Pentair (PNR) 10-K 19 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Jun. 30, 2017
Document Documentand Entity Information [Abstract]
Entity Registrant Name	PENTAIR PLC
Entity Central Index Key	77,360
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Trading Symbol	PNR
Entity Well-known Seasoned Issuer	Yes
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding	171,363,615
Entity Public Float		$ 6,703,824,353

Consolidated Statements Of Oper

Consolidated Statements Of Operations And Comprehensive Income (Loss) - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Income Statement [Abstract]
Net sales	[1]	$ 2,965.1		$ 2,845.7		$ 2,780.6
Cost of goods sold		1,917.4		1,858.2		1,821.5
Gross profit		1,047.7		987.5		959.1
Selling, general and administrative		534.3		536		531.4
Research and development		76.7		73.2		73.3
Operating income		436.7		378.3		354.4
Other (income) expense
Loss on sale of businesses		7.3		4.2		3.9
Loss on early extinguishment of debt		17.1		101.4		0
Net interest expense		32.6		87.3		140.1
Other Income		(0.1)				(10.5)
Other expense				12.6
Income from continuing operations before income taxes		379.8		172.8		220.9
Provision for income taxes		58.1		58.7		42.7
Net income from continuing operations		321.7		114.1		178.2
Income from discontinued operations, net of tax		25.7		371.3		343.4
Income (loss) from discontinued operations, net of tax		25.7		371.3		343.4
Gain from sale / impairment of discontinued operations, net of tax		0		181.1		0.6
Net income		347.4		666.5		522.2
Comprehensive income, net of tax
Net income		347.4		666.5		522.2
Changes in cumulative translation adjustment (inclusive of divestiture of business reclassified to gain from sale of $374.2 for the year ended December 31, 2017)		10		497.5		(83)
Changes in market value of derivative financial instruments, net of tax		4.8		(4.6)		(8.3)
Comprehensive income		$ 362.2		$ 1,159.4		$ 430.9
Earnings per ordinary share
Continuing operations (USD per share)		$ 1.83		$ 0.63		$ 0.98
Discontinued operations (USD per share)		0.15		3.04		1.90
Basic earnings per ordinary share (USD per share)		1.98	[2]	3.67	[3]	2.88
Continuing operations (USD per share)		1.81		0.62		0.97
Discontinued operations (USD per share)		0.15		3.01		1.88
Diluted earnings per ordinary share (USD per share)		$ 1.96	[2]	$ 3.63	[3]	$ 2.85
Weighted average ordinary shares outstanding
Basic (shares)		175.8		181.7		181.3
Diluted (shares)		177.3		183.7		183.1
[1]	(1) One customer in the Aquatic Systems segment, Pool Corporation, represented approximately 15% of our consolidated net sales in 2018, 2017 and 2016.
[2]	(2) 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.
[3]	(3) 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 Op_2

Consolidated Statements Of Operations And Comprehensive Income (Loss) (Parenthetical) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Changes in Cumulative translation adjustment inclusive of divestiture of business reclassified to gain from sale	$ 374.2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 74.3	$ 86.3
Accounts receivable, net of allowances of $14.0 and $14.2, respectively	488.2	483.1
Inventories	387.5	356.9
Other current assets	89.4	114.5
Current assets held for sale	0	708
Total current assets	1,039.4	1,748.8
Property, plant and equipment, net	272.6	279.8
Other assets
Goodwill	2,072.7	2,112.8
Intangibles, net	276.3	321.8
Other non-current assets	145.5	180.9
Non-current assets held for sale	0	3,989.6
Total other assets	2,494.5	6,605.1
Total assets	3,806.5	8,633.7
Current liabilities
Accounts payable	378.6	321.5
Employee compensation and benefits	111.7	115.8
Other current liabilities	328.4	401.3
Current liabilities held for sale	0	360.8
Total current liabilities	818.7	1,199.4
Other liabilities
Long-term debt	787.6	1,440.7
Pension and other post-retirement compensation and benefits	90	96.4
Deferred tax liabilities	105.9	108.6
Other non-current liabilities	168.2	213.8
Non-current liabilities held for sale	0	537
Total liabilities	1,970.4	3,595.9
Equity
Ordinary shares $0.01 par value, 426.0 authorized, 171.4 and 180.3 issued at December 31, 2018 and December 31, 2017, respectively	1.7	1.8
Additional paid-in capital	1,893.8	2,797.7
Retained earnings	169.2	2,481.7
Accumulated other comprehensive loss	(228.6)	(243.4)
Total equity	1,836.1	5,037.8
Total liabilities and equity	$ 3,806.5	$ 8,633.7

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts and notes receivable, allowances	$ 14	$ 14.2
Common stock, par value (per share)	$ 0.01	$ 0.01
Common stock, shares authorized	426,000,000	426,000,000
Common stock, shares issued	171,400,000	180,300,000

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 347.4	$ 666.5	$ 522.2
(Income) loss from discontinued operations, net of tax	(25.7)	(371.3)	(343.4)
Gain from sale / impairment of discontinued operations, net of tax	0	(181.1)	(0.6)
Adjustments to reconcile net income from continuing operations to net cash provided by operating activities of continuing operations
Equity income of unconsolidated subsidiaries	(8.4)	(1.3)	(4.3)
Depreciation	49.7	50.8	53
Amortization	34.9	36.4	35.4
Loss on sale of businesses	7.3	4.2	3.9
Deferred income taxes	(4.1)	(18)	1.2
Share-based compensation	20.9	39.6	34.2
Impairment of trade names	12	15.6	0
Loss on early extinguishment of debt	17.1	101.4	0
Excess tax benefits from share-based compensation	0	0	(8)
Changes in assets and liabilities, net of effects of business acquisitions
Accounts receivable	(15.3)	(13.4)	16.6
Inventories	(40.1)	(20.5)	33.9
Other current assets	31.2	(13)	2.1
Accounts payable	58.3	15.6	22.8
Employee compensation and benefits	(0.6)	(1.4)	26.7
Other current liabilities	(3.3)	(54.6)	90.3
Other non-current assets and liabilities	(23.2)	23.1	(106.1)
Net cash provided by operating activities of continuing operations	458.1	278.6	379.9
Net cash provided by (used for) operating activities of discontinued operations	(19)	341.6	481.5
Net cash provided by operating activities of continuing operations	439.1	620.2	861.4
Investing activities
Capital expenditures	(48.2)	(39.1)	(43.3)
Proceeds from sale of property and equipment	0.2	3.7	18.8
(Payments due to) proceeds from sale of businesses and other	(12.8)	2,759.4	(5.1)
Acquisitions, net of cash acquired	(0.9)	(45.9)	(25)
Net cash provided by (used for) investing activities of continuing operations	(61.7)	2,678.1	(54.6)
Net cash used for investing activities of discontinued operations	(7.1)	(47.7)	(67.2)
Net cash provided by (used for) investing activities	(68.8)	2,630.4	(121.8)
Financing activities
Net receipts (repayments) of commercial paper and revolving long-term debt	39.7	(913.1)	(385.3)
Repayment of long-term debt	(675.1)	(2,009.3)	(0.7)
Premium paid on early extinguishment of debt	(16)	(94.9)	0
Transfer of cash to nVent	(74.2)	0	0
Distribution of cash from nVent	993.6	0	0
Shares issued to employees, net of shares withheld	13.3	37.2	20.7
Repurchases of ordinary shares	(500)	(200)	0
Dividends paid	(187.2)	(251.7)	(243.6)
Other	2	0.8	(8.8)
Net cash provided by (used for) financing activities of continuing operations	(407.9)	(3,432.6)	(600.1)
Change in cash held for sale	27	(5.4)	1.1
Effect of exchange rate changes on cash and cash equivalents	(1.4)	56.8	(27.3)
Change in cash and cash equivalents	(12)	(130.6)	113.3
Cash and cash equivalents, beginning of year	86.3	216.9	103.6
Cash and cash equivalents, end of year	74.3	86.3	216.9
Cash paid for interest, net	43.7	107.2	143.4
Income Taxes Paid	$ 92.9	$ 362.1	$ 145.1

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Equity - USD ($) shares in Millions, $ in Millions	Total	Common shares	Capital contribution reserve	Retained earnings	Accumulated other comprehensive income (loss)	Total Pentair plc
Net Income (Loss) Attributable to Parent	$ 522.2			$ 522.2
Beginning Balance at Dec. 31, 2015	4,008.8	$ 1.8	$ 2,860.3	1,791.7	$ (645)
Balance (in shares) at Dec. 31, 2015		(180.5)
Net income	522.2
Other comprehensive income, net of tax	(91.3)				(91.3)
Tax benefit of share-based compensation	5.5		5.5
Dividends declared	(245.8)		0	245.8
Share repurchase (in shares)		(3)
Share repurchases	$ (200)		(200)
Exercise of options, net of shares tendered for payment (in shares)	1
Exercise of options, net of shares tendered for payment	$ 31.6		31.6
Issuance of restricted shares, net of cancellations (in shares)	0.5
Issuance of restricted shares, net of cancellations			0
Shares surrendered by employees to pay taxes (in shares)		(0.2)
Shares surrendered by employees to pay taxes	$ (10.8)		(10.8)
Share-based compensation	34.2		34.2
Balance (in shares) at Dec. 31, 2016		(181.8)
Ending Balance at Dec. 31, 2016	4,254.4	$ 1.8	2,920.8	2,068.1	(736.3)
Net Income (Loss) Attributable to Parent	666.5			666.5
Net income	666.5
Other comprehensive income, net of tax	492.9				492.9
Dividends declared	(252.9)		0	(252.9)
Exercise of options, net of shares tendered for payment (in shares)		1.2
Exercise of options, net of shares tendered for payment	45.6		45.6
Issuance of restricted shares, net of cancellations (in shares)		0.4
Issuance of restricted shares, net of cancellations			0
Shares surrendered by employees to pay taxes (in shares)		(0.1)
Shares surrendered by employees to pay taxes	(8.3)		(8.3)
Share-based compensation	39.6		39.6
Balance (in shares) at Dec. 31, 2017		(180.3)
Ending Balance at Dec. 31, 2017	5,037.8	$ 1.8	2,797.7	2,481.7	(243.4)
Cumulative Effect of New Accounting Principle in Period of Adoption				(214)		$ (214)
Net Income (Loss) Attributable to Parent	347.4			347.4
Distributions To Spin-Off Successor	(2,777)		(438.2)	(2,291)	(47.8)
Net income	347.4					347.4
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent					62.6	$ 62.6
Dividends declared	(154.9)			(154.9)
Share repurchase (in shares)		(10.2)
Share repurchases	$ (500)	$ (0.1)	(499.9)
Exercise of options, net of shares tendered for payment (in shares)	0.8	0.9
Exercise of options, net of shares tendered for payment	$ 24.3		24.3
Issuance of restricted shares, net of cancellations (in shares)		0.5
Shares surrendered by employees to pay taxes (in shares)		(0.1)
Shares surrendered by employees to pay taxes	(11)		(11)
Share-based compensation	20.9		20.9
Balance (in shares) at Dec. 31, 2018		(171.4)
Ending Balance at Dec. 31, 2018	$ 1,836.1	$ 1.7	$ 1,893.8	$ 169.2	$ (228.6)

