Financial Statements of Parent Company Guarantor - Condensed Consolidating Balance Sheet (Detail) (USD $) In Millions, unless otherwise specified	Sep. 28, 2013	Dec. 31, 2012	Sep. 29, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 237.7	$ 261.3	$ 642.6	$ 50.1
Accounts and notes receivable, net	1,299.2	1,274.6
Inventories	1,296.1	1,333.9
Other current assets	378.3	341.1
Total current assets	3,211.3	3,210.9
Property, plant and equipment, net	1,171.9	1,188.2
Other assets
Goodwill	5,122.0	5,111.0
Intangibles, net	1,817.2	1,926.9
Other non-current assets	481.8	504.8
Total other assets	7,421.0	7,542.7
Total assets	11,804.2	11,941.8
Current liabilities
Current maturities of long-term debt and short-term borrowings	3.0	3.1
Accounts payable	579.4	567.0
Employee compensation and benefits	317.5	296.7
Other current liabilities	778.5	778.1
Total current liabilities	1,678.4	1,644.9
Other liabilities
Long-term debt	2,570.7	2,454.3
Pension and other post-retirement compensation and benefits	388.2	378.8
Deferred tax liabilities	497.8	480.9
Other non-current liabilities	467.4	495.1
Total liabilities	5,602.5	5,454.0
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries	6,082.2	6,371.3
Noncontrolling interest	119.5	116.5
Total equity	6,201.7	6,487.8	6,996.4	2,047.4
Total liabilities and equity	11,804.2	11,941.8
Parent Company Guarantor
Current assets
Cash and cash equivalents		0
Accounts and notes receivable, net	5.7	20.2
Inventories		0
Other current assets	10.8	85.8
Total current assets	16.5	106.0
Property, plant and equipment, net		0
Other assets
Investments in subsidiaries	6,488.9	6,486.6
Other non-current assets	31.6	31.6
Total other assets	6,520.5	6,518.2
Total assets	6,537.0	6,624.2
Current liabilities
Current maturities of long-term debt and short-term borrowings		0
Accounts payable	0.5	54.3
Other current liabilities	150.4	180.9
Total current liabilities	150.9	235.2
Other liabilities
Long-term debt	286.2
Other non-current liabilities	17.7	17.7
Total liabilities	454.8	252.9
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries	6,082.2	6,371.3
Total equity	6,082.2	6,371.3
Total liabilities and equity	6,537.0	6,624.2
Subsidiary Issuer
Current assets
Cash and cash equivalents	0.2	0
Accounts and notes receivable, net	20.7	1,458.3
Inventories		0
Other current assets		0
Total current assets	20.9	1,458.3
Property, plant and equipment, net		0
Other assets
Investments in subsidiaries	7,953.9	7,464.9
Other non-current assets	1,544.9	6.9
Total other assets	9,498.8	7,471.8
Total assets	9,519.7	8,930.1
Current liabilities
Current maturities of long-term debt and short-term borrowings		0
Accounts payable	6.0	1.7
Other current liabilities	15.8	11.5
Total current liabilities	21.8	13.2
Other liabilities
Long-term debt	2,412.1	2,297.7
Total liabilities	2,433.9	2,310.9
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries	7,085.8	6,619.2
Total equity	7,085.8	6,619.2
Total liabilities and equity	9,519.7	8,930.1
Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	237.5	261.3
Accounts and notes receivable, net	1,305.7	1,330.7
Inventories	1,296.1	1,333.9
Other current assets	378.3	339.7
Total current assets	3,217.6	3,265.6
Property, plant and equipment, net	1,171.9	1,188.2
Other assets
Goodwill	5,122.0	5,111.0
Intangibles, net	1,817.2	1,926.9
Other non-current assets	443.1	466.3
Total other assets	7,382.3	7,504.2
Total assets	11,771.8	11,958.0
Current liabilities
Current maturities of long-term debt and short-term borrowings	3.0	3.1
Accounts payable	605.8	587.3
Employee compensation and benefits	317.5	296.7
Other current liabilities	623.1	670.1
Total current liabilities	1,549.4	1,557.2
Other liabilities
Long-term debt	1,410.2	1,614.9
Pension and other post-retirement compensation and benefits	388.2	378.8
Deferred tax liabilities	497.8	480.9
Other non-current liabilities	449.7	477.4
Total liabilities	4,295.3	4,509.2
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries	7,357.0	7,332.3
Noncontrolling interest	119.5	116.5
Total equity	7,476.5	7,448.8
Total liabilities and equity	11,771.8	11,958.0
Eliminations
Current assets
Accounts and notes receivable, net	(32.9)	(1,534.6)
Other current assets	(10.8)	(84.4)
Total current assets	(43.7)	(1,619.0)
Other assets
Investments in subsidiaries	(14,442.8)	(13,951.5)
Other non-current assets	(1,537.8)	0
Total other assets	(15,980.6)	(13,951.5)
Total assets	(16,024.3)	(15,570.5)
Current liabilities
Accounts payable	(32.9)	(76.3)
Other current liabilities	(10.8)	(84.4)
Total current liabilities	(43.7)	(160.7)
Other liabilities
Long-term debt	(1,537.8)	(1,458.3)
Other non-current liabilities	0	0
Total liabilities	(1,581.5)	(1,619.0)
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries	(14,442.8)	(13,951.5)
Total equity	(14,442.8)	(13,951.5)
Total liabilities and equity	$ (16,024.3)	$ (15,570.5)