Pentair (PNR) 10-K 24 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Jun. 28, 2014
Document Information [Line Items]
Entity Registrant Name	PENTAIR PLC
Entity Central Index Key	77360
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Trading Symbol	PNR
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding	182,442,197
Entity Public Float		$13,741,728,602

Consolidated_Statements_Of_Ope

Consolidated Statements Of Operations And Comprehensive Income (Loss) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Net sales	$7,039		$6,999.70		$4,306.80
Cost of goods sold	4,576		4,629.60		3,040.90
Gross profit	2,463		2,370.10		1,265.90
Selling, general and administrative	1,493.80		1,493.70		1,117.70
Research and development	117.3		122.8		92.3
Impairment of trade names	0		11		60.7
Operating income (loss)	851.9		742.6		-4.8
Other (income) expense
Loss (gain) on sale of businesses, net	0.2		-20.8		0
Loss on early extinguishment of debt	0		0		75.4
Equity income of unconsolidated subsidiaries	-1.2		-2		-2.3
Interest income	-3.7		-4.4		-2
Interest expense	72.3		75.3		70.2
Income (loss) from continuing operations before income taxes and noncontrolling interest	784.3		694.5		-146.1
Provision (benefit) for income taxes	177.3		177		-67.2
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	607		517.5		-78.9
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	-6.4		25.9		-25.7
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	-385.7		-0.8		0
Net income (loss) from continuing operations before noncontrolling interest	214.9		542.6		-104.6
Noncontrolling interest	0		5.8		2.6
Net income (loss) attributable to Pentair plc	214.9		536.8		-107.2
Income (Loss) from Continuing Operations Attributable to Parent	607		511.7		-81.5
Comprehensive income (loss), net of tax
Net income (loss) from continuing operations before noncontrolling interest	214.9		542.6		-104.6
Net income (loss) from continuing operations before noncontrolling interest	214.9		542.6		-104.6
Changes in cumulative translation adjustment	-336.3		-29.1		31.4
Amortization of pension and other post-retirement prior service cost, net of $0, $0.2 and $0.2 tax, respectively	0		0.4		0.3
Changes in market value of derivative financial instruments, net of $1.1, $0.7 and $3.7 tax, respectively	-0.4		-0.3		-3.6
Total comprehensive income (loss)	-121.8		512.8		-77.1
Less: Comprehensive income attributable to noncontrolling interest	0		8		4
Comprehensive income (loss) attributable to Pentair plc	($121.80)		$504.80		($81.10)
Earnings (loss) per ordinary share attributable to Pentair plc
Income (Loss) from Continuing Operations, Per Basic Share	$3.19		$2.54		($0.64)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	($2.06)		$0.13		($0.20)
Basic	$1.13	[1]	$2.67	[1]	($0.84)
Income (Loss) from Continuing Operations, Per Diluted Share	$3.14		$2.50		($0.64)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	($2.03)		$0.12		($0.20)
Diluted	$1.11	[1]	$2.62	[1]	($0.84)
Weighted average ordinary shares outstanding
Basic (shares)	190.6		201.1		127.4
Diluted (shares)	193.7		204.6		127.4
[1]	Amounts may not total to annual earnings because each quarter and year are calculated separately based on basic and diluted weighted-average ordinary shares outstanding during that period

Consolidated_Statements_Of_Ope1

Consolidated Statements Of Operations And Comprehensive Income (Loss) (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortization of pension and other post-retirement prior service cost, tax	$0	$0.20	$0.20
Changes in market value of derivative financial instruments, tax	$1.10	$0.70	$3.70

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current assets
Cash and cash equivalents	$110.40	$256
Accounts and notes receivable, net of allowances of $96.5 and $112.4, respectively	1,205.90	1,285
Inventories	1,130.40	1,195.10
Other current assets	366.8	361.6
Disposal Group, Including Discontinued Operation, Assets, Current	80.6	134.4
Total current assets	2,894.10	3,232.10
Property, plant and equipment, net	950	1,044.30
Other assets
Goodwill	4,741.90	4,860.70
Intangibles, net	1,608.10	1,749.90
Other non-current assets	436.2	390
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	24.9	466.3
Total other assets	6,811.10	7,466.90
Total assets	10,655.20	11,743.30
Current liabilities
Current maturities of long-term debt and short-term borrowings	6.7	2.5
Accounts payable	583.1	576.9
Employee compensation and benefits	305.5	312.4
Other current liabilities	709.1	645.9
Disposal Group, Including Discontinued Operation, Liabilities, Current	35.1	72.5
Total current liabilities	1,639.50	1,610.20
Other liabilities
Long-term debt	2,997.40	2,547.90
Pension and other post-retirement compensation and benefits	322	320.2
Deferred tax liabilities	528.3	557
Other non-current liabilities	497.7	456.4
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	6.5	33.9
Total liabilities	5,991.40	5,525.60
Equity
Ordinary shares $0.01 and CHF 0.50 par value, 426.0 and 213.0 authorized, 202.4 and 213.0 issued at December 31, 2014 and December 31, 2013, respectively	2	113.5
Ordinary shares held in treasury, 19.9 and 15.6 shares at December 31, 2014 and December 31, 2013, respectively	-1,251.90	-875.1
Additional paid-in capital	4,250	5,071.40
Retained earnings	2,044	1,829.10
Accumulated other comprehensive loss	-380.3	-43.6
Shareholders’ equity attributable to Pentair plc	4,663.80	6,095.30
Noncontrolling interest	0	122.4
Total equity	4,663.80	6,217.70
Total liabilities and equity	$10,655.20	$11,743.30

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2013
In Millions, except Per Share data, unless otherwise specified	USD ($)	USD ($)	CHF
Accounts and notes receivable, allowances	$96.50	$112.40
Common stock, par value (per share)	$0.01		0.5
Common stock, shares authorized	426	213	213
Common stock, shares issued	202.4	213	213
Treasury stock, shares	19.9	15.6	15.6

Consolidated_Statements_Of_Cas

Consolidated Statements Of Cash Flows (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities
Net income (loss) from continuing operations before noncontrolling interest	$214.90	$542.60	($104.60)
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	6.4	-25.9	25.7
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	385.7	0.8	0
Adjustments to reconcile net income (loss) from continuing operations before noncontrolling interest to net cash provided by (used for) operating activities of continuing operations
Equity income of unconsolidated subsidiaries	-1.2	-2	-2.3
Depreciation	138.7	141.3	85.2
Amortization	114	134.1	74.9
Loss (gain) on sale of businesses, net	0.2	-20.8	0
Deferred income taxes	2	54	-138.9
Share-based compensation	33.6	31.1	35.8
Impairment of trade names	0	11	60.7
Loss on early extinguishment of debt	0	0	75.4
Excess tax benefits from share-based compensation	-12.6	-16.8	-5
Pension and other post-retirement expense (income)	76.2	-31.3	167.5
Pension and other post-retirement contributions	-27.7	-34	-238
Loss (gain) on sale of assets	-1.5	3.9	-2.4
Changes in assets and liabilities, net of effects of business acquisitions
Accounts and notes receivable	9	-106.3	31.2
Inventories	-3.7	58.1	108.3
Other current assets	-22	-5.7	-0.2
Accounts payable	34.5	41.1	-53.8
Employee compensation and benefits	13.2	66.3	-91.9
Other current liabilities	58.5	41.2	69.2
Other non-current assets and liabilities	-13.2	48.6	-30.9
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	1,005	931.3	65.9
Cash Provided by (Used in) Operating Activities, Discontinued Operations	3.4	-3.4	-22.2
Net cash provided by (used for) operating activities of continuing operations	1,008.40	927.9	43.7
Investing activities
Capital expenditures	-129.6	-170	-94.5
Proceeds from sale of property and equipment	13.1	6	5.5
Proceeds from sale of businesses, net	0.3	43.5	0
Acquisitions, net of cash acquired	-12.3	-92.4	470.5
Other	0.2	1.7	-5.9
Net cash provided by (used for) investing activities	-128.3	-211.2	375.6
Financing activities
Net repayments of short-term borrowings	0.5	0	-3.7
Net receipts of commercial paper and revolving long-term debt	468.6	104.2	253.8
Proceeds from long-term debt	2.2	0.7	594.3
Repayment of long-term debt	-16.8	-7.4	-617.2
Debt issuance costs	-3.1	-1.4	-9.7
Debt extinguishment costs	0	0	-74.8
Excess tax benefits from share-based compensation	12.6	16.8	5
Shares issued to employees, net of shares withheld	37	80	68.2
Repurchases of ordinary shares	-1,150	-715.8	-334.2
Dividends paid	-211.4	-194.2	-112.4
Purchase of / distribution to noncontrolling interest	-134.7	-2	-1.6
Net cash provided by (used for) financing activities	-995.1	-719.1	-232.3
Effect of exchange rate changes on cash and cash equivalents	-30.6	21	0.3
Change in cash and cash equivalents	-145.6	18.6	187.3
Cash and cash equivalents, beginning of year	256	237.4	50.1
Cash and cash equivalents, end of year	$110.40	$256	$237.40

Consolidated_Statements_Of_Cha

Consolidated Statements Of Changes In Equity (USD $)	Total	Common shares	Treasury shares	Capital contribution reserve	Retained earnings	Accumulated other comprehensive income (loss)	Total Pentair plc	Noncontrolling interest
In Millions
Balance at Dec. 31, 2011	$2,047.40	$47.50	$0	$457.80	$1,465.80	($37.70)	$1,933.40	$114
Balance (in shares) at Dec. 31, 2011		-98.6	0
Net income (loss) from continuing operations before noncontrolling interest	-104.6				-107.2		-107.2	2.6
Other comprehensive income (loss), net of tax	27.5					26.1	26.1	1.4
Tax benefit of share-based compensation	5.6			5.6			5.6
Dividends declared	-207.4			-141.1	-66.3		-207.4
Distribution to noncontrolling interest	-1.6							-1.6
Stock Issued During Period, Shares, Conversion of Units		113.6	-2.7
Conversion of Stock, Amount Issued	4,931.70	65.5	-119.6	4,985.80			4,931.70
Share repurchase (in shares)		0	-7.3
Share repurchase	-334.2	0	-334.2	0			-334.2
Exercise of options, net of shares tendered for payment (in shares)		0.7	2.3
Exercise of options, net of shares tendered for payment	90.2	0.4	97.6	-7.8			90.2
Issuance of restricted shares, net of cancellations (in shares)		0.2	1.2
Issuance of restricted shares, net of cancellations	19	0.1	59.8	-40.9			19
Shares surrendered by employees to pay taxes (in shares)		-0.1	-0.4
Shares surrendered by employees to pay taxes	-21.9	0	-19.1	-2.8			-21.9
Share-based compensation	35.8			35.8			35.8
Balance at Dec. 31, 2012	6,487.50	113.5	-315.5	5,292.40	1,292.30	-11.6	6,371.10	116.4
Balance (in shares) at Dec. 31, 2012		-213	-6.9
Net income (loss) from continuing operations before noncontrolling interest	542.6				536.8		536.8	5.8
Other comprehensive income (loss), net of tax	-29.8					-32	-32	2.2
Tax benefit of share-based compensation	22.6			22.6			22.6
Dividends declared	-198.5			-198.5	0		-198.5
Distribution to noncontrolling interest	-2							-2
Share repurchase (in shares)			-12.3
Share repurchase	-715.8		-715.8	0			-715.8
Exercise of options, net of shares tendered for payment (in shares)		0	3
Exercise of options, net of shares tendered for payment	96.2	0	131.8	-35.6			96.2
Issuance of restricted shares, net of cancellations (in shares)		0	0.9
Issuance of restricted shares, net of cancellations	0	0	37	-37			0
Shares surrendered by employees to pay taxes (in shares)		0	-0.3
Shares surrendered by employees to pay taxes	-16.2	0	-12.6	-3.6			-16.2
Share-based compensation	31.1			31.1			31.1
Balance at Dec. 31, 2013	6,217.70	113.5	-875.1	5,071.40	1,829.10	-43.6	6,095.30	122.4
Balance (in shares) at Dec. 31, 2013		-213	-15.6
Net income (loss) from continuing operations before noncontrolling interest	214.9				214.9		214.9	0
Other comprehensive income (loss), net of tax	-336.7					-336.7	-336.7	0
Tax benefit of share-based compensation	11.4			11.4			11.4
Dividends declared	-229.5			-229.5			-229.5
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	134.7			12.3			12.3	122.4
Conversion of Stock, Amount Issued		-111.4		111.4
Share repurchase (in shares)		-10.6	-5.8
Share repurchase	-1,150	-0.1	-450.7	-699.2			-1,150
Exercise of options, net of shares tendered for payment (in shares)	0.9		1.3
Exercise of options, net of shares tendered for payment	46.5		60.9	-14.4			46.5
Issuance of restricted shares, net of cancellations (in shares)			0.3
Issuance of restricted shares, net of cancellations	0		19.3	-19.3			0
Shares surrendered by employees to pay taxes (in shares)			-0.1
Shares surrendered by employees to pay taxes	-9.4		-6.3	-3.1			-9.4
Share-based compensation	33.6			33.6			33.6
Balance at Dec. 31, 2014	$4,663.80	$2	($1,251.90)	$4,250	$2,044	($380.30)	$4,663.80	$0
Balance (in shares) at Dec. 31, 2014		-202.4	-19.9

Basis_of_Presentation_and_Summ

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies
	Business
	Pentair plc and its consolidated subsidiaries (the "Company” or “Pentair") is a focused diversified industrial manufacturing company comprising four reporting segments: Valves & Controls, Process Technologies, Flow Technologies and Technical Solutions.
	In December 2013, the Company’s Board of Directors approved changing the Company’s jurisdiction of organization from Switzerland to Ireland. At an extraordinary meeting of shareholders on May 20, 2014, Pentair Ltd. shareholders voted in favor of a reorganization proposal pursuant to which Pentair Ltd. would merge into Pentair plc, an Irish company, and all Pentair Ltd. CHF 0.50 par value common shares would be canceled and all holders of such shares would receive $0.01 par value ordinary shares of Pentair plc on a one-for-one basis. The reorganization transaction was completed on June 3, 2014, at which time Pentair plc replaced Pentair Ltd. as our ultimate parent company (the "Redomicile"). Shares of Pentair plc began trading on the New York Stock Exchange on June 3, 2014 under the symbol “PNR,” the same symbol under which Pentair Ltd. shares were previously traded. Although our jurisdiction of organization is Ireland, we manage our affairs so that we are centrally managed and controlled in the United Kingdom (the “U.K.”) and therefore have our tax residency in the U.K.
	Basis of presentation
	The accompanying consolidated financial statements include the accounts of Pentair and all subsidiaries, both the United States ("U.S.") and non-U.S., which we control. Intercompany accounts and transactions have been eliminated. Investments in companies of which we own 20% to 50% of the voting stock or have the ability to exercise significant influence over operating and financial policies of the investee are accounted for using the equity method of accounting and as a result, our share of the earnings or losses of such equity affiliates is included in the Consolidated Statements of Operations and Comprehensive Income (Loss).
	The consolidated financial statements have been prepared in U.S. dollars (“USD”) and in accordance with accounting principles generally accepted in the United States of America (“GAAP”).
	Fiscal year
	Our fiscal year ends on December 31. We report our interim quarterly periods on a 13-week basis ending on a Saturday.
	Use of estimates
	The preparation of our consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes, disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. These estimates include our accounting for valuation of goodwill and indefinite lived intangible assets, estimated losses on accounts receivable, estimated realizable value on excess and obsolete inventory, percentage of completion revenue recognition, assets acquired and liabilities assumed in acquisitions, estimated selling proceeds from assets held for sale, contingent liabilities, income taxes and pension and other post-retirement benefits. Actual results could differ from our estimates.
	Revenue recognition
	We recognize revenue when it is realized or realizable and has been earned. Revenue is recognized when persuasive evidence of an arrangement exists, shipment or delivery has occurred (depending on the terms of the sale), our price to the buyer is fixed or determinable, and collectability is reasonably assured.
	Generally, there is no post-shipment obligation on product sold other than warranty obligations in the normal and ordinary course of business. In the event significant post-shipment obligations were to exist, revenue recognition would be deferred until substantially all obligations were satisfied.
	Percentage of completion
	Revenue from certain long-term contracts is recognized over the contractual period under the percentage of completion method of accounting. Under this method, sales and gross profit are recognized as work is performed either based on the relationship between the actual costs incurred and the total estimated costs at completion (“the cost-to-cost method”) or based on efforts for measuring progress towards completion in situations in which this approach is more representative of the progress on the contract than the cost-to-cost method. Changes to the original estimates may be required during the life of the contract and such estimates are reviewed on a regular basis. Sales and gross profit are adjusted using the cumulative catch-up method for revisions in estimated total contract costs. These reviews have not resulted in adjustments that were significant to our results of operations. Estimated losses are recorded when identified. Claims against customers are recognized as revenue upon settlement.
	We record costs and earnings in excess of billings on uncompleted contracts within Other current assets and billings in excess of costs and earnings on uncompleted contracts within Other current liabilities in the Consolidated Balance Sheets. Amounts included in Other current assets related to these contracts were $103.5 million and $91.6 million at December 31, 2014 and 2013, respectively. Amounts included in Other current liabilities related to these contracts were $41.4 million and $35.4 million at December 31, 2014 and 2013, respectively.
	Sales returns
	The right of return may exist explicitly or implicitly with our customers. Generally, our return policy allows for customer returns only upon our authorization. Goods returned must be product we continue to market and must be in salable condition. Returns of custom or modified goods are normally not allowed. At the time of sale, we reduce revenue for the estimated effect of returns. Estimated sales returns include consideration of historical sales levels, the timing and magnitude of historical sales return levels as a percent of sales, type of product, type of customer and a projection of this experience into the future.
	Pricing and sales incentives
	We record estimated reductions to revenue for customer programs and incentive offerings including pricing arrangements, promotions and other volume-based incentives at the later of the date revenue is recognized or the incentive is offered. Sales incentives given to our customers are recorded as a reduction of revenue unless we (1) receive an identifiable benefit for the goods or services in exchange for the consideration and (2) we can reasonably estimate the fair value of the benefit received.
	Pricing is established at or prior to the time of sale with our customers and we record sales at the agreed-upon net selling price. However, one of our businesses allows customers to apply for a refund of a percentage of the original purchase price if they can demonstrate sales to a qualifying end customer. At the time of sale, we estimate the anticipated refund to be paid based on historical experience and reduce sales for the probable cost of the discount. The cost of these refunds is recorded as a reduction in gross sales.
	Volume-based incentives involve rebates that are negotiated at or prior to the time of sale with the customer and are redeemable only if the customer achieves a specified cumulative level of sales or sales increase. Under these incentive programs, at the time of sale, we reforecast the anticipated rebate to be paid based on forecasted sales levels. These forecasts are updated at least quarterly for each customer and sales are reduced for the anticipated cost of the rebate. If the forecasted sales for a customer changes, the accrual for rebates is adjusted to reflect the new amount of rebates expected to be earned by the customer.
	Shipping and handling costs
	Amounts billed to customers for shipping and handling are recorded in Net sales in the accompanying Consolidated Statements of Operations and Comprehensive Income (Loss). Shipping and handling costs incurred by Pentair for the delivery of goods to customers are included in Cost of goods sold in the accompanying Consolidated Statements of Operations and Comprehensive Income (Loss).
	Research and development
	We conduct research and development (“R&D”) activities in our own facilities, which consist primarily of the development of new products, product applications and manufacturing processes. We expense R&D costs as incurred. R&D expenditures during 2014, 2013 and 2012 were $117.3 million, $122.8 million and $92.3 million, respectively.
	Cash equivalents
	We consider highly liquid investments with original maturities of three months or less to be cash equivalents.
	Trade receivables and concentration of credit risk
	We record an allowance for doubtful accounts, reducing our receivables balance to an amount we estimate is collectible from our customers. Estimates used in determining the allowance for doubtful accounts are based on current trends, aging of accounts receivable, periodic credit evaluations of our customers’ financial condition, and historical collection experience. We generally do not require collateral. No customer receivable balances exceeded 10% of total net receivable balances as of December 31, 2014 or December 31, 2013.
	Inventories
	Inventories are stated at the lower of cost or market with substantially all inventories recorded using the first-in, first-out (“FIFO”) cost method and with an insignificant amount of inventories located outside the United States recorded using a moving average cost method which approximates FIFO.
	Property, plant and equipment, net
	Property, plant and equipment is stated at historical cost. We compute depreciation by the straight-line method based on the following estimated useful lives:
		Years
	Land improvements	5 to 20
	Buildings and leasehold improvements	5 to 50
	Machinery and equipment	3 to 15
	Significant improvements that add to productive capacity or extend the lives of properties are capitalized. Costs for repairs and maintenance are charged to expense as incurred. When property is retired or otherwise disposed of, the recorded cost of the assets and their related accumulated depreciation are removed from the Consolidated Balance Sheets and any related gains or losses are included in income.
	We review the recoverability of long-lived assets to be held and used, such as property, plant and equipment, when events or changes in circumstances occur that indicate the carrying value of the asset or asset group may not be recoverable. The assessment of possible impairment is based on our ability to recover the carrying value of the asset or asset group from the expected future pre-tax cash flows (undiscounted and without interest charges) of the related operations. If these cash flows are less than the carrying value of such asset or asset group, an impairment loss is recognized for the difference between estimated fair value and carrying value. Impairment losses on long-lived assets held for sale are determined in a similar manner, except that fair values are reduced for the cost to dispose of the assets. The measurement of impairment requires us to estimate future cash flows and the fair value of long-lived assets. During 2014 and 2013, we recorded impairment charges of $20.9 million and $16.6 million, respectively, in conjunction with restructuring activities. There were no material impairment charges recorded related to long-lived assets in 2012.
	Goodwill and identifiable intangible assets
	Goodwill
	Goodwill represents the excess of the cost of acquired businesses over the net of the fair value of identifiable tangible net assets and identifiable intangible assets purchased and liabilities assumed.
	Goodwill is tested annually for impairment and is tested for impairment more frequently if events or changes in circumstances indicate that the asset might be impaired. The impairment test is performed using a two-step process. In the first step, the fair value of each reporting unit is compared with the carrying amount of the reporting unit, including goodwill. If the estimated fair value is less than the carrying amount of the reporting unit there is an indication that goodwill impairment exists and a second step must be completed in order to determine the amount of the goodwill impairment, if any, that should be recorded. In the second step, an impairment loss is recognized for any excess of the carrying amount of the reporting unit’s goodwill over the implied fair value of that goodwill. The implied fair value of goodwill is determined by allocating the fair value of the reporting unit in a manner similar to a purchase price allocation.
	The fair value of each reporting unit is determined using a discounted cash flow analysis and market approach. Projecting discounted future cash flows requires us to make significant estimates regarding future revenues and expenses, projected capital expenditures, changes in working capital and the appropriate discount rate. Use of the market approach consists of comparisons to comparable publicly-traded companies that are similar in size and industry. Actual results may differ from those used in our valuations. This non-recurring fair value measurement is a “Level 3” measurement under the fair value hierarchy described below.
	In developing our discounted cash flow analysis, assumptions about future revenues and expenses, capital expenditures and changes in working capital, are based on our annual operating plan and long-term business plan for each of our reporting units. These plans take into consideration numerous factors including historical experience, anticipated future economic conditions, changes in raw material prices and growth expectations for the industries and end markets we participate in. These assumptions are determined over a six year long-term planning period. The six year growth rates for revenues and operating profits vary for each reporting unit being evaluated. Revenues and operating profit beyond 2020 are projected to grow at a perpetual growth rate of 3.0%.
	Discount rate assumptions for each reporting unit take into consideration our assessment of risks inherent in the future cash flows of the respective reporting unit and our weighted-average cost of capital. We utilized discount rates ranging from 11.0% to 12.0% in determining the discounted cash flows in our fair value analysis.
	In estimating fair value using the market approach, we identify a group of comparable publicly-traded companies for each reporting unit that are similar in terms of size and product offering. These groups of comparable companies are used to develop multiples based on total market-based invested capital as a multiple of earnings before interest, taxes, depreciation and amortization ("EBITDA"). We determine our estimated values by applying these comparable EBITDA multiples to the operating results of our reporting units. The ultimate fair value of each reporting unit is determined considering the results of both valuation methods.
	We completed step one of our annual goodwill impairment evaluation during the fourth quarter of 2014, 2013 and 2012 with each reporting unit’s fair value exceeding its carrying value. Accordingly, step two of the impairment analysis was not required for 2014, 2013 or 2012.
	Identifiable intangible assets
	Our primary identifiable intangible assets include: customer relationships, trade names, proprietary technology, patents and backlog. Identifiable intangibles with finite lives are amortized and those identifiable intangibles with indefinite lives are not amortized. Identifiable intangible assets that are subject to amortization are evaluated for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Identifiable intangible assets not subject to amortization are tested for impairment annually or more frequently if events warrant.
	The impairment test for trade names consists of a comparison of the fair value of the trade name with its carrying value. Fair value is measured using the relief-from-royalty method. This method assumes the trade name has value to the extent that the owner is relieved of the obligation to pay royalties for the benefits received from them. This method requires us to estimate the future revenue for the related brands, the appropriate royalty rate and the weighted average cost of capital. The non-recurring fair value measurement is a “Level 3” measurement under the fair value hierarchy described below. The impairment charges recorded in 2013 and 2012 were the result of rebranding strategies implemented in the fourth quarters of 2013 and 2012, respectively.
	At December 31, 2014 our goodwill and intangible assets were $6,350.0 million and represented 60% of our total assets. If we experience future declines in sales and operating profit or do not meet our operating forecasts, we may be subject to future impairments. Additionally, changes in assumptions regarding the future performance of our businesses, increases in the discount rate used to determine the discounted cash flows of our businesses or significant declines in our share price or the market as a whole could result in additional impairment indicators. Because of the significance of our goodwill and intangible assets, any future impairment of these assets could have a material adverse effect on our financial results.
	Equity and cost method investments
	We have investments that are accounted for using the equity method. Our proportionate share of income or losses from investments accounted for under the equity method is recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss). We write down or write off an investment and recognize a loss when events or circumstances indicate there is impairment in the investment that is other-than-temporary. This requires significant judgment, including assessment of the investees’ financial condition and in certain cases the possibility of subsequent rounds of financing, as well as the investees’ historical and projected results of operations and cash flows. If the actual outcomes for the investees are significantly different from projections, we may incur future charges for the impairment of these investments. Our investment in and loans to equity method investees was $12.9 million and $12.2 million at December 31, 2014 and December 31, 2013, respectively, net of our proportionate share of the results of their operations.
	Investments for which we do not have significant influence are accounted for under the cost method. The aggregate balance of these investments was $8.6 million and $8.3 million at December 31, 2014 and December 31, 2013.
	Income taxes
	We use the asset and liability approach to account for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of differences between the carrying amounts of assets and liabilities and their respective tax bases using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period when the change is enacted. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Changes in valuation allowances from period to period are included in our tax provision in the period of change. We recognize the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
	Pension and other post-retirement plans
	We sponsor U.S. and Non-U.S. defined-benefit pension and other post-retirement plans. The pension and other post-retirement benefit costs for company-sponsored benefit plans are determined from actuarial assumptions and methodologies, including discount rates, expected returns on plan assets and health care cost trend rates. These assumptions are updated annually and are disclosed in Note 13.
	We recognize changes in the fair value of plan assets and net actuarial gains or losses for pension and other post-retirement benefits annually in the fourth quarter each year ("mark-to-market adjustment") and, if applicable, in any quarter in which an interim remeasurement is triggered. Net actuarial gains and losses occur when the actual experience differs from any of the various assumptions used to value our pension and other post-retirement plans or when assumptions change, as they may each year. The remaining components of pension expense, primarily service and interest costs and estimated return on plan assets, are recorded on a quarterly basis.
	Environmental
	We recognize environmental clean-up liabilities on an undiscounted basis when a loss is probable and can be reasonably estimated. Such liabilities generally are not subject to insurance coverage. The cost of each environmental clean-up is estimated by engineering, financial and legal specialists based on current law. Such estimates are based primarily upon the estimated cost of investigation and remediation required and the likelihood that, where applicable, other potentially responsible parties (“PRPs”) will be able to fulfill their commitments at the sites where Pentair may be jointly and severally liable. The process of estimating environmental clean-up liabilities is complex and dependent primarily on the nature and extent of historical information and physical data relating to a contaminated site, the complexity of the site, the uncertainty as to what remedy and technology will be required and the outcome of discussions with regulatory agencies and other PRPs at multi-party sites. In future periods, new laws or regulations, advances in clean-up technologies and additional information about the ultimate clean-up remedy that is used could significantly change our estimates. Accruals for environmental liabilities are included in Other current liabilities and Other non-current liabilities in the Consolidated Balance Sheets.
Asbestos Matters
We recognize asbestos-related liabilities on an undiscounted basis when a loss is probable and can be reasonably estimated. Certain of these liabilities are subject to insurance coverage. Our subsidiaries and numerous other companies are named as defendants in personal injury lawsuits based on alleged exposure to asbestos-containing materials. These cases typically involve product liability claims based primarily on allegations of manufacture, sale or distribution of industrial products that either contained asbestos or were attached to or used with asbestos-containing components manufactured by third-parties. The process of estimating asbestos-related liabilities and the corresponding insurance recoveries receivable is complex and dependent primarily on our historical claim experience, estimates of potential future claims, our legal strategy for resolving these claims, the availability of insurance coverage, and the solvency and creditworthiness of insurers. On an annual basis, we review, and update as appropriate, such estimated asbestos liabilities and assets and the underlying assumptions.
Accruals for asbestos-related liabilities are included in Other non-current liabilities and the estimated receivable for insurance recoveries are recorded in Other non-current assets in the Consolidated Balance Sheets.
Insurance subsidiary
We insure certain general and product liability, property, workers’ compensation and automobile liability risks through our regulated wholly-owned captive insurance subsidiary, Penwald Insurance Company (“Penwald”). Reserves for policy claims are established based on actuarial projections of ultimate losses. As of December 31, 2014 and 2013, reserves for policy claims were $58.1 million ($13.2 million included in Other current liabilities and $44.9 million included in Other non-current liabilities) and $51.1 million ($13.2 million included in Other current liabilities and $37.9 million included in Other non-current liabilities), respectively.
Share-based compensation
We account for share-based compensation awards on a fair value basis. The estimated grant date fair value of each option award is recognized in income on an accelerated basis over the requisite service period (generally the vesting period). The estimated fair value of each option award is calculated using the Black-Scholes option-pricing model. From time to time, we have elected to modify the terms of the original grant. These modified grants are accounted for as a new award and measured using the fair value method, resulting in the inclusion of additional compensation expense in our Consolidated Statements of Operations and Comprehensive Income (Loss). Restricted share awards and units are recorded as compensation cost on an accelerated basis over the requisite service periods based on the market value on the date of grant.
Earnings (loss) per ordinary share
Basic earnings (loss) per share are computed by dividing net income (loss) attributable to Pentair plc by the weighted-average number of ordinary shares outstanding. Diluted earnings (loss) per share are computed by dividing net income (loss) attributable to Pentair plc by the weighted-average number of ordinary shares outstanding including the dilutive effects of ordinary share equivalents.
Derivative financial instruments
We recognize all derivatives, including those embedded in other contracts, as either assets or liabilities at fair value in our Consolidated Balance Sheets. If the derivative is designated and is effective as a cash-flow hedge, changes in the fair value of the derivative are recorded in Accumulated other comprehensive income (loss) (“AOCI”) as a separate component of equity in the Consolidated Balance Sheets and is recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) when the hedged item affects earnings. If the underlying hedged transaction ceases to exist or if the hedge becomes ineffective, all changes in fair value of the related derivatives that have not been settled are recognized in current earnings. For a derivative that is not designated as or does not qualify as a hedge, changes in fair value are reported in earnings immediately.
We use derivative instruments for the purpose of hedging interest rate and currency exposures, which exist as part of ongoing business operations. We do not hold or issue derivative financial instruments for trading or speculative purposes. All other contracts that contain provisions meeting the definition of a derivative also meet the requirements of and have been designated as, normal purchases or sales. Our policy is not to enter into contracts with terms that cannot be designated as normal purchases or sales. From time to time, we may enter into short duration foreign currency contracts to hedge foreign currency risks.
Fair value measurements
Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Assets and liabilities measured at fair value are classified using the following hierarchy, which is based upon the transparency of inputs to the valuation as of the measurement date:
Level 1: Valuation is based on observable inputs such as quoted market prices (unadjusted) for identical assets or liabilities in active markets.
Level 2: Valuation is based on inputs such as quoted market prices for similar assets or liabilities in active markets or other inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument.
Level 3: Valuation is based upon other unobservable inputs that are significant to the fair value measurement.
In making fair value measurements, observable market data must be used when available. When inputs used to measure fair value fall within different levels of the hierarchy, the level within which the fair value measurement is categorized is based on the lowest level input that is significant to the fair value measurement.
Foreign currency translation
The financial statements of subsidiaries located outside of the U.S. are generally measured using the local currency as the functional currency, except for certain corporate entities outside of the U.S. which are measured using USD. Assets and liabilities of these subsidiaries are translated at the rates of exchange at the balance sheet date. Income and expense items are translated at average monthly rates of exchange. The resultant translation adjustments are included in AOCI, a separate component of equity.
New accounting standards
In May 2014, the Financial Accounting Standards Board issued new accounting requirements for the recognition of revenue from contracts with customers. The new requirements also include additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract.  The requirements are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, with earlier adoption not permitted. We have not yet determined the potential effects on our financial condition or results of operations.

Acquisitions_and_Divestitures

Acquisitions and Divestitures	12 Months Ended
	Dec. 31, 2014
Acquisitions	Acquisitions
	Material acquisitions
	Our former parent, Pentair Ltd., took its form on September 28, 2012 as a result of a reverse acquisition (the "Merger") involving Pentair, Inc. and an indirect, wholly-owned subsidiary of Flow Control (defined below), with Pentair, Inc. surviving as an indirect, wholly-owned subsidiary of Pentair Ltd. "Flow Control" refers to Pentair Ltd. prior the Merger. Prior to the Merger, Tyco International Ltd. ("Tyco") engaged in an internal restructuring whereby it transferred to Flow Control certain assets related to the flow control business of Tyco, and Flow Control assumed from Tyco certain liabilities related to the flow control business of Tyco. On September 28, 2012 prior to the Merger, Tyco effected a spin-off of Flow Control through the pro-rata distribution of 100% of the outstanding ordinary shares of Flow Control to Tyco’s shareholders (the “Distribution”), resulting in the distribution of approximately 110.9 million of our ordinary shares to Tyco’s shareholders. The Merger was accounted for as a reverse acquisition under the purchase method of accounting with Pentair, Inc. treated as the acquirer.
	Pro forma results of material acquisitions
	The following unaudited pro forma condensed consolidated financial results of operations are presented as if the Merger had been completed on January 1, 2011:
		Year ended December 31
	In millions, except per-share data	2012
	Pro forma net sales	$	6,846.60
	Pro forma net income from continuing operations attributable to Pentair plc	183.3
	Diluted earnings from continuing operations per ordinary share attributable to Pentair plc	0.87
	The 2012 unaudited pro forma net income excludes the impact of $57.3 million of transaction related costs, $21.8 million of change of control costs and $156.2 million of non-recurring items related to acquisition date fair value adjustments to inventory and customer backlog associated with the Merger.
	The pro forma consolidated financial information was prepared for comparative purposes only and includes certain adjustments, as noted above. The adjustments are estimates based on currently available information and actual amounts may have differed materially from these estimates. They do not reflect the effect of costs or synergies that would have been expected to result from the integration of Flow Control. The pro forma information does not purport to be indicative of the results of operations that actually would have resulted had the business combination occurred at the beginning of the period presented or of future results of the consolidated entities.
	Other acquisitions
	On January 30, 2014, we acquired, as part of Process Technologies, the remaining 19.9 percent ownership interest in two entities, a U.S. entity and an international entity (collectively, Pentair Residential Filtration or “PRF”), from GE Water & Process Technologies (a unit of General Electric Company) (“GE”) for $134.3 million in cash. Prior to the acquisition, we held a 80.1 percent ownership equity interest in PRF, representing our and GE's respective global water softener and residential water filtration businesses. There was no material pro forma impact from this acquisition as the results of PRF were consolidated into our financial statements prior to acquiring the remaining interest.
	On October 4, 2012, we acquired, as part of Valves & Controls, the remaining 25 percent equity interest in Pentair Middle East Holding S.a.r.l. (“KEF”), a privately held company, for $100.0 million in cash. Prior to the acquisition, we held a 75 percent equity interest in KEF, a vertically integrated valve manufacturer in the Middle East. There was no pro forma impact from this acquisition as the results of KEF were consolidated into Flow Control’s financial statements prior to acquiring the remaining 25 percent interest in KEF.
	Additionally, during the year ended December 31, 2012, we completed other small acquisitions as part of Process Technologies with purchase prices totaling $121.2 million in cash, net of cash acquired. Total goodwill recorded as part of the purchase price allocations was $80.9 million, $67.1 million of which is tax deductible. The pro forma impact of these acquisitions was not material.
	Total transaction costs related to acquisition activities in 2013 and 2012 were $8.2 million and $57.3 million, respectively, and were expensed as incurred and recorded in Selling, general and administrative in our Consolidated Statements of Operations and Comprehensive Income (Loss).

Discontinued_Operations_and_Di

Discontinued Operations and Divestitures Discontinues Operations and Divestitures	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
	3	Discontinued Operations and Divestitures
	Discontinued Operations
	On July 28, 2014, our Board of Directors approved a decision to exit our Water Transport business in Australia. The results of the Water Transport business have been presented as discontinued operations and the assets and liabilities of the Water Transport business have been reclassified as held for sale for all periods presented.
	During the third quarter of 2014, we recognized an impairment charge related to allocated amounts of goodwill, intangible assets, property, plant & equipment and other non-current assets totaling $380.1 million, net of a $12.3 million tax benefit, representing our estimated loss on disposal of the Water Transport business. The impairment charge was determined using significant unobservable inputs ("Level 3" fair value measurements). In addition, during the first quarter of 2014 and fourth quarter of 2013, we sold portions of our Water Transport business in Australia and New Zealand, respectively, resulting in losses of $5.6 million, net of a $2.4 million tax benefit, and $0.8 million, net of a $0.3 million tax benefit, respectively.
	The sale of a portion of the Water Transport business was completed in January 2015. The remaining portions are expected to be disposed of by mid-2015.
	Operating results of discontinued operations are summarized below:
		Years ended December 31
	In millions	2014			2013			2012
	Net sales	$	295.8		$	490.1		$	112.1
	Income (loss) from discontinued operations before income taxes	$	1.5		$	33		$	(37.9	)
	Income tax benefit (provision)	(7.9		)	(7.1		)	12.2
	Income (loss) from discontinued operations, net of tax	$	(6.4	)	$	25.9		$	(25.7	)
	Loss from sale / impairment of discontinued operations before income taxes	$	(400.4	)	$	(1.1	)	$	—
	Income tax benefit	14.7			0.3			—
	Loss from sale / impairment of discontinued operations, net of tax	$	(385.7	)	$	(0.8	)	$	—
	The carrying amounts of major classes of assets and liabilities that were classified as held for sale on the Consolidated Balance Sheets were as follows:
		December 31
	In millions	2014			2013
	Cash and cash equivalents	$	7		$	9.1
	Accounts and notes receivable, net	28.8			49.3
	Inventories	30.1			48.2
	Other current assets	14.7			27.8
	Current assets held for sale	$	80.6		$	134.4
	Property, plant and equipment, net	$	18.5		$	125.7
	Goodwill	—			273.5
	Intangibles, net	—			26.2
	Other non-current assets	6.4			40.9
	Non-current assets held for sale	$	24.9		$	466.3
	Accounts payable	$	12.2		$	19.7
	Employee compensation and benefits	11.3			34.7
	Other current liabilities	11.6			18.1
	Current liabilities held for sale	$	35.1		$	72.5
	Long-term debt	$	4		$	4.7
	Pension and other post-retirement compensation and benefits	2.5			4.6
	Deferred tax liabilities	—			23.6
	Other non-current liabilities	—			1
	Non-current liabilities held for sale	$	6.5		$	33.9
	Divestitures
	During 2013, we sold businesses that were part of Technical Solutions and Flow Technologies for a cash purchase price of $30.1 million and $13.4 million, respectively, net of transaction costs, resulting in a gain of $16.8 million and $4.0 million, respectively. Goodwill of $5.3 million and $5.7 million was included in the assets of the business sold for Technical Solutions and Flow Technologies, respectively.