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
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 (“we,” “us,” “our,” “Pentair” or the “Company”) is a pure play water company comprised of three reporting segments: Aquatic Systems, Filtration Solutions and Flow Technologies. Electrical separation On April 30, 2018, Pentair completed the separation of its Electrical business from the rest of Pentair (the “Separation”) by means of a dividend in specie of the Electrical business, which was effected by the transfer of the Electrical business from Pentair to nVent Electric plc (“nVent”) and the issuance by nVent of ordinary shares directly to Pentair shareholders (the “Distribution”). On May 1, 2018, following the Separation and Distribution, nVent became an independent publicly traded company, trading on the New York Stock Exchange under the symbol “NVT.” The Company did not retain any equity interest in nVent. nVent’s historical financial results are reflected in the Company’s consolidated financial statements as a discontinued operation. Refer to Note 2 for further discussion. In connection with the Distribution of nVent, the Company and nVent entered into several agreements covering administrative and tax matters to provide or obtain services on a transitional basis, as needed, for varying periods after the Distribution. The administrative agreements cover various services such as information technology, human resources and finance. The Company expects all services to be substantially complete within one year after the Distribution. 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. 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 calendar quarter basis. 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, pension and other post-retirement benefits and the estimated impact of the new lease standard, discussed below. Actual results could differ from our estimates. Revenue recognition Revenue is recognized when control of the promised goods or services are transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for transferring those goods or providing services. We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. When determining whether the customer has obtained control of the goods or services, we consider any future performance obligations. 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 Pentair has substantially accomplished what it must do to be entitled to the benefits represented by the revenue. Performance obligations A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account for purposes of revenue recognition. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The majority of our contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and, therefore, not distinct. For contracts with multiple performance obligations, standalone selling price is generally readily observable. Our performance obligations are satisfied at a point in time or over time as work progresses. Revenue from goods and services transferred to customers at a point in time accounted for 92.5% , 92.4% and 94.0% of our revenue for the twelve months ended December 31, 2018, 2017 and 2016, respectively. Revenue on these contracts is recognized when obligations under the terms of the contract with our customer are satisfied; generally this occurs with the transfer of control upon shipment. Revenue from products and services transferred to customers over time accounted for 7.5% , 7.6% and 6.0% of our revenue for the twelve months ended December 31, 2018, 2017 and 2016, respectively. For the majority of our revenue recognized over time, we use an input measure to determine progress towards completion. Under this method, sales and gross profit are recognized as work is performed generally 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. Contract costs include labor, material, overhead and, when appropriate, general and administrative expenses. 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. For performance obligations related to long term contracts, when estimates of total costs to be incurred on a performance obligation exceed total estimates of revenue to be earned, a provision for the entire loss on the performance obligation is recognized in the period the loss is determined. On December 31, 2018, we had $57.2 million of remaining performance obligations on contracts with an original expected duration of one year or more. We expect to recognize the majority of our remaining performance obligations on these contracts within the next 12 to 18 months. Sales returns The right of return may exist explicitly or implicitly with our customers. 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. When the right of return exists, we adjust the transaction price for the estimated effect of returns. We estimate the expected returns based on 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 Our contracts may give customers the option to purchase additional goods or services priced at a discount. Options to acquire additional goods or services at a discount can come in many forms, such as customer programs and incentive offerings including pricing arrangements, promotions and other volume-based incentives. We reduce the transaction price for certain customer programs and incentive offerings including pricing arrangements, promotions and other volume-based incentives that represent variable consideration. Sales incentives given to our customers are recorded using either the expected value method or most likely amount approach for estimating the amount of consideration to which Pentair shall be entitled. The expected value is the sum of probability-weighted amounts in a range of possible consideration amounts. An expected value is an appropriate estimate of the amount of variable consideration when there are a large number of contracts with similar characteristics. The most likely amount is the single most likely amount in a range of possible consideration amounts (that is, the single most likely outcome of the contract). The most likely amount is an appropriate estimate of the amount of variable consideration if the contract has limited possible outcomes (for example, an entity either achieves a performance bonus or does not). 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. We use the expected value method to 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 of the transaction price. 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 determine the most likely amount of the rebate to be paid based on forecasted sales levels. These forecasts are updated at least quarterly for each customer, and the transaction price is reduced for the anticipated cost of the rebate. If the forecasted sales for a customer change, 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 activities after the customer obtains control are treated as a promised service performance obligation and recorded in Net sales in the accompanying Consolidated Statements of Operations and Comprehensive Income. Shipping and handling costs incurred by Pentair for the delivery of goods to customers are considered a cost to fulfill the contract and are included in Cost of goods sold in the accompanying Consolidated Statements of Operations and Comprehensive Income. Contract assets and liabilities Contract assets consist of unbilled amounts resulting from sales under long-term contracts when the cost-to-cost method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the customer, such as when the customer retains a small portion of the contract price until completion of the contract. We typically receive interim payments on sales under long-term contracts as work progresses, although for some contracts, we may be entitled to receive an advance payment. Contract liabilities consist of advanced payments, billings in excess of costs incurred and deferred revenue. Contract assets are recorded within Other current assets , and contract liabilities are recorded within Other current liabilities in the Consolidated Balance Sheets. Contract assets and liabilities consisted of the following: December 31 In millions 2018 2017 $ Change % Change Contract assets $ 36.5 $ 51.5 $ (15.0 ) (29.1 )% Contract liabilities 32.8 29.2 3.6 12.3 % Net contract assets $ 3.7 $ 22.3 $ (18.6 ) (83.4 )% The $18.6 million decrease in net contract assets from December 31, 2017 to December 31, 2018 was primarily the result of timing of milestone payments. Approximately 70% of our contract liabilities at December 31, 2017 were recognized in revenue during the twelve months ended December 31, 2018 . There were no impairment losses recognized on our contract assets for the twelve months ended December 31, 2018 . Practical expedients and exemptions We generally expense incremental costs of obtaining a contract when incurred because the amortization period would be less than one year. These costs primarily relate to sales commissions and are recorded in Selling, general and administrative expense in the Consolidated Statements of Operations and Comprehensive Income. We do not disclose the value of unsatisfied performance obligations for contracts with an original expected length of one year or less. Further, we do not adjust the promised amount of consideration for the effects of a significant financing component if we expect, at contract inception, that the period between when we transfer a promised good or service to a customer and when the customer pays for that good or service will be one year or less. Revenue by category We disaggregate our revenue from contracts with customers by segment, geographic location and vertical, as we believe these best depict how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors. Refer to Note 14 for revenue disaggregated by segment. Geographic net sales information for continuing operations, based on geographic destination of the sale, was as follows: Years ended December 31 In millions 2018 2017 2016 U.S. $ 1,858.1 $ 1,752.7 $ 1,690.0 Western Europe 402.7 381.9 377.7 Developing (1) 476.5 478.2 492.0 Other Developed (2) 227.8 232.9 220.9 Consolidated net sales (3) $ 2,965.1 $ 2,845.7 $ 2,780.6 (1) Developing includes China, Eastern Europe, Latin America, the Middle East and Southeast Asia. (2) Other Developed includes Australia, Canada and Japan. (3) Net sales held in Ireland, for each of the years presented, were not material. Vertical net sales information was as follows: Years ended December 31 In millions 2018 2017 2016 Residential $ 1,665.9 $ 1,579.0 $ 1,498.7 Commercial 630.7 604.4 586.5 Industrial 668.5 662.3 695.4 Consolidated net sales $ 2,965.1 $ 2,845.7 $ 2,780.6 Research and development We conduct research and development (“R&D”) activities primarily in our own facilities, which mostly consist of development of new products, product applications and manufacturing processes. We expense R&D costs as incurred. R&D expenditures from continuing operations during 2018 , 2017 and 2016 were $76.7 million , $73.2 million and $73.3 million , respectively. Cash equivalents We consider highly liquid investments with original maturities of three months or less at the date of acquisition 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. 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. 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. The following table presents geographic Property, plant and equipment, net by region as of December 31: In millions 2018 2017 U.S. $ 156.9 $ 151.9 Western Europe 76.6 82.8 Developing (1) 28.8 33.0 Other Developed (2) 10.3 12.1 Consolidated (3) $ 272.6 $ 279.8 (1) Developing includes China, Eastern Europe, Latin America, the Middle East and Southeast Asia. (2) Other Developed includes Australia, Canada and Japan. (3) Property, plant and equipment, net held in Ireland, for each of the years presented, were not material. 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. We recorded no long-lived asset impairment charges in 2018 , 2017 , or 2016 in conjunction with restructuring activities. 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 at least annually for impairment and is tested for impairment more frequently if events or changes in circumstances indicate that the asset might be impaired. We complete our annual goodwill impairment evaluation as of the first day of the fourth quarter. We last performed a two-step assessment of goodwill impairment as of October 1, 2017, referred to as a “step 1” approach. In the first step of the step 1 approach, 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 of the step 1 approach, 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. 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. 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. 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. As of October 1, 2018, we performed a qualitative assessment, referred to as a “step 0” approach, and determined that it was more likely than not that the fair value of the reporting units exceeded their respective carrying amounts. As a result, the Company was not required to proceed to a “step 1” impairment assessment. Factors considered included the 2017 “step 1” analysis and the calculated excess fair value over carrying amount, financial performance, forecasts and trends, market cap, regulatory and environmental issues, macro-economic conditions, industry and market considerations, raw material costs and management stability. We consider the extent to which each of the adverse events and circumstances identified affect the comparison of the respective reporting unit’s fair value with its carrying amount. We place more weight on the events and circumstances that most affect the respective reporting unit’s fair value or the carrying amount of its net assets. We consider positive and mitigating events and circumstances that may affect its determination of whether it is more likely than not that the fair value exceeds the carrying amount. We completed our annual goodwill impairment evaluation as of the first day of the fourth quarter of 2018, 2017 and 2016 with no indications of impairment. This non-recurring fair value measurement is a “Level 3” measurement under the fair value hierarchy described in Note 9. Identifiable intangible assets Our primary identifiable intangible assets include: customer relationships, trade names, proprietary technology and patents. 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. We complete our annual impairment test during the fourth quarter each year for those identifiable assets not subject to amortization. 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 in Note 9. There were no impairment charges recorded in 2018 for identifiable intangible assets. An impairment charge of $8.8 million was recorded in 2017 related to certain trade names in Filtration Solutions and Flow Technologies as a result of lower forecasted sales volume or rebranding strategies implemented in the fourth quarter of 2017. The trade name impairment charges were recorded in Selling, general and administrative in our Consolidated Statements of Operations and Comprehensive Income. There were no impairment charges recorded in 2016 for identifiable intangible assets. 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. We maintain valuation allowances unless it is more likely than not that all or a portion of the deferred tax assets will 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 and expected returns on plan assets. These assumptions are updated annually and are disclosed in Note 11. 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, including service and interest costs and estimated return on plan assets, are recorded on a quarterly basis. 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, 2018 and 2017, reserves for policy claims were $60.9 million , of which $13.2 million was included in Other current liabilities and $47.7 million was included in Other non-current liabilities , and $61.5 million , of which $13.2 million was included in Other current liabilities and $48.3 million was 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. Restricted share awards and units (“RSUs”) are recorded as compensation cost over the requisite service periods based on the market value on the date of grant. Performance share units (“PSUs”) are stock awards where the ultimate number of shares issued will be contingent on the Company’s performance against certain financial performance targets. The fair value of each PSU is based on the market value on the date of grant. We recognize expense related to the estimated vesting of our PSUs granted. The estimated vesting of the PSUs is based on the probability of achieving certain financial performance thresholds over the specified performance period. Earnings per ordinary share We present two calculations of earnings per ordinary share (“EPS”). Basic EPS equals net income divided by the weighted-average number of ordinary shares outstanding during the period. Diluted EPS is computed by dividing net income by the sum of weighted-average number of ordinary shares outstanding plus 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, the effective portion of 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 are recognized in the Consolidated Statements of Operations and Comprehensive Income 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. Gains and losses on net investment hedges are included in AOCI as a separate component of equity in the Consolidated Balance Sheets. 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. 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 (Loss) and expense items are translated at average monthly rates of exchange. The resultant translation adjustments are included in AOCI, a component of equity. New accounting standards In February 2016, the Financial Accounting Standards Board issued ASU No. 2016-02, “Leases” (“the new lease standard” or “ASC 842”), which requires an entity to recognize both assets and liabilities arising from financing and operating leases, along with additional qualitative and quantitative disclosures. The new lease standard requirements are effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. We adopted the new lease guidance as of January 1, 2019, using the transition method of adoption applied to those leases which were not completed as of that date. Under the transition method of adoption, comparative periods will not be restated for the new standard. We also elected the package of practical expedients permitted under the transition guidance, which among other things allowed us to carry forward the historical lease classification

