Guarantor Financial Statements - Condensed Consolidating Balance Sheet (Details) - USD ($) $ in Millions		Jun. 27, 2015	Dec. 31, 2014	Jun. 28, 2014	Dec. 31, 2013
Current Assets:
Unrestricted cash and cash equivalents		$ 26.2	$ 58.4	$ 91.3	$ 80.9
Restricted cash		0.3	0.6
Accounts receivable, less allowances		422.4	324.9
Intercompany receivables		0.0	0.0
Inventories, net		394.4	374.3
Prepaid expenses		19.3	18.4
Other current assets		22.6	18.1
Deferred tax assets		37.5	28.1
Total current assets		922.7	822.8
Property and Equipment, at Cost:
Total property and equipment, net		228.1	238.0
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries		0.0	0.0
Goodwill	[1]	499.5	474.3
Intangible assets, less accumulated amortization		630.7	642.6
Deferred tax asset		0.0	0.0
Other assets		30.3	31.4
Total other long-term assets		1,160.5	1,148.3
Total Assets		2,311.3	2,209.1
Current Liabilities:
Short-term bank obligations		0.3	0.6
Current maturities of long-term debt		7.9	6.3
Accounts payable		293.2	288.8
Accrued expenses and taxes		216.7	222.4
Current deferred taxes		0.0	0.0
Intercompany payables		0.0	0.0
Total current liabilities		518.1	518.1
Other Liabilities:
Deferred income taxes		117.5	123.5
Other long-term liabilities		177.7	185.9
Long-term intercompany payables		0.0	0.0
Total other long-term liabilities		295.2	309.4
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities		1,473.8	1,339.4
Stockholders' investment (deficit)		24.2	42.2
Total Liabilities and Stockholders' Investment		2,311.3	2,209.1
Eliminations
Current Assets:
Unrestricted cash and cash equivalents		0.0	0.0
Restricted cash		0.0	0.0
Accounts receivable, less allowances		0.0	0.0
Intercompany receivables		(95.6)	(84.0)
Inventories, net		(7.6)	(7.4)
Prepaid expenses		0.0	0.0
Other current assets		0.0	0.0
Deferred tax assets		(0.4)	(1.1)
Total current assets		(103.6)	(92.5)
Property and Equipment, at Cost:
Total property and equipment, net		0.0	0.0
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries		(1,800.6)	(1,792.1)
Goodwill		0.0	0.0
Intangible assets, less accumulated amortization		(9.2)	(9.6)
Deferred tax asset		(14.1)	(13.9)
Other assets		0.0	0.0
Total other long-term assets		(1,823.9)	(1,815.6)
Total Assets		(1,927.5)	(1,908.1)
Current Liabilities:
Short-term bank obligations		0.0	0.0
Current maturities of long-term debt		0.0	0.0
Accounts payable		0.0	0.0
Accrued expenses and taxes		0.0	0.0
Current deferred taxes		(0.4)	(1.1)
Intercompany payables		(95.6)	(84.0)
Total current liabilities		(96.0)	(85.1)
Other Liabilities:
Deferred income taxes		(17.0)	(16.7)
Other long-term liabilities		0.0	0.0
Long-term intercompany payables		(110.6)	(119.6)
Total other long-term liabilities		(127.6)	(136.3)
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities		0.0	0.0
Stockholders' investment (deficit)		(1,703.9)	(1,686.7)
Total Liabilities and Stockholders' Investment		(1,927.5)	(1,908.1)
Nortek | Reportable Legal Entities
Current Assets:
Unrestricted cash and cash equivalents		4.4	17.5	37.5	23.2
Restricted cash		0.1	0.2
Accounts receivable, less allowances		0.0	0.0
Intercompany receivables		1.1	3.2
Inventories, net		0.0	0.0
Prepaid expenses		2.1	2.5
Other current assets		0.1	0.0
Deferred tax assets		11.0	4.1
Total current assets		18.8	27.5
Property and Equipment, at Cost:
Total property and equipment, net		11.7	11.9
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries		1,530.2	1,376.2
Goodwill		0.0	0.0
Intangible assets, less accumulated amortization		0.0	0.0
Deferred tax asset		14.1	13.9
Other assets		17.0	19.1
Total other long-term assets		1,561.3	1,409.2
