192.4
Prepaid expenses	10.9	8.7
Other current assets	6.8	10.7
Prepaid income taxes	16.5	12.6
Total current assets	531.3	429.2
Property and Equipment, at Cost:
Total property and equipment, net	146.2	128.7
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	403.5	321.2
Goodwill	361.2	292.7
Intangible assets, less accumulated amortization	639.7	591.6
Deferred tax asset	0	0
Other assets	16.2	15.7
Total other long-term assets	1,420.6	1,221.2
Total Assets	2,098.1	1,779.1
Current Liabilities:
Short-term bank obligations	0	0
Current maturities of long-term debt	2.4	2.1
Accounts payable	122.8	76.7
Accrued expenses and taxes, net	156.4	119.4
Current deferred taxes	0	0
Intercompany payables	54.5	43.3
Total current liabilities	336.1	241.5
Other Liabilities:
Deferred income taxes	159.8	137.3
Other	123.8	110.3
Long-term intercompany payables	0	0
Total other liabilities	283.6	247.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	11.2	12.8
Stockholders' investment (deficit)	1,467.2	1,277.2
Total Liabilities and Stockholders' Investment (Deficit)	2,098.1	1,779.1
Non-Guarantor Subsidiaries [Member]
Current Assets:
Unrestricted cash and cash equivalents	30.8	36.7	32.7	31.1
Restricted cash	0.2	0.2
Accounts receivable, less allowances	64.7	65.7
Intercompany receivables	52.8	42.3
Inventories, net	79.3	71.6
Prepaid expenses	5.6	4.5
Other current assets	11.1	10.4
Prepaid income taxes	0	0
Total current assets	244.5	231.4
Property and Equipment, at Cost:
Total property and equipment, net	68.0	67.8
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries	0	0
Goodwill	15.7	14.9
Intangible assets, less accumulated amortization	32.9	34.5
Deferred tax asset	0	0
Other assets	0.8	0.6
Total other long-term assets	49.4	50.0
Total Assets	361.9	349.2
Current Liabilities:
Short-term bank obligations	0.7	0.7
Current maturities of long-term debt	0	0
Accounts payable	107.2	93.6
Accrued expenses and taxes, net	45.0	48.8
Current deferred taxes	1.6	1.6
Intercompany payables	0	0
Total current liabilities	154.5	144.7
Other Liabilities:
Deferred income taxes	8.7	8.7
Other	24.8	28.9
Long-term intercompany payables	44.9	44.0
Total other liabilities	78.4	81.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	0.1	0
Stockholders' investment (deficit)	128.9	122.9
Total Liabilities and Stockholders' Investment (Deficit)	361.9	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	(54.5)	(43.3)
Inventories, net	(8.4)	(5.6)
Prepaid expenses	0	0
Other current assets	0	(1.1)
Prepaid income taxes	(1.6)	(1.6)
Total current assets	(64.5)	(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	(1,625.2)	(1,429.0)
Goodwill	0	0
Intangible assets, less accumulated amortization	(10.6)	(11.2)
Deferred tax asset	(10.3)	(10.9)
Other assets	0	0
Total other long-term assets	(1,646.1)	(1,451.1)
Total Assets	(1,710.6)	(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	(0.4)
Current deferred taxes	(1.6)	(1.6)
Intercompany payables	(54.5)	(43.3)
Total current liabilities	(56.1)	(45.3)
Other Liabilities:
Deferred income taxes	(13.5)	(13.3)
Other	0	0
Long-term intercompany payables	(44.9)	(44.0)
Total other liabilities	(58.4)	(57.3)
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities	0	0
Stockholders' investment (deficit)	(1,596.1)	(1,400.1)
Total Liabilities and Stockholders' Investment (Deficit)	$ (1,710.6)	$ (1,502.7)