Acquisitions and Discontinued O

Acquisitions and Discontinued Operations	12 Months Ended
	Dec. 31, 2018
Business Combination And Disposal Groups, Including Discontinued Operations, Disclosure [Abstract]
Acquisitions and Discontinued Operations	Acquisitions and Discontinued Operations Acquisitions In January 2019, as part of Filtration Solutions, we entered into definitive agreements to acquire Aquion Inc. (“Aquion”) and Pelican Water Systems (“Pelican”) for $160.0 million and $120.0 million in cash, respectively, and subject to certain customary adjustments. We completed the Aquion acquisition on February 13, 2019 and the Pelican acquisition on February 12, 2019. Aquion offers a diverse line of water conditioners, water filters, drinking-water purifiers, ozone and ultraviolet disinfection systems, reverse osmosis systems and acid neutralizers for the residential and commercial water treatment industry. Pelican Water Systems provides residential whole home water treatment systems. These acquisitions are not expected to have a material impact on our consolidated financial position, results of operations or cash flows. During 2017, our continuing operations completed acquisitions with purchase prices totaling $45.9 million in cash, net of cash acquired. Identifiable intangible assets acquired included $19.1 million of definite-lived customer relationships with an estimated useful life of 11 years . In November 2016, our continuing operations completed an acquisition with a purchase price of $25.0 million in cash, net of cash acquired. The pro forma impact of these acquisitions was not material. Discontinued Operations Electrical separation On April 30, 2018, we completed the Separation and Distribution. The results of the Electrical business have been presented as discontinued operations and the related assets and liabilities were reclassified as held for sale for all periods presented. The Electrical business had been previously disclosed as a stand-alone reporting segment. Separation costs related to the Separation and Distribution were $84.2 million and $39.3 million for the twelve months ended December 31, 2018 and 2017, respectively. These costs are reported in discontinued operations as they represent a cost directly related to the Separation and Distribution and were included within Income from discontinued operations, net of tax presented below. There were no separation costs related to the Separation and Distribution for the twelve months ended December 31, 2016. Sale of Valves & Controls On April 28, 2017, we completed the sale of the Valves & Controls business to Emerson Electric Co. for $3.15 billion in cash. The sale resulted in a gain of $181.1 million , net of tax. The results of the Valves & Controls business have been presented as discontinued operations. The Valves & Controls business was previously disclosed as a stand-alone reporting segment. Transaction costs of $56.4 million related to the sale of Valves & Controls were incurred during the year ended December 31, 2017 and were recorded within Gain from sale/impairment of discontinued operations before income taxes presented below. Operating results of discontinued operations are summarized below: Years ended December 31 In millions 2018 2017 2016 Net sales $ 693.9 $ 2,548.2 $ 3,755.4 Cost of goods sold 424.0 1,596.2 2,457.1 Gross profit 269.9 952.0 1,298.3 Selling, general and administrative 237.8 589.2 803.2 Research and development 14.6 48.3 59.0 Operating income $ 17.5 $ 314.5 $ 436.1 Income from discontinued operations before income taxes $ 31.8 $ 317.1 $ 418.5 Income tax provision (benefit) 6.1 (54.2 ) 75.1 Income from discontinued operations, net of tax $ 25.7 $ 371.3 $ 343.4 Gain from sale / impairment of discontinued operations before income taxes $ — $ 183.5 $ 0.6 Provision for income taxes — 2.4 — Gain from sale / impairment of discontinued operations, net of tax $ — $ 181.1 $ 0.6 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 2017 Cash and cash equivalents $ 27.0 Accounts receivable, net 348.5 Inventories 224.1 Other current assets 108.4 Current assets held for sale $ 708.0 Property, plant and equipment, net $ 265.8 Goodwill 2,238.2 Intangibles, net 1,236.6 Other non-current assets 249.0 Non-current assets held for sale $ 3,989.6 Accounts payable $ 174.1 Employee compensation and benefits 70.8 Other current liabilities 115.9 Current liabilities held for sale $ 360.8 Pension and other post-retirement compensation and benefits $ 189.2 Deferred tax liabilities 286.2 Other non-current liabilities 61.6 Non-current liabilities held for sale $ 537.0

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share, Basic and Diluted [Abstract]
Earnings (Loss) Per Share	Earnings Per Share Basic and diluted earnings per share were calculated as follows: Years ended December 31 In millions, except per share data 2018 2017 2016 Net income $ 347.4 $ 666.5 $ 522.2 Net income from continuing operations $ 321.7 $ 114.1 $ 178.2 Weighted average ordinary shares outstanding Basic 175.8 181.7 181.3 Dilutive impact of stock options and restricted stock awards 1.5 2.0 1.8 Diluted 177.3 183.7 183.1 Earnings per ordinary share Basic Continuing operations $ 1.83 $ 0.63 $ 0.98 Discontinued operations 0.15 3.04 1.90 Basic earnings per ordinary share $ 1.98 $ 3.67 $ 2.88 Diluted Continuing operations $ 1.81 $ 0.62 $ 0.97 Discontinued operations 0.15 3.01 1.88 Diluted earnings per ordinary share $ 1.96 $ 3.63 $ 2.85 Anti-dilutive stock options excluded from the calculation of diluted earnings per share 1.2 1.8 1.2

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring During 2018 , 2017 and 2016 , we initiated and continued execution of certain business restructuring initiatives aimed at reducing our fixed cost structure and realigning our business. Initiatives during the years ended December 31, 2018 , 2017 and 2016 included a reduction in hourly and salaried headcount of approximately 300 employees, 250 employees and 300 employees, respectively. Restructuring related costs included in Selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income included costs for severance and other restructuring costs as follows: Years ended December 31 In millions 2018 2017 2016 Severance and related costs $ 13.2 $ 27.3 $ 12.2 Other 27.4 0.9 — Total restructuring costs $ 40.6 $ 28.2 $ 12.2 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 2018 2017 2016 Aquatic Systems $ 15.3 $ 3.6 $ 1.8 Filtration Solutions 14.6 13.0 7.4 Flow Technologies 9.3 7.0 1.3 Other 1.4 4.6 1.7 Consolidated $ 40.6 $ 28.2 $ 12.2 Activity related to accrued severance and related costs recorded in Other current liabilities in the Consolidated Balance Sheets is summarized as follows: Years ended December 31 In millions 2018 2017 Beginning balance $ 34.5 $ 15.1 Costs incurred 13.2 27.3 Cash payments and other (20.6 ) (7.9 ) Ending balance $ 27.1 $ 34.5

Goodwill and Other Identifiable

Goodwill and Other Identifiable Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Identifiable Intangible Assets	oodwill and Other Identifiable Intangible Assets The changes in the carrying amount of goodwill for the years ended December 31, 2018 and 2017 by reportable segment were as follows: In millions December 31, 2017 Foreign currency December 31, 2018 Aquatic Systems $ 973.1 $ (7.2 ) $ 965.9 Filtration Solutions 667.6 (24.1 ) 643.5 Flow Technologies 472.1 (8.8 ) 463.3 Total goodwill $ 2,112.8 $ (40.1 ) $ 2,072.7 In millions December 31, 2016 Acquisitions/ Foreign currency December 31, 2017 Aquatic Systems $ 918.7 $ — $ 54.4 $ 973.1 Filtration Solutions 630.2 27.3 10.1 667.6 Flow Technologies 445.7 — 26.4 472.1 Total goodwill $ 1,994.6 $ 27.3 $ 90.9 $ 2,112.8 There has been no impairment of goodwill for any of the years presented. Identifiable intangible assets consisted of the following at December 31: 2018 2017 In millions Cost Accumulated amortization Net Cost Accumulated amortization Net Definite-life intangibles Customer relationships $ 347.1 $ (247.9 ) $ 99.2 $ 360.9 $ (229.9 ) $ 131.0 Trade names 0.4 (0.4 ) — 1.5 (1.4 ) 0.1 Proprietary technology and patents 86.2 (68.4 ) 17.8 117.0 (89.3 ) 27.7 Total finite-life intangibles 433.7 (316.7 ) 117.0 479.4 (320.6 ) 158.8 Indefinite-life intangibles Trade names 159.3 — 159.3 163.0 — 163.0 Total intangibles $ 593.0 $ (316.7 ) $ 276.3 $ 642.4 $ (320.6 ) $ 321.8 Identifiable intangible asset amortization expense in 2018 , 2017 and 2016 was $34.9 million , $36.4 million and $35.4 million , respectively. There was no impairment charge for trade name intangible assets in 2018 . In 2017 , we recorded an impairment charge for trade name intangible assets of $8.8 million in Filtration Solutions and Flow Technologies. In 2016 , there was no impairment charge for trade name intangible assets. Estimated future amortization expense for identifiable intangible assets during the next five years is as follows: In millions 2019 2020 2021 2022 2023 Estimated amortization expense $ 27.4 $ 22.4 $ 17.3 $ 10.1 $ 7.8

