Condensed Consolidating Statement of Operations and Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,774	$ 858
Cost of goods sold	1,250	577
Gross profit	524	281
Selling, general and administrative	416	174
Research and development	34	21
Operating income (loss)	74	86
Other (income) expense:
Gain on sale of business	(17)
Net interest expense	17	15
Income before income taxes and noncontrolling interest	74	73
Provision for income taxes	21	10
Net income (loss) before noncontrolling interest	53	63
Noncontrolling interest	1	1
Net income (loss) attributable to Pentair Ltd.	52	62
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest	53	63
Changes in cumulative translation adjustment	(76)	40
Changes in market value of derivative financial instruments	1
Total comprehensive income (loss)	(22)	105
Less: Comprehensive income attributable to noncontrolling interest	1	2
Comprehensive income (loss) attributable to Pentair Ltd.	(23)	103
Parent Company Guarantor
Condensed Financial Statements, Captions [Line Items]
Selling, general and administrative	(1)
Operating income (loss)	1
Loss (earnings) from investment in subsidiaries	(51)
Other (income) expense:
Income before income taxes and noncontrolling interest	52
Net income (loss) before noncontrolling interest	52
Net income (loss) attributable to Pentair Ltd.	52
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest	52
Changes in cumulative translation adjustment	(76)
Changes in market value of derivative financial instruments	1
Total comprehensive income (loss)	(23)
Comprehensive income (loss) attributable to Pentair Ltd.	(23)
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Selling, general and administrative	3
Operating income (loss)	(3)
Loss (earnings) from investment in subsidiaries	(55)
Other (income) expense:
Net interest expense	3
Income before income taxes and noncontrolling interest	49
Net income (loss) before noncontrolling interest	49
Net income (loss) attributable to Pentair Ltd.	49
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest	49
Changes in cumulative translation adjustment	(76)
Changes in market value of derivative financial instruments	1
Total comprehensive income (loss)	(26)
Comprehensive income (loss) attributable to Pentair Ltd.	(26)
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	1,774
Cost of goods sold	1,250
Gross profit	524
Selling, general and administrative	414
Research and development	34
Operating income (loss)	76
Other (income) expense:
Gain on sale of business	(17)
Net interest expense	14
Income before income taxes and noncontrolling interest	79
Provision for income taxes	21
Net income (loss) before noncontrolling interest	58
Noncontrolling interest	1
Net income (loss) attributable to Pentair Ltd.	57
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest	58
Changes in cumulative translation adjustment	(76)
Changes in market value of derivative financial instruments	1
Total comprehensive income (loss)	(17)
Less: Comprehensive income attributable to noncontrolling interest	1
Comprehensive income (loss) attributable to Pentair Ltd.	(18)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries	106
Other (income) expense:
Income before income taxes and noncontrolling interest	(106)
Net income (loss) before noncontrolling interest	(106)
Net income (loss) attributable to Pentair Ltd.	(106)
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest	(106)
Changes in cumulative translation adjustment	152
Changes in market value of derivative financial instruments	(2)
Total comprehensive income (loss)	44
Comprehensive income (loss) attributable to Pentair Ltd.	$ 44