Earnings_Loss_Per_Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2014
Earnings (Loss) Per Share	Earnings (Loss) Per Share
	Basic and diluted earnings (loss) per share were calculated as follows:
		Years ended December 31
	In millions, except per share data	2014			2013		2012
	Net income (loss) attributable to Pentair plc	$	214.9		$	536.8	$	(107.2	)
	Net income (loss) from continuing operations attributable to Pentair plc	$	607		$	511.7	$	(81.5	)
	Weighted average ordinary shares outstanding
	Basic	190.6			201.1		127.4
	Dilutive impact of stock options and restricted stock awards	3.1			3.5		—
	Diluted	193.7			204.6		127.4
	Earnings (loss) per ordinary share attributable to Pentair plc
	Basic
	Continuing operations	$	3.19		$	2.54	$	(0.64	)
	Discontinued operations	(2.06		)	0.13		(0.20		)
	Basic earnings (loss) per ordinary share attributable to Pentair plc	$	1.13		$	2.67	$	(0.84	)
	Diluted
	Continuing operations	$	3.14		$	2.5	$	(0.64	)
	Discontinued operations	(2.03		)	0.12		(0.20		)
	Diluted earnings (loss) per ordinary share attributable to Pentair plc	$	1.11		$	2.62	$	(0.84	)
	Anti-dilutive stock options excluded from the calculation of diluted earnings per share	0.5			0.2		16

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2014
Restructuring	Restructuring
	During 2014, 2013 and 2012, we initiated and continued execution of certain business restructuring initiatives aimed at reducing our fixed cost structure and realigning our business. The 2014 initiatives included a reduction in hourly and salaried headcount of approximately 1,150 employees, which included 600 in Valves & Controls, 100 in Process Technologies, 300 in Flow Technologies and 150 in Technical Solutions. The 2013 initiatives included the reduction in hourly and salaried headcount of approximately 1,100 employees, which included 500 in Valves & Controls, 150 in Process Technologies, 150 in Flow Technologies and 300 in Technical Solutions. The 2012 initiatives included the reduction in hourly and salaried headcount of approximately 800 employees, which included 300 in Valves & Controls, 200 in Process Technologies, 100 in Flow Technologies and 200 in Technical Solutions.
	Restructuring related costs included in Selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss) included costs for severance and other restructuring costs as follows:
		Years ended December 31
	In millions	2014			2013			2012
	Severance and related costs	$	58.9		$	81.5		$	43.4
	Other	29.4			21.7			5.3
	Total restructuring costs	$	88.3		$	103.2		$	48.7
	Other restructuring costs primarily consist of asset impairment and various contract termination costs.
	Restructuring costs by reportable segment were as follows:
		Years ended December 31
	In millions	2014			2013			2012
	Valves & Controls	$	48.8		$	51		$	5.1
	Process Technologies	18.6			9.4			25.2
	Flow Technologies	10.6			13.4			5.7
	Technical Solutions	4.3			19.4			12.7
	Other	6			10			—
	Consolidated	$	88.3		$	103.2		$	48.7
	Activity in the restructuring accrual recorded in Other current liabilities and Employee compensation and benefits in the Consolidated Balance Sheets is summarized as follows:
		Years ended December 31
	In millions	2014			2013
	Beginning balance	$	68.6		$	40.4
	Costs incurred	58.9			81.5
	Cash payments and other	(54.1		)	(53.3		)
	Ending balance	$	73.4		$	68.6

Goodwill_and_Other_Identifiabl

Goodwill and Other Identifiable Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill and Other Identifiable Intangible Assets	Goodwill and Other Identifiable Intangible Assets
	The changes in the carrying amount of goodwill for the year ended December 31, 2014 and December 31, 2013 by reportable segment were as follows:
	In millions	December 31, 2013		Acquisitions/			Foreign currency			December 31, 2014
				divestitures			translation/other
	Valves & Controls	$	1,511.60	$	—		$	—		$	1,511.60
	Process Technologies	1,524.50		6.8			(79.8		)	1,451.50
	Flow Technologies	666.6		—			(38.1		)	628.5
	Technical Solutions	1,158.00		—			(7.7		)	1,150.30
	Total goodwill	$	4,860.70	$	6.8		$	(125.6	)	$	4,741.90
	In millions	December 31, 2012		Acquisitions/			Foreign currency			December 31, 2013
				divestitures			translation/other
	Valves & Controls	$	1,511.60	$	—		$	—		$	1,511.60
	Process Technologies	1,500.40		7.6			16.5			1,524.50
	Flow Technologies	663.8		(5.7		)	8.5			666.6
	Technical Solutions	1,161.70		(5.3		)	1.6			1,158.00
	Total goodwill	$	4,837.50	$	(3.4	)	$	26.6		$	4,860.70
	Accumulated goodwill impairment losses were $200.5 million as of December 31, 2014 and 2013.
	Identifiable intangible assets consisted of the following at December 31:
		2014									2013
	In millions	Cost		Accumulated			Net				Cost			Accumulated			Net
				amortization										amortization
	Finite-life intangibles
	Customer relationships	$	1,247.80	$	(325.2	)	$	922.6			$	1,271.20		$	(243.1	)	$	1,028.10
	Trade names	2		(1.1		)	0.9				2.1			(0.9		)	1.2
	Proprietary technology and patents	255.7		(96.7		)	159				263.7			(80.0		)	183.7
	Total finite-life intangibles	1,505.50		(423.0		)	1,082.50				1,537.00			(324.0		)	1,213.00
	Indefinite-life intangibles
	Trade names	525.6		—			525.6				536.9			—			536.9
	Total intangibles	$	2,031.10	$	(423.0	)	$	1,608.10			$	2,073.90		$	(324.0	)	$	1,749.90
	Identifiable intangible asset amortization expense in 2014, 2013 and 2012 was $114.0 million, $134.1 million and $74.9 million, respectively.
	There were no impairment charges recorded in 2014. In 2013 we recorded an impairment charge for trade name intangible assets of $11.0 million in Technical Solutions. In 2012 we recorded an impairment charge for trade name intangible assets of $23.2 million, $25.9 million and $11.6 million in Process Technologies, Flow Technologies and Technical Solutions, respectively.
	Estimated future amortization expense for identifiable intangible assets during the next five years is as follows:
	In millions	2015		2016			2017			2018			2019
	Estimated amortization expense	$	111.5	$	110.6		$	109		$	106.5		$	99.4

Supplemental_Balance_Sheet_Inf

Supplemental Balance Sheet Information	12 Months Ended
	Dec. 31, 2014
Supplemental Balance Sheet Information	Supplemental Balance Sheet Information
		December 31
	In millions	2014		2013
	Inventories
	Raw materials and supplies	$	460.1	$	549.8
	Work-in-process	229		164.4
	Finished goods	441.3		480.9
	Total inventories	$	1,130.40	$	1,195.10
	Other current assets
	Cost in excess of billings	$	103.5	$	91.6
	Prepaid expenses	109.6		97.6
	Deferred income taxes	139.4		149.7
	Other current assets	14.3		22.7
	Total other current assets	$	366.8	$	361.6
	Property, plant and equipment, net
	Land and land improvements	$	165.1	$	186.4
	Buildings and leasehold improvements	493.5		502.6
	Machinery and equipment	1,169.10		1,155.10
	Construction in progress	71		70.9
	Total property, plant and equipment	1,898.70		1,915.00
	Accumulated depreciation and amortization	948.7		870.7
	Total property, plant and equipment, net	$	950	$	1,044.30
	Other non-current assets
	Asbestos-related insurance receivable	$	115.8	$	119.6
	Deferred income taxes	87.9		92.4
	Other non-current assets	232.5		178
	Total other non-current assets	$	436.2	$	390
	Other current liabilities
	Deferred revenue and customer deposits	$	112.7	$	90.8
	Dividends payable	116.8		98.7
	Billings in excess of cost	41.4		35.4
	Accrued warranty	66.4		56
	Other current liabilities	371.8		365
	Total other current liabilities	$	709.1	$	645.9
	Other non-current liabilities
	Asbestos-related liabilities	$	249.1	$	254.7
	Taxes payable	61.6		48.9
	Other non-current liabilities	187		152.8
	Total other non-current liabilities	$	497.7	$	456.4

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Information	Supplemental Cash Flow Information
		Years ended December 31
	In millions	2014		2013		2012
	Cash paid for interest, net	$	67.5	$	69.4	$	66.7
	Cash paid for income taxes, net	134.2		91.2		82

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)
	Components of AOCI consist of the following:
		December 31
	In millions	2014			2013
	Cumulative translation adjustments	$	(371.0	)	$	(34.7	)
	Market value of derivative financial instruments, net of tax	(9.3		)	(8.9		)
	Accumulated other comprehensive loss	$	(380.3	)	$	(43.6	)

Debt

Debt	12 Months Ended
	Dec. 31, 2014
Debt	Debt
	Debt and the average interest rates on debt outstanding were as follows:
	In millions	Average	Maturity	December 31
		interest rate at	year
		December 31, 2014		2014			2013
	Commercial paper	0.68%	2019	$	987.6		$	528.9
	Revolving credit facilities	1.42%	2019	9.8			—
	Senior notes - fixed rate	1.35%	2015	350			350
	Senior notes - fixed rate	1.88%	2017	350			350
	Senior notes - fixed rate	2.65%	2019	250			250
	Senior notes - fixed rate	5.00%	2021	500			500
	Senior notes - fixed rate	3.15%	2022	550			550
	Capital lease obligations	6.19%	2015	6.7			21.5
	Total debt			3,004.10			2,550.40
	Less: Current maturities and short-term borrowings			(6.7		)	(2.5		)
	Long-term debt			$	2,997.40		$	2,547.90
	The 1.35% Senior Notes due 2015, 1.875% Senior Notes due 2017, 2.65% Senior Notes due 2019, 3.15% Senior Notes due 2022 and $373.0 million of the 5.00% Senior Notes due 2021 (collectively, the “Notes”) were all issued in transactions exempt from the registration requirements of the Securities Act of 1933, as amended. In March 2013, Pentair Ltd. and our 100 percent-owned subsidiary, Pentair Finance S.A. (“PFSA”), filed a Registration Statement with the SEC offering to exchange the Notes for new, registered Notes. The exchange offer expired on April 19, 2013 and did not impact the aggregate principle amount or the terms of the Notes outstanding. Effective upon the Redomicile, the Notes are guaranteed as to payment by Pentair plc and Pentair Investments Switzerland GmbH ("PISG"), a 100-percent owned subsidiary of Pentair plc and the 100-percent owner of PFSA. Prior to the Redomicile, the registered Notes were guaranteed as to payment by Pentair Ltd.
	In December 2012, PFSA completed an exchange offer (the “Exchange Offer”) pursuant to which it exchanged $373.0 million in aggregate principal amount of 5.00% Senior Notes due 2021 of Pentair, Inc., a wholly-owned, indirect subsidiary of the Company (the “2021 Notes”) for a like amount of new 5.00% Senior Notes due 2021 of PFSA (the “New 2021 Notes”) plus $5.6 million in transaction-related costs. Upon completion of the Exchange Offer, $127.0 million in aggregate principal amount of 2021 Notes remained outstanding. The remaining 2021 Notes and New 2021 Notes are guaranteed as to payment by Pentair plc.
	In November 2012, PFSA completed a private offering of $350.0 million aggregate principal amount of 1.35% Senior Notes due 2015 (the “2015 Notes”) and $250.0 million aggregate principal amount of 2.65% Senior Notes due 2019 (the “2019 Notes” and, collectively, the “2015/2019 Notes”), which are guaranteed as to payment by Pentair plc. In certain circumstances, PFSA may be required to pay additional interest on the 2015/2019 Notes. We used the net proceeds from the sale of the 2015/2019 Notes to repay commercial paper and for general corporate purposes.
	In October 2012, we redeemed the remaining outstanding aggregate principal of our 5.65% fixed rate senior notes due 2013-2017 totaling $400.0 million and our 1.05% floating rate senior notes due 2013 totaling $100.0 million (the “Fixed/Floating Rate Notes”). The redemptions included make-whole premiums of $65.8 million. Concurrent with the redemption of the Fixed/Floating Rate Notes, we terminated a related interest rate swap that was designated as a cash flow hedge, which resulted in the reclassification of $3.4 million of previously unrecognized variable to fixed swap losses from AOCI to earnings in October 2012. All costs associated with the redemption were recorded as a Loss on the early extinguishment of debt including $0.6 million of unamortized deferred financing costs.
	In September 2012, PFSA, completed a private offering of $550.0 million aggregate principal amount of 3.15% Senior Notes due 2022 (the “2022 Notes”) and $350 million aggregate principal amount of 1.875% Senior Notes due 2017 (the “2017 Notes” and, collectively, the “2017/2022 Notes”), which are guaranteed as to payment by Pentair Ltd. In certain circumstances, PFSA may be required to pay additional interest on the 2017/2022 Notes. The 2017/2022 Notes remained outstanding after the Merger. A portion of the net proceeds from the 2017/2022 Notes offering were used to repay $435.0 million to Tyco in conjunction with the Distribution and the Merger.
	In September 2012, Pentair, Inc. entered into a credit agreement providing for an unsecured, committed revolving credit facility, originally set to mature in September 2017 (the "Prior Credit Facility"). Upon the completion of the Merger, Pentair Ltd. became the guarantor under the Prior Credit Facility and PFSA and certain other of our subsidiaries became affiliate borrowers under the Prior Credit Facility. In October 2014, Pentair plc, PISG, PFSA and Pentair, Inc. entered into an amended and restated credit agreement related to the Prior Credit Facility (the "Amended Credit Facility), with Pentair plc and PISG as guarantors and PFSA and Pentair, Inc. as borrowers. The Amended Credit Facility increased the the maximum aggregate availability to $2,100.0 million and extended the maturity date to October 3, 2019. Borrowings under the Amended Credit Facility generally bear interest at a variable rate equal to the London Interbank Offered Rate ("LIBOR") plus a specified margin based upon PFSA's credit ratings. PFSA must pay a facility fee ranging from 9.0 to 25.0 basis points per annum (based upon PFSA's credit ratings) on the amount of each lender's commitment and letter of credit fee for each letter of credit issued and outstanding under the Amended Credit Facility.
	PFSA is authorized to sell short-term commercial paper notes to the extent availability exists under the Amended Credit Facility. PFSA uses the Amended Credit Facility as back-up liquidity to support 100% of commercial paper outstanding. As of December 31, 2014 and 2013, we had $987.6 million and $528.9 million, respectively, of commercial paper outstanding, all of which was classified as long-term as we have the intent and the ability to refinance such obligations on a long-term basis under the Amended Credit Facility.
	Total availability under the Amended Credit Facility was $1,102.6 million, which was not limited by any covenants contained in the Amended Credit Facility’s credit agreement. Subsequent to the Merger, we used the remaining proceeds from the 2017/2022 Notes offering and issuances of commercial paper to redeem the Fixed/Floating Rate Notes as discussed above, to repurchase shares in conjunction with our share repurchase as discussed in Note 14 and to purchase the remaining 25 percent interest in KEF for $100.0 million as discussed in Note 2.
	Our debt agreements contain certain financial covenants, the most restrictive of which are in the Amended Credit Facility, including that we may not permit (i) the ratio of our consolidated debt plus synthetic lease obligations to our consolidated net income (excluding, among other things, non-cash gains and losses) before interest, taxes, depreciation, amortization, non-cash share-based compensation expense, and up to a lifetime maximum $25.0 million of costs, fees and expenses arising out of Permitted Acquisitions, ("EBITDA") for the four consecutive fiscal quarters then ended (the “Leverage Ratio”) to exceed 3.50 to 1.00 on the last day of each fiscal quarter, and (ii) the ratio of our EBITDA for the four consecutive fiscal quarters then ended to our consolidated interest expense, including consolidated yield or discount accrued as to outstanding securitization obligations (if any), for the same period to be less than 3.00 to 1.00 as of the end of each fiscal quarter. For purposes of the Leverage Ratio, the Amended Credit Facility provides for the calculation of EBITDA giving pro forma effect to certain acquisitions, divestitures and liquidations during the period to which such calculation relates. As of December 31, 2014, we were in compliance with all financial covenants in our debt agreements.
	In addition to the Amended Credit Facility, we have various other credit facilities with an aggregate availability of $78.3 million, of which none was outstanding at December 31, 2014. Borrowings under these credit facilities bear interest at variable rates.
	We have $350.0 million of fixed rate senior notes maturing in December 2015. We classified this debt as long-term as of December 31, 2014 as we have the intent and ability to refinance such obligation on a long-term basis under the Amended Credit Facility.
	Debt outstanding at December 31, 2014 matures on a calendar year basis as follows:
	In millions	2015			2016			2017		2018		2019		Thereafter		Total
	Contractual debt obligation maturities	$	—		$	—		$	350	$	—	$	1,597.40	$	1,050.00	$	2,997.40
	Capital lease obligations	6.7			—			—		—		—		—		6.7
	Total maturities	$	6.7		$	—		$	350	$	—	$	1,597.40	$	1,050.00	$	3,004.10
	As part of 2012 and 2011 acquisitions, we assumed capital lease obligations related primarily to land and buildings. As of December 31, 2014 and 2013, the recorded values of the assets acquired under those capital leases were $19.5 million and $41.7 million, respectively, less accumulated amortization of $2.4 million and $7.6 million, respectively, all of which were included in Property, plant and equipment, net on the Consolidated Balance Sheets.
	Capital lease obligations consisted of total future minimum lease payments of $6.9 million, less the imputed interest of $0.2 million, as of December 31, 2014.

Derivatives_and_Financial_Inst

Derivatives and Financial Instruments	12 Months Ended
	Dec. 31, 2014
Derivatives and Financial Instruments	Derivatives and Financial Instruments
	Derivative financial instruments
	We are exposed to market risk related to changes in foreign currency exchange rates and interest rates on our floating rate indebtedness. To manage the volatility related to these exposures, we periodically enter into a variety of derivative financial instruments. Our objective is to reduce, where it is deemed appropriate to do so, fluctuations in earnings and cash flows associated with changes in foreign currency rates and interest rates. The derivative contracts contain credit risk to the extent that our bank counterparties may be unable to meet the terms of the agreements. The amount of such credit risk is generally limited to the unrealized gains, if any, in such contracts. Such risk is minimized by limiting those counterparties to major financial institutions of high credit quality.
	Interest rate swaps
	During 2012, we used floating to fixed rate interest rate swaps to mitigate our exposure to future changes in interest rates related to our floating rate indebtedness. We designated these interest rate swap arrangements as cash flow hedges. As a result, changes in the fair value of the interest rate swaps were recorded in AOCI on the Consolidated Balance Sheets throughout the contractual term of each of the interest rate swap arrangements.
	During the year ended December 31, 2012, all of our interest rate swaps expired or were terminated and, as a result, we had no outstanding interest rate swap arrangements at December 31, 2014 or 2013.
	In September 2005, we entered into a $100.0 million interest rate swap agreement with several major financial institutions to exchange variable rate interest payment obligations for fixed rate obligations without the exchange of the underlying principal amounts in order to manage interest rate exposures. The effective date of the fixed rate swap was April 25, 2006. The swap agreement has a fixed interest rate of 4.68% and was set to expire in July 2013. The fixed interest rate of 4.68% plus the 0.60% interest rate spread over LIBOR results in an effective fixed interest rate of 5.28%. This swap was terminated in October 2012. A loss of $3.3 million was recognized upon termination and was recorded in Loss on early extinguishment of debt in the Consolidated Statements of Operations and Comprehensive Income (Loss) for the year ended December 31, 2012.
	Derivative gains and losses on interest rate swaps included in AOCI were reclassified into earnings at the time the related interest expense was recognized or the settlement of the related commitment occurred. Interest expense from swaps was $5.3 million in 2012 and was recorded in Interest expense in the Consolidated Statements of Operations and Comprehensive Income (Loss).
	In April 2011, as part of our planned debt issuance to fund an acquisition, we entered into interest rate swap contracts to hedge movement in interest rates through the expected date of closing for a portion of the expected fixed rate debt offering. The swaps had a notional amount of $400.0 million with an average interest rate of 3.65%. In May 2011, upon the sale of the 2021 Notes, the swaps were terminated at a cost of $11.0 million. Because we used the contracts to hedge future interest payments, this was recorded in AOCI in the Consolidated Balance Sheets and will be amortized as interest expense over the 10 year life of the 2021 Notes. The ending unrealized net loss in AOCI at December 31, 2014 and 2013 was $7.0 million and $8.1 million, respectively.
	Foreign currency contracts
	We conduct business in various locations throughout the world and are subject to market risk due to changes in the value of foreign currencies in relation to our reporting currency, the U.S. dollar. We manage our economic and transaction exposure to certain market-based risks through the use of foreign currency derivative financial instruments. Our objective in holding these derivatives is to reduce the volatility of net earnings and cash flows associated with changes in foreign currency exchange rates. The majority of our foreign currency contracts have an original maturity date of less than one year. At December 31, 2014 and 2013, we had outstanding foreign currency derivative contracts with gross notional U.S. dollar equivalent amounts of $250.8 million and $130.3 million, respectively. The impact of these contracts on the Consolidated Statements of Operations and Comprehensive Income (Loss) was not material for any period presented.
	Gains or losses on foreign currency contracts designated as hedges are reclassified out of AOCI and into Selling, general and administrative expense in the Consolidated Statements of Operations and Comprehensive Income (Loss) upon settlement. Such reclassifications during 2014, 2013 and 2012 were not material.
	Fair value of financial instruments
	The following methods were used to estimate the fair values of each class of financial instrument:
	•	short-term financial instruments (cash and cash equivalents, accounts and notes receivable, accounts and notes payable and variable-rate debt) — recorded amount approximates fair value because of the short maturity period;
	•	long-term fixed-rate debt, including current maturities — fair value is based on market quotes available for issuance of debt with similar terms, which are inputs that are classified as Level 2 in the valuation hierarchy defined by the accounting guidance; and
	•	foreign currency contract agreements — fair values are determined through the use of models that consider various assumptions, including time value, yield curves, as well as other relevant economic measures, which are inputs that are classified as Level 2 in the valuation hierarchy defined by the accounting guidance.
	The recorded amounts and estimated fair values of total debt at December 31 were as follows:
		2014						2013
	In millions	Recorded		Fair Value				Recorded			Fair Value
		Amount						Amount
	Variable rate debt	$	997.4	$	997.4			$	528.9		$	528.9
	Fixed rate debt	2,006.70		2,070.40				2,021.50			1,997.50
	Total debt	$	3,004.10	$	3,067.80			$	2,550.40		$	2,526.40
	Financial assets and liabilities measured at fair value on a recurring and nonrecurring basis were as follows:
	Recurring fair value measurements	December 31, 2014
	In millions	Level 1		Level 2			Level 3			Total
	Foreign currency contract assets	$	—	$	0.9		$	—		$	0.9
	Foreign currency contract liabilities	—		(6.6		)	—			(6.6		)
	Deferred compensation plans assets (1)	47.9		7.4			—			55.3
	Total recurring fair value measurements	$	47.9	$	1.7		$	—		$	49.6
	Nonrecurring fair value measurements (2)
	Recurring fair value measurements	December 31, 2013
	In millions	Level 1		Level 2			Level 3			Total
	Foreign currency contract assets	$	—	$	3.6		$	—		$	3.6
	Deferred compensation plan assets (1)	32.1		—			—			32.1
	Total recurring fair value measurements	$	32.1	$	3.6		$	—		$	35.7
	Nonrecurring fair value measurements  (3)
	-1	Deferred compensation plan assets include mutual funds, common/collective trusts and cash equivalents for payment of certain non-qualified benefits for retired, terminated and active employees. The fair value of mutual funds and cash equivalents were based on quoted market prices in active markets. The underlying investments in the common/collective trusts primarily include intermediate and long-term debt securities, corporate debt securities, equity securities and fixed income securities. The overall fair value of the common/collective trusts are based on observable inputs.
	-2	During the third quarter of 2014, we recognized an impairment charge related to allocated amounts of goodwill, intangible assets, property, plant & equipment and other non-current assets totaling $380.1 million, net of a $12.3 million tax benefit, representing our estimated loss on disposal of the Water Transport business. The impairment charge was determined using significant unobservable inputs ("Level 3" fair value measurements). See Note 3 for additional information about the impairment.
	-3	In the fourth quarter of 2013, we completed our annual intangible assets impairment review. As a result, we recorded a pre-tax non-cash impairment charge of $11.0 million for a trade name intangible in 2013. The impairment charge reduced the fair value of the impacted trade name intangible to $0. The fair value of trade names is measured using the relief-from-royalty method. This method assumes the trade name has value to the extent that the owner is relieved of the obligation to pay royalties for the benefits received from them. This method requires us to estimate the future revenue for the related brands, the appropriate royalty rate and the weighted average cost of capital.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes	Income Taxes
	Income (loss) from continuing operations before income taxes and noncontrolling interest consisted of the following:
		Years ended December 31
	In millions	2014			2013			2012
	Federal (1)	$	13.3		$	328.7		$	39.5
	International	771			365.8			(185.6		)
	Income (loss) from continuing operations before income taxes and noncontrolling interest	$	784.3		$	694.5		$	(146.1	)
	-1	As a result of the Redomicile, “Federal” reflects income (loss) from continuing operations before income taxes and noncontrolling interest for the U.K. in 2014 and for Switzerland in 2013 and 2012.
	The provision (benefit) for income taxes consisted of the following:
		Years ended December 31
	In millions	2014			2013			2012
	Currently payable
	Federal (1)	$	(0.4	)	$	17.4		$	6.5
	International (2)	175.7			105.6			65.2
	Total current taxes	175.3			123			71.7
	Deferred
	Federal (1)	2.2			18.9			1.3
	International (2)	(0.2		)	35.1			(140.2		)
	Total deferred taxes	2			54			(138.9		)
	Total provision (benefit) for income taxes	$	177.3		$	177		$	(67.2	)
	-1	As a result of the Redomicile, “Federal” represents U.K. taxes for 2014 and Swiss taxes for 2013 and 2012.
	-2	As a result of the Redomicile, "International" represents non-U.K. taxes for 2014 and non-Swiss taxes for 2013 and 2012.
	Reconciliations of the federal statutory income tax rate to our effective tax rate were as follows:
		Years ended December 31
	Percentages	2014		2013	2012
	Federal statutory income tax rate (1)	21		7.8	7.8
	Tax effect of international operations (2)	(4.9	)	10.4	23.5
	Change in valuation allowances	3.4		5.7	—
	Withholding taxes	2.3		1.1	—
	Interest limitations	0.8		0.5	—
	Non-deductible transaction costs	—		—	(5.9	)
	Impact of debt-financing	—		—	13.6
	Resolution of tax audits	—		—	7
	Effective tax rate	22.6		25.5	46
	-1	The statutory rate for 2014 reflects the U.K. statutory rate of 21 percent. For 2013 and 2012, the statutory rate reflects the Swiss statutory rate of 7.8 percent.
	-2	The tax effect of international operations for 2014 consists of non-U.K. jurisdictions. For 2013 and 2012, the tax effect of international operations consists of non-Swiss jurisdictions.
	Reconciliations of the beginning and ending gross unrecognized tax benefits were as follows:
		Years ended December 31
	In millions	2014			2013			2012
	Beginning balance	$	60.8		$	53.4		$	26.5
	Gross increases for tax positions in prior periods	2.3			12.2			2.2
	Gross decreases for tax positions in prior periods	(0.5		)	(0.6		)	(0.6		)
	Gross increases based on tax positions related to the current year	1.8			2.7			13.6
	Gross decreases related to settlements with taxing authorities	(0.1		)	(5.1		)	(13.2		)
	Reductions due to statute expiration	(1.2		)	(1.8		)	(0.4		)
	Gross decreases due to currency fluctuations	(1.0		)	—			—
	Gross increases due to acquisitions	—			—			25.3
	Ending balance	$	62.1		$	60.8		$	53.4
	Included in the $62.1 million of total gross unrecognized tax benefits as of December 31, 2014 was $60.7 million of tax benefits that, if recognized, would impact the effective tax rate. It is reasonably possible that the gross unrecognized tax benefits as of December 31, 2014 may decrease by a range of $0 to $25.3 million during 2015, primarily as a result of the resolution of non-U.K. examinations, including U.S. federal and state examinations, and the expiration of various statutes of limitations.
	The determination of annual income tax expense takes into consideration amounts which may be needed to cover exposures for open tax years. The Internal Revenue Service ("IRS") is currently examining the Pentair, Inc. U.S. federal income tax return for the tax year ending September 28, 2012, and the Panthro Acquisition Co. U.S. federal income tax returns for tax years ending December 31, 2012 and December 31, 2013. A number of tax periods from 2002 to present are under audit by tax authorities in various jurisdictions, including Germany, India and Italy. We anticipate that several of these audits may be concluded in the foreseeable future. We are also subject to the 2012 Tax Sharing Agreement, discussed below, which generally applies to pre-Distribution Tyco tax periods beginning in 1997 which remain subject to audit by the IRS.
	We record penalties and interest related to unrecognized tax benefits in Provision (benefit) for income taxes and Interest expense, respectively. As of December 31, 2014 and 2013, we have liabilities of $1.2 million and $0.9 million, respectively, for the possible payment of penalties and $9.8 million and $8.9 million, respectively, for the possible payment of interest expense, which are recorded in Other current liabilities in the Consolidated Balance Sheets.
	Deferred taxes in the amount of $11.8 million have been provided on undistributed earnings of certain subsidiaries. Taxes have not been provided on undistributed earnings of subsidiaries where it is our intention to reinvest these earnings permanently or to repatriate the earnings only when it is tax effective to do so. It is not practicable to estimate the amount of tax that might be payable if such earnings were to be remitted.
	Deferred taxes arise because of different treatment between financial statement accounting and tax accounting, known as “temporary differences.” We record the tax effect of these temporary differences as “deferred tax assets” (generally items that can be used as a tax deduction or credit in future periods) and “deferred tax liabilities” (generally items for which we received a tax deduction but the tax impact has not yet been recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss)).
	Deferred taxes were recorded in the Consolidated Balance Sheets as follows:
		December 31
	In millions	2014			2013
	Other current assets	$	139.4		$	149.7
	Other non-current assets	87.9			92.4
	Deferred tax liabilities	528.3			557
	Net deferred tax liabilities	$	301		$	314.9
	The tax effects of the major items recorded as deferred tax assets and liabilities were as follows:
		December 31
	In millions	2014			2013
	Deferred tax assets
Accrued liabilities and reserves	$	200.3		$	192.2
Pension and other post-retirement benefits	68.4			76.8
Employee compensation & benefits	100			82.2
Tax loss and credit carryforwards	291.9			351.7
Total deferred tax assets	660.6			702.9
Valuation allowance	235.8			235.5
Deferred tax assets, net of valuation allowance	424.8			467.4
Deferred tax liabilities
Property, plant and equipment	51.6			57.9
Goodwill and other intangibles	645.6			697.1
Other liabilities	28.6			27.3
Total deferred tax liabilities	725.8			782.3
Net deferred tax liabilities	$	301		$	314.9
As of December 31, 2014, tax loss carryforwards of $1,118.3 million were available to offset future income. A valuation allowance of $207.3 million exists for deferred income tax benefits related to the tax loss carryforwards which may not be realized. We believe sufficient taxable income will be generated in the respective jurisdictions to allow us to fully recover the remainder of the tax losses. The tax losses relate to Non-U.S. carryforwards of $1,010.7 million which are subject to varying expiration periods and will begin to expire in 2015. In addition, there were $21.4 million of U.S. federal and $86.2 million of state tax loss carryforwards as of December 31, 2014, which will expire in future years through 2034.
Tax sharing agreement and other income tax matters
In connection with the Distribution, we entered into a tax sharing agreement (the “2012 Tax Sharing Agreement”) with Tyco and The ADT Corporation (“ADT”), which governs the rights and obligations of Tyco, ADT and us for certain pre-Distribution tax liabilities, including Tyco’s obligations under a separate tax sharing agreement (the “2007 Tax Sharing Agreement”) that Tyco, Covidien Ltd. (“Covidien”) and TE Connectivity Ltd. (“TE Connectivity”) entered into in connection with the 2007 distributions of Covidien and TE Connectivity by Tyco (the “2007 Separation”). The 2007 Tax Sharing Agreement governs the rights and obligations of Tyco, Covidien and TE Connectivity with respect to certain pre-2007 Separation tax liabilities and certain tax liabilities arising in connection with the 2007 Separation. More specifically, Tyco, Covidien and TE Connectivity share 27%, 42% and 31%, respectively, of income tax liabilities that arise from adjustments made by tax authorities to Tyco's, Covidien's and TE Connectivity's U.S. and certain non-U.S. 2007 and prior income tax returns.
The 2012 Tax Sharing Agreement provides that we, Tyco and ADT will share (i) certain pre-Distribution income tax liabilities that arise from adjustments made by tax authorities to our, Tyco’s and ADT’s U.S. income tax returns, and (ii) payments required to be made by Tyco in respect to the 2007 Tax Sharing Agreement (collectively, “Shared Tax Liabilities”). Tyco is responsible for the first $500 million of Shared Tax Liabilities. As of December 31, 2014, Tyco has paid $52.0 million of Shared Tax Liabilities. We and ADT will share 42% and 58%, respectively, of the next $225 million of Shared Tax Liabilities. We, ADT and Tyco will share 20%, 27.5% and 52.5%, respectively, of Shared Tax Liabilities above $725 million. Under these tax sharing agreements, the amount ultimately assessed would have to be in excess of $1.85 billion before we would be required to pay any of the amounts assessed.
In the event the Distribution, the spin-off of ADT, or certain internal transactions undertaken in connection therewith were determined to be taxable as a result of actions taken after the Distribution by us, ADT or Tyco, the party responsible for such failure would be responsible for all taxes imposed on us, ADT or Tyco as a result thereof. Taxes resulting from the determination that the Distribution, the spin-off of ADT, or any internal transaction is taxable are referred to herein as “Distribution Taxes.” If such failure is not the result of actions taken after the Distribution by us, ADT or Tyco, then we, ADT and Tyco would be responsible for any Distribution Taxes imposed on us, ADT or Tyco as a result of such determination in the same manner and in the same proportions as the Shared Tax Liabilities. ADT will have sole responsibility for any income tax liability arising as a result of Tyco’s acquisition of Brink’s Home Security Holdings, Inc. (“BHS”) in May 2010, including any liability of BHS under the tax sharing agreement between BHS and The Brink’s Company dated October 31, 2008 (collectively, the “BHS Tax Liabilities”). Costs and expenses associated with the management of Shared Tax Liabilities, Distribution Taxes and BHS Tax Liabilities will generally be shared 20% by us, 27.5% by ADT and 52.5% by Tyco. We are responsible for all of our own taxes that are not shared pursuant to the 2012 Tax Sharing Agreement’s sharing formulae. In addition, Tyco and ADT are responsible for their tax liabilities that are not subject to the 2012 Tax Sharing Agreement’s sharing formula.
The 2012 Tax Sharing Agreement also provides that, if any party were to default in its obligation to another party to pay its share of the distribution taxes that arise as a result of no party’s fault, each non-defaulting party would be required to pay, equally with any other non-defaulting party, the amounts in default. In addition, if another party to the 2012 Tax Sharing Agreement that is responsible for all or a portion of an income tax liability were to default in its payment of such liability to a taxing authority, we could be legally liable under applicable tax law for such liabilities and required to make additional tax payments. Accordingly, under certain circumstances, we may be obligated to pay amounts in excess of our agreed-upon share of our, Tyco’s and ADT’s tax liabilities.
On July 1, 2013, Tyco announced that the Internal Revenue Service (“IRS”) issued Notices of Deficiency (“Tyco IRS Notices”) to Tyco asserting that several of Tyco's former U.S. subsidiaries collectively owe additional taxes in the aggregate amount of $883.3 million plus penalties of $154 million based on audits of the 1997 through 2000 tax years of Tyco and its subsidiaries as they existed at that time. These amounts exclude interest and do not reflect the impact on subsequent periods if the IRS challenge to Tyco's tax filings as described below is ultimately successful. If the IRS should successfully assert its position, our share of the collective liability, if any, would be determined pursuant to the 2007 Tax Sharing Agreement and the 2012 Tax Sharing Agreement. Tyco has filed petitions with the U.S. Tax Court to contest the IRS assessments.
As we have previously disclosed, in connection with U.S. federal tax audits of Tyco and its subsidiaries, the IRS has previously raised issues and proposed tax adjustments for periods beginning with the 1997 tax year. The adjustments now asserted by the IRS under the Tyco IRS Notices primarily relate to the treatment of certain intercompany debt transactions. The IRS has asserted in the Tyco IRS Notices that substantially all of the intercompany debt originated during the 1997 - 2000 period should not be treated as debt for U.S. federal income tax purposes, and has therefore disallowed interest and related deductions recognized associated with that intercompany debt on the U.S. income tax returns for those periods totaling approximately $2.9 billion. If the IRS is successful in asserting its claim, it would have an adverse impact on interest deductions related to the same Tyco intercompany debt in subsequent time periods, totaling approximately $6.6 billion, which Tyco has advised us that it expects the IRS to disallow. Under the 2012 Tax Sharing Agreement, Tyco has the right to administer, control, and settle all U.S. income tax audits for periods prior to and including the Distribution. As mentioned above, Tyco has filed petitions with the U.S. Tax Court to contest the IRS assessments. Tyco has advised us that it strongly disagrees with the IRS position and believes (i) it has meritorious defenses for the respective tax filings, (ii) the IRS positions with regard to these matters are inconsistent with applicable tax laws and Treasury regulations, and (iii) the previously reported taxes for the years in question are appropriate.
No payments with respect to these matters would be required until the dispute is resolved in the U.S. Tax Court, which Tyco has advised us, based on the experience of other companies, could take several years. However, the ultimate resolution of these matters is uncertain, and to the extent we are responsible for any Shared Tax Liability or Distribution Tax, including if the IRS were to prevail with respect to the matter set forth above, there could be a material adverse impact on our financial condition, results of operations, or cash flows in future reporting periods.