Supplemental Balance Sheet Info

Supplemental Balance Sheet Information	12 Months Ended
	Dec. 31, 2018
Disclosure Supplemental Balance Sheet Information [Abstract]
Supplemental Balance Sheet Information	Supplemental Balance Sheet Information December 31 In millions 2018 2017 Inventories Raw materials and supplies $ 191.3 $ 190.8 Work-in-process 64.0 57.9 Finished goods 132.2 108.2 Total inventories $ 387.5 $ 356.9 Other current assets Cost in excess of billings $ 36.5 $ 51.5 Prepaid expenses 36.7 51.4 Prepaid income taxes 8.5 7.8 Other current assets 7.7 3.8 Total other current assets $ 89.4 $ 114.5 Property, plant and equipment, net Land and land improvements $ 33.5 $ 33.5 Buildings and leasehold improvements 178.9 184.3 Machinery and equipment 593.8 609.6 Construction in progress 35.7 23.7 Total property, plant and equipment 841.9 851.1 Accumulated depreciation and amortization 569.3 571.3 Total property, plant and equipment, net $ 272.6 $ 279.8 Other non-current assets Prepaid income taxes $ — $ 52.8 Deferred income taxes 26.2 29.0 Deferred compensation plan assets 20.9 23.2 Other non-current assets 98.4 75.9 Total other non-current assets $ 145.5 $ 180.9 Other current liabilities Dividends payable $ 30.8 $ 63.1 Accrued warranty 33.9 38.1 Accrued rebates 55.7 49.8 Billings in excess of cost 21.3 20.1 Income taxes payable 10.4 39.7 Accrued restructuring 27.1 34.5 Other current liabilities 149.2 156.0 Total other current liabilities $ 328.4 $ 401.3 Other non-current liabilities Income taxes payable $ 46.8 $ 61.3 Self-insurance liabilities 47.7 48.3 Deferred compensation plan liabilities 20.9 23.2 Foreign currency contract liabilities 30.6 47.2 Other non-current liabilities 22.2 33.8 Total other non-current liabilities $ 168.2 $ 213.8

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Loss Components of Accumulated Other Comprehensive Loss consist of the following: December 31 In millions 2018 2017 Cumulative translation adjustments $ (211.4 ) $ (221.4 ) Market value of derivative financial instruments, net of tax (17.2 ) (22.0 ) Accumulated other comprehensive loss $ (228.6 ) $ (243.4 )

Debt

Debt	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Debt	Debt Debt and the average interest rates on debt outstanding were as follows: In millions Average Maturity year December 31 December 31, 2018 2018 2017 Commercial paper 3.248% 2023 $ 76.0 $ 34.0 Revolving credit facilities 3.703% 2023 26.2 28.4 Senior notes - fixed rate (1) 2.900% 2018 — 255.3 Senior notes - fixed rate (1) 2.650% 2019 250.0 250.0 Senior notes - fixed rate - Euro (1) 2.450% 2019 155.1 594.4 Senior notes - fixed rate (1) 3.625% 2020 74.0 74.0 Senior notes - fixed rate (1) 5.000% 2021 103.8 103.8 Senior notes - fixed rate (1) 3.150% 2022 88.3 88.3 Senior notes - fixed rate (1) 4.650% 2025 19.3 19.3 Unamortized issuance costs and discounts N/A N/A (5.1 ) (6.8 ) Total debt $ 787.6 $ 1,440.7 (1) Senior notes guaranteed as to payment by Pentair plc and PISG (“the Notes”) On April 25, 2018, Pentair, Pentair Investments Switzerland GmbH (“PISG”), Pentair Finance S.à r.l. (“PFSA”) and Pentair, Inc. entered into a credit agreement, providing for a five -year $800.0 million senior unsecured revolving credit facility (the “Senior Credit Facility”), with Pentair and PISG as guarantors and PFSA and Pentair, Inc. as borrowers. The Senior Credit Facility replaced PFSA’s existing credit facility under that certain Amended and Restated Credit Agreement, dated as of October 3, 2014. PFSA has the option to request to increase the Senior Credit Facility in an aggregate amount of up to $300.0 million , subject to customary conditions, including the commitment of the participating lenders. The Senior Credit Facility has a maturity date of April 25, 2023. Borrowings under the Senior Credit Facility bear interest at a rate equal to an adjusted base rate or the London Interbank Offered Rate, plus, in each case, an applicable margin. The applicable margin is based on, at PFSA’s election, Pentair’s leverage level or PFSA’s public credit rating. PFSA is authorized to sell short-term commercial paper notes to the extent availability exists under the Senior Credit Facility. PFSA uses the Senior Credit Facility as back-up liquidity to support 100% of commercial paper outstanding. PFSA had $76.0 million of commercial paper outstanding as of December 31, 2018 and $34.0 million as of December 31, 2017 , all of which was classified as long-term debt as we have the intent and the ability to refinance such obligations on a long-term basis under the Senior Credit Facility. Our debt agreements contain various financial covenants, but the most restrictive covenants are contained in the Senior Credit Facility. The Senior Credit Facility contains covenants requiring us not to permit (i) the ratio of our consolidated debt (net of its consolidated unrestricted cash in excess of $5.0 million but not to exceed $250.0 million ) to our consolidated net income (excluding, among other things, non-cash gains and losses) before interest, taxes, depreciation, amortization and non-cash share-based compensation expense (“EBITDA”) on the last day of any period of four consecutive fiscal quarters to exceed 3.75 to 1.00 (the “Leverage Ratio”) and (ii) the ratio of our EBITDA to our consolidated interest expense, 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 Senior 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, 2018 , we were in compliance with all financial covenants in our debt agreements. Total availability under the Senior Credit Facility was $697.8 million as of December 31, 2018 . In addition to the Senior Credit Facility, we have various other credit facilities with an aggregate availability of $21.1 million , of which there were no outstanding borrowings at December 31, 2018 . Borrowings under these credit facilities bear interest at variable rates. In June 2018, we used the $993.6 million of cash received from nVent as a result of the Distribution to pay down commercial paper and revolving credit facilities, redeem the remaining $255.3 million aggregate principal of our 2.9% fixed rate senior notes due 2018, and complete a cash tender offer in the amount of €363.4 million aggregate principal of our 2.45% senior notes due 2019. All costs associated with the repurchases of debt were recorded as a Loss on early extinguishment of debt in the Consolidated Statements of Operations and Comprehensive Income , including $16.0 million premium paid on early extinguishment and $1.1 million of unamortized deferred financing costs. In May 2017, we repurchased an aggregate principal amount of certain series of outstanding senior notes totaling $1,659.3 million . All costs associated with the repurchases were recorded as Loss on early extinguishment of debt , including $6.5 million of unamortized deferred financing costs. We have $405.1 million aggregate principle amount of fixed rate senior notes maturing in 2019. We classified this debt as long-term as of December 31, 2018 as we have the intent and ability to refinance such obligation on a long-term basis under the Credit Facility. Debt outstanding, excluding unamortized issuance costs and discounts , at December 31, 2018 matures on a calendar year basis as follows: In millions 2019 2020 2021 2022 2023 Thereafter Total Contractual debt obligation maturities $ 405.1 $ 74.0 $ 103.8 $ 88.3 $ 102.1 $ 19.4 $ 792.7