Total Assets		1,591.8	1,448.6
Current Liabilities:
Short-term bank obligations		0.0	0.0
Current maturities of long-term debt		6.3	3.8
Accounts payable		2.2	2.4
Accrued expenses and taxes		36.5	32.7
Current deferred taxes		0.0	0.0
Intercompany payables		0.0	0.0
Total current liabilities		45.0	38.9
Other Liabilities:
Deferred income taxes		0.0	0.0
Other long-term liabilities		53.7	34.6
Long-term intercompany payables		0.0	0.0
Total other long-term liabilities		53.7	34.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities		1,468.9	1,332.9
Stockholders' investment (deficit)		24.2	42.2
Total Liabilities and Stockholders' Investment		1,591.8	1,448.6
Guarantor Subsidiaries | Reportable Legal Entities
Current Assets:
Unrestricted cash and cash equivalents		0.5	5.1	14.1	20.0
Restricted cash		0.2	0.4
Accounts receivable, less allowances		354.4	257.3
Intercompany receivables		0.0	0.0
Inventories, net		318.0	303.5
Prepaid expenses		12.2	10.5
Other current assets		9.8	7.2
Deferred tax assets		26.9	25.1
Total current assets		722.0	609.1
Property and Equipment, at Cost:
Total property and equipment, net		160.1	163.0
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries		270.4	415.9
Goodwill		459.5	434.4
Intangible assets, less accumulated amortization		586.7	596.5
Deferred tax asset		0.0	0.0
Other assets		12.3	11.4
Total other long-term assets		1,328.9	1,458.2
Total Assets		2,211.0	2,230.3
Current Liabilities:
Short-term bank obligations		0.0	0.0
Current maturities of long-term debt		1.6	2.5
Accounts payable		153.4	157.0
Accrued expenses and taxes		138.3	145.7
Current deferred taxes		0.0	0.0
Intercompany payables		95.6	84.0
Total current liabilities		388.9	389.2
Other Liabilities:
Deferred income taxes		120.2	126.4
Other long-term liabilities		99.7	125.1
Long-term intercompany payables		0.0	0.0
Total other long-term liabilities		219.9	251.5
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities		4.9	6.5
Stockholders' investment (deficit)		1,597.3	1,583.1
Total Liabilities and Stockholders' Investment		2,211.0	2,230.3
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current Assets:
Unrestricted cash and cash equivalents		21.3	35.8	$ 39.7	$ 37.7
Restricted cash		0.0	0.0
Accounts receivable, less allowances		68.0	67.6
Intercompany receivables		94.5	80.8
Inventories, net		84.0	78.2
Prepaid expenses		5.0	5.4
Other current assets		12.7	10.9
Deferred tax assets		0.0	0.0
Total current assets		285.5	278.7
Property and Equipment, at Cost:
Total property and equipment, net		56.3	63.1
Other Long-term Assets:
Investment in subsidiaries and long-term receivable from (to) subsidiaries		0.0	0.0
Goodwill		40.0	39.9
Intangible assets, less accumulated amortization		53.2	55.7
Deferred tax asset		0.0	0.0
Other assets		1.0	0.9
Total other long-term assets		94.2	96.5
Total Assets		436.0	438.3
Current Liabilities:
Short-term bank obligations		0.3	0.6
Current maturities of long-term debt		0.0	0.0
Accounts payable		137.6	129.4
Accrued expenses and taxes		41.9	44.0
Current deferred taxes		0.4	1.1
Intercompany payables		0.0	0.0
Total current liabilities		180.2	175.1
Other Liabilities:
Deferred income taxes		14.3	13.8
Other long-term liabilities		24.3	26.2
Long-term intercompany payables		110.6	119.6
Total other long-term liabilities		149.2	159.6
Notes, Mortgage Notes and Obligations Payable, Less Current Maturities		0.0	0.0
Stockholders' investment (deficit)		106.6	103.6
Total Liabilities and Stockholders' Investment		$ 436.0	$ 438.3

[1] The CAS and combined AVC reporting units did not have goodwill for any periods presented.