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2014
Benefit Plans	Benefit Plans
	Pension and other post-retirement plans
	We sponsor U.S. and Non-U.S. defined-benefit pension and other post-retirement plans. Pension benefits are based principally on an employee’s years of service and/or compensation levels near retirement. In addition, we provide certain post-retirement health care and life insurance benefits. Generally, the post-retirement health care and life insurance plans require contributions from retirees. In December 2007, we announced that we will be freezing certain U.S. pension plans as of December 31, 2017.
	Obligations and funded status
	The following tables present reconciliations of plan benefit obligations, fair value of plan assets and the funded status of pension plans and other post-retirement plans as of and for the years ended December 31, 2014 and 2013:
		U.S. pension plans							Non-U.S. pension plans							Other post-retirement
																plans
	In millions	2014			2013				2014			2013				2014			2013
	Change in benefit obligations
	Benefit obligation beginning of year	$	346.9		$	394.3			$	462		$	460.8			$	42.4		$	59.3
	Service cost	13.1			15.6				7.4			8.4				0.2			0.3
	Interest cost	15.4			14.3				17.3			17.9				1.7			1.9
	Actuarial loss (gain)	50.1			(56.9		)		73			(16.6		)		0.3			(15.9		)
	Translation loss (gain)	—			—				(36.6		)	9.7				—			—
	Benefits paid	(9.3		)	(20.4		)		(17.9		)	(18.2		)		(3.1		)	(3.2		)
	Benefit obligation end of year	$	416.2		$	346.9			$	505.2		$	462			$	41.5		$	42.4
	Change in plan assets
	Fair value of plan assets beginning of year	$	285.8		$	326.2			$	286.5		$	249			$	—		$	—
	Actual return on plan assets	63.7			(28.9		)		35.2			28.6				—			—
	Company contributions	3.7			8.9				20.9			21.9				3.1			3.2
	Translation gain (loss)	—			—				(15.0		)	5.2				—			—
	Benefits paid	(9.3		)	(20.4		)		(17.9		)	(18.2		)		(3.1		)	(3.2		)
	Fair value of plan assets end of year	$	343.9		$	285.8			$	309.7		$	286.5			$	—		$	—
	Funded status
	Benefit obligations in excess of the fair value of plan assets	$	(72.3	)	$	(61.1	)		$	(195.5	)	$	(175.5	)		$	(41.5	)	$	(42.4	)
	Amounts recorded in the Consolidated Balance Sheets were as follows:
		U.S. pension plans							Non-U.S. pension plans							Other post-
																retirement plans
	In millions	2014			2013				2014			2013				2014			2013
	Other non-current assets	$	2.7		$	0.7			$	6.5		$	3.7			$	—		$	—
	Current liabilities	(4.0		)	(3.9		)		(4.7		)	(4.7		)		(3.4		)	(3.7		)
	Non-current liabilities	(71.0		)	(57.9		)		(197.3		)	(174.5		)		(38.1		)	(38.7		)
	Benefit obligations in excess of the fair value of plan assets	$	(72.3	)	$	(61.1	)		$	(195.5	)	$	(175.5	)		$	(41.5	)	$	(42.4	)
	The accumulated benefit obligation for all defined benefit plans was $887.5 million and $772.2 million at December 31, 2014 and 2013, respectively.
	Information for pension plans with an accumulated benefit obligation or projected benefit obligation in excess of plan assets as of December 31 was as follows:
		Projected benefit obligation							Accumulated benefit  obligation
		exceeds the fair value							exceeds the fair value of
		of plan assets							plan assets
	In millions	2014			2013				2014			2013
	U.S. pension plans
	Projected benefit obligation	$	92.5		$	76.3			$	92.5		$	76.3
	Fair value of plan assets	17.5			14.5				17.5			14.5
	Accumulated benefit obligation	N/A			N/A				85.1			73.1
	Non-U.S. pension plans
	Projected benefit obligation	$	460		$	438.2			$	453.2		$	420.4
	Fair value of plan assets	258.1			259				252.3			244.5
	Accumulated benefit obligation	N/A			N/A				440.9			411.5
	Components of net periodic benefit expense (income) for our pension plans for the years ended December 31 were as follows:
		U. S. pension plans										Non-U.S. pension plans
	In millions	2014			2013			2012				2014			2013			2012
	Service cost	$	13.1		$	15.6		$	12.9			$	7.4		$	8.4		$	3.3
	Interest cost	15.4			14.3			28.2				17.3			17.9			7.5
	Expected return on plan assets	(10.5		)	(9.7		)	(29.4		)		(15.9		)	(15.2		)	(3.9		)
	Amortization of prior year service cost (benefit)	—			0.4			—				—			(0.2		)	—
	Net actuarial (gain) loss	(3.1		)	(18.3		)	114.3				50.3			(30.0		)	24.2
	Net periodic benefit expense (income)	$	14.9		$	2.3		$	126			$	59.1		$	(19.1	)	$	31.1
	Components of net periodic benefit expense (income) for our other post-retirement plans for the years ended December 31 were as follows:
		Other post-retirement plans
	In millions	2014			2013			2012
	Service cost	$	0.2		$	0.3		$	0.2
	Interest cost	1.7			1.9			1.9
	Amortization of prior year service benefit	—			(0.8		)	—
	Net actuarial loss (gain)	0.3			(15.9		)	8.1
	Net periodic benefit expense (income)	$	2.2		$	(14.5	)	$	10.2
Assumptions
Weighted-average assumptions used to determine benefit obligations as of December 31 were as follows:
	U.S. pension plans							Non-U.S. pension plans							Other post-retirement
															plans
Percentages	2014		2013		2012			2014		2013		2012			2014		2013		2012
Discount rate	3.63	%	4.51	%	3.67	%		3.04	%	4.13	%	3.85	%		3.6	%	4.35	%	3.4	%
Rate of compensation increase	4	%	4	%	4.37	%		2.95	%	3.02	%	3.02	%		—		—		—
Weighted-average assumptions used to determine net periodic benefit expense (income) for years ended December 31 were as follows:
	U.S. pension plans							Non-U.S. pension plans							Other post-retirement
															plans
Percentages	2014		2013		2012			2014		2013		2012			2014		2013		2012
Discount rate	4.51	%	3.67	%	5.05	%		4.13	%	3.85	%	4.82	%		4.35	%	3.4	%	5.05	%
Expected long-term return on plan assets	4.56	%	3.75	%	7.5	%		5.95	%	5.98	%	4.09	%		—		—		—
Rate of compensation increase	4	%	4.37	%	4.21	%		3.02	%	3.02	%	2.98	%		—		—		—
Uncertainty in the securities markets and U.S. economy could result in investment returns less than those assumed. Should the securities markets decline or medical and prescription drug costs increase at a rate greater than assumed, we would expect increasing annual combined net pension and other post-retirement costs for the next several years. Should actual experience differ from actuarial assumptions, the projected pension benefit obligation and net pension cost and accumulated other post-retirement benefit obligation and other post-retirement benefit cost would be affected in future years.
Discount rates
The discount rate reflects the current rate at which the pension liabilities could be effectively settled at the end of the year based on our December 31 measurement date. The discount rate was determined by matching our expected benefit payments to payments from a stream of bonds rated AA or higher available in the marketplace, adjusted to eliminate the effects of call provisions. This produced a weighted-average discount rate for our U.S. pension plans of 3.63%, 4.51% and 3.67% in 2014, 2013 and 2012, respectively. The discount rates on our non-U.S. pension plans ranged from 0.50% to 4.25%, 0.50% to 5.00% and 0.50% to 4.50% in 2014, 2013 and 2012, respectively. There are no known or anticipated changes in our discount rate assumptions that will impact our pension expense in 2015.
Expected rates of return
Our expected rates of return on U.S. pension plan assets were 4.56%, 3.75% and 7.50% for 2014, 2013 and 2012, respectively. The expected rates of return on non-U.S. pension plan assets ranged from 1.00% to 6.40%, 1.00% to 6.50% and 1.00% to 4.60% in 2014, 2013 and 2012, respectively. The expected rate of return is designed to be a long-term assumption that may be subject to considerable year-to-year variance from actual returns. In developing the expected long-term rate of return, we considered our historical returns, with consideration given to forecasted economic conditions, our asset allocations, input from external consultants and broader longer-term market indices. U.S. pension plan assets yielded returns of 22.30%, (9.90)% and 10.80% in 2014, 2013 and 2012, respectively. As a result of our de-risking strategy to reduce U.S. pension plan liability, we anticipate the expected rate of return on our U.S. funded pension plans will continue to be consistent with the discount rate utilized. Any difference in the expected rate and actual returns will be included with the actuarial gain or loss recorded in the fourth quarter when our plans are remeasured.
Healthcare cost trend rates
The assumed healthcare cost trend rates for other post-retirement plans as of December 31 were as follows:
	2014		2013
Healthcare cost trend rate assumed for following year	6.8	%	7	%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.5	%	4.5	%
Year the cost trend rate reaches the ultimate trend rate	2027		2027
The assumed healthcare cost trend rates can have a significant effect on the amounts reported for healthcare plans. A one-percentage-point change in the assumed healthcare cost trend rates would have the following effects as of and for the year ended December 31, 2014:
	One Percentage Point
In millions	Increase			Decrease
Increase (decrease) in annual service and interest cost	$	0.1		$	(0.1	)
Increase (decrease) in other post-retirement benefit obligations	1			(0.9		)
Pension plans assets
Objective
The primary objective of our investment strategy is to meet the pension obligation to our employees at a reasonable cost to us. This is primarily accomplished through growth of capital and safety of the funds invested.
During 2012, we adopted an investment strategy for our U.S. pension plans with a primary objective of preserving the funded status of the U.S. plans. This was achieved through investments in fixed interest instruments with interest rate sensitivity characteristics closely reflecting the interest rate sensitivity of our benefit obligations. Shifting of allocations away from equities to liability hedging fixed income investments, by reinvesting in fixed income instruments as equity investments were redeemed, was completed during 2013. As of December 31, 2014, the U.S. pension plans have an approximately 97 percent allocation to fixed income investments.
Asset allocation
Our actual overall asset allocation for our U.S. and non-U.S. pension plans as compared to our investment policy goals as of December 31 was as follows:
	U.S. pension plans
	Actual					Target
Percentages	2014		2013			2014		2013
Fixed income	97	%	92	%		100	%	100	%
Alternative	3	%	7	%		—		—
Cash	—	%	1	%		—		—
	Non-U.S. pension plans
	Actual					Target
Percentages	2014		2013			2014		2013
Equity securities	40	%	54	%		45	%	56	%
Fixed income	53	%	41	%		55	%	44	%
Alternative	5	%	3	%		—		—
Cash	2	%	2	%		—		—
While the target allocations do not have a percentage allocated to cash, the plan assets will always include some cash due to cash flow requirements.
Fair value measurement
The fair values of our pension plan assets and their respective levels in the fair value hierarchy as of December 31, 2014 and December 31, 2013 were as follows:
	31-Dec-14
In millions	Level 1			Level 2			Level 3			Total
Cash and cash equivalents	$	3.1		$	4.5		$	—		$	7.6
Fixed income:
Corporate and non U.S. government	—			373.6			—			373.6
U.S. treasuries	—			70.7			—			70.7
Mortgage-backed securities	—			8.3			—			8.3
Other	—			45.5			—			45.5
Global equity securities:
Mid cap equity	—			3.1			—			3.1
Large cap equity	—			43.7			—			43.7
International equity	—			77			—			77
Other investments	—			17.4			6.7			24.1
Total fair value of plan assets	$	3.1		$	643.8		$	6.7		$	653.6
	31-Dec-13
In millions	Level 1			Level 2			Level 3			Total
Cash and cash equivalents	$	1.8		$	5.9		$	—		$	7.7
Fixed income:
Corporate and non U.S. government	—			262.2			—			262.2
U.S. treasuries	—			75.5			—			75.5
Mortgage-backed securities	—			8.7			—			8.7
Other	—			34.1			—			34.1
Global equity securities:
Mid cap equity	—			7.3			—			7.3
Large cap equity	—			43.5			—			43.5
International equity	—			101.9			—			101.9
Long/short equity	—			0.6			—			0.6
Other investments	—			11.8			19			30.8
Total fair value of plan assets	$	1.8		$	551.5		$	19		$	572.3
Valuation methodologies used for investments measured at fair value were as follows:
•	Cash and cash equivalents: Cash consists of cash held in bank accounts and was classified as Level 1. Cash equivalents consist of investments in commingled funds valued based on observable market data. Such investments were classified as Level 2.
•	Fixed income: Investments in corporate bonds, government securities, mortgages and asset backed securities were valued based upon quoted market prices for similar securities and other observable market data. Investments in commingled funds were generally valued at the net asset value of units held at the end of the period based upon the value of the underlying investments as determined by quoted market prices or by a pricing service. Such investments were classified as Level 2.
•	Global equity securities: Investments in commingled funds were valued at the net asset value of units held at the end of the period based upon the value of the underlying investments as determined by quoted market prices or by a pricing service. Such investments were classified as Level 2.
•	Other investments: Other investments include investments in commingled funds with diversified investment strategies. Investments in commingled funds that were valued at the net asset value of units held at the end of the period based upon the value of the underlying investments as determined by quoted market prices or by a pricing service were classified as Level 2. Investments in commingled funds that were valued based on unobservable inputs due to liquidation restrictions were classified as Level 3.
The following tables present a reconciliation of Level 3 assets held during the years ended December 31, 2014 and 2013, respectively:
In millions	January 1,			Net realized			Net issuances			Net transfers			December 31, 2014
	2014			and unrealized			and			into (out of)
				gains (losses)			settlements			level 3
Other investments	$	19		$	0.7		$	(11.8	)	$	(1.2	)	$	6.7
In millions	January 1,			Net realized			Net issuances			Net transfers			December 31, 2013
	2013			and unrealized			and			into (out of)
				gains (losses)			settlements			level 3
Other investments	$	18.3		$	1.9		$	(1.2	)	$	—		$	19
Cash flows
Contributions
Pension contributions totaled $24.6 million and $30.8 million in 2014 and 2013, respectively. Our 2015 pension contributions are expected to be approximately $30.0 million to $35.0 million. The 2015 expected contributions will equal or exceed our minimum funding requirements.
Estimated future benefit payments
The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans for the years ended December 31 as follows:
In millions	U.S. pension			Non-U.S.			Other post-
	plans			pension plans			retirement
							plans
2015	$	10		$	15		$	3.4
2016	12.2			15.9			3.3
2017	13.7			17.1			3.2
2018	16.2			18.1			3.1
2019	18.7			18.9			3.1
Thereafter	109.7			108.4			13.8
Savings plan
We have a 401(k) plan (the "401(k) plan”) with an employee share ownership (“ESOP”) bonus component, which covers certain union and all non-union U.S. employees who meet certain age requirements. Under the 401(k) plan, eligible U.S. employees may voluntarily contribute a percentage of their eligible compensation. We match contributions made by employees who meet certain eligibility and service requirements. Our matching contribution is 100% of eligible employee contributions for the first 1% of eligible compensation and 50% of the next 5% of eligible compensation.
In addition to the matching contribution, all employees who meet certain service requirements receive a discretionary ESOP contribution equal to 1.5% of annual eligible compensation.
Additionally, we had a 401(k) plan acquired as part of the Merger (the "Flow 401(k) plan”) which covered certain union and all non-union U.S. employees who met certain age requirements. On December 31, 2013, the Flow 401(k) plan merged into the 401(k) plan and all employees covered by the Flow 401(k) plan became fully vested in their Flow 401(k) plan employer matching contributions and all future employer matching contributions were made under the 401(k) plan matching contribution formula. Under the Flow 401(k) plan, eligible U.S. employees could voluntarily contribute a percentage of their eligible compensation. We matched contributions made by employees who met certain eligibility and service requirements. Our matching contribution was 500% of eligible employee contributions for the first 1% of eligible compensation. Additional company match was based on years of service, as follows: an additional 1% match at 10 – 19 years of service, an additional 2% match at 20 – 24 years, an additional 3% match at 25 – 29 years and an additional 4% match at 30+ years. Participants were 100% vested in the employer match after 3 years of service.
Our combined expense for the 401(k) plan, the Flow 401(k) plan and the ESOP was $21.5 million, $26.8 million and $19.7 million in 2014, 2013 and 2012, respectively.
Other retirement compensation
Total other accrued retirement compensation, primarily related to deferred compensation and supplemental retirement plans, was $70.2 million and $53.3 million as of December 31, 2014 and 2013, respectively, and is included in Pension and other post-retirement compensation and benefits and Other non-current liabilities in the Consolidated Balance Sheets.
Multi-employer defined benefit plans
We participate in a number of multi-employer defined benefit plans on behalf of certain employees. Pension expense related to multi-employer plans was not material in 2014, 2013 and 2012.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2014
Shareholders' Equity	Shareholders’ Equity
	Authorized shares
	Our authorized share capital consists of 426.0 million ordinary shares with a par value of $0.01 per share.
	Share repurchases
	Prior to the closing of the Merger, our board of directors, and Tyco as our sole shareholder, authorized the repurchase of our ordinary shares with a maximum aggregate value of $400.0 million following the closing of the Merger. This authorization does not have an expiration date. On October 1, 2012, our board of directors authorized the repurchase of our ordinary shares with a maximum aggregate value of $800.0 million. This authorization expires on December 31, 2015 and is in addition to the $400.0 million share repurchase authorization. There is no remaining availability under these 2012 authorizations.
	In December 2013, the Board of Directors authorized the repurchase of our ordinary shares up to a maximum dollar limit of $1.0 billion. This authorization is in addition to the combined $1.2 billion 2012 share repurchase authorizations. The authorization expires on December 31, 2016.
	In December 2014, the Board of Directors authorized the repurchase of our ordinary shares up to a maximum dollar limit of $1.0 billion. This authorization is in addition to the 2012 and 2013 share repurchase authorizations. The authorization expires on December 31, 2019 and there were no repurchases made in 2014 under this authorization.
	During the year ended December 31, 2014, we repurchased 16.4 million of our ordinary shares for $1.2 billion pursuant to these authorizations and had no remaining availability for repurchases under the 2013 authorization.
	Dividends payable
	At our 2014 annual meeting of shareholders held on May 20, 2014, our shareholders approved a proposal to pay quarterly cash dividends through the second quarter of 2015. The authorization provided that dividends of $1.20 per share will be paid to our shareholders in quarterly installments of $0.30 for each of the third and fourth quarters of 2014 and first and second quarters of 2015. In December 2014, the Board of Directors approved an increase of $0.02 per share for the remaining dividends to be paid in the first and second quarters of 2015, bringing the total quarterly dividend for those quarters to $0.32 per share. As a result, the balance of dividends payable included in Other current liabilities on our Consolidated Balance Sheets was $116.8 million at December 31, 2014. Dividends paid per ordinary share were $1.10, $0.96 and $0.88 for the years ended December 31, 2014, 2013 and 2012, respectively.

Share_Plans

Share Plans	12 Months Ended
	Dec. 31, 2014
Share Plans	Share Plans
	Share-based compensation expense
	Total share-based compensation expense for 2014, 2013 and 2012 was as follows:
		31-Dec
	In millions	2014			2013			2012
	Restricted stock units	$	22.6		$	20.2		$	24.2
	Stock options	11			10.9			11.6
	Total share-based compensation expense	$	33.6		$	31.1		$	35.8
	The expense for 2012 included $13.5 million of expense due to the Merger triggering change of control provisions of Pentair, Inc. share-based compensation plans resulting in immediate vesting of certain outstanding awards.
	Share Incentive Plans
	Prior to the Merger, our board of directors approved, and Tyco as our sole shareholder approved, the Pentair plc 2012 Stock and Incentive Plan (the “2012 Plan”). The 2012 Plan became effective on September 28, 2012 and authorizes the issuance of 9.0 million of our ordinary shares. The shares may be issued as new shares or from shares held in treasury. Our practice is to settle equity-based awards from shares held in treasury. The 2012 Plan terminates in September 2022. The 2012 Plan allows for the granting to our officers, directors, employees and consultants of nonqualified stock options, incentive stock options, stock appreciation rights, performance shares, performance units, restricted shares, restricted stock units, deferred stock rights, annual incentive awards, dividend equivalent units and other equity-based awards.
	The 2012 Plan is administered by our compensation committee (the “Committee”), which is made up of independent members of our board of directors. Employees eligible to receive awards under the 2012 Plan are managerial, administrative or other key employees who are in a position to make a material contribution to the continued profitable growth and long-term success of our company. The Committee has the authority to select the recipients of awards, determine the type and size of awards, establish certain terms and conditions of award grants and take certain other actions as permitted under the 2012 Plan. The 2012 Plan prohibits the Committee from re-pricing awards or cancelling and reissuing awards at lower prices.
	The 2008 Omnibus Stock Incentive Plan as Amended and Restated (the “2008 Plan”) terminated upon the completion of the Merger. Prior grants of restricted stock units and stock options made under the 2008 Plan and earlier stock incentive plans outstanding at completion of the Merger were converted into equity-based awards with respect to our ordinary shares and were assumed by us on the terms in effect at the time of grant and are outstanding under the 2012 Plan.
	Non-qualified and incentive stock options
	Under the 2012 Plan, we may grant stock options to any eligible employee with an exercise price equal to the market value of the shares on the dates the options were granted. Options generally vest over a three-year period commencing on the grant date and expire ten years after the grant date.
	Restricted shares and restricted stock units
	Under the 2012 Plan, eligible employees may be awarded restricted shares or restricted stock units of our common stock. Restricted shares and restricted stock units generally vest three to four years after issuance, subject to continuous employment and certain other conditions. Restricted shares and restricted stock units are valued at market value on the date of grant and are expensed over the vesting period.
	Stock appreciation rights, performance shares and performance units
	Under the 2012 Plan, the Committee is permitted to issue these awards which are generally earned over a three-year vesting period and tied to specific financial metrics.
	Stock options
	The following table summarizes stock option activity under all plans for the year ended December 31, 2014:
	Shares and intrinsic value in millions	Number of shares		Weighted-			Weighted-	Aggregate
				average			average	intrinsic
				exercise			remaining	value
				price			contractual life
							(years)
	Outstanding as of January 1, 2014	6.2		$	35.53
	Granted	0.5		77.93
	Exercised	(0.9	)	35.53
	Forfeited	(0.1	)	49.29
	Outstanding as of December 31, 2014	5.7		$	39.08		5.1	$	157.8
	Options exercisable as of December 31, 2014	4.5		$	33.53		4.2	$	144
	Options expected to vest as of December 31, 2014	1.2		$	59.46		8.2	$	13.8
	Fair value of options granted
	The weighted average grant date fair value of options granted under Pentair plans in 2014, 2013 and 2012 was estimated to be $23.23, $13.96 and $9.63 per share, respectively. The weighted-average grant date fair value of options assumed in the Merger was estimated to be $11.76. The total intrinsic value of options that were exercised during 2014, 2013 and 2012 was $34.8 million, $68.9 million and $41.6 million, respectively. At December 31, 2014, the total unrecognized compensation cost related to stock options was $5.5 million. This cost is expected to be recognized over a weighted average period of 1.3 years.
	We estimated the fair value of each stock option award on the date of grant using a Black-Scholes option pricing model, modified for dividends and using the following weighted average assumptions:
		December 31
		2014			2013			2012
		Granted by			Granted by			Assumed in		Granted by
		Pentair plans			Pentair plans			Merger		Pentair plans
	Risk-free interest rate	1.44	%		0.69	%		0.02 - 0.68%		0.96	%
	Expected dividend yield	1.46	%		2.01	%		2.12	%	2.48	%
	Expected share price volatility	35.3	%		36	%		33	%	36.5	%
	Expected term (years)	5.6			5.7			0.1 - 5.1		5.7
	These estimates require us to make assumptions based on historical results, observance of trends in our share price, changes in option exercise behavior, future expectations and other relevant factors. If other assumptions had been used, share-based compensation expense, as calculated and recorded under the accounting guidance, could have been affected.
	We based the expected life assumption on historical experience as well as the terms and vesting periods of the options granted. For purposes of determining expected volatility, we considered a rolling average of historical volatility measured over a period approximately equal to the expected option term. The risk-free rate for periods that coincide with the expected life of the options is based on the U.S. Treasury Department yield curve in effect at the time of grant.
	Cash received from option exercises for the years ended December 31, 2014, 2013 and 2012 was $46.6 million, $102.3 million and $91.6 million, respectively. The actual tax benefit realized for the tax deductions from option exercises totaled $8.3 million, $23.5 million and $12.2 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Restricted stock units
	The following table summarizes restricted stock unit activity under all plans for the year ended December 31, 2014:
	Shares in millions	Number of		Weighted
		shares		average
				grant date
				fair value
	Outstanding as of January 1, 2014	1.3		$	43.25
	Granted	0.3		78.39
	Vested	(0.4	)	39.68
	Forfeited	(0.1	)	46.42
	Outstanding as of December 31, 2014	1.1		$	50.55
	As of December 31, 2014, there was $17.2 million of unrecognized compensation cost related to restricted share compensation arrangements granted under the 2012 Plan and previous plans. That cost is expected to be recognized over a weighted-average period of 1.3 years. The total fair value of shares vested during the years ended December 31, 2014, 2013 and 2012, was $26.3 million, $23.4 million and $58.0 million, respectively. The actual tax benefits realized related to restricted share compensation arrangements totaled $3.1 million, $7.2 million and $18.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Information	Segment Information
	We classify our operations into the following business segments based primarily on types of products offered and markets served:
	•	Valves & Controls — The Valves & Controls segment designs, manufactures, markets and services valves, fittings, automation and controls and actuators for the energy and industrial verticals and operates as a stand-alone Global Business Unit ("GBU").
	•	Process Technologies — The Process Technologies segment designs, manufactures, markets and services innovative water system products and solutions to meet filtration, separation and fluid process management challenges in food and beverage, water, wastewater, swimming pools and aquaculture applications. The Filtration & Process and Water Quality Systems GBUs comprise this segment.
	•	Flow Technologies — The Flow Technologies segment designs, manufactures and markets products and services designed for the transfer and flow of clean water, wastewater and a variety of industrial applications. The Flow Technologies segment operates as a stand-alone GBU.
	•	Technical Solutions — The Technical Solutions segment designs, manufactures, markets and services products that guard and protect some of the world’s most sensitive electronics and electronic equipment, as well as heat management solutions designed to provide thermal protection to temperature sensitive fluid applications. The Technical Solutions segment operates as a stand-alone GBU.
	•	Other — Other is primarily composed of unallocated corporate expenses, our captive insurance subsidiary and intermediate finance companies.
	During the first quarter of 2015, we reorganized our business segments to reflect a new operating structure and management of our GBUs, resulting in a change to our reporting segments in 2015. All segment information presented in this note and throughout this Annual Report on Form 10-K was prepared based on the reporting segments in place during 2014, unless otherwise noted.
	The accounting policies of our reporting segments are the same as those described in the summary of significant accounting policies. We evaluate performance based on the net sales and segment income (loss) and use a variety of ratios to measure performance of our reporting segments. These results are not necessarily indicative of the results of operations that would have occurred had each segment been an independent, stand-alone entity during the periods presented. Segment income (loss) represents operating income (loss) exclusive of certain acquisition related expenses, costs of restructuring activities, "mark-to-market" gain/loss for pension and other post-retirement plans, impairments and other unusual non-operating items.
	Financial information by reportable segment is included in the following summary:
		2014			2013			2012			2014			2013			2012
	In millions	Net sales									Segment income (loss)
	Valves & Controls	$	2,394.80		$	2,469.20		$	548.6		$	350.8		$	302.8		$	41.8
	Process Technologies	1,833.20			1,765.90			1,521.10			267.2			253.2			181.1
	Flow Technologies	1,106.60			1,131.60			1,025.50			138.5			132.3			104.7
	Technical Solutions	1,728.10			1,663.40			1,236.40			358.8			322.4			232.1
	Other	(23.7		)	(30.4		)	(24.8		)	(93.6		)	(108.4		)	(76.2		)
	Consolidated	$	7,039.00		$	6,999.70		$	4,306.80		$	1,021.70		$	902.3		$	483.5
		2014			2013				2014		2013			2012
	In millions	Identifiable assets (1)							Depreciation
	Valves & Controls	$	4,049.90		$	4,204.00			$	59	$	64		$	15.1
	Process Technologies	2,586.90			2,730.60				31.1		29.2			29.2
	Flow Technologies	1,276.70			1,426.40				14.5		14.5			14
	Technical Solutions	2,117.30			2,093.40				24.2		23.6			18.9
	Other	624.4			1,288.90				9.9		10			8
	Consolidated	$	10,655.20		$	11,743.30			$	138.7	$	141.3		$	85.2
		2014			2013			2012			2014			2013			2012
	In millions	Amortization									Capital expenditures
	Valves & Controls	$	53.4		$	69.3		$	21.7		$	45.9		$	67.2		$	21.9
	Process Technologies	27.2			26			24.4			30			45.2			31.2
	Flow Technologies	13.5			13.6			12.5			15.5			26.2			18.7
	Technical Solutions	19.9			25.2			16.2			24			16.2			13.5
	Other	—			—			0.1			14.2			15.2			9.2
	Consolidated	$	114		$	134.1		$	74.9		$	129.6		$	170		$	94.5
	-1	All cash and cash equivalents and assets held for sale are included in “Other.”
	The following table presents a reconciliation of consolidated segment income to consolidated operating income (loss):
	In millions	2014			2013			2012
	Segment income	$	1,021.70		$	902.3		$	483.5
	Deal related costs and expenses	—			—			(82.8		)
	Inventory step-up and customer backlog	—			(86.6		)	(157.7		)
	Restructuring and other	(109.6		)	(119.9		)	(45.4		)
	Pension and other post-retirement mark-to-market gain (loss)	(49.9		)	63.2			(141.7		)
	Trade name impairment	—			(11.0		)	(60.7		)
	Redomicile related expenses	(10.3		)	(5.4		)	—
	Operating income (loss)	$	851.9		$	742.6		$	(4.8	)
	The following tables present certain geographic information by region:
		2014			2013			2012			2014			2013
	In millions	Net sales									Long-lived assets
	U.S.	$	3,541.10		$	3,431.30		$	2,624.30		$	350		$	365.4
	Western Europe	1,701.00			1,795.30			909.1			340			393.9
	Fast Growth	998.5			921.6			473.8			180.9			193.3
	Other Developed	798.4			851.5			299.6			79.1			91.7
	Consolidated	$	7,039.00		$	6,999.70		$	4,306.80		$	950		$	1,044.30
	Net sales are based on the location in which the sale originated. Long-lived assets represent property, plant and equipment, net of related depreciation.
	We offer a broad array of products and systems to multiple markets and customers for which we do not have the information systems to track revenues by primary product category. However, our net sales by segment are representative of our sales by major product category. We sell our products through various distribution channels including wholesale and retail distributors, original equipment manufacturers and home centers. No customer accounted for more than 10% of net sales in 2014, 2013, or 2012.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies	Commitments and Contingencies
	Operating lease commitments
	Net rental expense under operating leases was as follows:
		Years ended December 31
	In millions	2014			2013			2012
	Gross rental expense	$	68.7		$	76		$	44.6
	Sublease rental income	(1.3		)	(0.9		)	(0.5		)
	Net rental expense	$	67.4		$	75.1		$	44.1
	Future minimum lease commitments under non-cancelable operating leases, principally related to facilities, machinery, equipment and vehicles as of December 31, 2014 were as follows:
	In millions	2015			2016			2017			2018			2019			Thereafter		Total
	Minimum lease payments	$	52.4		$	40.1		$	31.2		$	19.7		$	15.7		$	19.1	$	178.2
	Minimum sublease rentals	(0.5		)	(0.4		)	(0.4		)	(0.4		)	(0.4		)	—		(2.1		)
	Net future minimum lease commitments	$	51.9		$	39.7		$	30.8		$	19.3		$	15.3		$	19.1	$	176.1
	Asbestos Matters
	Our subsidiaries and numerous other companies are named as defendants in personal injury lawsuits based on alleged exposure to asbestos-containing materials. These cases typically involve product liability claims based primarily on allegations of manufacture, sale or distribution of industrial products that either contained asbestos or were attached to or used with asbestos-containing components manufactured by third-parties. Each case typically names between dozens to hundreds of corporate defendants. While we have observed an increase in the number of these lawsuits over the past several years, including lawsuits by plaintiffs with mesothelioma-related claims, a large percentage of these suits have not presented viable legal claims and, as a result, have been dismissed by the courts. Our historical strategy has been to mount a vigorous defense aimed at having unsubstantiated suits dismissed, and, where appropriate, settling suits before trial. Although a large percentage of litigated suits have been dismissed, we cannot predict the extent to which we will be successful in resolving lawsuits in the future.
	As of December 31, 2014, there were approximately 3,400 claims outstanding against our subsidiaries. This amount includes adjustments for claims that are not actively being prosecuted. This amount is not adjusted for claims that identify incorrect defendants, or duplicate other actions. In addition, the amount does not include certain claims pending against third parties for which we have been provided an indemnification.
	Periodically, we perform an analysis with the assistance of outside counsel and other experts to update our estimated asbestos-related assets and liabilities. Our estimate of the liability and corresponding insurance recovery for pending and future claims and defense costs is based on our historical claim experience and estimates of the number and resolution cost of potential future claims that may be filed. Our legal strategy for resolving claims also impacts these estimates.
	Our estimate of asbestos-related insurance recoveries represents estimated amounts due to us for previously paid and settled claims and the probable reimbursements relating to our estimated liability for pending and future claims. In determining the amount of insurance recoverable, we consider a number of factors, including available insurance, allocation methodologies and the solvency and creditworthiness of insurers.
	Our estimated liability for asbestos-related claims was $249.1 million and $254.7 million as of December 31, 2014 and 2013, respectively, and was recorded in Other non-current liabilities in the Consolidated Balance Sheets for pending and future claims and related defense costs. Our estimated receivable for insurance recoveries was $115.8 million and $119.6 million, respectively, at December 31, 2014 and 2013 and was recorded in Other non-current assets in the Consolidated Balance Sheets.
	The amounts recorded by us for asbestos-related liabilities and insurance-related assets are based on our strategies for resolving our asbestos claims and currently available information as well as estimates and assumptions. Key variables and assumptions include the number and type of new claims filed each year, the average cost of resolution of claims, the resolution of coverage issues with insurance carriers, the amounts of insurance and the related solvency risk with respect to our insurance carriers, and the indemnifications we have provided to third parties. Furthermore, predictions with respect to these variables are subject to greater uncertainty in the latter portion of the projection period. Other factors that may affect our liability and cash payments for asbestos-related matters include uncertainties surrounding the litigation process from jurisdiction to jurisdiction and from case to case, reforms of state or federal tort legislation and the applicability of insurance policies among subsidiaries. As a result, actual liabilities or insurance recoveries could be significantly higher or lower than those recorded if assumptions used in our calculations vary significantly from actual results.
	Environmental Matters
	We are involved in or have retained responsibility and potential liability for environmental obligations and legal proceedings related to our current business and, including pursuant to certain indemnification obligations, related to certain formerly owned businesses. We are responsible, or alleged to be responsible, for ongoing environmental investigation and/or remediation of sites in several countries. These sites are in various stages of investigation and/or remediation and at some of these sites our liability is considered de minimis. We received notification from the U.S. Environmental Protection Agency and from similar state and non-U.S. environmental agencies, that several sites formerly or currently owned and/or operated by us, and other properties or water supplies that may be or may have been impacted from those operations, contain disposed or recycled materials or waste and require environmental investigation and/or remediation. Those sites include instances where we have been identified as a potentially responsible party under U.S. federal, state and/or non-U.S. environmental laws and regulations. For several formerly owned businesses, we have also received claims for indemnification from purchasers of these businesses.
	Our accruals for environmental matters are recorded on a site-by-site basis when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated, based on current law and existing technologies. It can be difficult to estimate reliably the final costs of investigation and remediation due to various factors. In our opinion, the amounts accrued are appropriate based on facts and circumstances as currently known. Based upon our experience, current information regarding known contingencies and applicable laws, we have recorded reserves for these environmental matters of $31.4 million and $34.8 million as of December 31, 2014 and 2013, respectively. We do not anticipate these environmental conditions will have a material adverse effect on our financial position, results of operations or cash flows. However, unknown conditions, new details about existing conditions or changes in environmental requirements may give rise to environmental liabilities that will exceed the amount of our current reserves and could have a material adverse effect in the future.
	Compliance Matters
	Prior to the Merger, the Flow Control business was subject to investigations by the U.S. Department of Justice (“DOJ”) and the SEC related to allegations that improper payments were made by the Flow Control business and other Tyco subsidiaries and third-party intermediaries in recent years in violation of the Foreign Corrupt Practices Act. Tyco reported to the DOJ and the SEC the remedial measures that it had taken in response to the allegations and Tyco’s own internal investigations. As a result of discussions with the DOJ and SEC aimed at resolving these matters, on September 24, 2012, Tyco entered into a settlement with the SEC and a non-prosecution agreement with the DOJ, pursuant to which the Flow Control business is for a three year period subject to yearly reporting to the DOJ concerning its continuing compliance efforts.
	Other Matters
	In addition to the matters described above, from time to time, we are subject to disputes, administrative proceedings and other claims arising out of the normal conduct of our business. These matters generally relate to disputes arising out of the use or installation of our products, product liability litigation, personal injury claims, commercial and contract disputes and employment related matters. On the basis of information currently available to it, management does not believe that existing proceedings and claims will have a material impact on our Consolidated Financial Statements. However, litigation is unpredictable, and we could incur judgments or enter into settlements for current or future claims that could adversely affect our financial statements.
	Warranties and guarantees
	In connection with the disposition of our businesses or product lines, we may agree to indemnify purchasers for various potential liabilities relating to the sold business, such as pre-closing tax, product liability, warranty, environmental, or other obligations. The subject matter, amounts and duration of any such indemnification obligations vary for each type of liability indemnified and may vary widely from transaction to transaction.
	Generally, the maximum obligation under such indemnifications is not explicitly stated and as a result, the overall amount of these obligations cannot be reasonably estimated. Historically, we have not made significant payments for these indemnifications. We believe that if we were to incur a loss in any of these matters, the loss would not have a material effect on our financial condition or results of operations.
	We recognize, at the inception of a guarantee, a liability for the fair value of the obligation undertaken in issuing the guarantee.
	We provide service and warranty policies on our products. Liability under service and warranty policies is based upon a review of historical warranty and service claim experience. Adjustments are made to accruals as claim data and historical experience warrant.
	The changes in the carrying amount of service and product warranties for the years ended December 31, 2014 and 2013 were as follows:
		Years ended December 31
	In millions	2014			2013
	Beginning balance	$	56		$	52.5
	Service and product warranty provision	75.3			64.1
	Payments	(62.1		)	(60.8		)
	Foreign currency translation	(2.8		)	0.2
	Ending balance	$	66.4		$	56
	Subsequent to December 31, 2014, we became aware of a potential warranty issue related to certain product sold by Process Technologies, resulting in an increase to our warranty reserve of $13.0 million.
	Stand-by Letters of Credit, Bank Guarantees and Bonds
	In certain situations, Tyco guaranteed Flow Control’s performance to third parties or provided financial guarantees for financial commitments of Flow Control. In situations where Flow Control and Tyco were unable to obtain a release from these guarantees in connection with the spin-off of Flow Control from Tyco, we will indemnify Tyco for any losses it suffers as a result of such guarantees.
	In disposing of assets or businesses, we often provide representations, warranties and indemnities to cover various risks including unknown damage to the assets, environmental risks involved in the sale of real estate, liability to investigate and remediate environmental contamination at waste disposal sites and manufacturing facilities and unidentified tax liabilities and legal fees related to periods prior to disposition. We do not have the ability to reasonably estimate the potential liability due to the inchoate and unknown nature of these potential liabilities. However, we have no reason to believe that these uncertainties would have a material adverse effect on our financial position, results of operations or cash flows.
	In the ordinary course of business, we are required to commit to bonds, letters of credit and bank guarantees that require payments to our customers for any non-performance. The outstanding face value of these instruments fluctuates with the value of our projects in process and in our backlog. In addition, we issue financial stand-by letters of credit primarily to secure our performance to third parties under self-insurance programs.
	As of December 31, 2014 and 2013, the outstanding value of bonds, letters of credit and bank guarantees totaled $370.1 million and $484.0 million, respectively, of which $32.4 million and $25.3 million, respectively, relate to the Water Transport business.