Derivatives and Financial Instr

Derivatives and Financial Instruments	12 Months Ended
	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
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. To manage the volatility related to this exposure, 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. 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. 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. 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. At December 31, 2018 and 2017 , we had outstanding foreign currency derivative contracts with gross notional U.S. dollar equivalent amounts of $331.4 million and $481.4 million , respectively. The impact of these contracts on the Consolidated Statements of Operations and Comprehensive Income was not material for any period presented. Gains or losses on foreign currency contracts designated as hedges are reclassified out of Accumulated other comprehensive loss and into Selling, general and administrative expense in the Consolidated Statements of Operations and Comprehensive Income when the hedged item affects earnings. Such reclassifications during 2018 , 2017 and 2016 were not material. Net investment hedge We have net investments in foreign subsidiaries that are subject to changes in the foreign currency exchange rate. In September 2015, we designated the €500 million 2.45% Senior Notes due 2019 (the “2019 Euro Notes”) as a net investment hedge for a portion of our net investment in our Euro denominated subsidiaries . In June 2018, the Company completed a tender offer for €363.4 million of the 2019 Euro Notes. The remaining €136.6 million of the 2019 Euro Notes have been re-designated as a net investment hedge in our Euro denominated subsidiaries. The gains/losses on the 2019 Euro Notes have been included as a component of the cumulative translation adjustment account within Accumulated other comprehensive loss . As of December 31, 2018 and 2017 , we had deferred foreign currency losses of $0.8 million and $29.6 million , respectively, in Accumulated other comprehensive loss associated with the net investment hedge activity. 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. 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; • 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; and • deferred compensation plan assets (mutual funds, common/collective trusts and cash equivalents for payment of certain non-qualified benefits for retired, terminated and active employees) — fair value of mutual funds and cash equivalents are based on quoted market prices in active markets that are classified as Level 1 in the valuation hierarchy defined by the accounting guidance; fair value of common/collective trusts are valued at net asset value (“NAV”), which is based on the fair value of the underlying securities owned by the fund and divided by the number of shares outstanding. The recorded amounts and estimated fair values of total debt, excluding unamortized issuance costs and discounts , at December 31 were as follows: 2018 2017 In millions Recorded Fair Value Recorded Fair Value Variable rate debt $ 102.2 $ 102.2 $ 62.4 $ 62.4 Fixed rate debt 690.5 691.8 1,385.1 1,424.0 Total debt $ 792.7 $ 794.0 $ 1,447.5 $ 1,486.4 Financial assets and liabilities measured at fair value on a recurring and nonrecurring basis were as follows: Recurring fair value measurements December 31, 2018 In millions Level 1 Level 2 Level 3 NAV Total Foreign currency contract liabilities $ — $ (30.6 ) $ — $ — $ (30.6 ) Deferred compensation plan assets 17.6 — — 3.3 20.9 Total recurring fair value measurements $ 17.6 $ (30.6 ) $ — $ 3.3 $ (9.7 ) Recurring fair value measurements December 31, 2017 In millions Level 1 Level 2 Level 3 NAV Total Foreign currency contract assets $ — $ 0.6 $ — $ — $ 0.6 Foreign currency contract liabilities — (47.2 ) — — (47.2 ) Deferred compensation plan assets 18.7 — — 4.5 23.2 Total recurring fair value measurements $ 18.7 $ (46.6 ) $ — $ 4.5 $ (23.4 ) Nonrecurring fair value measurements (1) (1) During the fourth quarter of 2017, we completed our annual intangible assets impairment review. As a result, we recorded a pre-tax non-cash impairment charge of $8.8 million for trade name intangibles, reducing the carrying value of these intangibles to $10.8 million . 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, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income from continuing operations before income taxes consisted of the following: Years ended December 31 In millions 2018 2017 2016 Federal (1) $ (24.6 ) $ (34.1 ) $ (25.6 ) International (2) 404.4 206.9 246.5 Income from continuing operations before income taxes $ 379.8 $ 172.8 $ 220.9 (1) “Federal” reflects United Kingdom (“U.K.”) income from continuing operations before income taxes. (2) “International” reflects non-U.K. income from continuing operations before income taxes. The provision for income taxes consisted of the following: Years ended December 31 In millions 2018 2017 2016 Currently payable (receivable) Federal (1) $ (0.1 ) $ — $ — International (2) 62.3 76.7 41.5 Total current taxes 62.2 76.7 41.5 Deferred Federal (1) — — — International (2) (4.1 ) (18.0 ) 1.2 Total deferred taxes (4.1 ) (18.0 ) 1.2 Total provision for income taxes $ 58.1 $ 58.7 $ 42.7 (1) “Federal” represents U.K. taxes. (2) “International” represents non-U.K. taxes. Reconciliations of the federal statutory income tax rate to our effective tax rate were as follows: Years ended December 31 Percentages 2018 2017 2016 U.K. federal statutory income tax rate 19.0 % 19.3 % 20.0 % Tax effect of international operations (1) (12.0 ) (20.8 ) (26.5 ) Change in valuation allowances 7.9 27.6 22.1 Withholding taxes 0.3 0.4 1.8 Interest limitations 1.8 1.7 1.5 Excess tax benefits on stock-based compensation (1.7 ) (4.5 ) — Tax effect of U.S. tax reform (0.9 ) 1.3 — Tax effect of early extinguishment of debt 0.9 9.0 — Other — — 0.4 Effective tax rate 15.3 % 34.0 % 19.3 % (1) The tax effect of international operations consists of non-U.K. jurisdictions. Reconciliations of the beginning and ending gross unrecognized tax benefits were as follows: Years ended December 31 In millions 2018 2017 2016 Beginning balance $ 13.8 $ 46.3 $ 25.0 Gross increases for tax positions in prior periods 44.0 4.7 26.9 Gross decreases for tax positions in prior periods (4.4 ) (3.4 ) (2.2 ) Gross increases based on tax positions related to the current year 0.9 0.7 0.8 Gross decreases related to settlements with taxing authorities (1.8 ) (33.6 ) (3.4 ) Reductions due to statute expiration (1.1 ) (0.9 ) (0.8 ) Ending balance $ 51.4 $ 13.8 $ 46.3 We record gross unrecognized tax benefits in Other current liabilities and Other non-current liabilities in the Consolidated Balance Sheets. Included in the $51.4 million of total gross unrecognized tax benefits as of December 31, 2018 was $50.3 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, 2018 may decrease by a range of zero to $8.1 million during 2019 , primarily as a result of the resolution of non-U.K. examinations, including U.S. state examinations, and the expiration of various statutes of limitations. Based on the outcome of these examinations, or as a result of the expiration of statute of limitations for specific jurisdictions, it is reasonably possible that certain unrecognized tax benefits for tax positions taken on previously filed tax returns will materially change from those recorded as liabilities in our financial statements. A number of tax periods from 2003 to present are under audit by tax authorities in various jurisdictions, including China, Germany, India and New Zealand. We anticipate that several of these audits may be concluded in the foreseeable future. We record penalties and interest related to unrecognized tax benefits in Provision for income taxes and Net interest expense , respectively, in the Consolidated Statements of Operations and Comprehensive Income. As of December 31, 2018 and 2017 , we have liabilities of $0.5 million and $0.3 million , respectively, for the possible payment of penalties and $3.6 million and $2.9 million , respectively, for the possible payment of interest expense, which are recorded in Other current liabilities in the Consolidated Balance Sheets. 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). Deferred taxes were recorded in the Consolidated Balance Sheets as follows: December 31 In millions 2018 2017 Other non-current assets $ 26.2 $ 29.0 Deferred tax liabilities 105.9 108.6 Net deferred tax liabilities $ 79.7 $ 79.6 The tax effects of the major items recorded as deferred tax assets and liabilities were as follows: December 31 In millions 2018 2017 Deferred tax assets Accrued liabilities and reserves $ 42.9 $ 43.9 Pension and other post-retirement compensation and benefits 25.2 35.7 Employee compensation and benefits 21.8 39.2 Tax loss and credit carryforwards 724.7 670.5 Other assets 4.4 — Total deferred tax assets 819.0 789.3 Valuation allowance 711.9 656.2 Deferred tax assets, net of valuation allowance 107.1 133.1 Deferred tax liabilities Property, plant and equipment 7.1 3.7 Goodwill and other intangibles 179.7 190.6 Other liabilities — 18.4 Total deferred tax liabilities 186.8 212.7 Net deferred tax liabilities $ 79.7 $ 79.6 Included in tax loss and credit carryforwards in the table above is a deferred tax asset of $29.6 million as of December 31, 2018 related to foreign tax credit carryover from the tax period ended December 31, 2017 and related to transition taxes. The entire amount is subject to a valuation allowance. The foreign tax credit is eligible for carryforward until the tax period ending December 31, 2027. As of December 31, 2018 , tax loss carryforwards of $2,911.9 million were available to offset future income. A valuation allowance of $692.3 million exists for deferred income tax benefits related to the tax loss carryforwards which may not be realized. The increase in tax loss carryforwards and valuation allowance from 2017 to 2018 were primarily related to internal restructuring transactions. 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 primarily relate to non-U.S. carryforwards of $2,818.2 million which are subject to varying expiration periods. Non-U.S. carryforwards of $2,345.7 million are located in jurisdictions with unlimited tax loss carryforward periods, while the remainder will begin to expire in 2019 . In addition, there were $93.7 million of state tax loss carryforwards as of December 31, 2018 . State tax losses of $56.1 million are in jurisdictions with unlimited tax loss carryforward periods, while the remainder will expire in future years through 2038. U.S. tax reform On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the “Act”) was signed into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a corporate tax rate decrease from 35% to 21% effective for tax years beginning after December 31, 2017, the transition of U.S international taxation from a worldwide tax system to a territorial system, and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017. For 2018, the Company considered in its annual effective tax rate additional provisions of the Act including changes to the deduction for executive compensation and interest expense, a tax on global intangible low-taxed income provisions (“GILTI”), the base erosion anti-abuse tax, and a deduction for foreign-derived intangible income. The Company has elected to treat tax on GILTI income as a period cost and has therefore included it in its annual effective tax rate. Given the significance of the Act, Staff Accounting Bulletin No. 118 (“SAB 118”) was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. SAB 118 allows registrants to record provisional amounts during a one year “measurement period.” The measurement period is deemed to have ended earlier when the registrant has obtained, prepared, and analyzed the information necessary to finalize its accounting. During the measurement period, impacts of the law are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be recognized and adjusted as information becomes available, prepared, or analyzed. The Company calculated its best estimate of the impact of the Act in its December 31, 2017 income tax provision in accordance with its understanding of the Act and guidance available as of the date of the filing of the 2017 Annual Report on Form 10-K and as a result recorded a provisional income tax expense of $2.2 million in the fourth quarter of 2017, the period in which the legislation was enacted. We subsequently recorded a $3.6 million decrease to the provisional income tax expense in the third quarter of 2018, resulting in a $1.4 million net decrease to income tax expense as a result of the Act. The amount related to the remeasurement of certain deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future was a decrease to income tax expense of $28.0 million . The amount related to the one-time transition tax on the mandatory deemed repatriation of foreign earnings was an increase to income tax expense of $26.6 million . No additional income taxes have been provided for any remaining undistributed foreign earnings not subject to the transition tax, or any additional outside basis difference inherent in these entities, as these amounts continue to be indefinitely reinvested in foreign operations.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
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 November 2017, our Board of Directors authorized the termination of the Pentair Salaried Plan (the “Salaried Plan”), a U.S. qualified pension plan, effective December 31, 2017. The Salaried Plan participants will not be adversely affected by the plan termination. Those participants whose plan benefits were not in pay status as of July 1, 2018 were given the opportunity to elect a lump sum (or monthly annuity) payment during a special election window. Payments of $171.9 million were made to participants who elected to receive a lump sum during this window. For all participants whose Salaried Plan benefits were not paid in lump sum, the Company will purchase an annuity for them with an annuity provider within 120 days after all required government approvals for the Salaried Plan termination have been received. The termination is expected to be completed in 2019. At December 31, 2018 , the projected benefit obligation of the Salaried Plan was $175.9 million and the plan assets were $153.7 million . Due to the changing nature of these assumptions, it is at least reasonably possible that changes in these assumptions will occur in the near term and, due to the uncertainties inherent in setting assumptions, that the effect of such changes could be material to the financial statements. As described in Note 1, during the first quarter of 2018, the Company adopted ASU 2017-07. As a result, service costs are classified as employee compensation costs within Cost of goods sold and Selling, general and administrative expense within the Consolidated Statements of Operations and Comprehensive Income. All other components of net periodic benefit expense are classified within Other (income) expense for the periods presented. The information herein relates to defined-benefit pension and other post-retirement plans of our continuing operations only. 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, 2018 and 2017 : Pension plans Other post-retirement plans In millions 2018 2017 2018 2017 Change in benefit obligations Benefit obligation beginning of year $ 473.8 $ 423.8 $ 17.5 $ 18.9 Service cost 4.1 11.7 — — Interest cost 11.5 16.4 0.6 0.7 Actuarial loss (gain) (23.6 ) 41.4 (1.4 ) (0.1 ) Foreign currency translation (0.2 ) 0.6 — — Benefits paid (187.7 ) (20.1 ) (1.8 ) (2.0 ) Benefit obligation end of year $ 277.9 $ 473.8 $ 14.9 $ 17.5 Change in plan assets Fair value of plan assets beginning of year $ 382.8 $ 352.3 $ — $ — Actual return on plan assets (21.4 ) 42.4 — — Company contributions 7.1 6.3 1.8 2.0 Foreign currency translation (0.1 ) 1.9 — — Benefits paid (187.7 ) (20.1 ) (1.8 ) (2.0 ) Fair value of plan assets end of year $ 180.7 $ 382.8 $ — $ — Funded status Benefit obligations in excess of the fair value of plan assets $ (97.2 ) $ (91.0 ) $ (14.9 ) $ (17.5 ) Amounts recorded in the Consolidated Balance Sheets were as follows: Pension plans Other post-retirement plans In millions 2018 2017 2018 2017 Current liabilities $ (28.3 ) $ (6.1 ) $ (1.7 ) $ (1.9 ) Non-current liabilities (68.9 ) (84.9 ) (13.2 ) (15.6 ) Benefit obligations in excess of the fair value of plan assets $ (97.2 ) $ (91.0 ) $ (14.9 ) $ (17.5 ) The accumulated benefit obligation for all defined benefit plans was $275.0 million and $470.4 million at December 31, 2018 and 2017 , 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 exceeds the fair value of plan assets Accumulated benefit obligation exceeds the fair value of plan assets In millions 2018 2017 2018 2017 Projected benefit obligation $ 277.9 $ 473.8 $ 270.6 $ 464.9 Fair value of plan assets 180.7 382.8 173.7 374.5 Accumulated benefit obligation N/A N/A 268.3 462.3 Components of net periodic benefit expense for our pension plans for the years ended December 31 were as follows: In millions 2018 2017 2016 Service cost $ 4.1 $ 11.7 $ 12.8 Interest cost 11.5 16.4 16.5 Expected return on plan assets (7.6 ) (11.6 ) (11.5 ) Net actuarial loss (gain) 5.2 8.4 (11.5 ) Net periodic benefit expense $ 13.2 $ 24.9 $ 6.3 Components of net periodic benefit expense for our other post-retirement plans for the years ended December 31 2018 , 2017 and 2016 , were not material. Assumptions The following table provides the weighted-average assumptions used to determine benefit obligations and net periodic benefit cost as they pertain to our pension and other post-retirement plans. Pension plans Other post-retirement 2018 2017 2016 2018 2017 2016 Benefit obligation assumptions (1) Discount rate 3.73 % 4.00 % 3.92 % 3.95 % 3.40 % 3.80 % Rate of compensation increase 3.77 % 3.96 % 3.95 % NA NA NA Net periodic benefit expense assumptions Discount rate 4.00 % 3.94 % 4.12 % 3.40 % 3.80 % 3.95 % Expected long-term return on plan assets 4.17 % 4.05 % 4.19 % NA NA NA Rate of compensation increase 3.96 % 3.96 % 3.93 % NA NA NA (1) The benefit obligation for the Salaried Plan as of December 31, 2018 and 2017 were determined using assumptions reflecting the termination of the plan. As a result, the weighted-average assumptions for the pension plans reflected in the table above do not include the Salaried Plan. 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. There are no known or anticipated changes in our discount rate assumptions that will impact our pension expense in 2019 . Expected rates of return 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 long-term market indices. Pension plan assets yielded returns of (5.60)% , 12.00% and 7.40% in 2018 , 2017 and 2016 , 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 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: 2018 2017 Healthcare cost trend rate assumed for following year 6.2 % 6.6 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 4.4 % 4.4 % Year the cost trend rate reaches the ultimate trend rate 2038 2038 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, 2018 : One Percentage Point In millions Increase Decrease Increase (decrease) in annual service and interest cost $ — $ — Increase (decrease) in other post-retirement benefit obligations 0.6 (0.5 ) 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. Asset allocation Our actual overall asset allocation for our pension plans as compared to our investment policy goals as of December 31 was as follows: Actual Target 2018 2017 2018 2017 Fixed income 87 % 98 % 95 % 97 % Alternative 5 % 2 % 5 % 3 % Cash 8 % — % — % — % Fair value measurement The fair values of our pension plan assets and their respective levels in the fair value hierarchy as of December 31, 2018 and December 31, 2017 were as follows: December 31, 2018 In millions Level 1 Level 2 Level 3 Total Cash and cash equivalents $ — $ 12.0 $ — $ 12.0 Fixed income: Corporate and non U.S. government — 102.3 — 102.3 U.S. treasuries — 18.7 — 18.7 Other — 16.5 — 16.5 Other investments — — 9.3 9.3 Total investments at fair value $ — $ 149.5 $ 9.3 $ 158.8 Investments measured at NAV 21.9 Total $ 180.7 December 31, 2017 In millions Level 1 Level 2 Level 3 Total Fixed income: Corporate and non U.S. government $ — $ 262.8 $ — $ 262.8 U.S. treasuries — 43.2 — 43.2 Mortgage-backed securities — 3.3 — 3.3 Other — 37.0 — 37.0 Other investments — — 9.4 9.4 Total investments at fair value $ — $ 346.3 $ 9.4 $ 355.7 Investments measured at NAV 27.1 Total $ 382.8 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 is considered a Level 1 investment. 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 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 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. Activity for our Level 3 pension plan assets held during the years ended December 31, 2018 and 2017 was not material. Cash flows Contributions Pension contributions from continuing operations totaled $7.1 million and $6.3 million in 2018 and 2017 , respectively. We anticipate our 2019 pension contributions to be approximately $29.9 million , which includes the planned termination of the Salaried Plan. The changing nature of the termination assumptions used to value the Salaried Plan may cause 2019 pension contributions to be higher or lower than expected. The 2019 expected contributions will equal or exceed our minimum funding requirements. Estimated future benefit payments The following benefit payments, which reflect expected future service or payout from termination, as appropriate, are expected to be paid by the plans for the years ended December 31 as follows: In millions Pension Plans Other post- retirement plans 2019 $ 183.0 $ 1.7 2020 7.2 1.6 2021 7.2 1.6 2022 7.3 1.5 2023 6.8 1.4 Thereafter 36.2 5.4 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 met certain age requirements. Under the 401(k) plan, eligible U.S. employees could voluntarily contribute a percentage of their eligible compensation. We match contributions made by employees who met certain eligibility and service requirements. As of January 1, 2018, the 401(k) company match contribution was changed to a dollar-for-dollar ( 100% ) matching contribution on up to 5% of employee eligible earnings, contributed as before-tax contributions. This change replaced the ESOP component discussed below and offers the same 5% total company match. During 2017 and 2016, the 401(k) matching contribution was 100% of eligible employee contributions for the first 1% of eligible compensation and 50% of the next 5% of eligible compensation. During 2018, 2017 and 2016, in addition to the matching contribution, all employees who met certain service requirements received a discretionary ESOP contribution equal to 1.5% of annual eligible compensation. Our combined expense for the 401(k) plan and the ESOP was $23.4 million , $27.9 million and $27.1 million in 2018 , 2017 and 2016 , respectively. Other retirement compensation Total other accrued retirement compensation, primarily related to deferred compensation and supplemental retirement plans, was $28.2 million and $29.6 million as of December 31, 2018 and 2017 , respectively, and is included in Pension and other post-retirement compensation and benefits and Other non-current liabilities in the Consolidated Balance Sheets.

