Financial Statements of Parent Company Guarantor - Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 27, 2015	Jun. 30, 2016	Jun. 27, 2015
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 1,733.3	$ 1,661.2	$ 3,308.8	$ 3,136.2
Cost of goods sold	1,134.1	1,095.0	2,174.2	2,059.8
Gross profit	599.2	566.2	1,134.6	1,076.4
Selling, general and administrative	348.4	319.3	680.0	628.5
Research and development	33.9	29.0	67.1	58.8
Operating Income (Loss)	216.9	217.9	387.5	389.1
Other (income) expense:
Equity income of unconsolidated subsidiaries	(1.0)	(0.6)	(1.9)	(1.1)
Net interest expense	35.5	18.6	71.9	36.8
Income from continuing operations before income taxes	182.4	199.9	317.5	353.4
Provision for income taxes	39.6	46.0	67.3	81.3
Net Income (Loss) from Continuing Operations	142.8	153.9	250.2	272.1
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0.0	1.3	0.0	5.6
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	0.0	4.8	0.0	4.8
Net income (loss) attributable to Pentair plc	142.8	147.8	250.2	261.7
Comprehensive income (loss), net of tax
Net income	142.8	147.8	250.2	261.7
Changes in cumulative translation adjustment	25.8	(21.6)	(2.2)	152.6
Changes in market value of derivative financial instruments	10.9	(0.8)	(3.8)	(0.9)
Comprehensive income (loss) attributable to Pentair plc	127.9	168.6	248.6	108.2
Parent Company Guarantor
Condensed Financial Statements, Captions [Line Items]
Gross profit	0.0
Selling, general and administrative	1.1	9.5	9.5	12.7
Research and development			0.0
Operating Income (Loss)	(1.1)	(9.5)	(9.5)	(12.7)
Other (income) expense:
Net interest expense	0.0	0.0	0.0	0.0
Income from continuing operations before income taxes	142.7	153.8	250.1	271.4
Provision for income taxes	(0.1)	(0.1)	(0.1)	(0.7)
Net Income (Loss) from Continuing Operations		153.9		272.1
Net income (loss) attributable to Pentair plc	142.8	147.8	250.2	261.7
Comprehensive income (loss), net of tax
Net income	142.8	147.8	250.2	261.7
Changes in cumulative translation adjustment	25.8	(21.6)	(2.2)	152.6
Changes in market value of derivative financial instruments	10.9	(0.8)	(3.8)	(0.9)
Comprehensive income (loss) attributable to Pentair plc	127.9	168.6	248.6	108.2
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Gross profit	0.0
Selling, general and administrative	0.0	0.0	0.0	0.1
Operating Income (Loss)	0.0	0.0	0.0	(0.1)
Other (income) expense:
Net interest expense	0.0	0.5	0.0	1.3
Income from continuing operations before income taxes	143.8	163.3	259.6	284.1
Provision for income taxes	0.0	0.0	0.0	0.0
Net Income (Loss) from Continuing Operations		163.3		284.1
Net income (loss) attributable to Pentair plc	143.8	157.2	259.6	273.7
Comprehensive income (loss), net of tax
Net income	143.8	157.2	259.6	273.7
Changes in cumulative translation adjustment	25.8	(21.6)	(2.2)	152.6
Changes in market value of derivative financial instruments	10.9	(0.8)	(3.8)	(0.9)
Comprehensive income (loss) attributable to Pentair plc	128.9	178.0	258.0	120.2
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Gross profit	0.0
Selling, general and administrative	0.0	0.9	0.9	1.9
Operating Income (Loss)	0.0	(0.9)	(0.9)	(1.9)
Other (income) expense:
Net interest expense	28.8	0.4	56.2	3.9
Income from continuing operations before income taxes	143.8	160.4	259.6	274.4
Provision for income taxes	0.0	0.0	0.0	0.0
Net Income (Loss) from Continuing Operations		160.4		274.4
Net income (loss) attributable to Pentair plc	143.8	154.3	259.6	264.0
Comprehensive income (loss), net of tax
Net income	143.8	154.3	259.6	264.0
Changes in cumulative translation adjustment	25.8	(21.6)	(2.2)	152.6
Changes in market value of derivative financial instruments	10.9	(0.8)	(3.8)	(0.9)
Comprehensive income (loss) attributable to Pentair plc	128.9	175.1	258.0	110.5
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales	1,733.3	1,661.2	3,308.8	3,136.2
Cost of goods sold	1,134.1	1,095.0	2,174.2	2,059.8
Gross profit	599.2	566.2	1,134.6	1,076.4
Selling, general and administrative	347.3	308.9	669.6	613.8
Research and development	33.9	29.0	67.1	58.8
Operating Income (Loss)	218.0	228.3	397.9	403.8
Other (income) expense:
Equity income of unconsolidated subsidiaries	(1.0)	(0.6)	(1.9)	(1.1)
Net interest expense	6.7	17.7	15.7	31.6
Income from continuing operations before income taxes	212.3	211.2	384.1	373.3
Provision for income taxes	39.7	46.1	67.4	82.0
Net Income (Loss) from Continuing Operations		165.1		291.3
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		1.3		5.6
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax		4.8		4.8
Net income (loss) attributable to Pentair plc	172.6	159.0	316.7	280.9
Comprehensive income (loss), net of tax
Net income	172.6	159.0	316.7	280.9
Changes in cumulative translation adjustment	25.8	(21.6)	(2.2)	152.6
Changes in market value of derivative financial instruments	10.9	(0.8)	(3.8)	(0.9)
Comprehensive income (loss) attributable to Pentair plc	157.7	179.8	315.1	127.4
Eliminations
Condensed Financial Statements, Captions [Line Items]
Gross profit	0.0
Other (income) expense:
Income from continuing operations before income taxes	(460.2)	(488.8)	(835.9)	(849.8)
Net Income (Loss) from Continuing Operations		(488.8)		(849.8)
Net income (loss) attributable to Pentair plc	(460.2)	(470.5)	(835.9)	(818.6)
Comprehensive income (loss), net of tax
Net income	(460.2)	(470.5)	(835.9)	(818.6)
Changes in cumulative translation adjustment	(77.4)	64.8	6.6	(457.8)
Changes in market value of derivative financial instruments	(32.7)	2.4	11.4	2.7
Comprehensive income (loss) attributable to Pentair plc	(415.5)	(532.9)	(831.1)	(358.1)
Discontinued Operations [Member] | Parent Company Guarantor
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries		6.1		10.4
Discontinued Operations [Member] | Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries		6.1		10.4
Discontinued Operations [Member] | Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries		6.1		10.4
Discontinued Operations [Member] | Eliminations
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries		(18.3)		(31.2)
Continuing Operations [Member] | Parent Company Guarantor
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries	143.8	163.3	259.6	284.1
Continuing Operations [Member] | Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries	143.8	163.8	259.6	285.5
Continuing Operations [Member] | Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries	172.6	161.7	316.7	280.2
Continuing Operations [Member] | Eliminations
Condensed Financial Statements, Captions [Line Items]
Loss (earnings) from investment in subsidiaries	$ (460.2)	$ (488.8)	$ (835.9)	$ (849.8)