Selected_Quarterly_Data

Selected Quarterly Data	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Data	Selected Quarterly Data (Unaudited)
	The selected quarterly financial data does not agree to our previously issued quarterly reports prior to the third quarter of 2014 as a result of the reclassification of our Water Transport business to discontinued operations during the third quarter of 2014. See Note 3 for further discussion of discontinued operations. The following tables present 2014 and 2013 quarterly financial information:
		2014
	In millions, except per-share data	First			Second		Third			Fourth			Full
		Quarter			Quarter		Quarter			Quarter			Year
	Net sales	$	1,644.00		$	1,834.10	$	1,758.40		$	1,802.50		$	7,039.00
	Gross profit	564.1			646.3		624.7			627.9			2,463.00
	Operating income	182.1			226.4		267.4			176			851.9
	Net income from continuing operations	125.5			159.2		192.5			129.8			607
	Income (loss) from discontinued operations, net of tax	(1.3		)	2.3		1.6			(9.0		)	(6.4		)
	Loss from sale / impairment of discontinued operations, net of tax	(5.6		)	—		(380.1		)	—			(385.7		)
	Net income (loss) attributable to Pentair plc	118.6			161.5		(186.0		)	120.8			214.9
	Earnings (loss) per ordinary share attributable to Pentair plc (1)
	Basic
	Continuing operations	$	0.64		$	0.82	$	1.01		$	0.71		$	3.19
	Discontinued operations	(0.04		)	0.02		(1.99		)	(0.05		)	(2.06		)
	Basic earnings (loss) per ordinary share attributable to Pentair plc	$	0.6		$	0.84	$	(0.98	)	$	0.66		$	1.13
	Diluted
	Continuing operations	$	0.63		$	0.81	$	1		$	0.7		$	3.14
	Discontinued operations	(0.04		)	0.01		(1.95		)	(0.05		)	(2.03		)
	Diluted earnings (loss) per ordinary share attributable to Pentair plc	$	0.59		$	0.82	$	(0.95	)	$	0.65		$	1.11
		2013
	In millions, except per-share data	First			Second		Third			Fourth			Full
		Quarter			Quarter		Quarter			Quarter			Year
	Net sales	$	1,663.70		$	1,791.70	$	1,713.30		$	1,831.00		$	6,999.70
	Gross profit	497.5			627.4		614.7			630.5			2,370.10
	Operating income	66.4			204.9		230			241.3			742.6
	Net income from continuing operations before noncontrolling interest	46.8			139.9		166.4			164.4			517.5
	Income (loss) from discontinued operations, net of tax	6.5			15.5		7.8			(3.9		)	25.9
	Loss from sale / impairment of discontinued operations, net of tax	—			—		—			(0.8		)	(0.8		)
	Net income attributable to Pentair plc	51.7			154.1		172.8			158.2			536.8
	Net income from continuing operations attributable to Pentair plc	45.2			138.6		165			162.9			511.7
	Earnings (loss) per ordinary share attributable to Pentair plc (1)
	Basic
	Continuing operations	$	0.22		$	0.69	$	0.83		$	0.82		$	2.54
	Discontinued operations	0.03			0.07		0.04			(0.02		)	0.13
	Basic earnings per ordinary share attributable to Pentair plc	$	0.25		$	0.76	$	0.87		$	0.8		$	2.67
	Diluted
	Continuing operations	$	0.22		$	0.67	$	0.81		$	0.81		$	2.5
	Discontinued operations	0.03			0.08		0.04			(0.03		)	0.12
	Diluted earnings per ordinary share attributable to Pentair plc	$	0.25		$	0.75	$	0.85		$	0.78		$	2.62
	-1	Amounts may not total to annual earnings because each quarter and year are calculated separately based on basic and diluted weighted-average ordinary shares outstanding during that period.
	Fourth quarter 2014 includes a decrease in operating income of $49.9 million related to "mark-to-market" actuarial losses on pension and other post-retirement benefit plans for 2014. Fourth quarter 2014 also includes decreases in operating income due to restructuring costs of $35.5 million.
	Second quarter 2014 includes decreases in operating income due to restructuring costs of $35.4 million. First quarter 2014 includes decreases in operating income due to restructuring costs of $17.4 million.
	Fourth quarter 2013 includes an increase in operating income of $63.2 million related to "mark-to-market" actuarial gains on pension and other post-retirement benefit plans for 2013. Fourth quarter 2013 also includes decreases in operating income due to restructuring costs of $54.1 million and impairment charges of $11.0 million related to trade name intangibles.
	First quarter 2013 includes a decrease in operating income of $76.6 million due to inventory step-up and customer backlog related to the Merger and restructuring costs of $26.6 million.

Financial_Statements_of_Parent

Financial Statements of Parent Company Guarantor	12 Months Ended
	Dec. 31, 2014
Financial Statements of Parent Company Guarantor	ective upon the Redomicile, Pentair plc (the “Parent Company Guarantor”) and Pentair Investments Switzerland GmbH (the "Subsidiary Guarantor"), fully and unconditionally, guarantee the 1.35% Senior Notes due 2015, 1.875% Senior Notes due 2017, 2.65% Senior Notes due 2019, 5.00% Senior Notes due 2021 and 3.15% Senior Notes due 2022 (collectively, the “Notes”) of Pentair Finance S.A. (the “Subsidiary Issuer”). The Subsidiary Guarantor is a Switzerland limited liability company formed in April 2014 and 100 percent-owned subsidiary of the Parent Company Guarantor. The Subsidiary Issuer is a Luxembourg public limited liability company formed in January 2012 and 100 percent-owned subsidiary of the Subsidiary Guarantor. The guarantees provided by the Parent Company Guarantor and Subsidiary Guarantor are joint and several.
	The following supplemental financial information sets forth the Company's Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) and Condensed Consolidating Statement of Cash Flows for the years ended December 31, 2014, 2013 and 2012 and Condensed Consolidating Balance Sheet as of December 31, 2014 and 2013. The guarantees provided by the Parent Company Guarantor and Subsidiary Guarantor are joint and several. Condensed Consolidating financial information for Pentair plc, Pentair Investments Switzerland GmbH and Pentair Finance S.A. on a stand-alone basis is presented using the equity method of accounting for subsidiaries.
	Prior to the Redomicile, the Notes of the Subsidiary Issuer were guaranteed, fully and unconditionally, by the former parent company, Pentair Ltd. The supplemental financial information for the reporting periods prior to Redomicile are presented under this previous guarantee structure.
	Pentair plc and Subsidiaries
	Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)
	Year Ended December 31, 2014
	In millions	Parent			Subsidiary Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
		Company						Issuer			Subsidiaries
		Guarantor
	Net sales	$	—		$	—		$	—		$	7,039.00		$	—		$	7,039.00
	Cost of goods sold	—			—			—			4,576.00			—			4,576.00
	Gross profit	—			—			—			2,463.00			—			2,463.00
	Selling, general and administrative	25.3			2.6			7.7			1,458.20			—			1,493.80
	Research and development	—			—			—			117.3			—			117.3
	Operating (loss) income	(25.3		)	(2.6		)	(7.7		)	887.5			—			851.9
	Loss (earnings) from continuing operations of investment in subsidiaries	(615.5		)	(619.7		)	(611.1		)	—			1,846.30			—
	Other (income) expense:
	Loss on sale of businesses, net	—			—			—			0.2			—			0.2
	Equity income of unconsolidated subsidiaries	—			—			—			(1.2		)	—			(1.2		)
	Interest income	—			—			(92.3		)	(40.2		)	128.8			(3.7		)
	Interest expense	0.7			2.1			95.6			102.7			(128.8		)	72.3
	Income (loss) from continuing operations before income taxes	589.5			615			600.1			826			(1,846.3		)	784.3
	Provision (benefit) for income taxes	(17.5		)	(0.5		)	(2.4		)	197.7			—			177.3
	Net income (loss) from continuing operations	607			615.5			602.5			628.3			(1,846.3		)	607
	Loss from discontinued operations, net of tax	—			—			—			(6.4		)	—			(6.4		)
	Loss from sale / impairment of discontinued operations, net of tax	—			—			—			(385.7		)	—			(385.7		)
	Earnings (loss) from discontinued operations of investment in subsidiaries	(392.1		)	(392.1		)	(392.1		)	—			1,176.30			—
	Net income (loss) attributable to Pentair plc	$	214.9		$	223.4		$	210.4		$	236.2		$	(670.0	)	$	214.9
	Comprehensive income (loss), net of tax
	Net income (loss) attributable to Pentair plc	$	214.9		$	223.4		$	210.4		$	236.2		$	(670.0	)	$	214.9
	Changes in cumulative translation adjustment	(336.3		)	(336.3		)	(336.3		)	(336.3		)	1,008.90			(336.3		)
	Changes in market value of derivative financial instruments	(0.4		)	(0.4		)	(0.4		)	(0.4		)	1.2			(0.4		)
	Comprehensive income (loss) attributable to Pentair plc	$	(121.8	)	$	(113.3	)	$	(126.3	)	$	(100.5	)	$	340.1		$	(121.8	)
	Pentair plc and Subsidiaries
	Condensed Consolidating Balance Sheet
	December 31, 2014
	In millions	Parent			Subsidiary Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
		Company						Issuer			Subsidiaries
		Guarantor
	Assets
	Current assets
	Cash and cash equivalents	$	—		$	—		$	0.1		$	110.3		$	—		$	110.4
	Accounts and notes receivable, net	—			—			—			1,206.80			(0.9		)	1,205.90
	Inventories	—			—			—			1,130.40			—			1,130.40
	Other current assets	—			17.6			2			367.6			(20.4		)	366.8
	Current assets held for sale	—			—			—			80.6			—			80.6
	Total current assets	—			17.6			2.1			2,895.70			(21.3		)	2,894.10
	Property, plant and equipment, net	—			—			—			950			—			950
	Other assets
	Investments in subsidiaries	4,733.00			4,893.80			7,612.20			—			(17,239.0		)	—
	Goodwill	—			—			—			4,741.90			—			4,741.90
	Intangibles, net	—			—			—			1,608.10			—			1,608.10
	Other non-current assets	80.2			—			1,381.80			345			(1,370.8		)	436.2
	Non-current assets held for sale	—			—			—			24.9			—			24.9
	Total other assets	4,813.20			4,893.80			8,994.00			6,719.90			(18,609.8		)	6,811.10
	Total assets	$	4,813.20		$	4,911.40		$	8,996.10		$	10,565.60		$	(18,631.1	)	$	10,655.20
	Liabilities and Equity
	Current liabilities
	Current maturities of long-term debt and short-term borrowings	$	—		$	—		$	—		$	6.7		$	—		$	6.7
	Accounts payable	0.9			—			—			583.1			(0.9		)	583.1
	Employee compensation and benefits	0.2			0.6			—			304.7			—			305.5
	Other current liabilities	120.6			2.2			10.9			595.8			(20.4		)	709.1
	Current liabilities held for sale	—			—			—			35.1			—			35.1
	Total current liabilities	121.7			2.8			10.9			1,525.40			(21.3		)	1,639.50
Other liabilities
Long-term debt	11.4			175.6			2,860.60			1,320.60			(1,370.8		)	2,997.40
Pension and other post-retirement compensation and benefits	—			—			—			322			—			322
Deferred tax liabilities	—			—			2.9			525.4			—			528.3
Other non-current liabilities	16.3			—			—			481.4			—			497.7
Non-current liabilities held for sale	—			—			—			6.5			—			6.5
Total liabilities	149.4			178.4			2,874.40			4,181.30			(1,392.1		)	5,991.40
Equity	4,663.80			4,733.00			6,121.70			6,384.30			(17,239.0		)	4,663.80
Total liabilities and equity	$	4,813.20		$	4,911.40		$	8,996.10		$	10,565.60		$	(18,631.1	)	$	10,655.20
Pentair plc and Subsidiaries
Condensed Consolidating Statement of Cash Flows
Year Ended December 31, 2014
In millions	Parent			Guarantor Subsidiary			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
	Company						Issuer			Subsidiaries
	Guarantor
Operating activities
Net cash provided by (used for) operating activities	$	169		$	208.6		$	207		$	1,093.80		$	(670.0	)	$	1,008.40
Investing activities
Capital expenditures	—			—			—			(129.6		)	—			(129.6		)
Proceeds from sale of property and equipment	—			—			—			13.1			—			13.1
Proceeds from sale of businesses, net	—			—			—			0.3			—			0.3
Acquisitions, net of cash acquired	—			—			—			(12.3		)	—			(12.3		)
Net intercompany loan activity	—			—			37.8			112.2			(150.0		)	—
Other	—			—			—			0.2			—			0.2
Net cash provided by (used for) investing activities	—			—			37.8			(16.1		)	(150.0		)	(128.3		)
Financing activities
Net receipts of short-term borrowings	—			—			—			0.5			—			0.5
Net receipts of commercial paper and revolving long-term debt	—			—			458.7			9.9			—			468.6
Proceeds from long-term debt	—			—			—			2.2			—			2.2
Repayment of long-term debt	—			—			—			(16.8		)	—			(16.8		)
Debt issuance costs	—			—			(3.1		)	—			—			(3.1		)
Net change in advances to subsidiaries	741.1			(208.6		)	(747.3		)	(605.2		)	820			—
Excess tax benefits from share-based compensation	—			—			—			12.6			—			12.6
Shares issued to employees, net of shares withheld	—			—			—			37			—			37
Repurchases of ordinary shares	(699.2		)	—			—			(450.8		)	—			(1,150.0		)
Dividends paid	(211.4		)	—			—			—			—			(211.4		)
Purchase of noncontrolling interest	—			—			—			(134.7		)	—			(134.7		)
Net cash provided by (used for) financing activities	(169.5		)	(208.6		)	(291.7		)	(1,145.3		)	820			(995.1		)
Effect of exchange rate changes on cash and cash equivalents	—			—			—			(30.6		)	—			(30.6		)
Change in cash and cash equivalents	(0.5		)	—			(46.9		)	(98.2		)	—			(145.6		)
Cash and cash equivalents, beginning of year	0.5			—			47			208.5			—			256
Cash and cash equivalents, end of year	$	—		$	—		$	0.1		$	110.3		$	—		$	110.4
Pentair plc and Subsidiaries
Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)
Year Ended December 31, 2013
In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
	Company			Issuer			Subsidiaries
	Guarantor
Net sales	$	—		$	—		$	6,999.70		$	—		$	6,999.70
Cost of goods sold	—			—			4,629.60			—			4,629.60
Gross profit	—			—			2,370.10			—			2,370.10
Selling, general and administrative	21			13.3			1,459.40			—			1,493.70
Research and development	—			—			122.8			—			122.8
Impairment of trade names	—			—			11			—			11
Operating (loss) income	(21.0		)	(13.3		)	776.9			—			742.6
Loss (earnings) from continuing operations of investment in subsidiaries	(539.0		)	(508.6		)	—			1,047.60			—
Other (income) expense:
Gain on sale of businesses, net	—			—			(20.8		)	—			(20.8		)
Equity income of unconsolidated subsidiaries	—			—			(2.0		)	—			(2.0		)
Interest income	—			(99.2		)	(53.4		)	148.2			(4.4		)
Interest expense	5.6			106			111.9			(148.2		)	75.3
Income (loss) from continuing operations before income taxes and noncontrolling interest	512.4			488.5			741.2			(1,047.6		)	694.5
Provision for income taxes	0.7			1.4			174.9			—			177
Net income (loss) from continuing operations before noncontrolling interest	511.7			487.1			566.3			(1,047.6		)	517.5
Income from discontinued operations, net of tax	—			—			25.9			—			25.9
Loss from sale of discontinued operations, net of tax	—			—			(0.8		)	—			(0.8		)
Earnings (loss) from discontinued operations of investment in subsidiaries	25.1			25.1			—			(50.2		)	—
Net income (loss) before noncontrolling interest	536.8			512.2			591.4			(1,097.8		)	542.6
Noncontrolling interest	—			—			5.8			—			5.8
Net income (loss) attributable to Pentair plc	$	536.8		$	512.2		$	585.6		$	(1,097.8	)	$	536.8
Net income (loss) from continuing operations attributable to Pentair plc	$	511.7		$	487.1		$	560.5		$	(1,047.6	)	$	511.7
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest	$	536.8		$	512.2		$	591.4		$	(1,097.8	)	$	542.6
Changes in cumulative translation adjustment	(31.3		)	(31.3		)	(29.1		)	62.6			(29.1		)
Amortization of pension and other post-retirement prior service cost	(0.4		)	(0.4		)	(0.4		)	0.8			(0.4		)
Changes in market value of derivative financial instruments	(0.3		)	(0.3		)	(0.3		)	0.6			(0.3		)
Total comprehensive income (loss)	504.8			480.2			561.6			(1,033.8		)	512.8
Less: Comprehensive income (loss) attributable to noncontrolling interest	—			—			8			—			8
Comprehensive income (loss) attributable to Pentair plc	$	504.8		$	480.2		$	553.6		$	(1,033.8	)	$	504.8
Pentair plc and Subsidiaries
Condensed Consolidating Balance Sheet
December 31, 2013
In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
	Company			Issuer			Subsidiaries
	Guarantor
Assets
Current assets
Cash and cash equivalents	$	0.5		$	47		$	208.5		$	—		$	256
Accounts and notes receivable, net	2.9			4			1,341.70			(63.6		)	$	1,285.00
Inventories	—			—			1,195.10			—			$	1,195.10
Other current assets	1.4			0.6			359.6			—			$	361.6
Current assets held for sale	—			—			134.4			—			$	134.4
Total current assets	4.8			51.6			3,239.30			(63.6		)	3,232.10
Property, plant and equipment, net	—			—			1,044.30			—			1,044.30
Other assets
Investments in subsidiaries	6,224.70			8,066.60			—			(14,291.3		)	—
Goodwill	—			—			4,860.70			—			4,860.70
Intangibles, net	—			—			1,749.90			—			1,749.90
Other non-current assets	31.6			1,302.70			352.4			(1,296.7		)	390
Non-current assets held for sale	—			—			466.3			—			466.3
Total other assets	6,256.30			9,369.30			7,429.30			(15,588.0		)	7,466.90
Total assets	$	6,261.10		$	9,420.90		$	11,712.90		$	(15,651.6	)	$	11,743.30
Liabilities and Equity
Current liabilities
Current maturities of long-term debt and short-term borrowings	$	—		$	—		$	2.5		$	—		$	2.5
Accounts payable	48.1			8.6			583.8			(63.6		)	576.9
Employee compensation and benefits	0.5			—			311.9			—			312.4
Other current liabilities	99.6			11.7			534.6			—			645.9
Current liabilities held for sale	—			—			72.5			—			72.5
Total current liabilities	148.2			20.3			1,505.30			(63.6		)	1,610.20
Other liabilities
Long-term debt	—			2,401.90			1,442.70			(1,296.7		)	2,547.90
Pension and other post-retirement compensation and benefits	—			—			320.2			—			320.2
Deferred tax liabilities	—			2.2			554.8			—			557
Other non-current liabilities	17.6			—			438.8			—			456.4
Non-current liabilities held for sale	—			—			33.9			—			33.9
Total liabilities	165.8			2,424.40			4,295.70			(1,360.3		)	5,525.60
Equity
Shareholders’ equity attributable to Pentair plc and subsidiaries	6,095.30			6,996.50			7,294.80			(14,291.3		)	6,095.30
Noncontrolling interest	—			—			122.4			—			122.4
Total equity	6,095.30			6,996.50			7,417.20			(14,291.3		)	6,217.70
Total liabilities and equity	$	6,261.10		$	9,420.90		$	11,712.90		$	(15,651.6	)	$	11,743.30
Pentair plc and Subsidiaries
Condensed Consolidating Statement of Cash Flows
Year Ended December 31, 2013
In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
	Company			Issuer			Subsidiaries
	Guarantor
Operating activities
Net cash provided by (used for) operating activities	$	534.2		$	514		$	977.5		$	(1,097.8	)	$	927.9
Investing activities
Capital expenditures	—			—			(170.0		)	—			(170.0		)
Proceeds from sale of property and equipment	—			—			6			—			6
Proceeds from sale of businesses, net	—			—			43.5			—			43.5
Acquisitions, net of cash acquired	—			—			(92.4		)	—			(92.4		)
Other	—			—			1.7			—			1.7
Net cash provided by (used for) investing activities	—			—			(211.2		)	—			(211.2		)
Financing activities
Net receipts of commercial paper and revolving long-term debt	—			104.2			—			—			104.2
Proceeds from long-term debt	—			—			0.7			—			0.7
Repayment of long-term debt	—			—			(7.4		)	—			(7.4		)
Debt issuance costs	—			(1.4		)	—			—			(1.4		)
Net change in advances to subsidiaries	(339.5		)	(569.8		)	(188.5		)	1,097.80			—
Excess tax benefits from share-based compensation	—			—			16.8			—			16.8
Shares issued to employees, net of shares withheld	—			—			80			—			80
Repurchases of ordinary shares	—			—			(715.8		)	—			(715.8		)
Dividends paid	(194.2		)	—			—			—			(194.2		)
Distributions to noncontrolling interest	—			—			(2.0		)	—			(2.0		)
Net cash provided by (used for) financing activities	(533.7		)	(467.0		)	(816.2		)	1,097.80			(719.1		)
Effect of exchange rate changes on cash and cash equivalents	—			—			21			—			21
Change in cash and cash equivalents	0.5			47			(28.9		)	—			18.6
Cash and cash equivalents, beginning of year	—			—			237.4			—			237.4
Cash and cash equivalents, end of year	$	0.5		$	47		$	208.5		$	—		$	256
Pentair plc and Subsidiaries
Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)
Year Ended December 31, 2012
In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
	Company			Issuer			Subsidiaries
	Guarantor
Net sales	$	—		$	—		$	4,306.80		$	—		$	4,306.80
Cost of goods sold	—			—			3,040.90			—			3,040.90
Gross profit	—			—			1,265.90			—			1,265.90
Selling, general and administrative	5			(3.8		)	1,116.50			—			1,117.70
Research and development	—			—			92.3			—			92.3
Impairment of trade names	—			—			60.7			—			60.7
Operating (loss) income	(5.0		)	3.8			(3.6		)	—			(4.8		)
Loss (earnings) from continuing operations of investment in subsidiaries	75.7			76.6			—			(152.3		)	—
Other (income) expense:
Loss on early extinguishment of debt	—			—			75.4			—			75.4
Equity income of unconsolidated subsidiaries	—			—			(2.3		)	—			(2.3		)
Interest income	—			(9.2		)	(2.0		)	9.2			(2.0		)
Interest expense	0.1			10.2			69.1			(9.2		)	70.2
Income (loss) from continuing operations before income taxes and noncontrolling interest	(80.8		)	(73.8		)	(143.8		)	152.3			(146.1		)
Provision (benefit) for income taxes	0.7			1.1			(69.0		)	—			(67.2		)
Net income (loss) from continuing operations before noncontrolling interest	(81.5		)	(74.9		)	(74.8		)	152.3			(78.9		)
Loss from discontinued operations, net of tax	—			—			(25.7		)	—			(25.7		)
Earnings (loss) from discontinued operations of investment in subsidiaries	(25.7		)	(25.7		)	—			51.4			—
Net income (loss) before noncontrolling interest	(107.2		)	(100.6		)	(100.5		)	203.7			(104.6		)
Noncontrolling interest	—			—			2.6			—			2.6
Net income (loss) attributable to Pentair plc	$	(107.2	)	$	(100.6	)	$	(103.1	)	$	203.7		$	(107.2	)
Net income (loss) from continuing operations attributable to Pentair plc	$	(81.5	)	$	(74.9	)	$	(77.4	)	$	152.3		$	(81.5	)
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest	$	(107.2	)	$	(100.6	)	$	(100.5	)	$	203.7		$	(104.6	)
Changes in cumulative translation adjustment	30			30			31.4			(60.0		)	31.4
Amortization of pension and other post-retirement prior service cost	(0.3		)	(0.3		)	(0.3		)	0.6			(0.3		)
Changes in market value of derivative financial instruments	(3.6		)	(3.6		)	(3.6		)	7.2			(3.6		)
Total comprehensive income (loss)	(81.1		)	(74.5		)	(73.0		)	151.5			(77.1		)
Less: Comprehensive income (loss) attributable to noncontrolling interest	—			—			4			—			4
Comprehensive income (loss) attributable to Pentair plc	$	(81.1	)	$	(74.5	)	$	(77.0	)	$	151.5		$	(81.1	)
Pentair plc and Subsidiaries
Condensed Consolidating Statement of Cash Flows
Year Ended December 31, 2012
In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
	Company			Issuer			Subsidiaries
	Guarantor
Operating activities
Net cash provided by (used for) operating activities	$	(109.0	)	$	(88.2	)	$	37.2		$	203.7		$	43.7
Investing activities
Capital expenditures	—			—			(94.5		)	—			(94.5		)
Proceeds from sale of property and equipment	—			—			5.5			—			5.5
Acquisitions, net of cash acquired	—			300.1			170.4			—			470.5
Other	—			—			(5.9		)	—			(5.9		)
Net cash provided by (used for) investing activities	—			300.1			75.5			—			375.6
Financing activities
Net repayments of short-term borrowings	—			—			(3.7		)	—			(3.7		)
Net receipts (repayments) of commercial paper and revolving long-term debt	—			424.7			(170.9		)	—			253.8
Proceeds from long-term debt	—			594.3			—			—			594.3
Repayment of long-term debt	—			—			(617.2		)	—			(617.2		)
Debt issuance costs	—			(8.7		)	(1.0		)	—			(9.7		)
Debt extinguishment costs	—			—			(74.8		)	—			(74.8		)
Net change in advances to subsidiaries	157			(1,222.2		)	1,268.90			(203.7		)	—
Excess tax benefits from share-based compensation	—			—			5			—			5
Shares issued to employees, net of shares withheld	—			—			68.2			—			68.2
Repurchases of ordinary shares	—			—			(334.2		)	—			(334.2		)
Dividends paid	(48.0		)	—			(64.4		)	—			(112.4		)
Distributions to noncontrolling interest	—			—			(1.6		)	—			(1.6		)
Net cash provided by (used for) financing activities	109			(211.9		)	74.3			(203.7		)	(232.3		)
Effect of exchange rate changes on cash and cash equivalents	—			—			0.3			—			0.3
Change in cash and cash equivalents	—			—			187.3			—			187.3
Cash and cash equivalents, beginning of year	—			—			50.1			—			50.1
Cash and cash equivalents, end of year	$	—		$	—		$	237.4		$	—		$	237.4

Schedule_II_Valuation_and_Qual

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Schedule II - Valuation and Qualifying Accounts	Schedule II — Valuation and Qualifying Accounts
	Pentair plc and Subsidiaries
	In millions	Beginning		Additions charged (reductions credited) to costs and expenses			Deductions (1)		Other			Ending
		balance							changes (2)			balance
	Allowances for doubtful accounts
	Year ended December 31, 2014	$	58.7	$	(1.2	)	$	11.5	$	(3.5	)	$	42.5
	Year ended December 31, 2013	$	14	$	49.7		$	2.4	$	(2.6	)	$	58.7
	Year ended December 31, 2012	$	16	$	1.6		$	4	$	0.4		$	14
	-1	Uncollectible accounts written off, net of recoveries
	-2	Result of foreign currency effects

Basis_of_Presentation_and_Summ1

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Basis of Presentation	Basis of presentation
	The accompanying consolidated financial statements include the accounts of Pentair and all subsidiaries, both the United States ("U.S.") and non-U.S., which we control. Intercompany accounts and transactions have been eliminated. Investments in companies of which we own 20% to 50% of the voting stock or have the ability to exercise significant influence over operating and financial policies of the investee are accounted for using the equity method of accounting and as a result, our share of the earnings or losses of such equity affiliates is included in the Consolidated Statements of Operations and Comprehensive Income (Loss).
	The consolidated financial statements have been prepared in U.S. dollars (“USD”) and in accordance with accounting principles generally accepted in the United States of America (“GAAP”).
Fiscal Year	Fiscal year
	Our fiscal year ends on December 31. We report our interim quarterly periods on a 13-week basis ending on a Saturday.
Use of Estimates	Use of estimates
	The preparation of our consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes, disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. These estimates include our accounting for valuation of goodwill and indefinite lived intangible assets, estimated losses on accounts receivable, estimated realizable value on excess and obsolete inventory, percentage of completion revenue recognition, assets acquired and liabilities assumed in acquisitions, estimated selling proceeds from assets held for sale, contingent liabilities, income taxes and pension and other post-retirement benefits. Actual results could differ from our estimates.
Revenue Recognition	Revenue recognition
	We recognize revenue when it is realized or realizable and has been earned. Revenue is recognized when persuasive evidence of an arrangement exists, shipment or delivery has occurred (depending on the terms of the sale), our price to the buyer is fixed or determinable, and collectability is reasonably assured.
	Generally, there is no post-shipment obligation on product sold other than warranty obligations in the normal and ordinary course of business. In the event significant post-shipment obligations were to exist, revenue recognition would be deferred until substantially all obligations were satisfied.
	Percentage of completion
	Revenue from certain long-term contracts is recognized over the contractual period under the percentage of completion method of accounting. Under this method, sales and gross profit are recognized as work is performed either based on the relationship between the actual costs incurred and the total estimated costs at completion (“the cost-to-cost method”) or based on efforts for measuring progress towards completion in situations in which this approach is more representative of the progress on the contract than the cost-to-cost method. Changes to the original estimates may be required during the life of the contract and such estimates are reviewed on a regular basis. Sales and gross profit are adjusted using the cumulative catch-up method for revisions in estimated total contract costs. These reviews have not resulted in adjustments that were significant to our results of operations. Estimated losses are recorded when identified. Claims against customers are recognized as revenue upon settlement.
	We record costs and earnings in excess of billings on uncompleted contracts within Other current assets and billings in excess of costs and earnings on uncompleted contracts within Other current liabilities in the Consolidated Balance Sheets. Amounts included in Other current assets related to these contracts were $103.5 million and $91.6 million at December 31, 2014 and 2013, respectively. Amounts included in Other current liabilities related to these contracts were $41.4 million and $35.4 million at December 31, 2014 and 2013, respectively.
	Sales returns
	The right of return may exist explicitly or implicitly with our customers. Generally, our return policy allows for customer returns only upon our authorization. Goods returned must be product we continue to market and must be in salable condition. Returns of custom or modified goods are normally not allowed. At the time of sale, we reduce revenue for the estimated effect of returns. Estimated sales returns include consideration of historical sales levels, the timing and magnitude of historical sales return levels as a percent of sales, type of product, type of customer and a projection of this experience into the future.
	Pricing and sales incentives
	We record estimated reductions to revenue for customer programs and incentive offerings including pricing arrangements, promotions and other volume-based incentives at the later of the date revenue is recognized or the incentive is offered. Sales incentives given to our customers are recorded as a reduction of revenue unless we (1) receive an identifiable benefit for the goods or services in exchange for the consideration and (2) we can reasonably estimate the fair value of the benefit received.
	Pricing is established at or prior to the time of sale with our customers and we record sales at the agreed-upon net selling price. However, one of our businesses allows customers to apply for a refund of a percentage of the original purchase price if they can demonstrate sales to a qualifying end customer. At the time of sale, we estimate the anticipated refund to be paid based on historical experience and reduce sales for the probable cost of the discount. The cost of these refunds is recorded as a reduction in gross sales.
	Volume-based incentives involve rebates that are negotiated at or prior to the time of sale with the customer and are redeemable only if the customer achieves a specified cumulative level of sales or sales increase. Under these incentive programs, at the time of sale, we reforecast the anticipated rebate to be paid based on forecasted sales levels. These forecasts are updated at least quarterly for each customer and sales are reduced for the anticipated cost of the rebate. If the forecasted sales for a customer changes, the accrual for rebates is adjusted to reflect the new amount of rebates expected to be earned by the customer.
Shipping and Handling Costs	Shipping and handling costs
	Amounts billed to customers for shipping and handling are recorded in Net sales in the accompanying Consolidated Statements of Operations and Comprehensive Income (Loss). Shipping and handling costs incurred by Pentair for the delivery of goods to customers are included in Cost of goods sold in the accompanying Consolidated Statements of Operations and Comprehensive Income (Loss).
Research and Development	Research and development
	We conduct research and development (“R&D”) activities in our own facilities, which consist primarily of the development of new products, product applications and manufacturing processes. We expense R&D costs as incurred. R&D expenditures during 2014, 2013 and 2012 were $117.3 million, $122.8 million and $92.3 million, respectively.
Cash Equivalents	Cash equivalents
	We consider highly liquid investments with original maturities of three months or less to be cash equivalents.
Trade Receivables and Concentration of Credit Risk	Trade receivables and concentration of credit risk
	We record an allowance for doubtful accounts, reducing our receivables balance to an amount we estimate is collectible from our customers. Estimates used in determining the allowance for doubtful accounts are based on current trends, aging of accounts receivable, periodic credit evaluations of our customers’ financial condition, and historical collection experience. We generally do not require collateral. No customer receivable balances exceeded 10% of total net receivable balances as of December 31, 2014 or December 31, 2013.
Inventories	Inventories
	Inventories are stated at the lower of cost or market with substantially all inventories recorded using the first-in, first-out (“FIFO”) cost method and with an insignificant amount of inventories located outside the United States recorded using a moving average cost method which approximates FIFO.
Property, Plant and Equipment, Net	Property, plant and equipment, net
	Property, plant and equipment is stated at historical cost. We compute depreciation by the straight-line method based on the following estimated useful lives:
		Years
	Land improvements	5 to 20
	Buildings and leasehold improvements	5 to 50
	Machinery and equipment	3 to 15
	Significant improvements that add to productive capacity or extend the lives of properties are capitalized. Costs for repairs and maintenance are charged to expense as incurred. When property is retired or otherwise disposed of, the recorded cost of the assets and their related accumulated depreciation are removed from the Consolidated Balance Sheets and any related gains or losses are included in income.
	We review the recoverability of long-lived assets to be held and used, such as property, plant and equipment, when events or changes in circumstances occur that indicate the carrying value of the asset or asset group may not be recoverable. The assessment of possible impairment is based on our ability to recover the carrying value of the asset or asset group from the expected future pre-tax cash flows (undiscounted and without interest charges) of the related operations. If these cash flows are less than the carrying value of such asset or asset group, an impairment loss is recognized for the difference between estimated fair value and carrying value. Impairment losses on long-lived assets held for sale are determined in a similar manner, except that fair values are reduced for the cost to dispose of the assets. The measurement of impairment requires us to estimate future cash flows and the fair value of long-lived assets. During 2014 and 2013, we recorded impairment charges of $20.9 million and $16.6 million, respectively, in conjunction with restructuring activities. There were no material impairment charges recorded related to long-lived assets in 2012.
Goodwill and identifiable intangible assets	Goodwill and identifiable intangible assets
	Goodwill
	Goodwill represents the excess of the cost of acquired businesses over the net of the fair value of identifiable tangible net assets and identifiable intangible assets purchased and liabilities assumed.
	Goodwill is tested annually for impairment and is tested for impairment more frequently if events or changes in circumstances indicate that the asset might be impaired. The impairment test is performed using a two-step process. In the first step, the fair value of each reporting unit is compared with the carrying amount of the reporting unit, including goodwill. If the estimated fair value is less than the carrying amount of the reporting unit there is an indication that goodwill impairment exists and a second step must be completed in order to determine the amount of the goodwill impairment, if any, that should be recorded. In the second step, an impairment loss is recognized for any excess of the carrying amount of the reporting unit’s goodwill over the implied fair value of that goodwill. The implied fair value of goodwill is determined by allocating the fair value of the reporting unit in a manner similar to a purchase price allocation.
	The fair value of each reporting unit is determined using a discounted cash flow analysis and market approach. Projecting discounted future cash flows requires us to make significant estimates regarding future revenues and expenses, projected capital expenditures, changes in working capital and the appropriate discount rate. Use of the market approach consists of comparisons to comparable publicly-traded companies that are similar in size and industry. Actual results may differ from those used in our valuations. This non-recurring fair value measurement is a “Level 3” measurement under the fair value hierarchy described below.
	In developing our discounted cash flow analysis, assumptions about future revenues and expenses, capital expenditures and changes in working capital, are based on our annual operating plan and long-term business plan for each of our reporting units. These plans take into consideration numerous factors including historical experience, anticipated future economic conditions, changes in raw material prices and growth expectations for the industries and end markets we participate in. These assumptions are determined over a six year long-term planning period. The six year growth rates for revenues and operating profits vary for each reporting unit being evaluated. Revenues and operating profit beyond 2020 are projected to grow at a perpetual growth rate of 3.0%.
	Discount rate assumptions for each reporting unit take into consideration our assessment of risks inherent in the future cash flows of the respective reporting unit and our weighted-average cost of capital. We utilized discount rates ranging from 11.0% to 12.0% in determining the discounted cash flows in our fair value analysis.
	In estimating fair value using the market approach, we identify a group of comparable publicly-traded companies for each reporting unit that are similar in terms of size and product offering. These groups of comparable companies are used to develop multiples based on total market-based invested capital as a multiple of earnings before interest, taxes, depreciation and amortization ("EBITDA"). We determine our estimated values by applying these comparable EBITDA multiples to the operating results of our reporting units. The ultimate fair value of each reporting unit is determined considering the results of both valuation methods.
	We completed step one of our annual goodwill impairment evaluation during the fourth quarter of 2014, 2013 and 2012 with each reporting unit’s fair value exceeding its carrying value. Accordingly, step two of the impairment analysis was not required for 2014, 2013 or 2012.
	Identifiable intangible assets
	Our primary identifiable intangible assets include: customer relationships, trade names, proprietary technology, patents and backlog. Identifiable intangibles with finite lives are amortized and those identifiable intangibles with indefinite lives are not amortized. Identifiable intangible assets that are subject to amortization are evaluated for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. Identifiable intangible assets not subject to amortization are tested for impairment annually or more frequently if events warrant.
	The impairment test for trade names consists of a comparison of the fair value of the trade name with its carrying value. Fair value is measured using the relief-from-royalty method. This method assumes the trade name has value to the extent that the owner is relieved of the obligation to pay royalties for the benefits received from them. This method requires us to estimate the future revenue for the related brands, the appropriate royalty rate and the weighted average cost of capital. The non-recurring fair value measurement is a “Level 3” measurement under the fair value hierarchy described below. The impairment charges recorded in 2013 and 2012 were the result of rebranding strategies implemented in the fourth quarters of 2013 and 2012, respectively.
	At December 31, 2014 our goodwill and intangible assets were $6,350.0 million and represented 60% of our total assets. If we experience future declines in sales and operating profit or do not meet our operating forecasts, we may be subject to future impairments. Additionally, changes in assumptions regarding the future performance of our businesses, increases in the discount rate used to determine the discounted cash flows of our businesses or significant declines in our share price or the market as a whole could result in additional impairment indicators. Because of the significance of our goodwill and intangible assets, any future impairment of these assets could have a material adverse effect on our financial results.
Equity and Cost Method Investments	Equity and cost method investments
	We have investments that are accounted for using the equity method. Our proportionate share of income or losses from investments accounted for under the equity method is recorded in the Consolidated Statements of Operations and Comprehensive Income (Loss). We write down or write off an investment and recognize a loss when events or circumstances indicate there is impairment in the investment that is other-than-temporary. This requires significant judgment, including assessment of the investees’ financial condition and in certain cases the possibility of subsequent rounds of financing, as well as the investees’ historical and projected results of operations and cash flows. If the actual outcomes for the investees are significantly different from projections, we may incur future charges for the impairment of these investments. Our investment in and loans to equity method investees was $12.9 million and $12.2 million at December 31, 2014 and December 31, 2013, respectively, net of our proportionate share of the results of their operations.
	Investments for which we do not have significant influence are accounted for under the cost method. The aggregate balance of these investments was $8.6 million and $8.3 million at December 31, 2014 and December 31, 2013.
Income Taxes	Income taxes
	We use the asset and liability approach to account for income taxes. Under this method, deferred tax assets and liabilities are recognized for the expected future tax consequences of differences between the carrying amounts of assets and liabilities and their respective tax bases using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period when the change is enacted. Deferred tax assets are reduced by a valuation allowance when, in the opinion of management, it is more likely than not that some portion or all of the deferred tax assets will not be realized. Changes in valuation allowances from period to period are included in our tax provision in the period of change. We recognize the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
Pension and other post-retirement plans	Pension and other post-retirement plans
	We sponsor U.S. and Non-U.S. defined-benefit pension and other post-retirement plans. The pension and other post-retirement benefit costs for company-sponsored benefit plans are determined from actuarial assumptions and methodologies, including discount rates, expected returns on plan assets and health care cost trend rates. These assumptions are updated annually and are disclosed in Note 13.
	We recognize changes in the fair value of plan assets and net actuarial gains or losses for pension and other post-retirement benefits annually in the fourth quarter each year ("mark-to-market adjustment") and, if applicable, in any quarter in which an interim remeasurement is triggered. Net actuarial gains and losses occur when the actual experience differs from any of the various assumptions used to value our pension and other post-retirement plans or when assumptions change, as they may each year. The remaining components of pension expense, primarily service and interest costs and estimated return on plan assets, are recorded on a quarterly basis.
Environmental	Environmental
	We recognize environmental clean-up liabilities on an undiscounted basis when a loss is probable and can be reasonably estimated. Such liabilities generally are not subject to insurance coverage. The cost of each environmental clean-up is estimated by engineering, financial and legal specialists based on current law. Such estimates are based primarily upon the estimated cost of investigation and remediation required and the likelihood that, where applicable, other potentially responsible parties (“PRPs”) will be able to fulfill their commitments at the sites where Pentair may be jointly and severally liable. The process of estimating environmental clean-up liabilities is complex and dependent primarily on the nature and extent of historical information and physical data relating to a contaminated site, the complexity of the site, the uncertainty as to what remedy and technology will be required and the outcome of discussions with regulatory agencies and other PRPs at multi-party sites. In future periods, new laws or regulations, advances in clean-up technologies and additional information about the ultimate clean-up remedy that is used could significantly change our estimates. Accruals for environmental liabilities are included in Other current liabilities and Other non-current liabilities in the Consolidated Balance Sheets.
Asbestos Matters	Asbestos Matters
	We recognize asbestos-related liabilities on an undiscounted basis when a loss is probable and can be reasonably estimated. Certain of these liabilities are subject to insurance coverage. Our subsidiaries and numerous other companies are named as defendants in personal injury lawsuits based on alleged exposure to asbestos-containing materials. These cases typically involve product liability claims based primarily on allegations of manufacture, sale or distribution of industrial products that either contained asbestos or were attached to or used with asbestos-containing components manufactured by third-parties. The process of estimating asbestos-related liabilities and the corresponding insurance recoveries receivable is complex and dependent primarily on our historical claim experience, estimates of potential future claims, our legal strategy for resolving these claims, the availability of insurance coverage, and the solvency and creditworthiness of insurers. On an annual basis, we review, and update as appropriate, such estimated asbestos liabilities and assets and the underlying assumptions.
	Accruals for asbestos-related liabilities are included in Other non-current liabilities and the estimated receivable for insurance recoveries are recorded in Other non-current assets in the Consolidated Balance Sheets.
Insurance Subsidiary	Insurance subsidiary
	We insure certain general and product liability, property, workers’ compensation and automobile liability risks through our regulated wholly-owned captive insurance subsidiary, Penwald Insurance Company (“Penwald”). Reserves for policy claims are established based on actuarial projections of ultimate losses. As of December 31, 2014 and 2013, reserves for policy claims were $58.1 million ($13.2 million included in Other current liabilities and $44.9 million included in Other non-current liabilities) and $51.1 million ($13.2 million included in Other current liabilities and $37.9 million included in Other non-current liabilities), respectively.
Share-Based Compensation	Share-based compensation
	We account for share-based compensation awards on a fair value basis. The estimated grant date fair value of each option award is recognized in income on an accelerated basis over the requisite service period (generally the vesting period). The estimated fair value of each option award is calculated using the Black-Scholes option-pricing model. From time to time, we have elected to modify the terms of the original grant. These modified grants are accounted for as a new award and measured using the fair value method, resulting in the inclusion of additional compensation expense in our Consolidated Statements of Operations and Comprehensive Income (Loss). Restricted share awards and units are recorded as compensation cost on an accelerated basis over the requisite service periods based on the market value on the date of grant.
Earnings (Loss) Per Common Share	Earnings (loss) per ordinary share
	Basic earnings (loss) per share are computed by dividing net income (loss) attributable to Pentair plc by the weighted-average number of ordinary shares outstanding. Diluted earnings (loss) per share are computed by dividing net income (loss) attributable to Pentair plc by the weighted-average number of ordinary shares outstanding including the dilutive effects of ordinary share equivalents.
Derivative Financial Instruments	Derivative financial instruments
	We recognize all derivatives, including those embedded in other contracts, as either assets or liabilities at fair value in our Consolidated Balance Sheets. If the derivative is designated and is effective as a cash-flow hedge, changes in the fair value of the derivative are recorded in Accumulated other comprehensive income (loss) (“AOCI”) as a separate component of equity in the Consolidated Balance Sheets and is recognized in the Consolidated Statements of Operations and Comprehensive Income (Loss) when the hedged item affects earnings. If the underlying hedged transaction ceases to exist or if the hedge becomes ineffective, all changes in fair value of the related derivatives that have not been settled are recognized in current earnings. For a derivative that is not designated as or does not qualify as a hedge, changes in fair value are reported in earnings immediately.
	We use derivative instruments for the purpose of hedging interest rate and currency exposures, which exist as part of ongoing business operations. We do not hold or issue derivative financial instruments for trading or speculative purposes. All other contracts that contain provisions meeting the definition of a derivative also meet the requirements of and have been designated as, normal purchases or sales. Our policy is not to enter into contracts with terms that cannot be designated as normal purchases or sales. From time to time, we may enter into short duration foreign currency contracts to hedge foreign currency risks.
Fair Value Measurements	Fair value measurements
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Assets and liabilities measured at fair value are classified using the following hierarchy, which is based upon the transparency of inputs to the valuation as of the measurement date:
	Level 1: Valuation is based on observable inputs such as quoted market prices (unadjusted) for identical assets or liabilities in active markets.
	Level 2: Valuation is based on inputs such as quoted market prices for similar assets or liabilities in active markets or other inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument.
	Level 3: Valuation is based upon other unobservable inputs that are significant to the fair value measurement.
	In making fair value measurements, observable market data must be used when available. When inputs used to measure fair value fall within different levels of the hierarchy, the level within which the fair value measurement is categorized is based on the lowest level input that is significant to the fair value measurement.
Foreign Currency Translation	Foreign currency translation
	The financial statements of subsidiaries located outside of the U.S. are generally measured using the local currency as the functional currency, except for certain corporate entities outside of the U.S. which are measured using USD. Assets and liabilities of these subsidiaries are translated at the rates of exchange at the balance sheet date. Income and expense items are translated at average monthly rates of exchange. The resultant translation adjustments are included in AOCI, a separate component of equity.
New accounting standards	New accounting standards
	In May 2014, the Financial Accounting Standards Board issued new accounting requirements for the recognition of revenue from contracts with customers. The new requirements also include additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract.  The requirements are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period, with earlier adoption not permitted. We have not yet determined the potential effects on our financial condition or results of operations.