Shareholders' Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2018
Stockholders' Equity Note [Abstract]
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 In December 2014, the Board of Directors authorized the repurchase of our ordinary shares up to a maximum dollar limit of $1.0 billion (the “2014 Authorization). On May 8, 2018, the Board of Directors authorized the repurchase of our ordinary shares up to a maximum dollar limit of $750.0 million (the “2018 Authorization”), replacing the 2014 Authorization. The 2018 Authorization expires on May 31, 2021 . During the year ended December 31, 2017 , we repurchased 3.0 million of our ordinary shares for $200.0 million under the 2014 Authorization. During the year ended December 31, 2018 , we repurchased 10.2 million of our shares for $500.0 million , of which 2.2 million shares, or $150.0 million , and 8.0 million shares, or $350.0 million , were repurchased pursuant to the 2014 and 2018 Authorizations, respectively. As of December 31, 2018 , we had $400.0 million available for share repurchases under the 2018 Authorization. Dividends payable On December 10, 2018, the Board of Directors declared a quarterly cash dividend of $0.18 that was paid on February 8, 2019 to shareholders of record at the close of business on January 25, 2019. Additionally, the Board of Directors approved a plan to pay an annual cash dividend of $0.72 in 2019. As a result, the balance of dividends payable included in Other current liabilities on our Consolidated Balance Sheets was $30.8 million at December 31, 2018 . Dividends paid per ordinary share were $1.05 , $1.38 and $1.34 for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Share Plans

