Financial Statements of Parent Company Guarantor - Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,916.7	$ 1,824.8	$ 1,963.7	$ 1,774.5	$ 1,750.9	$ 865.5	$ 941.5	$ 858.2	$ 7,479.7	$ 4,416.1	$ 3,456.7
Cost of goods sold									5,006.8	3,146.5	2,383.0
Gross profit	644.1	637.6	667.4	523.8	398.7	278.1	312.1	280.7	2,472.9	1,269.6	1,073.7
Selling, general and administrative									1,562.1	1,158.4	694.8
Research and development									125.8	93.6	78.2
Impairment of trade names and goodwill									11.0	60.7	200.5
Operating income (loss)	233.8	240.0	225.9	74.3	(304.1)	55.2	119.3	86.5	774.0	(43.1)	100.2
Loss (earnings) from investment in subsidiaries									0	0
Gain on sale of businesses, net									(19.7)	0	0
Other (income) expense:
Loss on early extinguishment of debt					75.4				0	75.4	0
Equity income of unconsolidated subsidiaries									(1.8)	(2.1)	(1.9)
Interest income									(7.6)	(2.9)
Interest expense									76.7	70.5	60.3
Income (loss) before income taxes and noncontrolling interest									726.4	(184.0)	43.2
Provision (benefit) for income taxes									183.8	(79.4)	46.4
Net income (loss) before noncontrolling interest	159.7	174.2	155.4	53.3	(274.7)	32.6	74.4	63.1	542.6	(104.6)	(3.2)
Noncontrolling interest									5.8	2.6	4.3
Net income (loss) attributable to Pentair Ltd.	158.2	172.8	154.1	51.7	(273.1)	31.4	72.8	61.7	536.8	(107.2)	(7.5)
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									542.6	(104.6)
Changes in cumulative translation adjustment									(29.1)	31.4	(93.7)
Amortization of pension and other post-retirement prior service cost									(0.4)	(0.3)	0
Changes in market value of derivative financial instruments									(0.3)	(3.6)	4.4
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									512.8	(77.1)	(92.5)
Less: Comprehensive income (loss) attributable to noncontrolling interest									8.0	4.0	2.2
Comprehensive income (loss) attributable to Pentair Ltd.									504.8	(81.1)	(94.7)
Pentair Ltd.
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0
Cost of goods sold									0	0
Gross profit									0	0
Selling, general and administrative									21.0	5.0
Research and development									0	0
Impairment of trade names and goodwill									0	0
Operating income (loss)									(21.0)	(5.0)
Loss (earnings) from investment in subsidiaries									(564.1)	101.4
Gain on sale of businesses, net									0
Other (income) expense:
Loss on early extinguishment of debt										0
Equity income of unconsolidated subsidiaries									0	0
Interest income									0	0
Interest expense									5.6	0.1
Income (loss) before income taxes and noncontrolling interest									537.5	(106.5)
Provision (benefit) for income taxes									0.7	0.7
Net income (loss) before noncontrolling interest									536.8	(107.2)
Noncontrolling interest									0	0
Net income (loss) attributable to Pentair Ltd.									536.8	(107.2)
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									536.8	(107.2)
Changes in cumulative translation adjustment									(31.3)	30.0
Amortization of pension and other post-retirement prior service cost									(0.4)	(0.3)
Changes in market value of derivative financial instruments									(0.3)	(3.6)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									504.8	(81.1)
Less: Comprehensive income (loss) attributable to noncontrolling interest									0	0
Comprehensive income (loss) attributable to Pentair Ltd.									504.8	(81.1)
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0
Cost of goods sold									0	0
Gross profit									0	0
Selling, general and administrative									13.3	(3.8)
Research and development									0	0
Impairment of trade names and goodwill									0	0
Operating income (loss)									(13.3)	3.8
Loss (earnings) from investment in subsidiaries									(533.7)	102.3
Gain on sale of businesses, net									0
Other (income) expense:
Loss on early extinguishment of debt										0
Equity income of unconsolidated subsidiaries									0	0
Interest income									(99.2)	(9.2)
Interest expense									106.0	10.2
Income (loss) before income taxes and noncontrolling interest									513.6	(99.5)
Provision (benefit) for income taxes									1.4	1.1
Net income (loss) before noncontrolling interest									512.2	(100.6)
Noncontrolling interest									0	0
Net income (loss) attributable to Pentair Ltd.									512.2	(100.6)
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									512.2	(100.6)
Changes in cumulative translation adjustment									(31.3)	30.0
Amortization of pension and other post-retirement prior service cost									(0.4)	(0.3)
Changes in market value of derivative financial instruments									(0.3)	(3.6)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									480.2	(74.5)
Less: Comprehensive income (loss) attributable to noncontrolling interest									0	0
Comprehensive income (loss) attributable to Pentair Ltd.									480.2	(74.5)
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales									7,479.7	4,416.1
Cost of goods sold									5,006.8	3,146.5
Gross profit									2,472.9	1,269.6
Selling, general and administrative									1,527.8	1,157.2
Research and development									125.8	93.6
Impairment of trade names and goodwill									11.0	60.7
Operating income (loss)									808.3	(41.9)
Loss (earnings) from investment in subsidiaries									0	0
Gain on sale of businesses, net									(19.7)
Other (income) expense:
Loss on early extinguishment of debt										75.4
Equity income of unconsolidated subsidiaries									(1.8)	(2.1)
Interest income									(56.6)	(2.9)
Interest expense									113.3	69.4
Income (loss) before income taxes and noncontrolling interest									773.1	(181.7)
Provision (benefit) for income taxes									181.7	(81.2)
Net income (loss) before noncontrolling interest									591.4	(100.5)
Noncontrolling interest									5.8	2.6
Net income (loss) attributable to Pentair Ltd.									585.6	(103.1)
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									591.4	(100.5)
Changes in cumulative translation adjustment									(29.1)	31.4
Amortization of pension and other post-retirement prior service cost									(0.4)	(0.3)
Changes in market value of derivative financial instruments									(0.3)	(3.6)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									561.6	(73.0)
Less: Comprehensive income (loss) attributable to noncontrolling interest									8.0	4.0
Comprehensive income (loss) attributable to Pentair Ltd.									553.6	(77.0)
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0
Cost of goods sold									0	0
Gross profit									0	0
Selling, general and administrative									0	0
Research and development									0	0
Impairment of trade names and goodwill									0	0
Operating income (loss)									0	0
Loss (earnings) from investment in subsidiaries									1,097.8	(203.7)
Gain on sale of businesses, net									0
Other (income) expense:
Loss on early extinguishment of debt										0
Equity income of unconsolidated subsidiaries									0	0
Interest income									148.2	9.2
Interest expense									(148.2)	(9.2)
Income (loss) before income taxes and noncontrolling interest									(1,097.8)	203.7
Provision (benefit) for income taxes									0	0
Net income (loss) before noncontrolling interest									(1,097.8)	203.7
Noncontrolling interest									0	0
Net income (loss) attributable to Pentair Ltd.									(1,097.8)	203.7
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									(1,097.8)	203.7
Changes in cumulative translation adjustment									62.6	(60.0)
Amortization of pension and other post-retirement prior service cost									0.8	0.6
Changes in market value of derivative financial instruments									0.6	7.2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									(1,033.8)	151.5
Less: Comprehensive income (loss) attributable to noncontrolling interest									0	0
Comprehensive income (loss) attributable to Pentair Ltd.									$ (1,033.8)	$ 151.5