Basis_of_Presentation_and_Summ2

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Estimated Useful Lives of Property and Equipment	We compute depreciation by the straight-line method based on the following estimated useful lives:
		Years
	Land improvements	5 to 20
	Buildings and leasehold improvements	5 to 50
	Machinery and equipment	3 to 15

Acquisitions_and_Divestitures_

Acquisitions and Divestitures (Tables)	12 Months Ended
	Dec. 31, 2014
Pro Forma Consolidated Condensed Financial Results of Operations	The following unaudited pro forma condensed consolidated financial results of operations are presented as if the Merger had been completed on January 1, 2011:
		Year ended December 31
	In millions, except per-share data	2012
	Pro forma net sales	$	6,846.60
	Pro forma net income from continuing operations attributable to Pentair plc	183.3
	Diluted earnings from continuing operations per ordinary share attributable to Pentair plc	0.87

Discontinued_Operations_and_Di1

Discontinued Operations and Divestitures Discontinued Operations and Divestitures (Tables)	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]	Operating results of discontinued operations are summarized below:
		Years ended December 31
	In millions	2014			2013			2012
	Net sales	$	295.8		$	490.1		$	112.1
	Income (loss) from discontinued operations before income taxes	$	1.5		$	33		$	(37.9	)
	Income tax benefit (provision)	(7.9		)	(7.1		)	12.2
	Income (loss) from discontinued operations, net of tax	$	(6.4	)	$	25.9		$	(25.7	)
	Loss from sale / impairment of discontinued operations before income taxes	$	(400.4	)	$	(1.1	)	$	—
	Income tax benefit	14.7			0.3			—
	Loss from sale / impairment of discontinued operations, net of tax	$	(385.7	)	$	(0.8	)	$	—
	The carrying amounts of major classes of assets and liabilities that were classified as held for sale on the Consolidated Balance Sheets were as follows:
		December 31
	In millions	2014			2013
	Cash and cash equivalents	$	7		$	9.1
	Accounts and notes receivable, net	28.8			49.3
	Inventories	30.1			48.2
	Other current assets	14.7			27.8
	Current assets held for sale	$	80.6		$	134.4
	Property, plant and equipment, net	$	18.5		$	125.7
	Goodwill	—			273.5
	Intangibles, net	—			26.2
	Other non-current assets	6.4			40.9
	Non-current assets held for sale	$	24.9		$	466.3
	Accounts payable	$	12.2		$	19.7
	Employee compensation and benefits	11.3			34.7
	Other current liabilities	11.6			18.1
	Current liabilities held for sale	$	35.1		$	72.5
	Long-term debt	$	4		$	4.7
	Pension and other post-retirement compensation and benefits	2.5			4.6
	Deferred tax liabilities	—			23.6
	Other non-current liabilities	—			1
	Non-current liabilities held for sale	$	6.5		$	33.9

Earnings_Loss_Per_Share_Tables

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Basic and Diluted Earnings (Loss) Per Share	Basic and diluted earnings (loss) per share were calculated as follows:
		Years ended December 31
	In millions, except per share data	2014			2013		2012
	Net income (loss) attributable to Pentair plc	$	214.9		$	536.8	$	(107.2	)
	Net income (loss) from continuing operations attributable to Pentair plc	$	607		$	511.7	$	(81.5	)
	Weighted average ordinary shares outstanding
	Basic	190.6			201.1		127.4
	Dilutive impact of stock options and restricted stock awards	3.1			3.5		—
	Diluted	193.7			204.6		127.4
	Earnings (loss) per ordinary share attributable to Pentair plc
	Basic
	Continuing operations	$	3.19		$	2.54	$	(0.64	)
	Discontinued operations	(2.06		)	0.13		(0.20		)
	Basic earnings (loss) per ordinary share attributable to Pentair plc	$	1.13		$	2.67	$	(0.84	)
	Diluted
	Continuing operations	$	3.14		$	2.5	$	(0.64	)
	Discontinued operations	(2.03		)	0.12		(0.20		)
	Diluted earnings (loss) per ordinary share attributable to Pentair plc	$	1.11		$	2.62	$	(0.84	)
	Anti-dilutive stock options excluded from the calculation of diluted earnings per share	0.5			0.2		16

Restructuring_Tables

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2014
Restructuring Related Costs	Restructuring related costs included in Selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income (Loss) included costs for severance and other restructuring costs as follows:
		Years ended December 31
	In millions	2014			2013			2012
	Severance and related costs	$	58.9		$	81.5		$	43.4
	Other	29.4			21.7			5.3
	Total restructuring costs	$	88.3		$	103.2		$	48.7
Restructuring Accrual Activity Recorded on Consolidated Balance Sheets	Activity in the restructuring accrual recorded in Other current liabilities and Employee compensation and benefits in the Consolidated Balance Sheets is summarized as follows:
		Years ended December 31
	In millions	2014			2013
	Beginning balance	$	68.6		$	40.4
	Costs incurred	58.9			81.5
	Cash payments and other	(54.1		)	(53.3		)
	Ending balance	$	73.4		$	68.6
Restructuring Costs By Segment [Table Text Block]
		Years ended December 31
	In millions	2014			2013			2012
	Valves & Controls	$	48.8		$	51		$	5.1
	Process Technologies	18.6			9.4			25.2
	Flow Technologies	10.6			13.4			5.7
	Technical Solutions	4.3			19.4			12.7
	Other	6			10			—
	Consolidated	$	88.3		$	103.2		$	48.7

Goodwill_and_Other_Identifiabl1

Goodwill and Other Identifiable Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Changes in Carrying Amount of Goodwill by Segment	The changes in the carrying amount of goodwill for the year ended December 31, 2014 and December 31, 2013 by reportable segment were as follows:
	In millions	December 31, 2013		Acquisitions/			Foreign currency			December 31, 2014
				divestitures			translation/other
	Valves & Controls	$	1,511.60	$	—		$	—		$	1,511.60
	Process Technologies	1,524.50		6.8			(79.8		)	1,451.50
	Flow Technologies	666.6		—			(38.1		)	628.5
	Technical Solutions	1,158.00		—			(7.7		)	1,150.30
	Total goodwill	$	4,860.70	$	6.8		$	(125.6	)	$	4,741.90
	In millions	December 31, 2012		Acquisitions/			Foreign currency			December 31, 2013
				divestitures			translation/other
	Valves & Controls	$	1,511.60	$	—		$	—		$	1,511.60
	Process Technologies	1,500.40		7.6			16.5			1,524.50
	Flow Technologies	663.8		(5.7		)	8.5			666.6
	Technical Solutions	1,161.70		(5.3		)	1.6			1,158.00
	Total goodwill	$	4,837.50	$	(3.4	)	$	26.6		$	4,860.70
Identifiable Intangible Assets	Identifiable intangible assets consisted of the following at December 31:
		2014									2013
	In millions	Cost		Accumulated			Net				Cost			Accumulated			Net
				amortization										amortization
	Finite-life intangibles
	Customer relationships	$	1,247.80	$	(325.2	)	$	922.6			$	1,271.20		$	(243.1	)	$	1,028.10
	Trade names	2		(1.1		)	0.9				2.1			(0.9		)	1.2
	Proprietary technology and patents	255.7		(96.7		)	159				263.7			(80.0		)	183.7
	Total finite-life intangibles	1,505.50		(423.0		)	1,082.50				1,537.00			(324.0		)	1,213.00
	Indefinite-life intangibles
	Trade names	525.6		—			525.6				536.9			—			536.9
	Total intangibles	$	2,031.10	$	(423.0	)	$	1,608.10			$	2,073.90		$	(324.0	)	$	1,749.90
Estimated Future Amortization Expense for Identifiable Intangible Assets	Estimated future amortization expense for identifiable intangible assets during the next five years is as follows:
	In millions	2015		2016			2017			2018			2019
	Estimated amortization expense	$	111.5	$	110.6		$	109		$	106.5		$	99.4

Supplemental_Balance_Sheet_Inf1

Supplemental Balance Sheet Information (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Balance Sheet Information
		December 31
	In millions	2014		2013
	Inventories
	Raw materials and supplies	$	460.1	$	549.8
	Work-in-process	229		164.4
	Finished goods	441.3		480.9
	Total inventories	$	1,130.40	$	1,195.10
	Other current assets
	Cost in excess of billings	$	103.5	$	91.6
	Prepaid expenses	109.6		97.6
	Deferred income taxes	139.4		149.7
	Other current assets	14.3		22.7
	Total other current assets	$	366.8	$	361.6
	Property, plant and equipment, net
	Land and land improvements	$	165.1	$	186.4
	Buildings and leasehold improvements	493.5		502.6
	Machinery and equipment	1,169.10		1,155.10
	Construction in progress	71		70.9
	Total property, plant and equipment	1,898.70		1,915.00
	Accumulated depreciation and amortization	948.7		870.7
	Total property, plant and equipment, net	$	950	$	1,044.30
	Other non-current assets
	Asbestos-related insurance receivable	$	115.8	$	119.6
	Deferred income taxes	87.9		92.4
	Other non-current assets	232.5		178
	Total other non-current assets	$	436.2	$	390
	Other current liabilities
	Deferred revenue and customer deposits	$	112.7	$	90.8
	Dividends payable	116.8		98.7
	Billings in excess of cost	41.4		35.4
	Accrued warranty	66.4		56
	Other current liabilities	371.8		365
	Total other current liabilities	$	709.1	$	645.9
	Other non-current liabilities
	Asbestos-related liabilities	$	249.1	$	254.7
	Taxes payable	61.6		48.9
	Other non-current liabilities	187		152.8
	Total other non-current liabilities	$	497.7	$	456.4

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Disclosure of Cash Flow Information
		Years ended December 31
	In millions	2014		2013		2012
	Cash paid for interest, net	$	67.5	$	69.4	$	66.7
	Cash paid for income taxes, net	134.2		91.2		82

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2014
Components of Accumulated Other Comprehensive Income (Loss)	Components of AOCI consist of the following:
		December 31
	In millions	2014			2013
	Cumulative translation adjustments	$	(371.0	)	$	(34.7	)
	Market value of derivative financial instruments, net of tax	(9.3		)	(8.9		)
	Accumulated other comprehensive loss	$	(380.3	)	$	(43.6	)

Debt_Tables

Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Debt and Average Interest Rates on Debt Outstanding	Debt and the average interest rates on debt outstanding were as follows:
	In millions	Average	Maturity	December 31
		interest rate at	year
		December 31, 2014		2014			2013
	Commercial paper	0.68%	2019	$	987.6		$	528.9
	Revolving credit facilities	1.42%	2019	9.8			—
	Senior notes - fixed rate	1.35%	2015	350			350
	Senior notes - fixed rate	1.88%	2017	350			350
	Senior notes - fixed rate	2.65%	2019	250			250
	Senior notes - fixed rate	5.00%	2021	500			500
	Senior notes - fixed rate	3.15%	2022	550			550
	Capital lease obligations	6.19%	2015	6.7			21.5
	Total debt			3,004.10			2,550.40
	Less: Current maturities and short-term borrowings			(6.7		)	(2.5		)
	Long-term debt			$	2,997.40		$	2,547.90
Debt Outstanding Matures on Calendar Year Basis	Debt outstanding at December 31, 2014 matures on a calendar year basis as follows:
	In millions	2015			2016			2017		2018		2019		Thereafter		Total
	Contractual debt obligation maturities	$	—		$	—		$	350	$	—	$	1,597.40	$	1,050.00	$	2,997.40
	Capital lease obligations	6.7			—			—		—		—		—		6.7
	Total maturities	$	6.7		$	—		$	350	$	—	$	1,597.40	$	1,050.00	$	3,004.10

Derivatives_and_Financial_Inst1

Derivatives and Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Recorded Amounts and Estimated Fair Values of Long-term Debt and Derivative Financial Instruments	The recorded amounts and estimated fair values of total debt at December 31 were as follows:
		2014						2013
	In millions	Recorded		Fair Value				Recorded			Fair Value
		Amount						Amount
	Variable rate debt	$	997.4	$	997.4			$	528.9		$	528.9
	Fixed rate debt	2,006.70		2,070.40				2,021.50			1,997.50
	Total debt	$	3,004.10	$	3,067.80			$	2,550.40		$	2,526.40
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	Financial assets and liabilities measured at fair value on a recurring and nonrecurring basis were as follows:
	Recurring fair value measurements	December 31, 2014
	In millions	Level 1		Level 2			Level 3			Total
	Foreign currency contract assets	$	—	$	0.9		$	—		$	0.9
	Foreign currency contract liabilities	—		(6.6		)	—			(6.6		)
	Deferred compensation plans assets (1)	47.9		7.4			—			55.3
	Total recurring fair value measurements	$	47.9	$	1.7		$	—		$	49.6
	Nonrecurring fair value measurements (2)
	Recurring fair value measurements	December 31, 2013
	In millions	Level 1		Level 2			Level 3			Total
	Foreign currency contract assets	$	—	$	3.6		$	—		$	3.6
	Deferred compensation plan assets (1)	32.1		—			—			32.1
	Total recurring fair value measurements	$	32.1	$	3.6		$	—		$	35.7
	Nonrecurring fair value measurements  (3)
	-1	Deferred compensation plan assets include mutual funds, common/collective trusts and cash equivalents for payment of certain non-qualified benefits for retired, terminated and active employees. The fair value of mutual funds and cash equivalents were based on quoted market prices in active markets. The underlying investments in the common/collective trusts primarily include intermediate and long-term debt securities, corporate debt securities, equity securities and fixed income securities. The overall fair value of the common/collective trusts are based on observable inputs.
	-2	During the third quarter of 2014, we recognized an impairment charge related to allocated amounts of goodwill, intangible assets, property, plant & equipment and other non-current assets totaling $380.1 million, net of a $12.3 million tax benefit, representing our estimated loss on disposal of the Water Transport business. The impairment charge was determined using significant unobservable inputs ("Level 3" fair value measurements). See Note 3 for additional information about the impairment.
	-3	In the fourth quarter of 2013, we completed our annual intangible assets impairment review. As a result, we recorded a pre-tax non-cash impairment charge of $11.0 million for a trade name intangible in 2013. The impairment charge reduced the fair value of the impacted trade name intangible to $0. The fair value of trade names is measured using the relief-from-royalty method. This method assumes the trade name has value to the extent that the owner is relieved of the obligation to pay royalties for the benefits received from them. This method requires us to estimate the future revenue for the related brands, the appropriate royalty rate and the weighted average cost of capital.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income (loss) before income taxes and noncontrolling interest	Income (loss) from continuing operations before income taxes and noncontrolling interest consisted of the following:
		Years ended December 31
	In millions	2014			2013			2012
	Federal (1)	$	13.3		$	328.7		$	39.5
	International	771			365.8			(185.6		)
	Income (loss) from continuing operations before income taxes and noncontrolling interest	$	784.3		$	694.5		$	(146.1	)
	-1	As a result of the Redomicile, “Federal” reflects income (loss) from continuing operations before income taxes and noncontrolling interest for the U.K. in 2014 and for Switzerland in 2013 and 2012.
Provision for Income Taxes	The provision (benefit) for income taxes consisted of the following:
		Years ended December 31
	In millions	2014			2013			2012
	Currently payable
	Federal (1)	$	(0.4	)	$	17.4		$	6.5
	International (2)	175.7			105.6			65.2
	Total current taxes	175.3			123			71.7
	Deferred
	Federal (1)	2.2			18.9			1.3
	International (2)	(0.2		)	35.1			(140.2		)
	Total deferred taxes	2			54			(138.9		)
	Total provision (benefit) for income taxes	$	177.3		$	177		$	(67.2	)
	-1	As a result of the Redomicile, “Federal” represents U.K. taxes for 2014 and Swiss taxes for 2013 and 2012.
	-2	As a result of the Redomicile, "International" represents non-U.K. taxes for 2014 and non-Swiss taxes for 2013 and 2012
Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate	Reconciliations of the federal statutory income tax rate to our effective tax rate were as follows:
		Years ended December 31
	Percentages	2014		2013	2012
	Federal statutory income tax rate (1)	21		7.8	7.8
	Tax effect of international operations (2)	(4.9	)	10.4	23.5
	Change in valuation allowances	3.4		5.7	—
	Withholding taxes	2.3		1.1	—
	Interest limitations	0.8		0.5	—
	Non-deductible transaction costs	—		—	(5.9	)
	Impact of debt-financing	—		—	13.6
	Resolution of tax audits	—		—	7
	Effective tax rate	22.6		25.5	46
	-1	The statutory rate for 2014 reflects the U.K. statutory rate of 21 percent. For 2013 and 2012, the statutory rate reflects the Swiss statutory rate of 7.8 percent.
	-2	The tax effect of international operations for 2014 consists of non-U.K. jurisdictions. For 2013 and 2012, the tax effect of international operations consists of non-Swiss jurisdictions.
Reconciliations of Gross Unrecognized Tax Benefits	Reconciliations of the beginning and ending gross unrecognized tax benefits were as follows:
		Years ended December 31
	In millions	2014			2013			2012
	Beginning balance	$	60.8		$	53.4		$	26.5
	Gross increases for tax positions in prior periods	2.3			12.2			2.2
	Gross decreases for tax positions in prior periods	(0.5		)	(0.6		)	(0.6		)
	Gross increases based on tax positions related to the current year	1.8			2.7			13.6
	Gross decreases related to settlements with taxing authorities	(0.1		)	(5.1		)	(13.2		)
	Reductions due to statute expiration	(1.2		)	(1.8		)	(0.4		)
	Gross decreases due to currency fluctuations	(1.0		)	—			—
	Gross increases due to acquisitions	—			—			25.3
	Ending balance	$	62.1		$	60.8		$	53.4
Deferred Taxes	Deferred taxes were recorded in the Consolidated Balance Sheets as follows:
		December 31
	In millions	2014			2013
	Other current assets	$	139.4		$	149.7
	Other non-current assets	87.9			92.4
	Deferred tax liabilities	528.3			557
	Net deferred tax liabilities	$	301		$	314.9
Tax Effects of Major Items Recorded as Deferred Tax Assets and Liabilities	The tax effects of the major items recorded as deferred tax assets and liabilities were as follows:
		December 31
	In millions	2014			2013
	Deferred tax assets
	Accrued liabilities and reserves	$	200.3		$	192.2
	Pension and other post-retirement benefits	68.4			76.8
	Employee compensation & benefits	100			82.2
	Tax loss and credit carryforwards	291.9			351.7
	Total deferred tax assets	660.6			702.9
	Valuation allowance	235.8			235.5
	Deferred tax assets, net of valuation allowance	424.8			467.4
	Deferred tax liabilities
	Property, plant and equipment	51.6			57.9
	Goodwill and other intangibles	645.6			697.1
	Other liabilities	28.6			27.3
	Total deferred tax liabilities	725.8			782.3
	Net deferred tax liabilities	$	301		$	314.9

Benefit_Plans_Tables

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Reconciliations of Benefit Obligations, Plan Assets of Pension Plans and Funded Status of Plans	The following tables present reconciliations of plan benefit obligations, fair value of plan assets and the funded status of pension plans and other post-retirement plans as of and for the years ended December 31, 2014 and 2013:
		U.S. pension plans							Non-U.S. pension plans							Other post-retirement
																plans
	In millions	2014			2013				2014			2013				2014			2013
	Change in benefit obligations
	Benefit obligation beginning of year	$	346.9		$	394.3			$	462		$	460.8			$	42.4		$	59.3
	Service cost	13.1			15.6				7.4			8.4				0.2			0.3
	Interest cost	15.4			14.3				17.3			17.9				1.7			1.9
	Actuarial loss (gain)	50.1			(56.9		)		73			(16.6		)		0.3			(15.9		)
	Translation loss (gain)	—			—				(36.6		)	9.7				—			—
	Benefits paid	(9.3		)	(20.4		)		(17.9		)	(18.2		)		(3.1		)	(3.2		)
	Benefit obligation end of year	$	416.2		$	346.9			$	505.2		$	462			$	41.5		$	42.4
	Change in plan assets
	Fair value of plan assets beginning of year	$	285.8		$	326.2			$	286.5		$	249			$	—		$	—
	Actual return on plan assets	63.7			(28.9		)		35.2			28.6				—			—
	Company contributions	3.7			8.9				20.9			21.9				3.1			3.2
	Translation gain (loss)	—			—				(15.0		)	5.2				—			—
	Benefits paid	(9.3		)	(20.4		)		(17.9		)	(18.2		)		(3.1		)	(3.2		)
	Fair value of plan assets end of year	$	343.9		$	285.8			$	309.7		$	286.5			$	—		$	—
	Funded status
	Benefit obligations in excess of the fair value of plan assets	$	(72.3	)	$	(61.1	)		$	(195.5	)	$	(175.5	)		$	(41.5	)	$	(42.4	)
Amounts Recognized in Consolidated Balance Sheets	Amounts recorded in the Consolidated Balance Sheets were as follows:
		U.S. pension plans							Non-U.S. pension plans							Other post-
																retirement plans
	In millions	2014			2013				2014			2013				2014			2013
	Other non-current assets	$	2.7		$	0.7			$	6.5		$	3.7			$	—		$	—
	Current liabilities	(4.0		)	(3.9		)		(4.7		)	(4.7		)		(3.4		)	(3.7		)
	Non-current liabilities	(71.0		)	(57.9		)		(197.3		)	(174.5		)		(38.1		)	(38.7		)
	Benefit obligations in excess of the fair value of plan assets	$	(72.3	)	$	(61.1	)		$	(195.5	)	$	(175.5	)		$	(41.5	)	$	(42.4	)
Pension Plans with an Accumulated Benefit Obligation or Projected Benefit Obligation in Excess of Plan Assets	Information for pension plans with an accumulated benefit obligation or projected benefit obligation in excess of plan assets as of December 31 was as follows:
		Projected benefit obligation							Accumulated benefit  obligation
		exceeds the fair value							exceeds the fair value of
		of plan assets							plan assets
	In millions	2014			2013				2014			2013
	U.S. pension plans
	Projected benefit obligation	$	92.5		$	76.3			$	92.5		$	76.3
	Fair value of plan assets	17.5			14.5				17.5			14.5
	Accumulated benefit obligation	N/A			N/A				85.1			73.1
	Non-U.S. pension plans
	Projected benefit obligation	$	460		$	438.2			$	453.2		$	420.4
	Fair value of plan assets	258.1			259				252.3			244.5
	Accumulated benefit obligation	N/A			N/A				440.9			411.5
Weighted-Average Assumptions used to Determine Domestic Benefit Obligations and Domestic Net Periodic Benefit Cost	Weighted-average assumptions used to determine net periodic benefit expense (income) for years ended December 31 were as follows:
		U.S. pension plans							Non-U.S. pension plans							Other post-retirement
																plans
	Percentages	2014		2013		2012			2014		2013		2012			2014		2013		2012
	Discount rate	4.51	%	3.67	%	5.05	%		4.13	%	3.85	%	4.82	%		4.35	%	3.4	%	5.05	%
	Expected long-term return on plan assets	4.56	%	3.75	%	7.5	%		5.95	%	5.98	%	4.09	%		—		—		—
	Rate of compensation increase	4	%	4.37	%	4.21	%		3.02	%	3.02	%	2.98	%		—		—		—
	Weighted-average assumptions used to determine benefit obligations as of December 31 were as follows:
		U.S. pension plans							Non-U.S. pension plans							Other post-retirement
																plans
	Percentages	2014		2013		2012			2014		2013		2012			2014		2013		2012
	Discount rate	3.63	%	4.51	%	3.67	%		3.04	%	4.13	%	3.85	%		3.6	%	4.35	%	3.4	%
	Rate of compensation increase	4	%	4	%	4.37	%		2.95	%	3.02	%	3.02	%		—		—		—
Assumed Health Care Cost Trend Rates	The assumed healthcare cost trend rates for other post-retirement plans as of December 31 were as follows:
		2014		2013
	Healthcare cost trend rate assumed for following year	6.8	%	7	%
	Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.5	%	4.5	%
	Year the cost trend rate reaches the ultimate trend rate	2027		2027
Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates	A one-percentage-point change in the assumed healthcare cost trend rates would have the following effects as of and for the year ended December 31, 2014:
		One Percentage Point
	In millions	Increase			Decrease
	Increase (decrease) in annual service and interest cost	$	0.1		$	(0.1	)
	Increase (decrease) in other post-retirement benefit obligations	1			(0.9		)
Actual Overall Asset Allocation for U.S. And Non-U.S. Plans as Compared to Investment Policy Goals	Our actual overall asset allocation for our U.S. and non-U.S. pension plans as compared to our investment policy goals as of December 31 was as follows:
		U.S. pension plans
		Actual					Target
	Percentages	2014		2013			2014		2013
	Fixed income	97	%	92	%		100	%	100	%
	Alternative	3	%	7	%		—		—
	Cash	—	%	1	%		—		—
		Non-U.S. pension plans
		Actual					Target
	Percentages	2014		2013			2014		2013
	Equity securities	40	%	54	%		45	%	56	%
	Fixed income	53	%	41	%		55	%	44	%
	Alternative	5	%	3	%		—		—
	Cash	2	%	2	%		—		—
Plan Assets Using Fair Value Hierarchy	The fair values of our pension plan assets and their respective levels in the fair value hierarchy as of December 31, 2014 and December 31, 2013 were as follows:
		31-Dec-14
	In millions	Level 1			Level 2			Level 3			Total
	Cash and cash equivalents	$	3.1		$	4.5		$	—		$	7.6
	Fixed income:
	Corporate and non U.S. government	—			373.6			—			373.6
	U.S. treasuries	—			70.7			—			70.7
	Mortgage-backed securities	—			8.3			—			8.3
	Other	—			45.5			—			45.5
	Global equity securities:
	Mid cap equity	—			3.1			—			3.1
	Large cap equity	—			43.7			—			43.7
	International equity	—			77			—			77
	Other investments	—			17.4			6.7			24.1
	Total fair value of plan assets	$	3.1		$	643.8		$	6.7		$	653.6
		31-Dec-13
	In millions	Level 1			Level 2			Level 3			Total
	Cash and cash equivalents	$	1.8		$	5.9		$	—		$	7.7
	Fixed income:
	Corporate and non U.S. government	—			262.2			—			262.2
	U.S. treasuries	—			75.5			—			75.5
	Mortgage-backed securities	—			8.7			—			8.7
	Other	—			34.1			—			34.1
	Global equity securities:
	Mid cap equity	—			7.3			—			7.3
	Large cap equity	—			43.5			—			43.5
	International equity	—			101.9			—			101.9
	Long/short equity	—			0.6			—			0.6
	Other investments	—			11.8			19			30.8
	Total fair value of plan assets	$	1.8		$	551.5		$	19		$	572.3
Reconciliation of Level 3 Assets	The following tables present a reconciliation of Level 3 assets held during the years ended December 31, 2014 and 2013, respectively:
	In millions	January 1,			Net realized			Net issuances			Net transfers			December 31, 2014
		2014			and unrealized			and			into (out of)
					gains (losses)			settlements			level 3
	Other investments	$	19		$	0.7		$	(11.8	)	$	(1.2	)	$	6.7
	In millions	January 1,			Net realized			Net issuances			Net transfers			December 31, 2013
		2013			and unrealized			and			into (out of)
					gains (losses)			settlements			level 3
	Other investments	$	18.3		$	1.9		$	(1.2	)	$	—		$	19
Expected Future Service to Be Paid by Plans	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by the plans for the years ended December 31 as follows:
	In millions	U.S. pension			Non-U.S.			Other post-
		plans			pension plans			retirement
								plans
	2015	$	10		$	15		$	3.4
	2016	12.2			15.9			3.3
	2017	13.7			17.1			3.2
	2018	16.2			18.1			3.1
	2019	18.7			18.9			3.1
	Thereafter	109.7			108.4			13.8
Pension benefits
Components of Net Periodic Benefit Cost	Components of net periodic benefit expense (income) for our pension plans for the years ended December 31 were as follows:
		U. S. pension plans										Non-U.S. pension plans
	In millions	2014			2013			2012				2014			2013			2012
	Service cost	$	13.1		$	15.6		$	12.9			$	7.4		$	8.4		$	3.3
	Interest cost	15.4			14.3			28.2				17.3			17.9			7.5
	Expected return on plan assets	(10.5		)	(9.7		)	(29.4		)		(15.9		)	(15.2		)	(3.9		)
	Amortization of prior year service cost (benefit)	—			0.4			—				—			(0.2		)	—
	Net actuarial (gain) loss	(3.1		)	(18.3		)	114.3				50.3			(30.0		)	24.2
	Net periodic benefit expense (income)	$	14.9		$	2.3		$	126			$	59.1		$	(19.1	)	$	31.1
Post-retirement
Components of Net Periodic Benefit Cost	Components of net periodic benefit expense (income) for our other post-retirement plans for the years ended December 31 were as follows:
		Other post-retirement plans
	In millions	2014			2013			2012
	Service cost	$	0.2		$	0.3		$	0.2
	Interest cost	1.7			1.9			1.9
	Amortization of prior year service benefit	—			(0.8		)	—
	Net actuarial loss (gain)	0.3			(15.9		)	8.1
	Net periodic benefit expense (income)	$	2.2		$	(14.5	)	$	10.2

Share_Plans_Tables

Share Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]
		31-Dec
	In millions	2014			2013			2012
	Restricted stock units	$	22.6		$	20.2		$	24.2
	Stock options	11			10.9			11.6
	Total share-based compensation expense	$	33.6		$	31.1		$	35.8
Stock Option Activity	The following table summarizes stock option activity under all plans for the year ended December 31, 2014:
	Shares and intrinsic value in millions	Number of shares		Weighted-			Weighted-	Aggregate
				average			average	intrinsic
				exercise			remaining	value
				price			contractual life
							(years)
	Outstanding as of January 1, 2014	6.2		$	35.53
	Granted	0.5		77.93
	Exercised	(0.9	)	35.53
	Forfeited	(0.1	)	49.29
	Outstanding as of December 31, 2014	5.7		$	39.08		5.1	$	157.8
	Options exercisable as of December 31, 2014	4.5		$	33.53		4.2	$	144
	Options expected to vest as of December 31, 2014	1.2		$	59.46		8.2	$	13.8
Stock Option Fair Value Assumptions	We estimated the fair value of each stock option award on the date of grant using a Black-Scholes option pricing model, modified for dividends and using the following weighted average assumptions:
		December 31
		2014			2013			2012
		Granted by			Granted by			Assumed in		Granted by
		Pentair plans			Pentair plans			Merger		Pentair plans
	Risk-free interest rate	1.44	%		0.69	%		0.02 - 0.68%		0.96	%
	Expected dividend yield	1.46	%		2.01	%		2.12	%	2.48	%
	Expected share price volatility	35.3	%		36	%		33	%	36.5	%
	Expected term (years)	5.6			5.7			0.1 - 5.1		5.7
Restricted Stock Activity	The following table summarizes restricted stock unit activity under all plans for the year ended December 31, 2014:
	Shares in millions	Number of		Weighted
		shares		average
				grant date
				fair value
	Outstanding as of January 1, 2014	1.3		$	43.25
	Granted	0.3		78.39
	Vested	(0.4	)	39.68
	Forfeited	(0.1	)	46.42
	Outstanding as of December 31, 2014	1.1		$	50.55

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
Financial Information by Reportable Business Segment	Financial information by reportable segment is included in the following summary:
		2014			2013			2012			2014			2013			2012
	In millions	Net sales									Segment income (loss)
	Valves & Controls	$	2,394.80		$	2,469.20		$	548.6		$	350.8		$	302.8		$	41.8
	Process Technologies	1,833.20			1,765.90			1,521.10			267.2			253.2			181.1
	Flow Technologies	1,106.60			1,131.60			1,025.50			138.5			132.3			104.7
	Technical Solutions	1,728.10			1,663.40			1,236.40			358.8			322.4			232.1
	Other	(23.7		)	(30.4		)	(24.8		)	(93.6		)	(108.4		)	(76.2		)
	Consolidated	$	7,039.00		$	6,999.70		$	4,306.80		$	1,021.70		$	902.3		$	483.5
		2014			2013				2014		2013			2012
	In millions	Identifiable assets (1)							Depreciation
	Valves & Controls	$	4,049.90		$	4,204.00			$	59	$	64		$	15.1
	Process Technologies	2,586.90			2,730.60				31.1		29.2			29.2
	Flow Technologies	1,276.70			1,426.40				14.5		14.5			14
	Technical Solutions	2,117.30			2,093.40				24.2		23.6			18.9
	Other	624.4			1,288.90				9.9		10			8
	Consolidated	$	10,655.20		$	11,743.30			$	138.7	$	141.3		$	85.2
		2014			2013			2012			2014			2013			2012
	In millions	Amortization									Capital expenditures
	Valves & Controls	$	53.4		$	69.3		$	21.7		$	45.9		$	67.2		$	21.9
	Process Technologies	27.2			26			24.4			30			45.2			31.2
	Flow Technologies	13.5			13.6			12.5			15.5			26.2			18.7
	Technical Solutions	19.9			25.2			16.2			24			16.2			13.5
	Other	—			—			0.1			14.2			15.2			9.2
	Consolidated	$	114		$	134.1		$	74.9		$	129.6		$	170		$	94.5
	-1	All cash and cash equivalents and assets held for sale are included in “Other.”
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]	The following table presents a reconciliation of consolidated segment income to consolidated operating income (loss):
	In millions	2014			2013			2012
	Segment income	$	1,021.70		$	902.3		$	483.5
	Deal related costs and expenses	—			—			(82.8		)
	Inventory step-up and customer backlog	—			(86.6		)	(157.7		)
	Restructuring and other	(109.6		)	(119.9		)	(45.4		)
	Pension and other post-retirement mark-to-market gain (loss)	(49.9		)	63.2			(141.7		)
	Trade name impairment	—			(11.0		)	(60.7		)
	Redomicile related expenses	(10.3		)	(5.4		)	—
	Operating income (loss)	$	851.9		$	742.6		$	(4.8	)
Geographic Information	The following tables present certain geographic information by region:
		2014			2013			2012			2014			2013
	In millions	Net sales									Long-lived assets
	U.S.	$	3,541.10		$	3,431.30		$	2,624.30		$	350		$	365.4
	Western Europe	1,701.00			1,795.30			909.1			340			393.9
	Fast Growth	998.5			921.6			473.8			180.9			193.3
	Other Developed	798.4			851.5			299.6			79.1			91.7
	Consolidated	$	7,039.00		$	6,999.70		$	4,306.80		$	950		$	1,044.30

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Net rental expense	Net rental expense under operating leases was as follows:
		Years ended December 31
	In millions	2014			2013			2012
	Gross rental expense	$	68.7		$	76		$	44.6
	Sublease rental income	(1.3		)	(0.9		)	(0.5		)
	Net rental expense	$	67.4		$	75.1		$	44.1
Net future minimum lease commitments	Future minimum lease commitments under non-cancelable operating leases, principally related to facilities, machinery, equipment and vehicles as of December 31, 2014 were as follows:
	In millions	2015			2016			2017			2018			2019			Thereafter		Total
	Minimum lease payments	$	52.4		$	40.1		$	31.2		$	19.7		$	15.7		$	19.1	$	178.2
	Minimum sublease rentals	(0.5		)	(0.4		)	(0.4		)	(0.4		)	(0.4		)	—		(2.1		)
	Net future minimum lease commitments	$	51.9		$	39.7		$	30.8		$	19.3		$	15.3		$	19.1	$	176.1
Changes in Carrying Amount of Service and Product Warranties	The changes in the carrying amount of service and product warranties for the years ended December 31, 2014 and 2013 were as follows:
		Years ended December 31
	In millions	2014			2013
	Beginning balance	$	56		$	52.5
	Service and product warranty provision	75.3			64.1
	Payments	(62.1		)	(60.8		)
	Foreign currency translation	(2.8		)	0.2
	Ending balance	$	66.4		$	56

Selected_Quarterly_Data_Tables

Selected Quarterly Data (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information	The following tables present 2014 and 2013 quarterly financial information:
		2014
	In millions, except per-share data	First			Second		Third			Fourth			Full
		Quarter			Quarter		Quarter			Quarter			Year
	Net sales	$	1,644.00		$	1,834.10	$	1,758.40		$	1,802.50		$	7,039.00
	Gross profit	564.1			646.3		624.7			627.9			2,463.00
	Operating income	182.1			226.4		267.4			176			851.9
	Net income from continuing operations	125.5			159.2		192.5			129.8			607
	Income (loss) from discontinued operations, net of tax	(1.3		)	2.3		1.6			(9.0		)	(6.4		)
	Loss from sale / impairment of discontinued operations, net of tax	(5.6		)	—		(380.1		)	—			(385.7		)
	Net income (loss) attributable to Pentair plc	118.6			161.5		(186.0		)	120.8			214.9
	Earnings (loss) per ordinary share attributable to Pentair plc (1)
	Basic
	Continuing operations	$	0.64		$	0.82	$	1.01		$	0.71		$	3.19
	Discontinued operations	(0.04		)	0.02		(1.99		)	(0.05		)	(2.06		)
	Basic earnings (loss) per ordinary share attributable to Pentair plc	$	0.6		$	0.84	$	(0.98	)	$	0.66		$	1.13
	Diluted
	Continuing operations	$	0.63		$	0.81	$	1		$	0.7		$	3.14
	Discontinued operations	(0.04		)	0.01		(1.95		)	(0.05		)	(2.03		)
	Diluted earnings (loss) per ordinary share attributable to Pentair plc	$	0.59		$	0.82	$	(0.95	)	$	0.65		$	1.11
		2013
	In millions, except per-share data	First			Second		Third			Fourth			Full
		Quarter			Quarter		Quarter			Quarter			Year
	Net sales	$	1,663.70		$	1,791.70	$	1,713.30		$	1,831.00		$	6,999.70
	Gross profit	497.5			627.4		614.7			630.5			2,370.10
	Operating income	66.4			204.9		230			241.3			742.6
	Net income from continuing operations before noncontrolling interest	46.8			139.9		166.4			164.4			517.5
	Income (loss) from discontinued operations, net of tax	6.5			15.5		7.8			(3.9		)	25.9
	Loss from sale / impairment of discontinued operations, net of tax	—			—		—			(0.8		)	(0.8		)
	Net income attributable to Pentair plc	51.7			154.1		172.8			158.2			536.8
	Net income from continuing operations attributable to Pentair plc	45.2			138.6		165			162.9			511.7
	Earnings (loss) per ordinary share attributable to Pentair plc (1)
	Basic
	Continuing operations	$	0.22		$	0.69	$	0.83		$	0.82		$	2.54
	Discontinued operations	0.03			0.07		0.04			(0.02		)	0.13
	Basic earnings per ordinary share attributable to Pentair plc	$	0.25		$	0.76	$	0.87		$	0.8		$	2.67
	Diluted
	Continuing operations	$	0.22		$	0.67	$	0.81		$	0.81		$	2.5
	Discontinued operations	0.03			0.08		0.04			(0.03		)	0.12
	Diluted earnings per ordinary share attributable to Pentair plc	$	0.25		$	0.75	$	0.85		$	0.78		$	2.62
	-1	Amounts may not total to annual earnings because each quarter and year are calculated separately based on basic and diluted weighted-average ordinary shares outstanding during that period.

