Financial Statements of Parent Company Guarantor - Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Millions	Jun. 27, 2015	Dec. 31, 2014	Jun. 28, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 147.3	$ 110.4	$ 164.5	$ 256.0
Accounts and notes receivable, net	1,170.6	1,205.9
Inventories	1,200.4	1,130.4
Other current assets	383.9	366.8
Assets of Disposal Group, Including Discontinued Operation, Current	0.7	80.6
Total current assets	2,902.9	2,894.1
Property, plant and equipment, net	908.5	950.0
Other assets
Goodwill	4,732.1	4,741.9
Intangibles, net	1,587.4	1,608.1
Other non-current assets	416.7	436.2
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	17.1	24.9
Total other assets	6,753.3	6,811.1
Total assets	10,564.7	10,655.2
Current liabilities
Current maturities of long-term debt and short-term borrowings	5.3	6.7
Accounts payable	525.9	583.1
Employee compensation and benefits	250.0	305.5
Other current liabilities	675.7	709.1
Liabilities of Disposal Group, Including Discontinued Operation, Current	3.1	35.1
Total current liabilities	1,460.0	1,639.5
Other liabilities
Long-term debt	3,260.9	2,997.4
Pension and other post-retirement compensation and benefits	305.1	322.0
Deferred tax liabilities	465.1	528.3
Other non-current liabilities	521.0	497.7
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent	0.5	6.5
Total liabilities	6,012.6	5,991.4
Equity
Shareholders' equity attributable to Pentair plc and subsidiaries	4,552.1	4,663.8
Total equity	4,552.1	4,663.8	5,718.8	6,217.7
Total liabilities and equity	10,564.7	10,655.2
Parent Company Guarantor
Current assets
Cash and cash equivalents	0.0	0.0	0.0	0.5
Accounts and notes receivable, net	0.0	0.0
Inventories		0.0
Other current assets	1.0	0.0
Total current assets	1.0	0.0
Property, plant and equipment, net		0.0
Other assets
Investments in subsidiaries	4,879.6	4,733.0
Other non-current assets	80.4	80.2
Total other assets	4,960.0	4,813.2
Total assets	4,961.0	4,813.2
Current liabilities
Current maturities of long-term debt and short-term borrowings		0.0
Accounts payable	0.1	0.9
Employee compensation and benefits	0.6	0.2
Other current liabilities	60.0	120.6
Total current liabilities	60.7	121.7
Other liabilities
Long-term debt	334.4	11.4
Other non-current liabilities	13.8	16.3
Total liabilities	408.9	149.4
Equity
Shareholders' equity attributable to Pentair plc and subsidiaries	4,552.1
Total equity		4,663.8
Total liabilities and equity	4,961.0	4,813.2
Guarantor Subsidiary [Member]
Current assets
Cash and cash equivalents	0.0
Accounts and notes receivable, net	0.0
Other current assets	14.9	17.6
Total current assets	14.9	17.6
Other assets
Investments in subsidiaries	4,867.7	4,893.8
Other non-current assets	0.0
Total other assets	4,867.7	4,893.8
Total assets	4,882.6	4,911.4
Current liabilities
Accounts payable	0.0
Employee compensation and benefits	0.1	0.6
Other current liabilities	1.4	2.2
Total current liabilities	1.5	2.8
Other liabilities
Long-term debt	1.5	175.6
Other non-current liabilities	0.0
Total liabilities	3.0	178.4
Equity
Shareholders' equity attributable to Pentair plc and subsidiaries	4,879.6
Total equity		4,733.0
Total liabilities and equity	4,882.6	4,911.4
Subsidiary Issuer
Current assets
Cash and cash equivalents	0.1	0.1	0.0	47.0
Accounts and notes receivable, net	0.0	0.0
Inventories		0.0
Other current assets	5.2	2.0
Total current assets	5.3	2.1
Property, plant and equipment, net		0.0
Other assets
Investments in subsidiaries	7,553.1	7,612.2
Other non-current assets	1,789.1	1,381.8
Total other assets	9,342.2	8,994.0
Total assets	9,347.5	8,996.1
Current liabilities
Current maturities of long-term debt and short-term borrowings		0.0
Accounts payable	0.0	0.0
Other current liabilities	11.6	10.9
Total current liabilities	11.6	10.9
Other liabilities
Long-term debt	3,121.4	2,860.6
Deferred tax liabilities	2.9	2.9
Total liabilities	3,135.9	2,874.4
Equity
Shareholders' equity attributable to Pentair plc and subsidiaries	6,211.6
Total equity		6,121.7
Total liabilities and equity	9,347.5	8,996.1
Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	147.2	110.3	$ 164.5	$ 208.5
Accounts and notes receivable, net	1,170.6	1,206.8
Inventories	1,200.4	1,130.4
Other current assets	385.3	367.6
Assets of Disposal Group, Including Discontinued Operation, Current	0.7	80.6
Total current assets	2,904.2	2,895.7
Property, plant and equipment, net	908.5	950.0
Other assets
Goodwill	4,732.1	4,741.9
Intangibles, net	1,587.4	1,608.1
Other non-current assets	326.5	345.0
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	17.1	24.9
Total other assets	6,663.1	6,719.9
Total assets	10,475.8	10,565.6
Current liabilities
Current maturities of long-term debt and short-term borrowings	5.3	6.7
Accounts payable	525.8	583.1
Employee compensation and benefits	249.3	304.7
Other current liabilities	625.2	595.8
Liabilities of Disposal Group, Including Discontinued Operation, Current	3.1	35.1
Total current liabilities	1,408.7	1,525.4
Other liabilities
Long-term debt	1,582.9	1,320.6
Pension and other post-retirement compensation and benefits	305.1	322.0
Deferred tax liabilities	462.2	525.4
Other non-current liabilities	507.2	481.4
Liabilities of Disposal Group, Including Discontinued Operation, Noncurrent	0.5	6.5
Total liabilities	4,266.6	4,181.3
Equity
Shareholders' equity attributable to Pentair plc and subsidiaries	6,209.2
Total equity		6,384.3
Total liabilities and equity	10,475.8	10,565.6
Eliminations
Current assets
Accounts and notes receivable, net	0.0	(0.9)
Other current assets	(22.5)	(20.4)
Total current assets	(22.5)	(21.3)
Other assets
Investments in subsidiaries	(17,300.4)	(17,239.0)
Other non-current assets	(1,779.3)	(1,370.8)
Total other assets	(19,079.7)	(18,609.8)
Total assets	(19,102.2)	(18,631.1)
Current liabilities
Accounts payable	0.0	(0.9)
Other current liabilities	(22.5)	(20.4)
Total current liabilities	(22.5)	(21.3)
Other liabilities
Long-term debt	(1,779.3)	(1,370.8)
Other non-current liabilities	0.0	0.0
Total liabilities	(1,801.8)	(1,392.1)
Equity
Shareholders' equity attributable to Pentair plc and subsidiaries	(17,300.4)
Total equity		(17,239.0)
Total liabilities and equity	$ (19,102.2)	$ (18,631.1)