Share Plans	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share Plans	Share Plans Share-based compensation expense Total share-based compensation expense for 2018 , 2017 and 2016 was as follows: December 31 In millions 2018 2017 2016 Restricted stock units $ 8.9 $ 17.5 $ 17.3 Stock options 4.6 10.5 10.4 Performance share units 7.4 11.6 6.5 Total share-based compensation expense $ 20.9 $ 39.6 $ 34.2 Of the total share-based compensation expense noted above, $3.4 million , $7.6 million and $11.5 million for the years ended December 31, 2018 , 2017 and 2016 , respectively, was reported as part of Income from discontinued operations, net of tax. Share incentive plans In 2012, our Board of Directors, and Tyco International Ltd. (“Tyco”) as our sole shareholder at the time, 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 by issuing new shares. The 2012 Plan terminates in September 2022. The 2012 Plan allows for the granting to our officers, directors, employees and consultants of non-qualified 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 canceling and reissuing awards at lower prices. 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 one-third each year over a three -year period commencing on the grant date and expire 10 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 one-third each year over a three -year period commencing on the grant date, 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. In December 2015, the Committee approved the granting of PSUs to certain employees that vest based on the satisfaction of a three -year service period and the achievement of certain performance metrics over that same period. Upon vesting, PSU holders receive dividends that accumulate during the vesting period. The fair value of these PSUs is determined based on the closing market price of the Company’s ordinary shares at the date of grant. Compensation expense is recognized over the period an employee is required to provide service based on the estimated vesting of the PSUs granted. The estimated vesting of the PSUs is based on the probability of achieving certain financial performance metrics during the three year vesting period. Stock options The following table summarizes stock option activity under all plans for the year ended December 31, 2018 : Shares and intrinsic value in millions Number of shares Weighted- average exercise price Weighted- average remaining contractual life (years) Aggregate intrinsic value Outstanding as of January 1, 2018 5.2 $ 28.80 Granted 0.5 45.42 Exercised (0.8 ) 23.52 Forfeited (0.1 ) 43.77 Spin-off adjustment (0.7 ) — Outstanding as of December 31, 2018 4.1 $ 35.77 5.2 $ 20.6 Options exercisable as of December 31, 2018 3.0 $ 33.93 4.0 $ 19.5 Options expected to vest as of December 31, 2018 1.1 $ 40.55 8.2 $ 1.2 Fair value of options granted The weighted average grant date fair value of options granted under Pentair plans in 2018 , 2017 and 2016 was estimated to be $10.92 , $12.59 and $9.74 per share, respectively. The total intrinsic value of options that were exercised during 2018 , 2017 and 2016 was $18.2 million , $34.3 million and $27.1 million , respectively. At December 31, 2018 , the total unrecognized compensation cost related to stock options was $7.8 million . This cost is expected to be recognized over a weighted average period of 2.1 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 2018 2017 2016 Risk-free interest rate 2.58 % 1.65 % 1.56 % Expected dividend yield 1.56 % 2.35 % 2.49 % Expected share price volatility 24.8 % 26.9 % 27.3 % Expected term (years) 6.1 6.3 5.9 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, 2018 , 2017 and 2016 was $19.5 million , $46.0 million and $31.6 million , respectively. The actual tax benefit realized for the tax deductions from option exercised totaled $5.6 million , $7.8 million and $5.5 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Restricted stock units The following table summarizes restricted stock unit activity under all plans for the year ended December 31, 2018 : Shares in millions Number of shares Weighted average grant date fair value Outstanding as of January 1, 2018 0.6 $ 39.44 Granted 0.2 45.46 Vested (0.6 ) 43.89 Conversion of PSUs 0.5 — Spin-off adjustment (0.2 ) — Outstanding as of December 31, 2018 0.5 $ 41.74 As of December 31, 2018 , there was $18.4 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 1.0 years. The total fair value of shares vested during the years ended December 31, 2018 , 2017 and 2016 , was $24.4 million , $21.7 million and $27.2 million , respectively. The actual tax benefit realized for the year ended December 31, 2018 was $0.7 million . There were no actual tax benefits realized for the years ended December 31, 2017 and 2016 . Performance share units The following table summarizes performance share unit activity under all plans for the year ended December 31, 2018 : Shares in millions Number of shares Weighted average grant date fair value Outstanding as of January 1, 2018 0.5 $ 29.53 Granted 0.1 45.42 Conversion to RSUs (0.5 ) — Outstanding as of December 31, 2018 0.1 $ 45.42 The expense recognized each period is dependent upon our estimate of the number of shares that will ultimately be issued. As of December 31, 2018 , there was $4.3 million of unrecognized compensation cost related to performance share compensation arrangements granted under the 2012 Plan and previous plans. That cost is expected to be recognized over a weighted-average period of 2.2 years. The actual tax benefit realized for the year ended December 31, 2018 was $0.2 million . There were no actual tax benefits realized for the years ended December 31, 2017 and 2016 . Electrical separation In connection with the Separation and Distribution, the Company adjusted its outstanding equity awards on May 1, 2018 in accordance with the Employee Matters Agreement between Pentair and nVent. The outstanding awards will continue to vest over the original vesting period, which is generally three years from the grant date. The RSUs, PSUs, and stock option awards issued before May 9, 2017 (the date of Pentair’s announcement of its intention to separate its Water and Electrical businesses) were converted into awards of both Pentair and nVent regardless of which company the award holder was employed by immediately after the Separation. These awards were converted as follows: • Restricted stock units : For every unvested Pentair RSU award held, the holder received one nVent RSU. • Performance share units : Pentair PSUs were converted to Pentair RSUs immediately after the Distribution. The PSUs granted in 2016 were converted at rate of 125% of target, and the PSUs granted in 2017 were converted at a rate of 100% of target. For every converted RSU, the shareholder also received one nVent RSU. The converted RSUs retain the original vesting schedule of the awarded PSUs. • Stock options: Every holder of unexercised (vested and unvested) Pentair stock options received both adjusted stock options of Pentair and stock options of nVent, with the number of underlying shares and the exercise price adjusted accordingly to preserve the overall intrinsic value of the awards. The number of Pentair stock options was converted based upon the ratio of Pentair’s pre-Distribution stock price divided by the sum of the Pentair and nVent post-Distribution closing prices. The exercise price for the converted Pentair stock options was adjusted based on the Pentair post-Distribution closing price divided by the Pentair pre-Distribution closing price. The number of new nVent stock options awarded is the same as the converted number of Pentair stock options calculated as described above. The exercise price for the new nVent stock options was calculated based on nVent’s post-Distribution closing price divided by the Pentair pre-Distribution closing price. Generally, unvested awards issued after May 9, 2017 were converted to awards of the Company that the shareholder was employed by immediately after the Separation, with adjustments to the number of underlying shares as appropriate to preserve the intrinsic value of such awards immediately prior to the Distribution. The adjustment of the underlying shares was based on the ratio of Pentair’s pre-Distribution stock price divided by the post-Distribution closing price of the respective company’s ordinary shares. The exercise prices of the stock options were converted using the inverse ratio in a manner designed to preserve the intrinsic value of such awards.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information Effective May 1, 2018, we reorganized our business segments to reflect a new operating structure, resulting in a change to our reporting segments. All prior period amounts related to the segment change have been retrospectively reclassified to conform to the new presentation. As part of this reorganization the legacy Water segment was separated into three reportable business segments: • Aquatic Systems — This segment manufactures and sells a complete line of energy-efficient residential and commercial pool equipment and accessories including pumps, filters, heaters, lights, automatic controls, automatic cleaners, maintenance equipment and pool accessories. Applications for our Aquatic Systems products include residential and commercial pool maintenance, pool repair, renovation, service and construction and aquaculture solutions. • Filtration Solutions — This segment manufactures and sells water and fluid treatment products and systems, including pressure tanks and vessels, control valves, activated carbon products, conventional filtration products, point-of-entry and point-of-use systems, gas recovery solutions, membrane bioreactors, wastewater reuse systems and advanced membrane filtration and separation systems into the global residential, industrial and commercial markets. These products are used in a range of applications, including use in fluid filtration, ion exchange, desalination, food and beverage, food service and separation technologies for the oil and gas industry. • Flow Technologies — This segment manufactures and sells products ranging from light duty diaphragm pumps to high-flow turbine pumps and solid handling pumps while serving the global residential, commercial and industrial markets. These pumps are used in a range of applications, including residential and municipal wells, water treatment, wastewater solids handling, pressure boosting, fluid delivery, circulation and transfer, fire suppression, flood control, agricultural irrigation and crop spray. We evaluate performance based on 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 equity income of unconsolidated subsidiaries and operating income exclusive of intangible amortization, certain acquisition related expenses, costs of restructuring activities, impairments and other unusual non-operating items. Financial information by reportable segment is included in the following summary: 2018 2017 2016 2018 2017 2016 In millions Net sales Segment income (loss) Aquatic Systems $ 1,026.1 $ 939.6 $ 877.8 $ 277.6 $ 254.1 $ 217.4 Filtration Solutions 1,001.0 990.6 976.3 168.5 154.5 138.4 Flow Technologies 936.7 914.2 923.5 145.6 140.6 141.6 Other 1.3 1.3 3.0 (54.9 ) (52.7 ) (56.0 ) Consolidated (1) $ 2,965.1 $ 2,845.7 $ 2,780.6 $ 536.8 $ 496.5 $ 441.4 (1) One customer in the Aquatic Systems segment, Pool Corporation, represented approximately 15% of our consolidated net sales in 2018 , 2017 and 2016 . 2018 2017 2016 2018 2017 2016 2018 2017 2016 In millions Identifiable assets (1) Capital expenditures Depreciation Aquatic Systems $ 1,304.2 $ 1,323.0 $ 1,238.0 $ 10.6 $ 9.6 $ 12.0 $ 8.1 $ 10.6 $ 9.8 Filtration Solutions 1,232.4 1,333.3 1,362.4 16.6 19.2 17.8 23.2 21.6 23.7 Flow Technologies 1,003.6 1,010.8 865.2 10.3 7.3 11.0 13.1 13.4 13.3 Other 266.3 4,966.6 8,069.2 10.7 3.0 2.5 5.3 5.2 6.2 Consolidated $ 3,806.5 $ 8,633.7 $ 11,534.8 $ 48.2 $ 39.1 $ 43.3 $ 49.7 $ 50.8 $ 53.0 (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 income from continuing operations before income taxes: In millions 2018 2017 2016 Segment income $ 536.8 $ 496.5 $ 441.4 Restructuring and other (31.8 ) (28.2 ) (7.8 ) Intangible amortization (34.9 ) (36.4 ) (35.4 ) Pension and other post-retirement mark-to-market (loss) gain (3.6 ) (8.5 ) 12.0 Trade name and other impairment (12.0 ) (15.6 ) — Loss on sale of businesses (7.3 ) (4.2 ) (3.9 ) Loss on early extinguishment of debt (17.1 ) (101.4 ) — Interest expense, net (32.6 ) (87.3 ) (140.1 ) Corporate allocations (11.0 ) (36.7 ) (39.4 ) Deal related costs and expenses (2.0 ) — — Other expense (4.7 ) (5.4 ) (5.9 ) Income from continuing operations before income taxes $ 379.8 $ 172.8 $ 220.9

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating lease commitments Net rental expense under operating leases was as follows: Years ended December 31 In millions 2018 2017 2016 Gross rental expense $ 30.4 $ 29.7 $ 29.0 Sublease rental income (0.4 ) (0.2 ) (0.5 ) Net rental expense $ 30.0 $ 29.5 $ 28.5 Future minimum lease commitments under non-cancelable operating leases, principally related to facilities, machinery, equipment and vehicles as of December 31, 2018 were as follows: In millions 2019 2020 2021 2022 2023 Thereafter Total Minimum lease payments $ 23.2 $ 17.6 $ 13.3 $ 11.1 $ 9.5 $ 13.8 $ 88.5 Minimum sublease rentals (0.7 ) (0.6 ) (0.6 ) (0.6 ) (0.6 ) (0.6 ) (3.7 ) Net future minimum lease commitments $ 22.5 $ 17.0 $ 12.7 $ 10.5 $ 8.9 $ 13.2 $ 84.8 Other matters In addition to the matters described above, from time to time, we are subject to disputes, administrative proceedings and other claims relating to the conduct of our business. These matters include, without limitation, claims relating to commercial or contractual disputes with suppliers, customers or parties to acquisitions and divestitures, intellectual property matters, environmental, safety and health matters, product liability, the use or installation of our products, consumer matters, and employment and labor 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 position, results of operations or cash flows. We recognize, at the inception of a guarantee, a liability for the fair value of the obligation undertaken in issuing the guarantee. In connection with the disposition of the Valves & Controls business, we agreed to indemnify Emerson Electric Co. for certain pre-closing tax liabilities. In 2017, we recorded a liability representing the fair value of our expected future obligation for this matter. 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, 2018 , 2017 and 2016 were as follows: Years ended December 31 In millions 2018 2017 2016 Beginning balance $ 38.1 $ 36.3 $ 44.6 Service and product warranty provision 50.8 60.8 55.2 Payments (54.6 ) (59.6 ) (64.2 ) Foreign currency translation (0.4 ) 0.6 0.7 Ending balance $ 33.9 $ 38.1 $ 36.3 Stand-by letters of credit, bank guarantees and bonds In certain situations, Tyco guaranteed performance by the flow control business of Pentair Ltd. (“Flow Control”) 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, 2018 and 2017 , the outstanding value of bonds, letters of credit and bank guarantees totaled $123.6 million and $129.2 million , respectively.

Selected Quarterly Data (unaudi

Selected Quarterly Data (unaudited)	12 Months Ended
	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Data	Selected Quarterly Data (Unaudited) The following tables present 2018 and 2017 quarterly financial information: 2018 In millions, except per-share data First Quarter Second Quarter Third Quarter Fourth Quarter Full Year Net sales $ 732.6 $ 780.6 $ 711.4 $ 740.5 $ 2,965.1 Gross profit 253.3 282.6 243.8 268.0 1,047.7 Operating income 92.7 122.6 108.4 113.0 436.7 Net income from continuing operations 58.4 77.9 (1) 91.2 94.2 321.7 Income (loss) from discontinued operations, net of tax 44.5 (36.4 ) 18.9 (1.3 ) 25.7 Net income 102.9 41.5 110.1 92.9 347.4 Earnings (loss) per ordinary share (2) Basic Continuing operations $ 0.33 $ 0.44 $ 0.52 $ 0.55 $ 1.83 Discontinued operations 0.24 (0.21 ) 0.11 (0.01 ) 0.15 Basic earnings per ordinary share $ 0.57 $ 0.23 $ 0.63 $ 0.54 $ 1.98 Diluted Continuing operations $ 0.32 $ 0.44 $ 0.52 $ 0.54 $ 1.81 Discontinued operations 0.25 (0.21 ) 0.11 (0.01 ) 0.15 Diluted earnings per ordinary share $ 0.57 $ 0.23 $ 0.63 $ 0.53 $ 1.96 (1) Includes decrease of $17.1 million related to loss on early extinguishment of debt. (2) 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. 2017 In millions, except per-share data First Quarter Second Quarter Third Quarter Fourth Quarter Full Year Net sales $ 683.3 $ 754.0 $ 687.6 $ 720.8 $ 2,845.7 Gross profit 223.7 273.6 236.5 253.7 987.5 Operating income 61.9 129.2 101.8 85.4 378.3 Net income (loss) from continuing operations 12.7 (3.4 ) (1) 49.0 55.8 (2) 114.1 Income from discontinued operations, net of tax 75.0 66.5 78.2 151.6 371.3 Gain (loss) from sale of discontinued operations, net of tax — 200.6 (1.7 ) (17.8 ) 181.1 Net income 87.7 263.7 125.5 189.6 666.5 Earnings (loss) per ordinary share (3) Basic Continuing operations $ 0.07 $ (0.02 ) $ 0.27 $ 0.32 $ 0.63 Discontinued operations 0.41 1.47 0.42 0.73 3.04 Basic earnings per ordinary share $ 0.48 $ 1.45 $ 0.69 $ 1.05 $ 3.67 Diluted Continuing operations $ 0.07 $ (0.02 ) $ 0.27 $ 0.30 $ 0.62 Discontinued operations 0.41 1.45 0.41 0.74 3.01 Diluted earnings per ordinary share $ 0.48 $ 1.43 $ 0.68 $ 1.04 $ 3.63 (1) Includes decrease of $101.4 million related to loss on early extinguishment of debt. (2) Includes decrease of $15.6 million due to trade name and other impairment and $8.5 million related to a “mark-to-market” actuarial loss on pension and other post-retirement benefit plans. (3) 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.