Financial_Statements_of_Parent1

Financial Statements of Parent Company Guarantor (Tables)	12 Months Ended
	Dec. 31, 2014																			Dec. 31, 2013																Dec. 31, 2012
Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)	Pentair plc and Subsidiaries																			Pentair plc and Subsidiaries																Pentair plc and Subsidiaries
	Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)																			Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)																Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)
	Year Ended December 31, 2014																			Year Ended December 31, 2013																Year Ended December 31, 2012
	In millions	Parent			Subsidiary Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated Total			In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total			In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
		Company						Issuer			Subsidiaries										Company			Issuer			Subsidiaries										Company			Issuer			Subsidiaries
		Guarantor																			Guarantor																Guarantor
	Net sales	$	—		$	—		$	—		$	7,039.00		$	—		$	7,039.00		Net sales	$	—		$	—		$	6,999.70		$	—		$	6,999.70		Net sales	$	—		$	—		$	4,306.80		$	—		$	4,306.80
	Cost of goods sold	—			—			—			4,576.00			—			4,576.00			Cost of goods sold	—			—			4,629.60			—			4,629.60			Cost of goods sold	—			—			3,040.90			—			3,040.90
	Gross profit	—			—			—			2,463.00			—			2,463.00			Gross profit	—			—			2,370.10			—			2,370.10			Gross profit	—			—			1,265.90			—			1,265.90
	Selling, general and administrative	25.3			2.6			7.7			1,458.20			—			1,493.80			Selling, general and administrative	21			13.3			1,459.40			—			1,493.70			Selling, general and administrative	5			(3.8		)	1,116.50			—			1,117.70
	Research and development	—			—			—			117.3			—			117.3			Research and development	—			—			122.8			—			122.8			Research and development	—			—			92.3			—			92.3
	Operating (loss) income	(25.3		)	(2.6		)	(7.7		)	887.5			—			851.9			Impairment of trade names	—			—			11			—			11			Impairment of trade names	—			—			60.7			—			60.7
	Loss (earnings) from continuing operations of investment in subsidiaries	(615.5		)	(619.7		)	(611.1		)	—			1,846.30			—			Operating (loss) income	(21.0		)	(13.3		)	776.9			—			742.6			Operating (loss) income	(5.0		)	3.8			(3.6		)	—			(4.8		)
	Other (income) expense:																			Loss (earnings) from continuing operations of investment in subsidiaries	(539.0		)	(508.6		)	—			1,047.60			—			Loss (earnings) from continuing operations of investment in subsidiaries	75.7			76.6			—			(152.3		)	—
	Loss on sale of businesses, net	—			—			—			0.2			—			0.2			Other (income) expense:																Other (income) expense:
																				Gain on sale of businesses, net	—			—			(20.8		)	—			(20.8		)	Loss on early extinguishment of debt	—			—			75.4			—			75.4
	Equity income of unconsolidated subsidiaries	—			—			—			(1.2		)	—			(1.2		)
																				Equity income of unconsolidated subsidiaries	—			—			(2.0		)	—			(2.0		)	Equity income of unconsolidated subsidiaries	—			—			(2.3		)	—			(2.3		)
	Interest income	—			—			(92.3		)	(40.2		)	128.8			(3.7		)
																				Interest income	—			(99.2		)	(53.4		)	148.2			(4.4		)	Interest income	—			(9.2		)	(2.0		)	9.2			(2.0		)
	Interest expense	0.7			2.1			95.6			102.7			(128.8		)	72.3
																				Interest expense	5.6			106			111.9			(148.2		)	75.3			Interest expense	0.1			10.2			69.1			(9.2		)	70.2
	Income (loss) from continuing operations before income taxes	589.5			615			600.1			826			(1,846.3		)	784.3
																				Income (loss) from continuing operations before income taxes and noncontrolling interest	512.4			488.5			741.2			(1,047.6		)	694.5			Income (loss) from continuing operations before income taxes and noncontrolling interest	(80.8		)	(73.8		)	(143.8		)	152.3			(146.1		)
	Provision (benefit) for income taxes	(17.5		)	(0.5		)	(2.4		)	197.7			—			177.3
																				Provision for income taxes	0.7			1.4			174.9			—			177			Provision (benefit) for income taxes	0.7			1.1			(69.0		)	—			(67.2		)
	Net income (loss) from continuing operations	607			615.5			602.5			628.3			(1,846.3		)	607
																				Net income (loss) from continuing operations before noncontrolling interest	511.7			487.1			566.3			(1,047.6		)	517.5			Net income (loss) from continuing operations before noncontrolling interest	(81.5		)	(74.9		)	(74.8		)	152.3			(78.9		)
	Loss from discontinued operations, net of tax	—			—			—			(6.4		)	—			(6.4		)
																				Income from discontinued operations, net of tax	—			—			25.9			—			25.9			Loss from discontinued operations, net of tax	—			—			(25.7		)	—			(25.7		)
	Loss from sale / impairment of discontinued operations, net of tax	—			—			—			(385.7		)	—			(385.7		)
																				Loss from sale of discontinued operations, net of tax	—			—			(0.8		)	—			(0.8		)	Earnings (loss) from discontinued operations of investment in subsidiaries	(25.7		)	(25.7		)	—			51.4			—
	Earnings (loss) from discontinued operations of investment in subsidiaries	(392.1		)	(392.1		)	(392.1		)	—			1,176.30			—
																				Earnings (loss) from discontinued operations of investment in subsidiaries	25.1			25.1			—			(50.2		)	—			Net income (loss) before noncontrolling interest	(107.2		)	(100.6		)	(100.5		)	203.7			(104.6		)
	Net income (loss) attributable to Pentair plc	$	214.9		$	223.4		$	210.4		$	236.2		$	(670.0	)	$	214.9
																				Net income (loss) before noncontrolling interest	536.8			512.2			591.4			(1,097.8		)	542.6			Noncontrolling interest	—			—			2.6			—			2.6
	Comprehensive income (loss), net of tax
	Net income (loss) attributable to Pentair plc	$	214.9		$	223.4		$	210.4		$	236.2		$	(670.0	)	$	214.9		Noncontrolling interest	—			—			5.8			—			5.8			Net income (loss) attributable to Pentair plc	$	(107.2	)	$	(100.6	)	$	(103.1	)	$	203.7		$	(107.2	)
	Changes in cumulative translation adjustment	(336.3		)	(336.3		)	(336.3		)	(336.3		)	1,008.90			(336.3		)	Net income (loss) attributable to Pentair plc	$	536.8		$	512.2		$	585.6		$	(1,097.8	)	$	536.8		Net income (loss) from continuing operations attributable to Pentair plc	$	(81.5	)	$	(74.9	)	$	(77.4	)	$	152.3		$	(81.5	)
	Changes in market value of derivative financial instruments	(0.4		)	(0.4		)	(0.4		)	(0.4		)	1.2			(0.4		)	Net income (loss) from continuing operations attributable to Pentair plc	$	511.7		$	487.1		$	560.5		$	(1,047.6	)	$	511.7		Comprehensive income (loss), net of tax
																																				Net income (loss) before noncontrolling interest	$	(107.2	)	$	(100.6	)	$	(100.5	)	$	203.7		$	(104.6	)
	Comprehensive income (loss) attributable to Pentair plc	$	(121.8	)	$	(113.3	)	$	(126.3	)	$	(100.5	)	$	340.1		$	(121.8	)	Comprehensive income (loss), net of tax
																				Net income (loss) before noncontrolling interest	$	536.8		$	512.2		$	591.4		$	(1,097.8	)	$	542.6		Changes in cumulative translation adjustment	30			30			31.4			(60.0		)	31.4
																				Changes in cumulative translation adjustment	(31.3		)	(31.3		)	(29.1		)	62.6			(29.1		)	Amortization of pension and other post-retirement prior service cost	(0.3		)	(0.3		)	(0.3		)	0.6			(0.3		)
																				Amortization of pension and other post-retirement prior service cost	(0.4		)	(0.4		)	(0.4		)	0.8			(0.4		)	Changes in market value of derivative financial instruments	(3.6		)	(3.6		)	(3.6		)	7.2			(3.6		)
																				Changes in market value of derivative financial instruments	(0.3		)	(0.3		)	(0.3		)	0.6			(0.3		)	Total comprehensive income (loss)	(81.1		)	(74.5		)	(73.0		)	151.5			(77.1		)
																				Total comprehensive income (loss)	504.8			480.2			561.6			(1,033.8		)	512.8			Less: Comprehensive income (loss) attributable to noncontrolling interest	—			—			4			—			4
																				Less: Comprehensive income (loss) attributable to noncontrolling interest	—			—			8			—			8			Comprehensive income (loss) attributable to Pentair plc	$	(81.1	)	$	(74.5	)	$	(77.0	)	$	151.5		$	(81.1	)
																				Comprehensive income (loss) attributable to Pentair plc	$	504.8		$	480.2		$	553.6		$	(1,033.8	)	$	504.8
Condensed Consolidating Balance Sheet	Pentair plc and Subsidiaries																			Pentair plc and Subsidiaries
	Condensed Consolidating Balance Sheet																			Condensed Consolidating Balance Sheet
	December 31, 2014																			December 31, 2013
	In millions	Parent			Subsidiary Guarantor			Subsidiary			Non-guarantor			Eliminations			Consolidated Total			In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
		Company						Issuer			Subsidiaries										Company			Issuer			Subsidiaries
		Guarantor																			Guarantor
	Assets																			Assets
	Current assets																			Current assets
	Cash and cash equivalents	$	—		$	—		$	0.1		$	110.3		$	—		$	110.4		Cash and cash equivalents	$	0.5		$	47		$	208.5		$	—		$	256
	Accounts and notes receivable, net	—			—			—			1,206.80			(0.9		)	1,205.90			Accounts and notes receivable, net	2.9			4			1,341.70			(63.6		)	$	1,285.00
	Inventories	—			—			—			1,130.40			—			1,130.40			Inventories	—			—			1,195.10			—			$	1,195.10
	Other current assets	—			17.6			2			367.6			(20.4		)	366.8			Other current assets	1.4			0.6			359.6			—			$	361.6
	Current assets held for sale	—			—			—			80.6			—			80.6			Current assets held for sale	—			—			134.4			—			$	134.4
	Total current assets	—			17.6			2.1			2,895.70			(21.3		)	2,894.10			Total current assets	4.8			51.6			3,239.30			(63.6		)	3,232.10
	Property, plant and equipment, net	—			—			—			950			—			950			Property, plant and equipment, net	—			—			1,044.30			—			1,044.30
	Other assets																			Other assets
																				Investments in subsidiaries	6,224.70			8,066.60			—			(14,291.3		)	—
	Investments in subsidiaries	4,733.00			4,893.80			7,612.20			—			(17,239.0		)	—
																				Goodwill	—			—			4,860.70			—			4,860.70
	Goodwill	—			—			—			4,741.90			—			4,741.90
																				Intangibles, net	—			—			1,749.90			—			1,749.90
	Intangibles, net	—			—			—			1,608.10			—			1,608.10
																				Other non-current assets	31.6			1,302.70			352.4			(1,296.7		)	390
	Other non-current assets	80.2			—			1,381.80			345			(1,370.8		)	436.2
																				Non-current assets held for sale	—			—			466.3			—			466.3
	Non-current assets held for sale	—			—			—			24.9			—			24.9
																				Total other assets	6,256.30			9,369.30			7,429.30			(15,588.0		)	7,466.90
	Total other assets	4,813.20			4,893.80			8,994.00			6,719.90			(18,609.8		)	6,811.10
																				Total assets	$	6,261.10		$	9,420.90		$	11,712.90		$	(15,651.6	)	$	11,743.30
	Total assets	$	4,813.20		$	4,911.40		$	8,996.10		$	10,565.60		$	(18,631.1	)	$	10,655.20
																				Liabilities and Equity
	Liabilities and Equity																			Current liabilities
	Current liabilities																			Current maturities of long-term debt and short-term borrowings	$	—		$	—		$	2.5		$	—		$	2.5
	Current maturities of long-term debt and short-term borrowings	$	—		$	—		$	—		$	6.7		$	—		$	6.7
																				Accounts payable	48.1			8.6			583.8			(63.6		)	576.9
	Accounts payable	0.9			—			—			583.1			(0.9		)	583.1
																				Employee compensation and benefits	0.5			—			311.9			—			312.4
	Employee compensation and benefits	0.2			0.6			—			304.7			—			305.5
																				Other current liabilities	99.6			11.7			534.6			—			645.9
	Other current liabilities	120.6			2.2			10.9			595.8			(20.4		)	709.1
																				Current liabilities held for sale	—			—			72.5			—			72.5
	Current liabilities held for sale	—			—			—			35.1			—			35.1
																				Total current liabilities	148.2			20.3			1,505.30			(63.6		)	1,610.20
	Total current liabilities	121.7			2.8			10.9			1,525.40			(21.3		)	1,639.50
																				Other liabilities
	Other liabilities																			Long-term debt	—			2,401.90			1,442.70			(1,296.7		)	2,547.90
	Long-term debt	11.4			175.6			2,860.60			1,320.60			(1,370.8		)	2,997.40
																				Pension and other post-retirement compensation and benefits	—			—			320.2			—			320.2
	Pension and other post-retirement compensation and benefits	—			—			—			322			—			322
																				Deferred tax liabilities	—			2.2			554.8			—			557
	Deferred tax liabilities	—			—			2.9			525.4			—			528.3
																				Other non-current liabilities	17.6			—			438.8			—			456.4
	Other non-current liabilities	16.3			—			—			481.4			—			497.7
																				Non-current liabilities held for sale	—			—			33.9			—			33.9
	Non-current liabilities held for sale	—			—			—			6.5			—			6.5
																				Total liabilities	165.8			2,424.40			4,295.70			(1,360.3		)	5,525.60
	Total liabilities	149.4			178.4			2,874.40			4,181.30			(1,392.1		)	5,991.40
																				Equity
	Equity	4,663.80			4,733.00			6,121.70			6,384.30			(17,239.0		)	4,663.80			Shareholders’ equity attributable to Pentair plc and subsidiaries	6,095.30			6,996.50			7,294.80			(14,291.3		)	6,095.30
	Total liabilities and equity	$	4,813.20		$	4,911.40		$	8,996.10		$	10,565.60		$	(18,631.1	)	$	10,655.20		Noncontrolling interest	—			—			122.4			—			122.4
																				Total equity	6,095.30			6,996.50			7,417.20			(14,291.3		)	6,217.70
																				Total liabilities and equity	$	6,261.10		$	9,420.90		$	11,712.90		$	(15,651.6	)	$	11,743.30
Condensed Consolidating Statement of Cash Flows	Pentair plc and Subsidiaries																			Pentair plc and Subsidiaries																Pentair plc and Subsidiaries
	Condensed Consolidating Statement of Cash Flows																			Condensed Consolidating Statement of Cash Flows																Condensed Consolidating Statement of Cash Flows
	Year Ended December 31, 2014																			Year Ended December 31, 2013																Year Ended December 31, 2012
	In millions	Parent			Guarantor Subsidiary			Subsidiary			Non-guarantor			Eliminations			Consolidated Total			In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total			In millions	Parent			Subsidiary			Non-guarantor			Eliminations			Consolidated Total
		Company						Issuer			Subsidiaries										Company			Issuer			Subsidiaries										Company			Issuer			Subsidiaries
		Guarantor																			Guarantor																Guarantor
	Operating activities																			Operating activities																Operating activities
	Net cash provided by (used for) operating activities	$	169		$	208.6		$	207		$	1,093.80		$	(670.0	)	$	1,008.40		Net cash provided by (used for) operating activities	$	534.2		$	514		$	977.5		$	(1,097.8	)	$	927.9		Net cash provided by (used for) operating activities	$	(109.0	)	$	(88.2	)	$	37.2		$	203.7		$	43.7
	Investing activities																			Investing activities																Investing activities
	Capital expenditures	—			—			—			(129.6		)	—			(129.6		)	Capital expenditures	—			—			(170.0		)	—			(170.0		)	Capital expenditures	—			—			(94.5		)	—			(94.5		)
	Proceeds from sale of property and equipment	—			—			—			13.1			—			13.1			Proceeds from sale of property and equipment	—			—			6			—			6			Proceeds from sale of property and equipment	—			—			5.5			—			5.5
	Proceeds from sale of businesses, net	—			—			—			0.3			—			0.3			Proceeds from sale of businesses, net	—			—			43.5			—			43.5			Acquisitions, net of cash acquired	—			300.1			170.4			—			470.5
	Acquisitions, net of cash acquired	—			—			—			(12.3		)	—			(12.3		)	Acquisitions, net of cash acquired	—			—			(92.4		)	—			(92.4		)	Other	—			—			(5.9		)	—			(5.9		)
	Net intercompany loan activity	—			—			37.8			112.2			(150.0		)	—			Other	—			—			1.7			—			1.7			Net cash provided by (used for) investing activities	—			300.1			75.5			—			375.6
	Other	—			—			—			0.2			—			0.2			Net cash provided by (used for) investing activities	—			—			(211.2		)	—			(211.2		)	Financing activities
																																				Net repayments of short-term borrowings	—			—			(3.7		)	—			(3.7		)
	Net cash provided by (used for) investing activities	—			—			37.8			(16.1		)	(150.0		)	(128.3		)	Financing activities
																				Net receipts of commercial paper and revolving long-term debt	—			104.2			—			—			104.2			Net receipts (repayments) of commercial paper and revolving long-term debt	—			424.7			(170.9		)	—			253.8
	Financing activities
	Net receipts of short-term borrowings	—			—			—			0.5			—			0.5			Proceeds from long-term debt	—			—			0.7			—			0.7			Proceeds from long-term debt	—			594.3			—			—			594.3
	Net receipts of commercial paper and revolving long-term debt	—			—			458.7			9.9			—			468.6			Repayment of long-term debt	—			—			(7.4		)	—			(7.4		)	Repayment of long-term debt	—			—			(617.2		)	—			(617.2		)
	Proceeds from long-term debt	—			—			—			2.2			—			2.2			Debt issuance costs	—			(1.4		)	—			—			(1.4		)	Debt issuance costs	—			(8.7		)	(1.0		)	—			(9.7		)
	Repayment of long-term debt	—			—			—			(16.8		)	—			(16.8		)	Net change in advances to subsidiaries	(339.5		)	(569.8		)	(188.5		)	1,097.80			—			Debt extinguishment costs	—			—			(74.8		)	—			(74.8		)
	Debt issuance costs	—			—			(3.1		)	—			—			(3.1		)	Excess tax benefits from share-based compensation	—			—			16.8			—			16.8			Net change in advances to subsidiaries	157			(1,222.2		)	1,268.90			(203.7		)	—
	Net change in advances to subsidiaries	741.1			(208.6		)	(747.3		)	(605.2		)	820			—			Shares issued to employees, net of shares withheld	—			—			80			—			80			Excess tax benefits from share-based compensation	—			—			5			—			5
	Excess tax benefits from share-based compensation	—			—			—			12.6			—			12.6			Repurchases of ordinary shares	—			—			(715.8		)	—			(715.8		)	Shares issued to employees, net of shares withheld	—			—			68.2			—			68.2
	Shares issued to employees, net of shares withheld	—			—			—			37			—			37			Dividends paid	(194.2		)	—			—			—			(194.2		)	Repurchases of ordinary shares	—			—			(334.2		)	—			(334.2		)
	Repurchases of ordinary shares	(699.2		)	—			—			(450.8		)	—			(1,150.0		)	Distributions to noncontrolling interest	—			—			(2.0		)	—			(2.0		)	Dividends paid	(48.0		)	—			(64.4		)	—			(112.4		)
	Dividends paid	(211.4		)	—			—			—			—			(211.4		)	Net cash provided by (used for) financing activities	(533.7		)	(467.0		)	(816.2		)	1,097.80			(719.1		)	Distributions to noncontrolling interest	—			—			(1.6		)	—			(1.6		)
	Purchase of noncontrolling interest	—			—			—			(134.7		)	—			(134.7		)	Effect of exchange rate changes on cash and cash equivalents	—			—			21			—			21			Net cash provided by (used for) financing activities	109			(211.9		)	74.3			(203.7		)	(232.3		)
	Net cash provided by (used for) financing activities	(169.5		)	(208.6		)	(291.7		)	(1,145.3		)	820			(995.1		)	Change in cash and cash equivalents	0.5			47			(28.9		)	—			18.6			Effect of exchange rate changes on cash and cash equivalents	—			—			0.3			—			0.3
	Effect of exchange rate changes on cash and cash equivalents	—			—			—			(30.6		)	—			(30.6		)	Cash and cash equivalents, beginning of year	—			—			237.4			—			237.4			Change in cash and cash equivalents	—			—			187.3			—			187.3
	Change in cash and cash equivalents	(0.5		)	—			(46.9		)	(98.2		)	—			(145.6		)	Cash and cash equivalents, end of year	$	0.5		$	47		$	208.5		$	—		$	256		Cash and cash equivalents, beginning of year	—			—			50.1			—			50.1
	Cash and cash equivalents, beginning of year	0.5			—			47			208.5			—			256																			Cash and cash equivalents, end of year	$	—		$	—		$	237.4		$	—		$	237.4
	Cash and cash equivalents, end of year	$	—		$	—		$	0.1		$	110.3		$	—		$	110.4

Basis_of_Presentation_and_Summ3

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Significant Accounting Policies [Line Items]
Impairment of Long-Lived Assets Held-for-use		$20.90	$16.60
Revenue Recognition
Cost in excess of billings	91.6	103.5	91.6
Billings in excess of cost	35.4	41.4	35.4
Research and development
Research and development		117.3	122.8	92.3
Goodwill and identifiable intangible assets
Goodwill planning period		6 years
Perpetual growth rate		3.00%
Impairment charges, related to trade names	11	0	11	60.7
Goodwill and intangible assets		6,350
Goodwill and intangible assets as a percentage of total assets		60.00%
Equity and cost method investments
Investments in and loans to equity method investees	12.2	12.9	12.2
Aggregate balance cost method investments	8.3	8.6	8.3
Insurance subsidiary
Reserve for policy claims	51.1	58.1	51.1
Minimum
Basis of presentation
Equity method investment, ownership percentage		20.00%
Goodwill and identifiable intangible assets
Discounted cash flows discount rate		11.00%
Maximum
Basis of presentation
Equity method investment, ownership percentage		50.00%
Goodwill and identifiable intangible assets
Discounted cash flows discount rate		12.00%
Other Current Liabilities
Insurance subsidiary
Reserve for policy claims	13.2	13.2	13.2
Other Noncurrent Liabilities
Insurance subsidiary
Reserve for policy claims	$37.90	$44.90	$37.90
Credit Concentration Risk
Trade receivables and concentration of credit risk
Customer receivable balances to total trade receivables		10.00%	10.00%
Number of customers	0	0	0

Basis_of_Presentation_and_Summ4

Basis of Presentation and Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2014
Land Improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful lives	5 years
Land Improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful lives	20 years
Buildings and Leasehold Improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful lives	5 years
Buildings and Leasehold Improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful lives	50 years
Machinery and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful lives	3 years
Machinery and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful lives	15 years

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended	0 Months Ended	3 Months Ended	1 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 28, 2012	Jan. 30, 2014	Mar. 29, 2014	Oct. 04, 2012	Dec. 31, 2012
Pro forma results of material acquisitions
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests	$134.70
Other acquisitions
Cost and expenses incurred in connection with acquisition		8.2	57.3
Process Technologies
Other acquisitions
Goodwill			80.9					80.9
Expected tax deductible goodwill			67.1					67.1
Purchase Price			121.2					121.2
Tyco Flow Control International, Ltd
Material acquisitions
Percentage of ownership				100.00%
Shares issued for stock acquisition				110.9
Pro forma results of material acquisitions
Acquired Inventory			156.2
Pentair Residential Filtration [Member]
Pro forma results of material acquisitions
Percentage Of Ownership Interest Acquired					19.90%
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests						134.3
Other acquisitions
Percentage of ownership interests before acquisition					80.10%
Pentair Middle East Holding S.a.r.l.
Pro forma results of material acquisitions
Percentage Of Ownership Interest Acquired							25.00%
Other acquisitions
Cash paid								100
Percentage of ownership interests before acquisition							75.00%
Change In Control Of Company [Member] | Tyco Flow Control International, Ltd
Pro forma results of material acquisitions
Acquisition related costs			21.8
Transaction Costs [Member] | Tyco Flow Control International, Ltd
Pro forma results of material acquisitions
Acquisition related costs			$57.30

Acquisitions_Pro_Forma_Consoli

Acquisitions - Pro Forma Consolidated FInancial Results of Operations (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2012
Business Acquisition [Line Items]
Pro forma net sales	$6,846.60
Pro forma net income from continuing operations attributable to Pentair plc	$183.30
Diluted earnings from continuing operations per ordinary share attributable to Pentair plc	$0.87

Discontinued_Operations_and_Di2

Discontinued Operations and Divestitures Components of Discontinued Operations (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue									$295.80	$490.10	$112.10
Disposal Group, Including Discontinued Operation, Other Assets, Current	14.7				27.8				14.7	27.8
Disposal Group, Including Discontinued Operation, Inventory	30.1				48.2				30.1	48.2
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net	28.8				49.3				28.8	49.3
Disposal Group, Including Discontinued Operation, Assets, Current	80.6				134.4				80.6	134.4
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	18.5				125.7				18.5	125.7
Disposal Group, Including Discontinued Operation, Goodwill	0				273.5				0	273.5
Disposal Group, Including Discontinued Operation, Intangible Assets	0				26.2				0	26.2
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	6.4				40.9				6.4	40.9
Disposal Group, Including Discontinued Operation, Accounts Payable, Current	12.2				19.7				12.2	19.7
Disposal Group, Including Discontinued Operation, Employee Compensation and Benefits	11.3				34.7				11.3	34.7
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	24.9				466.3				24.9	466.3
Disposal Group, Including Discontinued Operation, Other Liabilities, Current	11.6				18.1				11.6	18.1
Disposal Group, Including Discontinued Operation, Deferred Tax Liabilities, Noncurrent	0				23.6				0	23.6
Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation	2.5				4.6				2.5	4.6
Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent	0				1				0	1
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	6.5				33.9				6.5	33.9
Disposal Group, Including Discontinued Operation, Long Term Debt	4				4.7				4	4.7
Disposal Group, Including Discontinued Operation, Liabilities, Current	35.1				72.5				35.1	72.5
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents	7				9.1				7	9.1
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax									1.5	33	-37.9
Discontinued Operation, Tax Effect of Discontinued Operation									-7.9	-7.1	12.2
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									-6.4	25.9	-25.7
Discontinued Operation, Provision for Loss (Gain) on Disposal, before Income Tax									-400.4	-1.1	0
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal		12.3		2.4	0.3				14.7	0.3	0
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	$0	($380.10)	$0	($5.60)	($0.80)	$0	$0	$0	($385.70)	($0.80)	$0

Discontinued_Operations_and_Di3

Discontinued Operations and Divestitures Additional Information (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
Proceeds from Divestiture of Businesses									$0.30	$43.50	$0
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal		12.3		2.4	0.3				14.7	0.3	0
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax				-5.6	-0.8
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	0	-380.1	0	-5.6	-0.8	0	0	0	-385.7	-0.8	0
Gain (Loss) on Disposition of Business									-0.2	20.8	0
Technical Solutions [Member]
Business Acquisition [Line Items]
Proceeds from Divestiture of Businesses										30.1
Gain (Loss) on Disposition of Business										16.8
Goodwill, Written off Related to Sale of Business Unit										5.3
Flow Technologies [Member]
Business Acquisition [Line Items]
Proceeds from Divestiture of Businesses										13.4
Gain (Loss) on Disposition of Business										4
Goodwill, Written off Related to Sale of Business Unit										$5.70

Earnings_Loss_Per_Share_Additi

Earnings (Loss) Per Share - Additional Information (Detail) (USD $)	3 Months Ended																12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 27, 2014		Jun. 28, 2014		Mar. 29, 2014		Dec. 31, 2013		Sep. 28, 2013		Jun. 29, 2013		Mar. 30, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Computation Of Earnings Per Share Line Items
Net income (loss) attributable to Pentair plc	$120.80		($186)		$161.50		$118.60		$158.20		$172.80		$154.10		$51.70		$214.90		$536.80		($107.20)
Income (Loss) from Continuing Operations Attributable to Parent									$162.90		$165		$138.60		$45.20		$607		$511.70		($81.50)
Weighted average common shares outstanding
Basic (shares)																	190.6		201.1		127.4
Dilutive impact of stock options and restricted stock awards (shares)																	3.1		3.5		0
Diluted (shares)																	193.7		204.6		127.4
Income (Loss) from Continuing Operations, Per Basic Share	$0.71		$1.01		$0.82		$0.64		$0.82		$0.83		$0.69		$0.22		$3.19		$2.54		($0.64)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	($0.05)		($1.99)		$0.02		($0.04)		($0.02)		$0.04		$0.07		$0.03		($2.06)		$0.13		($0.20)
Earnings (loss) per ordinary share attributable to Pentair plc
Basic earnings (loss) per common share (USD per share)	$0.66	[1]	($0.98)	[1]	$0.84	[1]	$0.60	[1]	$0.80	[1]	$0.87	[1]	$0.76	[1]	$0.25	[1]	$1.13	[1]	$2.67	[1]	($0.84)
Income (Loss) from Continuing Operations, Per Diluted Share	$0.70		$1		$0.81		$0.63		$0.81		$0.81		$0.67		$0.22		$3.14		$2.50		($0.64)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	($0.05)		($1.95)		$0.01		($0.04)		($0.03)		$0.04		$0.08		$0.03		($2.03)		$0.12		($0.20)
Diluted earnings (loss) per common share (USD per share)	$0.65	[1]	($0.95)	[1]	$0.82	[1]	$0.59	[1]	$0.78	[1]	$0.85	[1]	$0.75	[1]	$0.25	[1]	$1.11	[1]	$2.62	[1]	($0.84)
Anti-dilutive stock options excluded from the calculation of diluted earnings per share																	0.5		0.2		16
[1]	Amounts may not total to annual earnings because each quarter and year are calculated separately based on basic and diluted weighted-average ordinary shares outstanding during that period

Restructuring_Additional_Infor

Restructuring - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Person	Person	Person
Restructuring Cost and Reserve [Line Items]
Number of employees	1,150	1,100	800
Restructuring costs	$88.30	$103.20	$48.70
Valves And Controls [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees	600	500	300
Restructuring costs	48.8	51	5.1
Process Technologies [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees	100	150	200
Restructuring costs	18.6	9.4	25.2
Flow Technologies [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees	300	150	100
Restructuring costs	10.6	13.4	5.7
Technical Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees	150	300	200
Restructuring costs	$4.30	$19.40	$12.70

Restructuring_Costs_Included_i

Restructuring - Costs Included in Selling, General & Administrative expenses on Consolidated Statements of Income (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$88.30	$103.20	$48.70
Severance and related costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	58.9	81.5	43.4
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$29.40	$21.70	$5.30

Restructuring_Accrual_Activity

Restructuring - Accrual Activity recorded on Condensed Consolidated Balance Sheets (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restructuring Reserve [Roll Forward]
Beginning balance	$68.60	$40.40
Costs incurred	58.9	81.5
Cash payments and other	-54.1	-53.3
Ending balance	$73.40	$68.60

Restructuring_Restructuring_Co

Restructuring - Restructuring Costs by Segment (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$88.30	$103.20	$48.70
Valves And Controls [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	48.8	51	5.1
Process Technologies [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	18.6	9.4	25.2
Flow Technologies [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	10.6	13.4	5.7
Technical Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	4.3	19.4	12.7
Corporate and Other [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$6	$10	$0

Goodwill_and_Other_Identifiabl2

Goodwill and Other Identifiable Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amortization and Impairment
Accumulated goodwill impairment losses	$200.50	$200.50	$200.50
Amortization		114	134.1	74.9
Impairment charges, related to trade names	11	0	11	60.7
Process Technologies
Amortization and Impairment
Impairment charges, related to trade names				23.2
Flow Technologies
Amortization and Impairment
Impairment charges, related to trade names				25.9
Technical Solutions
Amortization and Impairment
Impairment charges, related to trade names			$11	$11.60

Goodwill_and_Other_Identifiabl3

Goodwill and Other Identifiable Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Beginning Balance	$4,860.70	$4,837.50
Acquisitions/ divestitures	6.8	-3.4
Foreign currency translation/other	-125.6	26.6
Ending Balance	4,741.90	4,860.70
Valves & Controls
Goodwill [Roll Forward]
Beginning Balance	1,511.60	1,511.60
Acquisitions/ divestitures	0	0
Foreign currency translation/other	0	0
Ending Balance	1,511.60	1,511.60
Process Technologies
Goodwill [Roll Forward]
Beginning Balance	1,524.50	1,500.40
Acquisitions/ divestitures	6.8	7.6
Foreign currency translation/other	-79.8	16.5
Ending Balance	1,451.50	1,524.50
Flow Technologies
Goodwill [Roll Forward]
Beginning Balance	666.6	663.8
Acquisitions/ divestitures	0	-5.7
Foreign currency translation/other	-38.1	8.5
Ending Balance	628.5	666.6
Technical Solutions
Goodwill [Roll Forward]
Beginning Balance	1,158	1,161.70
Acquisitions/ divestitures	0	-5.3
Foreign currency translation/other	-7.7	1.6
Ending Balance	$1,150.30	$1,158

Goodwill_and_Other_Identifiabl4

Goodwill and Other Identifiable Intangible Assets - Identifiable Intangible Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	$1,505.50	$1,537
Accumulated amortization	-423	-324
Finite-life intangibles, net	1,082.50	1,213
Indefinite-life intangibles	525.6	536.9
Total intangibles, cost	2,031.10	2,073.90
Total intangibles, net	1,608.10	1,749.90
Customer relationships
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	1,247.80	1,271.20
Accumulated amortization	-325.2	-243.1
Finite-life intangibles, net	922.6	1,028.10
Trade names
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	2	2.1
Accumulated amortization	-1.1	-0.9
Finite-life intangibles, net	0.9	1.2
Proprietary technology and patents
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	255.7	263.7
Accumulated amortization	-96.7	-80
Finite-life intangibles, net	$159	$183.70

Goodwill_and_Other_Identifiabl5

Goodwill and Other Identifiable Intangible Assets - Estimated Future Amortization Expense for Identifiable Intangible Assets (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Expected Amortization Expense
Estimated amortization expense 2015	$111.50
Estimated amortization expense 2016	110.6
Estimated amortization expense 2017	109
Estimated amortization expense 2018	106.5
Estimated amortization expense 2019	$99.40

Supplemental_Balance_Sheet_Inf2

Supplemental Balance Sheet Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventories
Raw materials and supplies	$460.10	$549.80
Work-in-process	229	164.4
Finished goods	441.3	480.9
Total inventories	1,130.40	1,195.10
Other current assets
Cost in excess of billings	103.5	91.6
Prepaid expenses	109.6	97.6
Deferred income taxes	139.4	149.7
Other current assets	14.3	22.7
Total other current assets	366.8	361.6
Property, plant and equipment, net
Land and land improvements	165.1	186.4
Buildings and leasehold improvements	493.5	502.6
Machinery and equipment	1,169.10	1,155.10
Construction in progress	71	70.9
Total property, plant and equipment	1,898.70	1,915
Accumulated depreciation and amortization	948.7	870.7
Total property, plant and equipment, net	950	1,044.30
Other non-current assets
Asbestos-related insurance receivable	115.8	119.6
Deferred income taxes	87.9	92.4
Other non-current assets	232.5	178
Total other non-current assets	436.2	390
Other current liabilities
Deferred revenue and customer deposits	112.7	90.8
Dividends payable	116.8	98.7
Billings in excess of cost	41.4	35.4
Accrued warranty	66.4	56
Other current liabilities	371.8	365
Total other current liabilities	709.1	645.9
Other non-current liabilities
Asbestos-related liabilities	249.1	254.7
Taxes payable	61.6	48.9
Other non-current liabilities	187	152.8
Total other non-current liabilities	$497.70	$456.40

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Cash Flow, Supplemental [Line Items]
Cash paid for interest, net	$67.50	$69.40	$66.70
Cash paid for income taxes, net	$134.20	$91.20	$82

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) - Components of AOCI (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative translation adjustments	($371)	($34.70)
Market value of derivative financial instruments, net of tax	-9.3	-8.9
Accumulated other comprehensive income (loss)	($380.30)	($43.60)

