Financial Statements of Parent Company Guarantor - Condensed Consolidating Statement of Cash Flows (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating activities
Net cash provided by (used for) operating activities	$ 915.3	$ 68.0	$ 320.2
Investing activities
Capital expenditures	(170.0)	(94.5)	(73.3)
Proceeds from sale of property and equipment	6.0	5.5	1.3
Proceeds from sale of businesses, net	43.5	0	0
Acquisitions, net of cash acquired	(92.4)	470.5	(733.1)
Other	1.7	(5.9)	(3.0)
Net cash provided by (used for) investing activities	(211.2)	375.6	(808.1)
Financing activities
Net receipts (repayments) of short-term borrowings	0	(3.7)	(1.2)
Net receipts of commercial paper and revolving long-term debt	104.2	253.8	74.5
Proceeds from long-term debt	0.7	594.3	515.3
Repayment of long-term debt	(7.4)	(617.2)	(0.3)
Debt issuance costs	(1.4)	(9.7)	(9.0)
Debt extinguishment costs	0	(74.8)	0
Net change in advances to subsidiaries	0	0
Excess tax benefits from share-based compensation	16.8	5.0	3.3
Shares issued to employees, net of shares withheld	80.0	68.2	13.3
Repurchases of common shares	(715.8)	(334.2)	(12.8)
Dividends paid	(194.2)	(112.4)	(79.5)
Distributions to noncontrolling interest	(2.0)	(1.6)	0
Net cash provided by (used for) financing activities	(719.1)	(232.3)	503.6
Effect of exchange rate changes on cash and cash equivalents	18.8	(0.1)	(11.7)
Change in cash and cash equivalents	3.8	211.2	4.0
Cash and cash equivalents, beginning of year	261.3	50.1	46.1
Cash and cash equivalents, end of year	265.1	261.3	50.1
Pentair Ltd.
Operating activities
Net cash provided by (used for) operating activities	534.2	(109.0)
Investing activities
Capital expenditures	0	0
Proceeds from sale of property and equipment	0	0
Proceeds from sale of businesses, net	0
Acquisitions, net of cash acquired	0	0
Other	0	0
Net cash provided by (used for) investing activities	0	0
Financing activities
Net receipts (repayments) of short-term borrowings		0
Net receipts of commercial paper and revolving long-term debt	0	0
Proceeds from long-term debt	0	0
Repayment of long-term debt	0	0
Debt issuance costs	0	0
Debt extinguishment costs		0
Net change in advances to subsidiaries	(339.5)	157.0
Excess tax benefits from share-based compensation	0	0
Shares issued to employees, net of shares withheld	0	0
Repurchases of common shares	0	0
Dividends paid	(194.2)	(48.0)
Distributions to noncontrolling interest	0	0
Net cash provided by (used for) financing activities	(533.7)	109.0
Effect of exchange rate changes on cash and cash equivalents	0	0
Change in cash and cash equivalents	0.5	0
Cash and cash equivalents, beginning of year	0	0
Cash and cash equivalents, end of year	0.5	0
Subsidiary Issuer
Operating activities
Net cash provided by (used for) operating activities	514.0	(88.2)
Investing activities
Capital expenditures	0	0
Proceeds from sale of property and equipment	0	0
Proceeds from sale of businesses, net	0
Acquisitions, net of cash acquired	0	300.1
Other	0	0
Net cash provided by (used for) investing activities	0	300.1
Financing activities
Net receipts (repayments) of short-term borrowings		0
Net receipts of commercial paper and revolving long-term debt	104.2	424.7
Proceeds from long-term debt	0	594.3
Repayment of long-term debt	0	0
Debt issuance costs	(1.4)	(8.7)
Debt extinguishment costs		0
Net change in advances to subsidiaries	(569.8)	(1,222.2)
Excess tax benefits from share-based compensation	0	0
Shares issued to employees, net of shares withheld	0	0
Repurchases of common shares	0	0
Dividends paid	0	0
Distributions to noncontrolling interest	0	0
Net cash provided by (used for) financing activities	(467.0)	(211.9)
Effect of exchange rate changes on cash and cash equivalents	0	0
Change in cash and cash equivalents	47.0	0
Cash and cash equivalents, beginning of year	0	0
Cash and cash equivalents, end of year	47.0	0
Non-Guarantor Subsidiaries
Operating activities
Net cash provided by (used for) operating activities	964.9	61.5
Investing activities
Capital expenditures	(170.0)	(94.5)
Proceeds from sale of property and equipment	6.0	5.5
Proceeds from sale of businesses, net	43.5
Acquisitions, net of cash acquired	(92.4)	170.4
Other	1.7	(5.9)
Net cash provided by (used for) investing activities	(211.2)	75.5
Financing activities
Net receipts (repayments) of short-term borrowings		(3.7)
Net receipts of commercial paper and revolving long-term debt	0	(170.9)
Proceeds from long-term debt	0.7	0
Repayment of long-term debt	(7.4)	(617.2)
Debt issuance costs	0	(1.0)
Debt extinguishment costs		(74.8)
Net change in advances to subsidiaries	(188.5)	1,268.9
Excess tax benefits from share-based compensation	16.8	5.0
Shares issued to employees, net of shares withheld	80.0	68.2
Repurchases of common shares	(715.8)	(334.2)
Dividends paid	0	(64.4)
Distributions to noncontrolling interest	(2.0)	(1.6)
Net cash provided by (used for) financing activities	(816.2)	74.3
Effect of exchange rate changes on cash and cash equivalents	18.8	(0.1)
Change in cash and cash equivalents	(43.7)	211.2
Cash and cash equivalents, beginning of year	261.3	50.1
Cash and cash equivalents, end of year	217.6	261.3
Eliminations
Operating activities
Net cash provided by (used for) operating activities	(1,097.8)	203.7
Investing activities
Capital expenditures	0	0
Proceeds from sale of property and equipment	0	0
Proceeds from sale of businesses, net	0
Acquisitions, net of cash acquired	0	0
Other	0	0
Net cash provided by (used for) investing activities	0	0
Financing activities
Net receipts (repayments) of short-term borrowings		0
Net receipts of commercial paper and revolving long-term debt	0	0
Proceeds from long-term debt	0	0
Repayment of long-term debt	0	0
Debt issuance costs	0	0
Debt extinguishment costs		0
Net change in advances to subsidiaries	1,097.8	(203.7)
Excess tax benefits from share-based compensation	0	0
Shares issued to employees, net of shares withheld	0	0
Repurchases of common shares	0	0
Dividends paid	0	0
Distributions to noncontrolling interest	0	0
Net cash provided by (used for) financing activities	1,097.8	(203.7)
Effect of exchange rate changes on cash and cash equivalents	0	0
Change in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of year	0	0
Cash and cash equivalents, end of year	$ 0	$ 0