Debt_Additional_Information_De

Debt - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended	3 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Oct. 04, 2012	Dec. 31, 2012	Sep. 29, 2012	Oct. 30, 2012	Dec. 31, 2012	Sep. 28, 2013	Oct. 31, 2012	Nov. 30, 2012
Debt Disclosure [Line Items]
Debt transaction cost paid	$0	$0	$74,800,000
Debt instrument proceeds used to repay amounts of other debt									435,000,000
Commercial paper outstanding	987,600,000	528,900,000
Cost and expenses incurred in connection with acquisition		8,200,000	57,300,000
Compliance with debt agreement financial covenants	we were in compliance with all financial covenants in our debt agreements.
Future minimum lease payments	6,900,000
Imputed interest	200,000
Debt, Long-term and Short-term, Combined Amount	3,004,100,000	2,550,400,000
Pentair Middle East Holding S.a.r.l.
Debt Disclosure [Line Items]
Percentage Of Ownership Interest Acquired				25.00%
Cash paid					100,000,000
CPT
Debt Disclosure [Line Items]
Capital lease obligation cost	19,500,000	41,700,000
Accumulated amortization	2,400,000	7,600,000
Credit Facility
Debt Disclosure [Line Items]
Facility Fees, minimum						0.001
Facility Fees, maximum						0.003
Remaining availability under Credit Facility	1,102,600,000
Other Credit Facilities
Debt Disclosure [Line Items]
Credit facility maximum borrowing capacity	78,300,000
Line of credit facility, amount outstanding	0
Minimum
Debt Disclosure [Line Items]
Debt agreement financial covenant, leverage ratio	3.5
Maximum
Debt Disclosure [Line Items]
Cost and expenses incurred in connection with acquisition	25,000,000
Debt agreement financial covenant, leverage ratio	3
Senior Notes
Debt Disclosure [Line Items]
Whole premium amount										65,800,000
Terminate related interest rate swaps							3,400,000
Unamortized deferred financing costs										600,000
Senior Notes, 5.000% Due 2021
Debt Disclosure [Line Items]
Aggregate principal amount	373,000,000
Debt, interest rate	5.00%
Debt transaction cost paid								5,600,000
Aggregate principal amount	127,000,000
Senior Notes, 5.000% Due 2021 | Senior Notes
Debt Disclosure [Line Items]
Debt, Weighted Average Interest Rate	5.00%
Debt, Long-term and Short-term, Combined Amount	500,000,000	500,000,000
Senior Notes 1.350% due 2015
Debt Disclosure [Line Items]
Aggregate principal amount											350,000,000
Debt, interest rate											1.35%
Senior Notes 1.350% due 2015 | Senior Notes
Debt Disclosure [Line Items]
Debt, Weighted Average Interest Rate	1.35%
Debt, Long-term and Short-term, Combined Amount	350,000,000	350,000,000
Senior Notes 2.650% due 2019
Debt Disclosure [Line Items]
Aggregate principal amount											250,000,000
Debt, interest rate											2.65%
Senior Notes 2.650% due 2019 | Senior Notes
Debt Disclosure [Line Items]
Debt, Weighted Average Interest Rate	2.65%
Debt, Long-term and Short-term, Combined Amount	250,000,000	250,000,000
Senior Notes 5.65% | Fixed Rate
Debt Disclosure [Line Items]
Debt, interest rate										5.65%
Outstanding aggregate principal										400,000,000
Senior Notes 1.05% Due 2013 | Floating Rate
Debt Disclosure [Line Items]
Floating rate notes										1.05%
Senior Notes 1.05% Due 2013 | Senior Notes
Debt Disclosure [Line Items]
Redemption value							100,000,000
Senior Notes 3.150% due 2022
Debt Disclosure [Line Items]
Aggregate principal amount									550,000,000
Debt, interest rate									3.15%
Senior Notes 3.150% due 2022 | Senior Notes
Debt Disclosure [Line Items]
Debt, Weighted Average Interest Rate	3.15%
Debt, Long-term and Short-term, Combined Amount	550,000,000	550,000,000
Senior Notes 1.875 % due 2017
Debt Disclosure [Line Items]
Aggregate principal amount									350,000,000
Debt, interest rate									1.88%
Senior Notes 1.875 % due 2017 | Senior Notes
Debt Disclosure [Line Items]
Debt, Weighted Average Interest Rate	1.88%
Debt, Long-term and Short-term, Combined Amount	350,000,000	350,000,000
Subsidiary Issuer
Debt Disclosure [Line Items]
Ownership percentage	100.00%
Debt transaction cost paid			0
Subsidiary Issuer | Senior Notes, 5.000% Due 2021
Debt Disclosure [Line Items]
Debt, interest rate	5.00%
Subsidiary Issuer | Senior Notes 1.350% due 2015
Debt Disclosure [Line Items]
Debt, interest rate	1.35%
Subsidiary Issuer | Senior Notes 2.650% due 2019
Debt Disclosure [Line Items]
Debt, interest rate	2.65%
Subsidiary Issuer | Senior Notes 3.150% due 2022
Debt Disclosure [Line Items]
Debt, interest rate	3.15%
Subsidiary Issuer | Senior Notes 1.875 % due 2017
Debt Disclosure [Line Items]
Debt, interest rate	1.88%
Revolving Credit Facility [Member]
Debt Disclosure [Line Items]
Credit facility maximum borrowing capacity	$2,100,000,000

Debt_Debt_Outstanding_and_Aver

Debt - Debt Outstanding and Average Interest Rates (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Disclosure [Line Items]
Total debt	$3,004.10	$2,550.40
Less: Current maturities and short-term borrowings	-6.7	-2.5
Long-term debt	2,997.40	2,547.90
Commercial Paper
Debt Disclosure [Line Items]
Debt, average interest rate	0.68%
Total debt	987.6	528.9
Capital Lease Obligations
Debt Disclosure [Line Items]
Debt, average interest rate	6.20%
Total debt	6.7	21.5
Long Term Revolving Credit Facility [Member]
Debt Disclosure [Line Items]
Debt, average interest rate	1.42%
Total debt	9.8	0
Senior Notes 1.350% due 2015 | Senior Notes
Debt Disclosure [Line Items]
Debt, average interest rate	1.35%
Total debt	350	350
Senior Notes 1.875 % due 2017 | Senior Notes
Debt Disclosure [Line Items]
Debt, average interest rate	1.88%
Total debt	350	350
Senior Notes 2.650% due 2019 | Senior Notes
Debt Disclosure [Line Items]
Debt, average interest rate	2.65%
Total debt	250	250
Senior Notes, 5.000% Due 2021 | Senior Notes
Debt Disclosure [Line Items]
Debt, average interest rate	5.00%
Total debt	500	500
Senior Notes 3.150% due 2022 | Senior Notes
Debt Disclosure [Line Items]
Debt, average interest rate	3.15%
Total debt	$550	$550

Debt_Debt_Outstanding_Amounts_

Debt - Debt Outstanding Amounts Maturing (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Debt Disclosure [Line Items]
Debt outstanding maturities 2015	$6.70
Debt outstanding maturities 2016	0
Debt outstanding maturities 2017	350
Debt outstanding maturities 2018	0
Debt outstanding maturities 2019	1,597.40
Debt outstanding maturities Thereafter	1,050
Total debt	3,004.10	2,550.40
Contractual Maturity
Debt Disclosure [Line Items]
Debt outstanding maturities 2015	0
Debt outstanding maturities 2016	0
Debt outstanding maturities 2017	350
Debt outstanding maturities 2018	0
Debt outstanding maturities 2019	1,597.40
Debt outstanding maturities Thereafter	1,050
Total debt	2,997.40
Capital Lease Obligations
Debt Disclosure [Line Items]
Debt outstanding maturities 2015	6.7
Debt outstanding maturities 2016	0
Debt outstanding maturities 2017	0
Debt outstanding maturities 2018	0
Debt outstanding maturities 2019	0
Debt outstanding maturities Thereafter	0
Total debt	$6.70	$21.50

Derivatives_and_Financial_Inst2

Derivatives and Financial Instruments - Additional Information (Detail) (USD $)

3 Months Ended

12 Months Ended

1 Months Ended

In Millions, unless otherwise specified

Dec. 31, 2014

Sep. 27, 2014

Jun. 28, 2014

Mar. 29, 2014

Dec. 31, 2013

Sep. 28, 2013

Jun. 29, 2013

Mar. 30, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Apr. 30, 2011

Aug. 31, 2007

Sep. 30, 2005

Derivative Instruments and Hedging Activities Disclosure [Line Items]

Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax

$0

($380.10)

$0

($5.60)

($0.80)

$0

$0

$0

($385.70)

($0.80)

$0

Outstanding interest rate swap arrangements

0

0

0

0

Loss on early extinguishment of debt

0

0

75.4

Location of the swap on the consolidated balance sheets

Derivative gains and losses on interest rate swaps included in AOCI

Incremental expense resulting from interest rate swaps

5.3

Interest Rate Swap

Derivative Instruments and Hedging Activities Disclosure [Line Items]

Average swap interest rate

3.65%

Cost of expiration (termination)

11

Derivative instrument contractual life

10 years

Unrealized net loss

7

8.1

Cross Currency Interest Rate Contract [Member]

Derivative Instruments and Hedging Activities Disclosure [Line Items]

Derivative Liability, Notional Amount

250.8

130.3

250.8

130.3

August 2007 Interest Rate Swap Agreement

Derivative Instruments and Hedging Activities Disclosure [Line Items]

Swap agreement expiration

2012-05

September 2005 Interest Rate Swap Agreement

Derivative Instruments and Hedging Activities Disclosure [Line Items]

Effective date of the fixed rate swap

25-Apr-06

Fixed interest rate paid

4.68%

Swap agreement expiration

2013-07

Effective fixed rate paid on debt

5.28%

Interest rate spread over LIBOR

0.60%

Loss on early extinguishment of debt

3.3

Location of the swap on the consolidated balance sheets

Other non-current liabilities

Other non-current liabilities

September 2005 Interest Rate Swap Agreement | Interest Rate Swap

Derivative Instruments and Hedging Activities Disclosure [Line Items]

Derivative Liability, Notional Amount

100

April 2011 Interest Rate Swap Agreement [Member] [Member] | Interest Rate Swap

Derivative Instruments and Hedging Activities Disclosure [Line Items]

Derivative Liability, Notional Amount

$400

Derivatives_and_Financial_Inst3

Derivatives and Financial Instruments - Recorded Amounts and Estimated Fair Values of Long-term Debt and Derivative Financial Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative [Line Items]
Total debt	$3,004.10	$2,550.40
Carrying (Reported) Amount, Fair Value Disclosure
Derivative [Line Items]
Variable rate debt	997.4	528.9
Fixed rate debt	2,006.70	2,021.50
Total debt	3,004.10	2,550.40
Estimate of Fair Value, Fair Value Disclosure
Derivative [Line Items]
Variable rate debt	997.4	528.9
Fixed rate debt	2,070.40	1,997.50
Total debt	$3,067.80	$2,526.40

Derivatives_and_Financial_Inst4

Derivatives and Financial Instruments - Assets and Liabilities Measured at Fair Value (Detail) (USD $)	3 Months Ended										12 Months Ended
	Dec. 31, 2014		Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013		Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	$0		$380,100,000	$0	$5,600,000	$800,000		$0	$0	$0	$385,700,000		$800,000		$0
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal			12,300,000		2,400,000	300,000					14,700,000		300,000		0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	900,000					3,600,000					900,000		3,600,000
Foreign currency contract liabilities	-6,600,000										-6,600,000
Deferred compensation plan assets	55,300,000	[1]				32,100,000	[1]				55,300,000	[1]	32,100,000	[1]
Total recurring fair value measurements	49,600,000					35,700,000					49,600,000		35,700,000
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-Lived Trade Names	0	[2]									0	[2]
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets	47,900,000	[1]				32,100,000	[1]				47,900,000	[1]	32,100,000	[1]
Total recurring fair value measurements	47,900,000					32,100,000					47,900,000		32,100,000
Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets	900,000					3,600,000					900,000		3,600,000
Foreign currency contract liabilities	-6,600,000										-6,600,000
Deferred compensation plan assets	7,400,000	[1]									7,400,000	[1]
Total recurring fair value measurements	$1,700,000					$3,600,000					$1,700,000		$3,600,000
[1]	Deferred compensation plan assets include mutual funds, common/collective trusts and cash equivalents for payment of certain non-qualified benefits for retired, terminated and active employees. The fair value of mutual funds and cash equivalents were based on quoted market prices in active markets. The underlying investments in the common/collective trusts primarily include intermediate and long-term debt securities, corporate debt securities, equity securities and fixed income securities. The overall fair value of the common/collective trusts are based on observable inputs.
[2]	During the third quarter of 2014, we recognized an impairment charge related to allocated amounts of goodwill, intangible assets, property, plant & equipment and other non-current assets totaling $380.1 million, net of a $12.3 million tax benefit, representing our estimated loss on disposal of the Water Transport business. The impairment charge was determined using significant unobservable inputs ("Level 3" fair value measurements). See Note 3 for additional information about the impairment.

Derivatives_and_Financial_Inst5

Derivatives and Financial Instruments - Assets and Liabilities Measured at Fair Value Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-lived Intangible Assets, Impairment Losses	$11

Income_Taxes_Income_Loss_Befor

Income Taxes - Income (Loss) Before Income Taxes and Noncontrolling Interest (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Income Taxes [Line Items]
Federal	$13.30	[1]	$328.70	[1]	$39.50	[1]
International	771		365.8		-185.6
Income (loss) from continuing operations before income taxes and noncontrolling interest	$784.30		$694.50		($146.10)
[1]	As a result of the Redomicile, “Federal” reflects income (loss) from continuing operations before income taxes and noncontrolling interest for the U.K. in 2014 and for Switzerland in 2013 and 2012.

Income_Taxes_Provision_for_Inc

Income Taxes - Provision for Income Taxes (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Currently payable
Federal	($0.40)	[1]	$17.40	[1]	$6.50	[1]
International	175.7	[2]	105.6	[2]	65.2	[2]
Total current taxes	175.3		123		71.7
Deferred
Federal	2.2	[1]	18.9	[1]	1.3	[1]
International	-0.2	[2]	35.1	[2]	-140.2	[2]
Total deferred taxes	2		54		-138.9
Total provision (benefit) for income taxes	$177.30		$177		($67.20)
[1]	As a result of the Redomicile, “Federal” represents U.K. taxes for 2014 and Swiss taxes for 2013 and 2012.
[2]	As a result of the Redomicile, "International" represents non-U.K. taxes for 2014 and non-Swiss taxes for 2013 and 2012

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Income Taxes [Line Items]
Federal statutory income tax rate	21.00%	[1]	7.80%	[1]	7.80%	[1]
Tax effect of international operations	-4.90%	[2]	10.40%	[2]	23.50%	[2]
Change in valuation allowances	3.40%		5.70%
Withholding taxes	2.30%		1.10%
Interest limitations	0.80%		0.50%
Non-deductible transaction costs					-5.90%
Impact of debt-financing					13.60%
Resolution of tax audits					7.00%
Effective tax rate	22.60%		25.50%		46.00%
[1]	The statutory rate for 2014 reflects the U.K. statutory rate of 21 percent. For 2013 and 2012, the statutory rate reflects the Swiss statutory rate of 7.8 percent.
[2]	The tax effect of international operations for 2014 consists of non-U.K. jurisdictions. For 2013 and 2012, the tax effect of international operations consists of non-Swiss jurisdictions.

Income_Taxes_Reconciliation_of1

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Income Taxes [Line Items]
Statutory income tax rate	21.00%	[1]	7.80%	[1]	7.80%	[1]
UNITED KINGDOM
Income Taxes [Line Items]
Statutory income tax rate	21.00%
SWITZERLAND
Income Taxes [Line Items]
Statutory income tax rate			7.80%		7.80%
[1]	The statutory rate for 2014 reflects the U.K. statutory rate of 21 percent. For 2013 and 2012, the statutory rate reflects the Swiss statutory rate of 7.8 percent.

Income_Taxes_Reconciliations_o

Income Taxes - Reconciliations of Gross Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$60.80	$53.40	$26.50
Gross increases for tax positions in prior periods	2.3	12.2	2.2
Gross decreases for tax positions in prior periods	-0.5	-0.6	-0.6
Gross increases based on tax positions related to the current year	1.8	2.7	13.6
Gross decreases related to settlements with taxing authorities	-0.1	-5.1	-13.2
Reductions due to statute expiration	-1.2	-1.8	-0.4
Unrecognized Tax Benefits, Decrease Resulting from Foreign Currency Translation	-1	0	0
Gross increases due to acquisitions	0	0	25.3
Ending balance	$62.10	$60.80	$53.40

Income_Taxes_Deferred_Taxes_De

Income Taxes - Deferred Taxes (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Income Taxes [Line Items]
Other current assets	$139.40	$149.70
Other non-current assets	87.9	92.4
Deferred tax liabilities	528.3	557
Net deferred tax liabilities	$301	$314.90

Income_Taxes_Deferred_Tax_Asse

Income Taxes - Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Deferred tax assets
Accrued liabilities and reserves	$200.30	$192.20
Pension and other post-retirement benefits	68.4	76.8
Employee compensation & benefits	100	82.2
Tax loss and credit carryforwards	291.9	351.7
Total deferred tax assets	660.6	702.9
Valuation allowance	235.8	235.5
Deferred tax assets, net of valuation allowance	424.8	467.4
Deferred tax liabilities
Property, plant and equipment	51.6	57.9
Goodwill and other intangibles	645.6	697.1
Other liabilities	28.6	27.3
Total deferred tax liabilities	725.8	782.3
Net deferred tax liabilities	$301	$314.90

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
Gross unrecognized tax benefits	$62,100,000	$60,800,000	$53,400,000	$26,500,000
Amount of tax benefits that, if recognized, would impact the effective tax rate	60,700,000
Payment of penalties	1,200,000	900,000
Payment of interest expense	9,800,000	8,900,000
Deferred taxes on undistributed earnings of certain subsidiaries	11,800,000
Tax loss carryforwards	1,118,300,000
Deferred tax assets, valuation allowance	235,800,000	235,500,000
Non-U.S. tax losses available for carry forward	1,010,700,000
U.S. federal loss available for carry forward	21,400,000
State tax losses available for carry forward	86,200,000
Shared tax liabilities description	Costs and expenses associated with the management of Shared Tax Liabilities, Distribution Taxes and BHS Tax Liabilities will generally be shared 20% by us, 27.5% by ADT and 52.5% by Tyco
Minimum
Income Taxes [Line Items]
Possible amount of decrease during the next twelve months primarily as a result of the resolution of federal, state and foreign examinations and the expiration of various statutes of limitations	0
Maximum
Income Taxes [Line Items]
Possible amount of decrease during the next twelve months primarily as a result of the resolution of federal, state and foreign examinations and the expiration of various statutes of limitations	25,300,000
Operating loss carryforwards expiration year	2034
2012 Tax Sharing Agreement
Income Taxes [Line Items]
Shared tax liabilities description	Tyco is responsible for the first $500 million of Shared Tax Liabilities. As of December 31, 2014, Tyco has paid $52.0 million of Shared Tax Liabilities. We and ADT will share 42% and 58%, respectively, of the next $225 million of Shared Tax Liabilities. We, ADT and Tyco will share 20%, 27.5% and 52.5%, respectively, of Shared Tax Liabilities above $725 million.
Foreign Country
Income Taxes [Line Items]
Deferred tax assets, valuation allowance	207,300,000
ADT
Income Taxes [Line Items]
Percentage of shared tax liabilities	27.50%
Adt Corporation and Pentair
Income Taxes [Line Items]
Tax sharing, liability	225,000,000
Tyco
Income Taxes [Line Items]
Tax sharing, liability	500,000,000
Tax Sharing, Liability, Paid	52,000,000
Percentage of shared tax liabilities	52.50%
Tyco | Minimum
Income Taxes [Line Items]
Tax sharing, liability	1,850,000,000
Pentair [Member]
Income Taxes [Line Items]
Percentage of shared tax liabilities	20.00%
Pentair ADT Tyco
Income Taxes [Line Items]
Tax sharing, liability	725,000,000
Tax Liability | Tyco
Income Taxes [Line Items]
Tax sharing, liability	883,300,000
Tax Penalties | Tyco
Income Taxes [Line Items]
Tax sharing, liability	154,000,000
Period One | Tyco
Income Taxes [Line Items]
Disallowed interest and related tax deductions	2,900,000,000
Period Two | Tyco
Income Taxes [Line Items]
Disallowed interest and related tax deductions	$6,600,000,000
Group One [Member] | 2012 Tax Sharing Agreement
Income Taxes [Line Items]
Percentage of shared tax liabilities	42.00%
Group One [Member] | ADT | 2012 Tax Sharing Agreement
Income Taxes [Line Items]
Percentage of shared tax liabilities	58.00%
Group One [Member] | Tyco | Agreement Two Member [Member]
Income Taxes [Line Items]
Percentage of shared tax liabilities	27.00%
Group One [Member] | Covidien | Agreement Two Member [Member]
Income Taxes [Line Items]
Percentage of shared tax liabilities	42.00%
Group One [Member] | TE Connectivity | Agreement Two Member [Member]
Income Taxes [Line Items]
Percentage of shared tax liabilities	31.00%
Group Two [Member] | 2012 Tax Sharing Agreement
Income Taxes [Line Items]
Percentage of shared tax liabilities	20.00%
Group Two [Member] | ADT | 2012 Tax Sharing Agreement
Income Taxes [Line Items]
Percentage of shared tax liabilities	27.50%
Group Two [Member] | Tyco | 2012 Tax Sharing Agreement
Income Taxes [Line Items]
Percentage of shared tax liabilities	52.50%

Benefit_Plans_Additional_Infor

Benefit Plans - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension and other post-retirement plans
Pension plan contribution	$24.60	$30.80
Obligations and funded status
Defined accumulated benefit obligation plans	887.5	772.2
Expected rate of return on plan assets	4.56%	3.75%	7.50%
Pension plan assets yielded returns	22.30%	-9.90%	10.80%
Pension plans assets
Asset allocation	97.00%
Savings plan
401(k) plan description	Under the 401(k) plan, eligible U.S. employees may voluntarily contribute a percentage of their eligible compensation. We match contributions made by employees who meet certain eligibility and service requirements. Our matching contribution is 100% of eligible employee contributions for the first 1% of eligible compensation and 50% of the next 5% of eligible compensation.
Annual eligible compensation percentage	1.50%
Participants are 100% vested in employer match	after 3 years of service.
Other retirement compensation
Other accrued retirement compensation	70.2	53.3
Maximum
Pension plans assets
Expected contribution	35
Minimum
Pension plans assets
Expected contribution	30
U.S. Pension Plans
Pension and other post-retirement plans
Benefits paid	9.3	20.4
Obligations and funded status
Discount rate	3.63%	4.51%	3.67%
Non-US Pension Plans
Pension and other post-retirement plans
Benefits paid	17.9	18.2
Non-US Pension Plans | Maximum
Obligations and funded status
Discount rate	0.50%	0.50%	0.50%
Expected rate of return on plan assets	6.40%	6.50%	4.60%
Non-US Pension Plans | Minimum
Obligations and funded status
Discount rate	4.25%	5.00%	4.50%
Expected rate of return on plan assets	1.00%	1.00%	1.00%
First 1%
Savings plan
Matching contribution to eligible employee contributions	100.00%
Percent of eligible compensation	1.00%
Next 5%
Savings plan
Matching contribution to eligible employee contributions	50.00%
Percent of eligible compensation	5.00%
Flow 401(K) Plan
Savings plan
Matching contribution to eligible employee contributions	500.00%
Percent of eligible compensation	1.00%
Years of service	3 years
Matching contribution to eligible employee contributions	100.00%
401(k) plan and ESOP combined expenese	$21.50	$26.80	19.7
An Additional 1% Match on Flow 401(K) Plan
Savings plan
Additional matching contribution to eligible employee contributions	1.00%
An Additional 1% Match on Flow 401(K) Plan | Maximum
Savings plan
Years of service	19 years
An Additional 1% Match on Flow 401(K) Plan | Minimum
Savings plan
Years of service	10 years
An Additional 2% Match on Flow 401(K) Plan
Savings plan
Additional matching contribution to eligible employee contributions	2.00%
An Additional 2% Match on Flow 401(K) Plan | Maximum
Savings plan
Years of service	24 years
An Additional 2% Match on Flow 401(K) Plan | Minimum
Savings plan
Years of service	20 years
An Additional 3% Match on Flow 401(K) Plan
Savings plan
Additional matching contribution to eligible employee contributions	3.00%
An Additional 3% Match on Flow 401(K) Plan | Maximum
Savings plan
Years of service	29 years
An Additional 3% Match on Flow 401(K) Plan | Minimum
Savings plan
Years of service	25 years
An Additional 4% Match on Flow 401(K) Plan
Savings plan
Additional matching contribution to eligible employee contributions	4.00%
An Additional 4% Match on Flow 401(K) Plan | Minimum
Savings plan
Years of service	30 years

Benefit_Plans_Reconciliations_

Benefit Plans - Reconciliations of Benefit Obligations, Fair Value of Plan Assets and Funded Status of Pension Plans and Other Post-Retirement Plans (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in benefit obligations
Service cost		$0.30
Change in plan assets
Fair value of plan assets end of year	653.6	572.3
U.S. Pension Plans
Change in benefit obligations
Benefit obligation beginning of year	346.9	394.3
Service cost	13.1	15.6	12.9
Interest cost	15.4	14.3	28.2
Actuarial loss	50.1	-56.9
Translation (gain) loss	0	0
Benefits paid	-9.3	-20.4
Benefit obligation end of year	416.2	346.9	394.3
Change in plan assets
Fair value of plan assets beginning of year	285.8	326.2
Actual return on plan assets	63.7	-28.9
Company contributions	3.7	8.9
Translation gain (loss)	0	0
Benefits paid	-9.3	-20.4
Fair value of plan assets end of year	343.9	285.8	326.2
Funded status
Plan assets less than benefit obligation	-72.3	-61.1
Non-US Pension Plans
Change in benefit obligations
Benefit obligation beginning of year	462	460.8
Service cost	7.4	8.4	3.3
Interest cost	17.3	17.9	7.5
Actuarial loss	73	-16.6
Translation (gain) loss	-36.6	9.7
Benefits paid	-17.9	-18.2
Benefit obligation end of year	505.2	462	460.8
Change in plan assets
Fair value of plan assets beginning of year	286.5	249
Actual return on plan assets	35.2	28.6
Company contributions	20.9	21.9
Translation gain (loss)	-15	5.2
Benefits paid	-17.9	-18.2
Fair value of plan assets end of year	309.7	286.5	249
Funded status
Plan assets less than benefit obligation	-195.5	-175.5
Post-retirement
Change in benefit obligations
Benefit obligation beginning of year	42.4	59.3
Service cost	0.2	0.3	0.2
Interest cost	1.7	1.9	1.9
Actuarial loss	0.3	-15.9
Translation (gain) loss	0	0
Benefits paid	-3.1	-3.2
Benefit obligation end of year	41.5	42.4	59.3
Change in plan assets
Fair value of plan assets beginning of year	0	0
Actual return on plan assets	0	0
Company contributions	3.1	3.2
Translation gain (loss)	0	0
Benefits paid	-3.1	-3.2
Fair value of plan assets end of year	0	0	0
Funded status
Plan assets less than benefit obligation	($41.50)	($42.40)

Benefit_Plans_Amounts_Recorded

Benefit Plans - Amounts Recorded in Consolidated Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]
Non-current liabilities	($322)	($320.20)
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Defined Benefit Plans, Assets, Noncurrent	2.7	0.7
Current liabilities	-4	-3.9
Non-current liabilities	-71	-57.9
Benefit obligations in excess of the fair value of plan assets	-72.3	-61.1
Non-US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Defined Benefit Plans, Assets, Noncurrent	6.5	3.7
Current liabilities	-4.7	-4.7
Non-current liabilities	-197.3	-174.5
Benefit obligations in excess of the fair value of plan assets	-195.5	-175.5
Post-retirement
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	-3.4	-3.7
Non-current liabilities	-38.1	-38.7
Benefit obligations in excess of the fair value of plan assets	($41.50)	($42.40)

Benefit_Plans_Pension_Plans_wi

Benefit Plans - Pension Plans with Accumulated Benefit Obligation or Projected Benefit Obligation in Excess of Plan Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
U.S. Pension Plans
Pension plans with a projected benefit obligation in excess of plan assets:
Projected benefit obligation	$92.50	$76.30
Fair value of plan assets	17.5	14.5
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	92.5	76.3
Fair value of plan assets	17.5	14.5
Accumulated benefit obligation	85.1	73.1
Non-US Pension Plans
Pension plans with a projected benefit obligation in excess of plan assets:
Projected benefit obligation	460	438.2
Fair value of plan assets	258.1	259
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	453.2	420.4
Fair value of plan assets	252.3	244.5
Accumulated benefit obligation	$440.90	$411.50

Benefit_Plans_Components_of_Ne

Benefit Plans - Components of Net Periodic Benefit Cost (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Service cost		$0.30
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	13.1	15.6	12.9
Interest cost	15.4	14.3	28.2
Expected return on plan assets	-10.5	-9.7	-29.4
Amortization of prior year service cost (benefit)	0	0.4	0
Net actuarial (gain) loss	-3.1	-18.3	114.3
Net periodic benefit expense (income)	14.9	2.3	126
Non-US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	7.4	8.4	3.3
Interest cost	17.3	17.9	7.5
Expected return on plan assets	-15.9	-15.2	-3.9
Amortization of prior year service cost (benefit)	0	-0.2	0
Net actuarial (gain) loss	50.3	-30	24.2
Net periodic benefit expense (income)	59.1	-19.1	31.1
Post-retirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.2	0.3	0.2
Interest cost	1.7	1.9	1.9
Amortization of prior year service cost (benefit)	0	-0.8	0
Net actuarial (gain) loss	0.3	-15.9	8.1
Net periodic benefit expense (income)	$2.20	($14.50)	$10.20

Benefit_Plans_WeightedAverage_

Benefit Plans - Weighted-Average Assumptions Used to Determine Domestic Benefit Obligations (Detail) (Defined Benefit Plan Benefit Obligations)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.63%	4.51%	3.67%
Rate of compensation increase	4.00%	4.00%	4.37%
Non-US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.04%	4.13%	3.85%
Rate of compensation increase	2.95%	3.02%	3.02%
Post-retirement
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.60%	4.35%	3.40%
Rate of compensation increase	0.00%	0.00%	0.00%

Benefit_Plans_WeightedAverage_1

Benefit Plans - Weighted-Average Assumptions Used (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.63%	4.51%	3.67%
Net Periodic Benefit Costs | U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.51%	3.67%	5.05%
Expected long-term return on plan assets	4.56%	3.75%	7.50%
Rate of compensation increase	4.00%	4.37%	4.21%
Net Periodic Benefit Costs | Non-US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.13%	3.85%	4.82%
Expected long-term return on plan assets	5.95%	5.98%	4.09%
Rate of compensation increase	3.02%	3.02%	2.98%
Net Periodic Benefit Costs | Post-retirement
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.35%	3.40%	5.05%
Expected long-term return on plan assets	0.00%	0.00%	0.00%
Rate of compensation increase	0.00%	0.00%	0.00%

Benefit_Plans_Assumed_Health_C

Benefit Plans - Assumed Health Care Cost Trend Rates (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Healthcare cost trend rate assumed for following year	6.80%	7.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50%	4.50%
Year the cost trend rate reaches the ultimate trend rate	2027	2027

Benefit_Plans_Effect_of_OnePer

Benefit Plans - Effect of One-Percentage-Point Change in Assumed Healthcare Cost Trend Rates (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Effect on total annual service and interest cost	$0.10
Effect on other post-retirement benefit obligations	1
Effect on total annual service and interest cost	-0.1
Effect on other post-retirement benefit obligations	($0.90)

Benefit_Plans_Actual_Overall_A

Benefit Plans - Actual Overall Asset Allocation for U.S. And Non-U.S. Plans as Compared to Investment Policy Goals (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Target Allocation
Asset allocation	97.00%
U.S. Pension Plans | Fixed income
Plan Assets
Asset allocation	97.00%	92.00%
Target Allocation
Asset allocation	100.00%	100.00%
U.S. Pension Plans | Alternative
Plan Assets
Asset allocation	3.00%	7.00%
Target Allocation
Asset allocation	0.00%	0.00%
U.S. Pension Plans | Cash
Plan Assets
Asset allocation	0.00%	1.00%
Target Allocation
Asset allocation	0.00%	0.00%
Non-US Pension Plans | Equity securities
Plan Assets
Asset allocation	40.00%	54.00%
Target Allocation
Asset allocation	45.00%	56.00%
Non-US Pension Plans | Fixed income
Plan Assets
Asset allocation	53.00%	41.00%
Target Allocation
Asset allocation	55.00%	44.00%
Non-US Pension Plans | Alternative
Plan Assets
Asset allocation	5.00%	3.00%
Target Allocation
Asset allocation	0.00%	0.00%
Non-US Pension Plans | Cash
Plan Assets
Asset allocation	2.00%	2.00%
Target Allocation
Asset allocation	0.00%	0.00%

Benefit_Plans_Plan_Assets_Usin

Benefit Plans - Plan Assets Using Fair Value Methodologies (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$653.60	$572.30
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7.6	7.7
Fixed income | Foreign Government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	373.6	262.2
Fixed income | US Treasury Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	70.7	75.5
Fixed income | Collateralized Mortgage Backed Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.3	8.7
Fixed income | Other securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45.5	34.1
Equity securities | U S Mid Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.1	7.3
Equity securities | U S Large Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43.7	43.5
Equity securities | International Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	77	101.9
Equity securities | US Long/Short Equity Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.6
Other Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	24.1	30.8
Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.1	1.8
Fair Value, Inputs, Level 1 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.1	1.8
Fair Value, Inputs, Level 1 | Equity securities | U S Mid Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Fair Value, Inputs, Level 1 | Equity securities | International Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	643.8	551.5
Fair Value, Inputs, Level 2 | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.5	5.9
Fair Value, Inputs, Level 2 | Fixed income | Foreign Government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	373.6	262.2
Fair Value, Inputs, Level 2 | Fixed income | US Treasury Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	70.7	75.5
Fair Value, Inputs, Level 2 | Fixed income | Collateralized Mortgage Backed Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.3	8.7
Fair Value, Inputs, Level 2 | Fixed income | Other securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45.5	34.1
Fair Value, Inputs, Level 2 | Equity securities | U S Mid Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.1	7.3
Fair Value, Inputs, Level 2 | Equity securities | U S Large Cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	43.7	43.5
Fair Value, Inputs, Level 2 | Equity securities | International Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	77	101.9
Fair Value, Inputs, Level 2 | Equity securities | US Long/Short Equity Fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.6
Fair Value, Inputs, Level 2 | Other Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17.4	11.8
Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6.7	19
Fair Value, Inputs, Level 3 | Fixed income | Foreign Government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Fair Value, Inputs, Level 3 | Fixed income | Collateralized Mortgage Backed Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Fair Value, Inputs, Level 3 | Fixed income | Other securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Fair Value, Inputs, Level 3 | Other Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$6.70	$19

Benefit_Plans_Reconciliation_o

Benefit Plans - Reconciliation of Level 3 Assets (Detail) (Other Investments, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Investments
Reconciliation of Level 3 Assets [Roll Forward]
Beginning balance	$19	$18.30
Net realized and unrealized gains (losses)	0.7	1.9
Net issuances and settlements	-11.8	-1.2
Net transfers into (out of) level 3	-1.2	0
Ending balance	$6.70	$19

Benefit_Plans_Expected_Future_

Benefit Plans - Expected Future Services to Be Paid by Plans (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
U.S. Pension Plans
Defined Benefit Plan Disclosure [Line Items]
2015	$10
2016	12.2
2017	13.7
2018	16.2
2019	18.7
2020-2024	109.7
Non-US Pension Plans
Defined Benefit Plan Disclosure [Line Items]
2015	15
2016	15.9
2017	17.1
2018	18.1
2019	18.9
2020-2024	108.4
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
2015	3.4
2016	3.3
2017	3.2
2018	3.1
2019	3.1
2020-2024	$13.80

Shareholders_Equity_Additional

Shareholder's Equity - Additional Information (Detail)

12 Months Ended

12 Months Ended

Share data in Millions, except Per Share data, unless otherwise specified

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Sep. 27, 2014

20-May-14

Dec. 31, 2013

Jun. 27, 2015

Mar. 28, 2015

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

CHF

Dividends payable per share

Dividends payable per share

September 2012 Share Repurchase Program

2012 Share Repurchase Programs [Member]

October 2012 Share Repurchase Program

December 2013 Share Repurchase Program

December 2014 Share Repurchase Program [Member] [Domain]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Shareholders Equity

Common stock, shares authorized

426

213

Common stock, par value (per share)

$0.01

0.5

Authorized amount to repurchase shares of common stock

$400,000,000

$1,200,000,000

$800,000,000

$1,000,000,000

$1,000,000,000

Common stock shares repurchased, shares

16.4

1.9

14.5

Common stock amount repurchased

1,200,000,000

200,000,000

1,000,000,000

Remaining authorized repurchase amount

0

Authorization expiry date

31-Dec-15

31-Dec-16

Dividends payable amount per share

$0.30

$0.30

$1.20

$0.32

$0.32

Dividends Payable, Amount Per Share, Quarterly Dividends Declared

$0.32

$0.30

Dividends Payable, Amount Per Share, Increase (Decrease) in Quarterly Dividends Declared

$0.02

Dividends payable

$116,800,000

$98,700,000

Dividends paid per common share

$1.10

$0.96

$0.88

Share_Plans_Additional_Informa

Share Plans - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 28, 2013
Share-based compensation expense
Share-based compensation	$33.60	$31.10	$35.80
Fair value of options granted
Weighted average grant date fair value of options granted	$23.23	$13.96	$9.63
Total intrinsic value of options exercised	34.8	68.9	41.6
Unrecognized compensation cost related to stock options	5.5
Cash received from option exercises	46.6	102.3	91.6
Tax benefit realized for tax deductions from option exercises	8.3	23.5	12.2
Restricted shares and restricted stock units
Unrecognized compensation cost related to restricted stock units	17.2
Total fair value of shares vested	26.3	23.4	58
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Expiration period	10 years
Share-based compensation expense
Share-based compensation	11	10.9	11.6
Restricted shares and restricted stock units
Weighted average period to recognize compensation cost	1 year 3 months 18 days
Restricted Stock Units
Share-based compensation expense
Share-based compensation	22.6	20.2	24.2
Restricted shares and restricted stock units
Tax benefit realized for tax deductions from option exercises	3.1	7.2	18.8
Weighted average period to recognize compensation cost	1 year 3 months 18 days
Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Maximum | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Minimum | Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
2012 Stock and Incentive Plan
Share Incentive Plans
Number of shares authorized for issuance				9
Tyco Flow Control International, Ltd
Share-based compensation expense
Share-based compensation			$13.50
Fair value of options granted
Weighted average grant date fair value of options granted			$11.76

Share_Plans_Stock_Option_Activ

Share Plans - Stock Option Activity (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014
Shares
Beginning balance	6.2
Granted	0.5
Exercised	-0.9
Forfeited	-0.1
Ending balance	5.7
Options exercisable	4.5
Options expected to vest at end of period	1.2
Weighted Average Exercise Price
Beginning balance (USD per share)	$35.53
Granted (USD per share)	$77.93
Exercised (USD per share)	$35.53
Forfeited (USD per share)	$49.29
Ending Balance (USD per share)	$39.08
Options exercisable at end of period (USD per share)	$33.53
Options expected to vest at end of period (USD per share)	$59.46
Weighted Average Remaining Contractual Life
Ending balance	5 years 1 month 6 days
Options exercisable at end of period	4 years 2 months 12 days
Options expected to vest at end of period	8 years 2 months 12 days
Aggregate Intrinsic value
Balance at end of period	$157.80
Options exercisable at end of period	144
Options expected to vest at end of period	$13.80

Share_Plans_Stock_Option_Fair_

Share Plans - Stock Option Fair Value Assumptions (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.44%	0.69%	0.96%
Expected dividend yield	1.46%	2.01%	2.48%
Expected share price volatility	35.30%	36.00%	36.50%
Expected term (years)	5 years 7 months 6 days	5 years 8 months 12 days	5 years 8 months 12 days
Tyco Flow Control International, Ltd
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield			2.12%
Expected share price volatility			33.00%
Tyco Flow Control International, Ltd | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate			0.02%
Expected term (years)			1 month 6 days
Tyco Flow Control International, Ltd | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate			0.68%
Expected term (years)			5 years 1 month 6 days

Share_Plans_Restricted_Stock_U

Share Plans - Restricted Stock Units (Detail) (Restricted Stock Units, USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014
Restricted Stock Units
Restricted Shares Outstanding Shares
Beginning balance	1.3
Granted	0.3
Vested	-0.4
Forfeited	-0.1
Ending Balance	1.1
Weighted Average Grant Date Fair Value
Beginning balance (USD per share)	$43.25
Granted (USD per share)	$78.39
Vested (USD per share)	$39.68
Forfeited (USD per share)	$46.42
Ending balance (USD per share)	$50.55

Share_Plans_Sharebased_compens

Share Plans - Share-based compensation expense (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated Share-based Compensation Expense	$33.60	$31.10	$35.80
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated Share-based Compensation Expense	22.6	20.2	24.2
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated Share-based Compensation Expense	$11	$10.90	$11.60

Segment_Information_Financial_

Segment Information - Financial Information By Reportable Segment (Detail) (USD $)	3 Months Ended										12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013		Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Segment Reporting Information [Line Items]
Net sales	$1,802.50		$1,758.40	$1,834.10	$1,644	$1,831		$1,713.30	$1,791.70	$1,663.70	$7,039		$6,999.70		$4,306.80
Segment income (loss)											1,021.70		902.3		483.5
Identifiable assets (1)	10,655.20					11,743.30					10,655.20		11,743.30
Depreciation											138.7		141.3		85.2
Amortization											114		134.1		74.9
Capital expenditures											129.6		170		94.5
Valves & Controls
Segment Reporting Information [Line Items]
Net sales											2,394.80		2,469.20		548.6
Segment income (loss)											350.8		302.8		41.8
Identifiable assets (1)	4,049.90	[1]				4,204	[1]				4,049.90	[1]	4,204	[1]
Depreciation											59		64		15.1
Amortization											53.4		69.3		21.7
Capital expenditures											45.9		67.2		21.9
Process Technologies
Segment Reporting Information [Line Items]
Net sales											1,833.20		1,765.90		1,521.10
Segment income (loss)											267.2		253.2		181.1
Identifiable assets (1)	2,586.90	[1]				2,730.60	[1]				2,586.90	[1]	2,730.60	[1]
Depreciation											31.1		29.2		29.2
Amortization											27.2		26		24.4
Capital expenditures											30		45.2		31.2
Flow Technologies
Segment Reporting Information [Line Items]
Net sales											1,106.60		1,131.60		1,025.50
Segment income (loss)											138.5		132.3		104.7
Identifiable assets (1)	1,276.70	[1]				1,426.40	[1]				1,276.70	[1]	1,426.40	[1]
Depreciation											14.5		14.5		14
Amortization											13.5		13.6		12.5
Capital expenditures											15.5		26.2		18.7
Technical Solutions
Segment Reporting Information [Line Items]
Net sales											1,728.10		1,663.40		1,236.40
Segment income (loss)											358.8		322.4		232.1
Identifiable assets (1)	2,117.30	[1]				2,093.40	[1]				2,117.30	[1]	2,093.40	[1]
Depreciation											24.2		23.6		18.9
Amortization											19.9		25.2		16.2
Capital expenditures											24		16.2		13.5
All Other Segments
Segment Reporting Information [Line Items]
Net sales											-23.7		-30.4		-24.8
Segment income (loss)											-93.6		-108.4		-76.2
Identifiable assets (1)	624.4	[1]				1,288.90	[1]				624.4	[1]	1,288.90	[1]
Depreciation											9.9		10		8
Amortization											0		0		0.1
Capital expenditures											$14.20		$15.20		$9.20
[1]	All cash and cash equivalents and assets held for sale are included in “Other.”

Segment_Information_Geographic

Segment Information - Geographic Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Geographic Information [Line Items]
Net sales	$1,802.50	$1,758.40	$1,834.10	$1,644	$1,831	$1,713.30	$1,791.70	$1,663.70	$7,039	$6,999.70	$4,306.80
Long-lived assets	950				1,044.30				950	1,044.30
U.S.
Geographic Information [Line Items]
Net sales									3,541.10	3,431.30	2,624.30
Long-lived assets	350				365.4				350	365.4
Western Europe
Geographic Information [Line Items]
Net sales									1,701	1,795.30	909.1
Long-lived assets	340				393.9				340	393.9
Fast Growth
Geographic Information [Line Items]
Net sales									998.5	921.6	473.8
Long-lived assets	180.9				193.3				180.9	193.3
Other Developed
Geographic Information [Line Items]
Net sales									798.4	851.5	299.6
Long-lived assets	$79.10				$91.70				$79.10	$91.70

Segment_Information_Additional

Segment Information - Additional Information (Detail) (Customer Concentration Risk)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Customer Concentration Risk
Revenue, Major Customer [Line Items]
Number of significant customers	0	0	0

Segment_Information_Reconcilia

Segment Information Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Income (Loss)									$1,021.70	$902.30	$483.50
Payments for Merger Related Costs											-82.8
Inventory Step Up Related To Merger								-76.6		-86.6	-157.7
Restructuring costs									88.3	103.2	48.7
Mark-to-market actuarial gains (losses) on pension and post-retirement benefit plans	-49.9				-63.2				-49.9	63.2	-141.7
Impairment of Intangible Assets (Excluding Goodwill)					-11				0	-11	-60.7
Redomicile Expense									-10.3	-5.4
Operating Income (Loss)	176	267.4	226.4	182.1	241.3	230	204.9	66.4	851.9	742.6	-4.8
Segment Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Restructuring costs									($109.60)	($119.90)	($45.40)

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	LegalMatter
Loss Contingencies [Line Items]
Product Warranty Accrual, Period Increase (Decrease)	$13
Number Of Claims In Lawsuit	3,400
Liability For claims and contingencies	249.1	254.7
Liability reserve for insurance claims	115.8	119.6
Environmental Reserve	31.4	34.8
Outstanding Value Of Letters Of Credit	370.1	484
Compliance Settlement Period	3 years
Water Transport [Domain]
Loss Contingencies [Line Items]
Outstanding Value Of Letters Of Credit	$32.40	$25.30

Commitments_and_Contingencies_2

Commitments and Contingencies - Net Rental Expense Under Operating Leases (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets [Line Items]
Gross rental expense	$68.70	$76	$44.60
Sublease rental income	-1.3	-0.9	-0.5
Net rental expense	$67.40	$75.10	$44.10

Commitments_and_Contingencies_3

Commitments and Contingencies - Future Minimum Lease Commitments Under Non-Cancelable Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Operating Leased Assets [Line Items]
2015	$51.90
2016	39.7
2017	30.8
2018	19.3
2019	15.3
Thereafter	19.1
Total	176.1
Minimum lease payments
Operating Leased Assets [Line Items]
2015	52.4
2016	40.1
2017	31.2
2018	19.7
2019	15.7
Thereafter	19.1
Total	178.2
Minimum sublease rentals
Operating Leased Assets [Line Items]
2015	-0.5
2016	-0.4
2017	-0.4
2018	-0.4
2019	-0.4
Thereafter	0
Total	($2.10)

Commitments_and_Contingencies_4

Commitments and Contingencies - Warranty Reserve Rollforward (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$56	$52.50
Service and product warranty provision	75.3	64.1
Payments	-62.1	-60.8
Foreign currency translation	-2.8	0.2
Ending balance	$66.40	$56

Selected_Quarterly_Data_Quarte

Selected Quarterly Data - Quarterly Financial Information (Detail) (USD $)	3 Months Ended																12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 27, 2014		Jun. 28, 2014		Mar. 29, 2014		Dec. 31, 2013		Sep. 28, 2013		Jun. 29, 2013		Mar. 30, 2013		Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Quarterly Financial Information [Line Items]
Net sales	$1,802.50		$1,758.40		$1,834.10		$1,644		$1,831		$1,713.30		$1,791.70		$1,663.70		$7,039		$6,999.70		$4,306.80
Gross profit	627.9		624.7		646.3		564.1		630.5		614.7		627.4		497.5		2,463		2,370.10		1,265.90
Operating income (loss)	176		267.4		226.4		182.1		241.3		230		204.9		66.4		851.9		742.6		-4.8
Net income (loss) from continuing operations before noncontrolling interest	129.8		192.5		159.2		125.5		164.4		166.4		139.9		46.8		214.9		542.6		-104.6
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest																	607		517.5		-78.9
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	-9		1.6		2.3		-1.3		-3.9		7.8		15.5		6.5		-6.4		25.9		-25.7
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	0		-380.1		0		-5.6		-0.8		0		0		0		-385.7		-0.8		0
Net income (loss) attributable to Pentair plc	120.8		-186		161.5		118.6		158.2		172.8		154.1		51.7		214.9		536.8		-107.2
Income (Loss) from Continuing Operations Attributable to Parent									$162.90		$165		$138.60		$45.20		$607		$511.70		($81.50)
Income (Loss) from Continuing Operations, Per Basic Share	$0.71		$1.01		$0.82		$0.64		$0.82		$0.83		$0.69		$0.22		$3.19		$2.54		($0.64)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	($0.05)		($1.99)		$0.02		($0.04)		($0.02)		$0.04		$0.07		$0.03		($2.06)		$0.13		($0.20)
Earnings (loss) per ordinary share attributable to Pentair plc
Basic	$0.66	[1]	($0.98)	[1]	$0.84	[1]	$0.60	[1]	$0.80	[1]	$0.87	[1]	$0.76	[1]	$0.25	[1]	$1.13	[1]	$2.67	[1]	($0.84)
Income (Loss) from Continuing Operations, Per Diluted Share	$0.70		$1		$0.81		$0.63		$0.81		$0.81		$0.67		$0.22		$3.14		$2.50		($0.64)
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	($0.05)		($1.95)		$0.01		($0.04)		($0.03)		$0.04		$0.08		$0.03		($2.03)		$0.12		($0.20)
Diluted	$0.65	[1]	($0.95)	[1]	$0.82	[1]	$0.59	[1]	$0.78	[1]	$0.85	[1]	$0.75	[1]	$0.25	[1]	$1.11	[1]	$2.62	[1]	($0.84)
[1]	Amounts may not total to annual earnings because each quarter and year are calculated separately based on basic and diluted weighted-average ordinary shares outstanding during that period

Selected_Quarterly_Data_Additi

Selected Quarterly Data - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effect of Fourth Quarter Events [Line Items]
Net sales	$1,802.50	$1,758.40	$1,834.10	$1,644	$1,831	$1,713.30	$1,791.70	$1,663.70	$7,039	$6,999.70	$4,306.80
Income (loss) from continuing operations					162.9	165	138.6	45.2	607	511.7	-81.5
Mark-to-market actuarial gains (losses) on pension and post-retirement benefit plans	49.9				63.2				49.9	-63.2	141.7
Inventory fair value step-up and customer backlog								76.6		86.6	157.7
Loss on early extinguishment of debt									0	0	75.4
Restructuring cost	35.5		35.4	17.4	54.1			26.6
Impairment charges, related to trade names					$11				$0	$11	$60.70

Financial_Statements_of_Parent2

Financial Statements of Parent Company Guarantor - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Nov. 30, 2012	Sep. 28, 2013
Senior Notes 1.350% due 2015
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate		1.35%
Senior Notes 1.875 % due 2017
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate			1.88%
Senior Notes 2.650% due 2019
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate		2.65%
Senior Notes, 5.000% Due 2021
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate	5.00%
Senior Notes 3.150% due 2022
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate			3.15%
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Ownership percentage	100.00%
Subsidiary Issuer | Senior Notes 1.350% due 2015
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate	1.35%
Subsidiary Issuer | Senior Notes 1.875 % due 2017
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate	1.88%
Subsidiary Issuer | Senior Notes 2.650% due 2019
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate	2.65%
Subsidiary Issuer | Senior Notes, 5.000% Due 2021
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate	5.00%
Subsidiary Issuer | Senior Notes 3.150% due 2022
Condensed Financial Statements, Captions [Line Items]
Debt, interest rate	3.15%

Financial_Statements_of_Parent3

Financial Statements of Parent Company Guarantor - Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 31, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Net sales	$1,802.50	$1,758.40	$1,834.10	$1,644	$1,831	$1,713.30	$1,791.70	$1,663.70	$7,039	$6,999.70	$4,306.80
Cost of goods sold									4,576	4,629.60	3,040.90
Gross profit	627.9	624.7	646.3	564.1	630.5	614.7	627.4	497.5	2,463	2,370.10	1,265.90
Selling, general and administrative									1,493.80	1,493.70	1,117.70
Research and development									117.3	122.8	92.3
Impairment of trade names									0	11	60.7
Operating income (loss)	176	267.4	226.4	182.1	241.3	230	204.9	66.4	851.9	742.6	-4.8
Loss (earnings) from investment in subsidiaries									0	0	0
Loss (gain) on sale of businesses, net									0.2	-20.8	0
Gains (Losses) on Extinguishment of Debt									0	0	-75.4
Other (income) expense:
Equity income of unconsolidated subsidiaries									-1.2	-2	-2.3
Interest income									-3.7	-4.4	-2
Interest expense									72.3	75.3	70.2
Income (loss) from continuing operations before income taxes and noncontrolling interest									784.3	694.5	-146.1
Provision (benefit) for income taxes									177.3	177	-67.2
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									607	517.5	-78.9
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax	-9	1.6	2.3	-1.3	-3.9	7.8	15.5	6.5	-6.4	25.9	-25.7
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax	0	-380.1	0	-5.6	-0.8	0	0	0	-385.7	-0.8	0
Discontinued Operation, Income (Loss) from Investment in Subsidiaries									0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	129.8	192.5	159.2	125.5	164.4	166.4	139.9	46.8	214.9	542.6	-104.6
Noncontrolling interest									0	5.8	2.6
Net income (loss) attributable to Pentair plc	120.8	-186	161.5	118.6	158.2	172.8	154.1	51.7	214.9	536.8	-107.2
Income (Loss) from Continuing Operations Attributable to Parent					162.9	165	138.6	45.2	607	511.7	-81.5
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									214.9	542.6	-104.6
Changes in cumulative translation adjustment									-336.3	-29.1	31.4
Amortization of pension and other post-retirement prior service cost									0	-0.4	-0.3
Changes in market value of derivative financial instruments									-0.4	-0.3	-3.6
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									-121.8	512.8	-77.1
Less: Comprehensive income attributable to noncontrolling interest									0	8	4
Comprehensive income (loss) attributable to Pentair plc									-121.8	504.8	-81.1
Parent Company Guarantor
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0	0
Cost of goods sold									0	0	0
Gross profit									0	0	0
Selling, general and administrative									25.3	21	5
Research and development									0	0	0
Impairment of trade names										0	0
Operating income (loss)									-25.3	-21	-5
Loss (earnings) from investment in subsidiaries									-615.5	-539	75.7
Loss (gain) on sale of businesses, net									0	0
Gains (Losses) on Extinguishment of Debt											0
Other (income) expense:
Equity income of unconsolidated subsidiaries									0	0	0
Interest income									0	0	0
Interest expense									0.7	5.6	0.1
Income (loss) from continuing operations before income taxes and noncontrolling interest									589.5	512.4	-80.8
Provision (benefit) for income taxes									-17.5	0.7	0.7
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									607	511.7	-81.5
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax									0	0	0
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax									0	0
Discontinued Operation, Income (Loss) from Investment in Subsidiaries									-392.1	25.1	-25.7
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest										536.8	-107.2
Noncontrolling interest										0	0
Net income (loss) attributable to Pentair plc									214.9	536.8	-107.2
Income (Loss) from Continuing Operations Attributable to Parent										511.7	-81.5
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									214.9	536.8	-107.2
Changes in cumulative translation adjustment									-336.3	-31.3	30
Amortization of pension and other post-retirement prior service cost										-0.4	-0.3
Changes in market value of derivative financial instruments									-0.4	-0.3	-3.6
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest										504.8	-81.1
Less: Comprehensive income attributable to noncontrolling interest										0	0
Comprehensive income (loss) attributable to Pentair plc									-121.8	504.8	-81.1
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net sales									0
Cost of goods sold									0
Gross profit									0
Selling, general and administrative									2.6
Research and development									0
Operating income (loss)									-2.6
Loss (earnings) from investment in subsidiaries									-619.7
Loss (gain) on sale of businesses, net									0
Other (income) expense:
Equity income of unconsolidated subsidiaries									0
Interest income									0
Interest expense									2.1
Income (loss) from continuing operations before income taxes and noncontrolling interest									615
Provision (benefit) for income taxes									-0.5
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									615.5
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax									0
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax									0
Discontinued Operation, Income (Loss) from Investment in Subsidiaries									-392.1		-25.7
Net income (loss) attributable to Pentair plc									223.4
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									223.4
Changes in cumulative translation adjustment									-336.3
Changes in market value of derivative financial instruments									-0.4
Comprehensive income (loss) attributable to Pentair plc									-113.3
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0	0
Cost of goods sold									0	0	0
Gross profit									0	0	0
Selling, general and administrative									7.7	13.3	-3.8
Research and development									0	0	0
Impairment of trade names										0	0
Operating income (loss)									-7.7	-13.3	3.8
Loss (earnings) from investment in subsidiaries									-611.1	-508.6	76.6
Loss (gain) on sale of businesses, net									0	0
Gains (Losses) on Extinguishment of Debt											0
Other (income) expense:
Equity income of unconsolidated subsidiaries									0	0	0
Interest income									-92.3	-99.2	-9.2
Interest expense									95.6	106	10.2
Income (loss) from continuing operations before income taxes and noncontrolling interest									600.1	488.5	-73.8
Provision (benefit) for income taxes									-2.4	1.4	1.1
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									602.5	487.1	-74.9
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax									0	0	0
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax									0	0
Discontinued Operation, Income (Loss) from Investment in Subsidiaries									-392.1	25.1	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest										512.2	-100.6
Noncontrolling interest										0	0
Net income (loss) attributable to Pentair plc									210.4	512.2	-100.6
Income (Loss) from Continuing Operations Attributable to Parent										487.1	-74.9
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									210.4	512.2	-100.6
Changes in cumulative translation adjustment									-336.3	-31.3	30
Amortization of pension and other post-retirement prior service cost										-0.4	-0.3
Changes in market value of derivative financial instruments									-0.4	-0.3	-3.6
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest										480.2	-74.5
Less: Comprehensive income attributable to noncontrolling interest										0	0
Comprehensive income (loss) attributable to Pentair plc									-126.3	480.2	-74.5
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales									7,039	6,999.70	4,306.80
Cost of goods sold									4,576	4,629.60	3,040.90
Gross profit									2,463	2,370.10	1,265.90
Selling, general and administrative									1,458.20	1,459.40	1,116.50
Research and development									117.3	122.8	92.3
Impairment of trade names										11	60.7
Operating income (loss)									887.5	776.9	-3.6
Loss (earnings) from investment in subsidiaries									0	0	0
Loss (gain) on sale of businesses, net									0.2	-20.8
Gains (Losses) on Extinguishment of Debt											-75.4
Other (income) expense:
Equity income of unconsolidated subsidiaries									-1.2	-2	-2.3
Interest income									-40.2	-53.4	-2
Interest expense									102.7	111.9	69.1
Income (loss) from continuing operations before income taxes and noncontrolling interest									826	741.2	-143.8
Provision (benefit) for income taxes									197.7	174.9	-69
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									628.3	566.3	-74.8
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax									-6.4	25.9	-25.7
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax									-385.7	-0.8
Discontinued Operation, Income (Loss) from Investment in Subsidiaries									0	0	51.4
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest										591.4	-100.5
Noncontrolling interest										5.8	2.6
Net income (loss) attributable to Pentair plc									236.2	585.6	-103.1
Income (Loss) from Continuing Operations Attributable to Parent										560.5	-77.4
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									236.2	591.4	-100.5
Changes in cumulative translation adjustment									-336.3	-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									-0.4	-0.3	-3.6
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest										561.6	-73
Less: Comprehensive income attributable to noncontrolling interest										8	4
Comprehensive income (loss) attributable to Pentair plc									-100.5	553.6	-77
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net sales									0	0	0
Cost of goods sold									0	0	0
Gross profit									0	0	0
Selling, general and administrative									0	0	0
Research and development									0	0	0
Impairment of trade names										0	0
Operating income (loss)									0	0	0
Loss (earnings) from investment in subsidiaries									1,846.30	1,047.60	-152.3
Loss (gain) on sale of businesses, net									0	0
Gains (Losses) on Extinguishment of Debt											0
Other (income) expense:
Equity income of unconsolidated subsidiaries									0	0	0
Interest income									128.8	148.2	9.2
Interest expense									-128.8	-148.2	-9.2
Income (loss) from continuing operations before income taxes and noncontrolling interest									-1,846.30	-1,047.60	152.3
Provision (benefit) for income taxes									0	0	0
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest									-1,846.30	-1,047.60	152.3
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax									0	0	0
Discontinued Operation, Provision for Loss (Gain) on Disposal, Net of Tax									0	0
Discontinued Operation, Income (Loss) from Investment in Subsidiaries									1,176.30	-50.2	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest										-1,097.80	203.7
Noncontrolling interest										0	0
Net income (loss) attributable to Pentair plc									-670	-1,097.80	203.7
Income (Loss) from Continuing Operations Attributable to Parent										-1,047.60	152.3
Comprehensive income (loss), net of tax
Net income (loss) before noncontrolling interest									-670	-1,097.80	203.7
Changes in cumulative translation adjustment									1,008.90	62.6	-60
Amortization of pension and other post-retirement prior service cost										0.8	0.6
Changes in market value of derivative financial instruments									1.2	0.6	7.2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest										-1,033.80	151.5
Less: Comprehensive income attributable to noncontrolling interest										0	0
Comprehensive income (loss) attributable to Pentair plc									$340.10	($1,033.80)	$151.50

Financial_Statements_of_Parent4

Financial Statements of Parent Company Guarantor - Condensed Consolidating Balance Sheet (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Millions, unless otherwise specified
Current assets
Cash and cash equivalents	$110.40	$256	$237.40	$50.10
Accounts and notes receivable, net	1,205.90	1,285
Inventories	1,130.40	1,195.10
Other current assets	366.8	361.6
Disposal Group, Including Discontinued Operation, Assets, Current	80.6	134.4
Total current assets	2,894.10	3,232.10
Property, plant and equipment, net	950	1,044.30
Other assets
Investments in subsidiaries	0	0
Goodwill	4,741.90	4,860.70	4,837.50
Intangibles, net	1,608.10	1,749.90
Other non-current assets	436.2	390
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	24.9	466.3
Total other assets	6,811.10	7,466.90
Total assets	10,655.20	11,743.30
Current liabilities
Current maturities of long-term debt and short-term borrowings	6.7	2.5
Accounts payable	583.1	576.9
Employee compensation and benefits	305.5	312.4
Other current liabilities	709.1	645.9
Disposal Group, Including Discontinued Operation, Liabilities, Current	35.1	72.5
Total current liabilities	1,639.50	1,610.20
Other liabilities
Long-term debt	2,997.40	2,547.90
Pension and other post-retirement compensation and benefits	322	320.2
Deferred tax liabilities	528.3	557
Other non-current liabilities	497.7	456.4
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	6.5	33.9
Total liabilities	5,991.40	5,525.60
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries	4,663.80	6,095.30
Noncontrolling interest	0	122.4
Total equity	4,663.80	6,217.70	6,487.50	2,047.40
Total liabilities and equity	10,655.20	11,743.30
Parent Company Guarantor
Current assets
Cash and cash equivalents	0	0.5	0	0
Accounts and notes receivable, net	0	2.9
Inventories	0	0
Other current assets	0	1.4
Disposal Group, Including Discontinued Operation, Assets, Current	0	0
Total current assets	0	4.8
Property, plant and equipment, net	0	0
Other assets
Investments in subsidiaries	4,733	6,224.70
Goodwill	0	0
Intangibles, net	0	0
Other non-current assets	80.2	31.6
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0	0
Total other assets	4,813.20	6,256.30
Total assets	4,813.20	6,261.10
Current liabilities
Current maturities of long-term debt and short-term borrowings	0	0
Accounts payable	0.9	48.1
Employee compensation and benefits	0.2	0.5
Other current liabilities	120.6	99.6
Disposal Group, Including Discontinued Operation, Liabilities, Current	0	0
Total current liabilities	121.7	148.2
Other liabilities
Long-term debt	11.4	0
Pension and other post-retirement compensation and benefits	0	0
Deferred tax liabilities	0	0
Other non-current liabilities	16.3	17.6
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	0	0
Total liabilities	149.4	165.8
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries		6,095.30
Noncontrolling interest		0
Total equity	4,663.80	6,095.30
Total liabilities and equity	4,813.20	6,261.10
Guarantor Subsidiaries [Member]
Current assets
Cash and cash equivalents	0	0
Accounts and notes receivable, net	0
Inventories	0
Other current assets	17.6
Disposal Group, Including Discontinued Operation, Assets, Current	0
Total current assets	17.6
Property, plant and equipment, net	0
Other assets
Investments in subsidiaries	4,893.80
Goodwill	0
Intangibles, net	0
Other non-current assets	0
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0
Total other assets	4,893.80
Total assets	4,911.40
Current liabilities
Current maturities of long-term debt and short-term borrowings	0
Accounts payable	0
Employee compensation and benefits	0.6
Other current liabilities	2.2
Disposal Group, Including Discontinued Operation, Liabilities, Current	0
Total current liabilities	2.8
Other liabilities
Long-term debt	175.6
Pension and other post-retirement compensation and benefits	0
Deferred tax liabilities	0
Other non-current liabilities	0
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	0
Total liabilities	178.4
Equity
Total equity	4,733
Total liabilities and equity	4,911.40
Subsidiary Issuer
Current assets
Cash and cash equivalents	0.1	47	0	0
Accounts and notes receivable, net	0	4
Inventories	0	0
Other current assets	2	0.6
Disposal Group, Including Discontinued Operation, Assets, Current	0	0
Total current assets	2.1	51.6
Property, plant and equipment, net	0	0
Other assets
Investments in subsidiaries	7,612.20	8,066.60
Goodwill	0	0
Intangibles, net	0	0
Other non-current assets	1,381.80	1,302.70
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0	0
Total other assets	8,994	9,369.30
Total assets	8,996.10	9,420.90
Current liabilities
Current maturities of long-term debt and short-term borrowings	0	0
Accounts payable	0	8.6
Employee compensation and benefits	0	0
Other current liabilities	10.9	11.7
Disposal Group, Including Discontinued Operation, Liabilities, Current	0	0
Total current liabilities	10.9	20.3
Other liabilities
Long-term debt	2,860.60	2,401.90
Pension and other post-retirement compensation and benefits	0	0
Deferred tax liabilities	2.9	2.2
Other non-current liabilities	0	0
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	0	0
Total liabilities	2,874.40	2,424.40
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries		6,996.50
Noncontrolling interest		0
Total equity	6,121.70	6,996.50
Total liabilities and equity	8,996.10	9,420.90
Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	110.3	208.5	237.4	50.1
Accounts and notes receivable, net	1,206.80	1,341.70
Inventories	1,130.40	1,195.10
Other current assets	367.6	359.6
Disposal Group, Including Discontinued Operation, Assets, Current	80.6	134.4
Total current assets	2,895.70	3,239.30
Property, plant and equipment, net	950	1,044.30
Other assets
Investments in subsidiaries	0	0
Goodwill	4,741.90	4,860.70
Intangibles, net	1,608.10	1,749.90
Other non-current assets	345	352.4
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	24.9	466.3
Total other assets	6,719.90	7,429.30
Total assets	10,565.60	11,712.90
Current liabilities
Current maturities of long-term debt and short-term borrowings	6.7	2.5
Accounts payable	583.1	583.8
Employee compensation and benefits	304.7	311.9
Other current liabilities	595.8	534.6
Disposal Group, Including Discontinued Operation, Liabilities, Current	35.1	72.5
Total current liabilities	1,525.40	1,505.30
Other liabilities
Long-term debt	1,320.60	1,442.70
Pension and other post-retirement compensation and benefits	322	320.2
Deferred tax liabilities	525.4	554.8
Other non-current liabilities	481.4	438.8
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	6.5	33.9
Total liabilities	4,181.30	4,295.70
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries		7,294.80
Noncontrolling interest		122.4
Total equity	6,384.30	7,417.20
Total liabilities and equity	10,565.60	11,712.90
Eliminations
Current assets
Cash and cash equivalents	0	0	0	0
Accounts and notes receivable, net	-0.9	-63.6
Inventories	0	0
Other current assets	-20.4	0
Disposal Group, Including Discontinued Operation, Assets, Current	0	0
Total current assets	-21.3	-63.6
Property, plant and equipment, net	0	0
Other assets
Investments in subsidiaries	-17,239	-14,291.30
Goodwill	0	0
Intangibles, net	0	0
Other non-current assets	-1,370.80	-1,296.70
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0	0
Total other assets	-18,609.80	-15,588
Total assets	-18,631.10	-15,651.60
Current liabilities
Current maturities of long-term debt and short-term borrowings	0	0
Accounts payable	-0.9	-63.6
Employee compensation and benefits	0	0
Other current liabilities	-20.4	0
Disposal Group, Including Discontinued Operation, Liabilities, Current	0	0
Total current liabilities	-21.3	-63.6
Other liabilities
Long-term debt	-1,370.80	-1,296.70
Pension and other post-retirement compensation and benefits	0	0
Deferred tax liabilities	0	0
Other non-current liabilities	0	0
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	0	0
Total liabilities	-1,392.10	-1,360.30
Equity
Shareholders' equity attributable to Pentair Ltd. and subsidiaries		-14,291.30
Noncontrolling interest		0
Total equity	-17,239	-14,291.30
Total liabilities and equity	($18,631.10)	($15,651.60)

Financial_Statements_of_Parent5

Financial Statements of Parent Company Guarantor - Condensed Consolidating Statement of Cash Flows (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Revenue, Net	$7,039	$6,999.70	$4,306.80
Operating activities
Net cash provided by (used for) operating activities	1,008.40	927.9	43.7
Investing activities
Capital expenditures	-129.6	-170	-94.5
Proceeds from sale of property and equipment	13.1	6	5.5
Proceeds from sale of businesses, net	0.3	43.5	0
Acquisitions, net of cash acquired	-12.3	-92.4	470.5
Intercompany Loan Activity, Net	0
Other	0.2	1.7	-5.9
Net cash provided by (used for) investing activities	-128.3	-211.2	375.6
Financing activities
Net repayments of short-term borrowings	0.5	0	-3.7
Net receipts of commercial paper and revolving long-term debt	468.6	104.2	253.8
Proceeds from long-term debt	2.2	0.7	594.3
Repayment of long-term debt	-16.8	-7.4	-617.2
Debt issuance costs	-3.1	-1.4	-9.7
Debt extinguishment costs	0	0	-74.8
Net change in advances to subsidiaries	0	0	0
Excess tax benefits from share-based compensation	12.6	16.8	5
Shares issued to employees, net of shares withheld	37	80	68.2
Repurchases of ordinary shares	-1,150	-715.8	-334.2
Dividends paid	-211.4	-194.2	-112.4
Distributions to noncontrolling interest	-134.7	-2	-1.6
Net cash provided by (used for) financing activities	-995.1	-719.1	-232.3
Effect of exchange rate changes on cash and cash equivalents	-30.6	21	0.3
Change in cash and cash equivalents	-145.6	18.6	187.3
Cash and cash equivalents, beginning of year	256	237.4	50.1
Cash and cash equivalents, end of year	110.4	256	237.4
Cost of goods sold	4,576	4,629.60	3,040.90
Gross profit	2,463	2,370.10	1,265.90
Selling, General and Administrative Expense	1,493.80	1,493.70	1,117.70
Research and Development Expense	117.3	122.8	92.3
Asset Impairment Charges	0	11	60.7
Operating Income (Loss)	851.9	742.6	-4.8
Parent Company Guarantor
Condensed Financial Statements, Captions [Line Items]
Revenue, Net	0	0	0
Operating activities
Net cash provided by (used for) operating activities	169	534.2	-109
Investing activities
Capital expenditures	0	0	0
Proceeds from sale of property and equipment	0	0	0
Proceeds from sale of businesses, net	0	0
Acquisitions, net of cash acquired	0	0	0
Intercompany Loan Activity, Net	0
Other	0	0	0
Net cash provided by (used for) investing activities	0	0	0
Financing activities
Net repayments of short-term borrowings	0		0
Net receipts of commercial paper and revolving long-term debt	0	0	0
Proceeds from long-term debt	0	0	0
Repayment of long-term debt	0	0	0
Debt issuance costs	0	0	0
Debt extinguishment costs			0
Net change in advances to subsidiaries	741.1	-339.5	157
Excess tax benefits from share-based compensation	0	0	0
Shares issued to employees, net of shares withheld	0	0	0
Repurchases of ordinary shares	-699.2	0	0
Dividends paid	-211.4	-194.2	-48
Distributions to noncontrolling interest	0	0	0
Net cash provided by (used for) financing activities	-169.5	-533.7	109
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Change in cash and cash equivalents	-0.5	0.5	0
Cash and cash equivalents, beginning of year	0.5	0	0
Cash and cash equivalents, end of year	0	0.5	0
Cost of goods sold	0	0	0
Gross profit	0	0	0
Selling, General and Administrative Expense	25.3	21	5
Research and Development Expense	0	0	0
Asset Impairment Charges		0	0
Operating Income (Loss)	-25.3	-21	-5
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenue, Net	0
Operating activities
Net cash provided by (used for) operating activities	208.6
Investing activities
Capital expenditures	0
Proceeds from sale of property and equipment	0
Proceeds from sale of businesses, net	0
Acquisitions, net of cash acquired	0
Intercompany Loan Activity, Net	0
Other	0
Net cash provided by (used for) investing activities	0
Financing activities
Net repayments of short-term borrowings	0
Net receipts of commercial paper and revolving long-term debt	0
Proceeds from long-term debt	0
Repayment of long-term debt	0
Debt issuance costs	0
Net change in advances to subsidiaries	-208.6
Excess tax benefits from share-based compensation	0
Shares issued to employees, net of shares withheld	0
Repurchases of ordinary shares	0
Dividends paid	0
Distributions to noncontrolling interest	0
Net cash provided by (used for) financing activities	-208.6
Effect of exchange rate changes on cash and cash equivalents	0
Change in cash and cash equivalents	0
Cash and cash equivalents, beginning of year	0
Cash and cash equivalents, end of year	0
Cost of goods sold	0
Gross profit	0
Selling, General and Administrative Expense	2.6
Research and Development Expense	0
Operating Income (Loss)	-2.6
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Revenue, Net	0	0	0
Operating activities
Net cash provided by (used for) operating activities	207	514	-88.2
Investing activities
Capital expenditures	0	0	0
Proceeds from sale of property and equipment	0	0	0
Proceeds from sale of businesses, net	0	0
Acquisitions, net of cash acquired	0	0	300.1
Intercompany Loan Activity, Net	37.8
Other	0	0	0
Net cash provided by (used for) investing activities	37.8	0	300.1
Financing activities
Net repayments of short-term borrowings	0		0
Net receipts of commercial paper and revolving long-term debt	458.7	104.2	424.7
Proceeds from long-term debt	0	0	594.3
Repayment of long-term debt	0	0	0
Debt issuance costs	-3.1	-1.4	-8.7
Debt extinguishment costs			0
Net change in advances to subsidiaries	-747.3	-569.8	-1,222.20
Excess tax benefits from share-based compensation	0	0	0
Shares issued to employees, net of shares withheld	0	0	0
Repurchases of ordinary shares	0	0	0
Dividends paid	0	0	0
Distributions to noncontrolling interest	0	0	0
Net cash provided by (used for) financing activities	-291.7	-467	-211.9
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Change in cash and cash equivalents	-46.9	47	0
Cash and cash equivalents, beginning of year	47	0	0
Cash and cash equivalents, end of year	0.1	47	0
Cost of goods sold	0	0	0
Gross profit	0	0	0
Selling, General and Administrative Expense	7.7	13.3	-3.8
Research and Development Expense	0	0	0
Asset Impairment Charges		0	0
Operating Income (Loss)	-7.7	-13.3	3.8
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Revenue, Net	7,039	6,999.70	4,306.80
Operating activities
Net cash provided by (used for) operating activities	1,093.80	977.5	37.2
Investing activities
Capital expenditures	-129.6	-170	-94.5
Proceeds from sale of property and equipment	13.1	6	5.5
Proceeds from sale of businesses, net	0.3	43.5
Acquisitions, net of cash acquired	-12.3	-92.4	170.4
Intercompany Loan Activity, Net	112.2
Other	0.2	1.7	-5.9
Net cash provided by (used for) investing activities	-16.1	-211.2	75.5
Financing activities
Net repayments of short-term borrowings	0.5		-3.7
Net receipts of commercial paper and revolving long-term debt	9.9	0	-170.9
Proceeds from long-term debt	2.2	0.7	0
Repayment of long-term debt	-16.8	-7.4	-617.2
Debt issuance costs	0	0	-1
Debt extinguishment costs			-74.8
Net change in advances to subsidiaries	-605.2	-188.5	1,268.90
Excess tax benefits from share-based compensation	12.6	16.8	5
Shares issued to employees, net of shares withheld	37	80	68.2
Repurchases of ordinary shares	-450.8	-715.8	-334.2
Dividends paid	0	0	-64.4
Distributions to noncontrolling interest	-134.7	-2	-1.6
Net cash provided by (used for) financing activities	-1,145.30	-816.2	74.3
Effect of exchange rate changes on cash and cash equivalents	-30.6	21	0.3
Change in cash and cash equivalents	-98.2	-28.9	187.3
Cash and cash equivalents, beginning of year	208.5	237.4	50.1
Cash and cash equivalents, end of year	110.3	208.5	237.4
Cost of goods sold	4,576	4,629.60	3,040.90
Gross profit	2,463	2,370.10	1,265.90
Selling, General and Administrative Expense	1,458.20	1,459.40	1,116.50
Research and Development Expense	117.3	122.8	92.3
Asset Impairment Charges		11	60.7
Operating Income (Loss)	887.5	776.9	-3.6
Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenue, Net	0	0	0
Operating activities
Net cash provided by (used for) operating activities	-670	-1,097.80	203.7
Investing activities
Capital expenditures	0	0	0
Proceeds from sale of property and equipment	0	0	0
Proceeds from sale of businesses, net	0	0
Acquisitions, net of cash acquired	0	0	0
Intercompany Loan Activity, Net	-150
Other	0	0	0
Net cash provided by (used for) investing activities	-150	0	0
Financing activities
Net repayments of short-term borrowings	0		0
Net receipts of commercial paper and revolving long-term debt	0	0	0
Proceeds from long-term debt	0	0	0
Repayment of long-term debt	0	0	0
Debt issuance costs	0	0	0
Debt extinguishment costs			0
Net change in advances to subsidiaries	820	1,097.80	-203.7
Excess tax benefits from share-based compensation	0	0	0
Shares issued to employees, net of shares withheld	0	0	0
Repurchases of ordinary shares	0	0	0
Dividends paid	0	0	0
Distributions to noncontrolling interest	0	0	0
Net cash provided by (used for) financing activities	820	1,097.80	-203.7
Effect of exchange rate changes on cash and cash equivalents	0	0	0
Change in cash and cash equivalents	0	0	0
Cash and cash equivalents, beginning of year	0	0	0
Cash and cash equivalents, end of year	0	0	0
Cost of goods sold	0	0	0
Gross profit	0	0	0
Selling, General and Administrative Expense	0	0	0
Research and Development Expense	0	0	0
Asset Impairment Charges		0	0
Operating Income (Loss)	$0	$0	$0

Schedule_II_Valuation_and_Qual1

Schedule II - Valuation and Qualifying Accounts - Disclosure Table (Detail) (Allowance for Doubtful Accounts, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance	$58.70		$14		$16
Additions charged to costs and expenses	-1.2		49.7		1.6
Deductions	11.5	[1]	2.4	[1]	4	[1]
Other changes	-3.5	[2]	-2.6	[2]	0.4	[2]
Ending balance	$42.50		$58.70		$14
[1]	Uncollectible accounts written off, net of recoveries
[2]	Result of foreign currency effects