Supplemental Guarantor Informat

Supplemental Guarantor Information	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Supplemental Guarantor Information	Supplemental Guarantor Information Pentair plc (the “Parent Company Guarantor”) and Pentair Investments Switzerland GmbH (the “Subsidiary Guarantor”), fully and unconditionally, guarantee the Notes of Pentair Finance S.à r.l. (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 and Condensed Consolidating Statement of Cash Flows for the years ended December 31, 2018 , 2017 and 2016 and Condensed Consolidating Balance Sheet as of December 31, 2018 and 2017 . Condensed Consolidating financial information for Pentair plc, Pentair Investments Switzerland GmbH and Pentair Finance S.à r.l. on a stand-alone basis is presented using the equity method of accounting for subsidiaries. Pentair plc and Subsidiaries Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) Year Ended December 31, 2018 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Net sales $ — $ — $ — $ 2,965.1 $ — $ 2,965.1 Cost of goods sold — — — 1,917.4 — 1,917.4 Gross profit — — — 1,047.7 — 1,047.7 Selling, general and administrative 11.8 0.9 1.2 520.4 — 534.3 Research and development — — — 76.7 — 76.7 Operating (loss) income (11.8 ) (0.9 ) (1.2 ) 450.6 — 436.7 Loss (earnings) from continuing operations of investment in subsidiaries (333.5 ) (333.4 ) (376.5 ) — 1,043.4 — Other (income) expense: Loss on sale of businesses — — — 7.3 — 7.3 Loss on early extinguishment of debt — — 17.1 — — 17.1 Net interest (income) expense — (1.0 ) 24.8 8.8 — 32.6 Other income — — — (0.1 ) — (0.1 ) Income (loss) from continuing operations before income taxes 321.7 333.5 333.4 434.6 (1,043.4 ) 379.8 Provision for income taxes — — — 58.1 — 58.1 Net income (loss) from continuing operations 321.7 333.5 333.4 376.5 (1,043.4 ) 321.7 Income from discontinued operations, net of tax — — — 25.7 — 25.7 Earnings (loss) from discontinued operations of investment in subsidiaries 25.7 25.7 25.7 — (77.1 ) — Net income (loss) $ 347.4 $ 359.2 $ 359.1 $ 402.2 $ (1,120.5 ) $ 347.4 Comprehensive income (loss), net of tax Net income (loss) $ 347.4 $ 359.2 $ 359.1 $ 402.2 $ (1,120.5 ) $ 347.4 Changes in cumulative translation adjustment 10.0 10.0 10.0 10.0 (30.0 ) 10.0 Changes in market value of derivative financial instruments, net of tax 4.8 4.8 4.8 4.8 (14.4 ) 4.8 Comprehensive income (loss) $ 362.2 $ 374.0 $ 373.9 $ 417.0 $ (1,164.9 ) $ 362.2 Pentair plc and Subsidiaries Condensed Consolidating Balance Sheet December 31, 2018 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Assets Current assets Cash and cash equivalents $ 0.1 $ — $ 0.1 $ 74.1 $ — $ 74.3 Accounts and notes receivable, net 4.6 — — 483.6 — 488.2 Inventories — — — 387.5 — 387.5 Other current assets 3.4 — 2.2 99.2 (15.4 ) 89.4 Total current assets 8.1 — 2.3 1,044.4 (15.4 ) 1,039.4 Property, plant and equipment, net — — — 272.6 — 272.6 Other assets Investments in subsidiaries 1,903.8 2,036.1 2,675.7 — (6,615.6 ) — Goodwill — — — 2,072.7 — 2,072.7 Intangibles, net — — — 276.3 — 276.3 Other non-current assets 23.3 — 696.1 729.7 (1,303.6 ) 145.5 Total other assets 1,927.1 2,036.1 3,371.8 3,078.7 (7,919.2 ) 2,494.5 Total assets $ 1,935.2 $ 2,036.1 $ 3,374.1 $ 4,395.7 $ (7,934.6 ) $ 3,806.5 Liabilities and Equity Current liabilities Accounts payable $ 0.9 $ — $ — $ 377.7 $ — $ 378.6 Employee compensation and benefits 0.2 — — 111.5 — 111.7 Other current liabilities 47.6 1.5 4.4 290.3 (15.4 ) 328.4 Total current liabilities 48.7 1.5 4.4 779.5 (15.4 ) 818.7 Other liabilities Long-term debt 29.9 130.8 1,333.9 596.6 (1,303.6 ) 787.6 Pension and other post-retirement compensation and benefits — — — 90.0 — 90.0 Deferred tax liabilities — — — 105.9 — 105.9 Other non-current liabilities 20.5 — — 147.7 — 168.2 Total liabilities 99.1 132.3 1,338.3 1,719.7 (1,319.0 ) 1,970.4 Equity 1,836.1 1,903.8 2,035.8 2,676.0 (6,615.6 ) 1,836.1 Total liabilities and equity $ 1,935.2 $ 2,036.1 $ 3,374.1 $ 4,395.7 $ (7,934.6 ) $ 3,806.5 Pentair plc and Subsidiaries Condensed Consolidating Statement of Cash Flows Year Ended December 31, 2018 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Operating activities Net cash provided by (used for) operating activities $ 266.3 $ 362.1 $ 370.6 $ 637.7 $ (1,197.6 ) $ 439.1 Investing activities Capital expenditures — — — (48.2 ) — (48.2 ) Proceeds from sale of property and equipment — — — 0.2 — 0.2 Payments due to sale of businesses and other — — — (12.8 ) — (12.8 ) Acquisitions, net of cash acquired — — — (0.9 ) — (0.9 ) Net intercompany loan activity — 94.1 181.0 1,655.7 (1,930.8 ) — Net cash provided by (used for) investing activities of continuing operations — 94.1 181.0 1,594.0 (1,930.8 ) (61.7 ) Net cash provided by (used for) investing activities of discontinued operations — — — (7.1 ) — (7.1 ) Net cash provided by (used for) investing activities — 94.1 181.0 1,586.9 (1,930.8 ) (68.8 ) Financing activities Net receipts (repayments) of commercial paper and revolving long-term debt — — 41.9 (2.2 ) — 39.7 Repayment of long-term debt — — (675.1 ) — — (675.1 ) Premium paid on early extinguishment of debt — — (16.0 ) — — (16.0 ) Transfer of cash to nVent — — — (74.2 ) — (74.2 ) Distribution of cash from nVent — — 993.6 — — 993.6 Net change in advances to subsidiaries 407.7 (456.2 ) (874.6 ) (2,205.3 ) 3,128.4 — Shares issued to employees, net of shares withheld 13.3 — — — — 13.3 Repurchases of ordinary shares (500.0 ) — — — — (500.0 ) Dividends paid (187.2 ) — — — — (187.2 ) Other — — (2.0 ) — — (2.0 ) Net cash provided by (used for) financing activities (266.2 ) (456.2 ) (532.2 ) (2,281.7 ) 3,128.4 (407.9 ) Change in cash held for sale — — — 27.0 — 27.0 Effect of exchange rate changes on cash and cash equivalents — — (19.3 ) 17.9 — (1.4 ) Change in cash and cash equivalents 0.1 — 0.1 (12.2 ) — (12.0 ) Cash and cash equivalents, beginning of year — — — 86.3 — 86.3 Cash and cash equivalents, end of year $ 0.1 $ — $ 0.1 $ 74.1 $ — $ 74.3 Pentair plc and Subsidiaries Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) Year Ended December 31, 2017 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Net sales $ — $ — $ — $ 2,845.7 $ — $ 2,845.7 Cost of goods sold — — — 1,858.2 — 1,858.2 Gross profit — — — 987.5 — 987.5 Selling, general and administrative 9.0 0.6 — 526.4 — 536.0 Research and development — — — 73.2 — 73.2 Operating (loss) income (9.0 ) (0.6 ) — 387.9 — 378.3 Loss (earnings) from continuing operations of investment in subsidiaries (122.2 ) (122.2 ) (283.4 ) — 527.8 — Other (income) expense: Loss on sale of businesses — — — 4.2 — 4.2 Loss on early extinguishment of debt — — 91.0 10.4 — 101.4 Net interest (income) expense — (0.6 ) 70.7 17.2 — 87.3 Other expense — — — 12.6 — 12.6 Income (loss) from continuing operations before income taxes 113.2 122.2 121.7 343.5 (527.8 ) 172.8 Provision (benefit) for income taxes (0.9 ) — — 59.6 — 58.7 Net income (loss) from continuing operations 114.1 122.2 121.7 283.9 (527.8 ) 114.1 Income from discontinued operations, net of tax — — — 371.3 — 371.3 Gain from sale of discontinued operations, net of tax — — — 181.1 — 181.1 Earnings (loss) from discontinued operations of investment in subsidiaries 552.4 552.4 552.4 — (1,657.2 ) — Net income (loss) $ 666.5 $ 674.6 $ 674.1 $ 836.3 $ (2,185.0 ) $ 666.5 Comprehensive income (loss), net of tax Net income (loss) $ 666.5 $ 674.6 $ 674.1 $ 836.3 $ (2,185.0 ) $ 666.5 Changes in cumulative translation adjustment 497.5 497.5 497.5 497.5 (1,492.5 ) 497.5 Changes in market value of derivative financial instruments, net of tax (4.6 ) (4.6 ) (4.6 ) (4.6 ) 13.8 (4.6 ) Comprehensive income (loss) $ 1,159.4 $ 1,167.5 $ 1,167.0 $ 1,329.2 $ (3,663.7 ) $ 1,159.4 Pentair plc and Subsidiaries Condensed Consolidating Balance Sheet December 31, 2017 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Assets Current assets Cash and cash equivalents $ — $ — $ — $ 86.3 $ — $ 86.3 Accounts and notes receivable, net — — — 483.1 — 483.1 Inventories — — — 356.9 — 356.9 Other current assets 10.8 1.8 1.5 109.6 (9.2 ) 114.5 Current assets held for sale — — — 708.0 — 708.0 Total current assets 10.8 1.8 1.5 1,743.9 (9.2 ) 1,748.8 Property, plant and equipment, net — — — 279.8 — 279.8 Other assets Investments in subsidiaries 5,205.1 5,109.6 7,156.1 — (17,470.8 ) — Goodwill — — — 2,112.8 — 2,112.8 Intangibles, net — — — 321.8 — 321.8 Other non-current assets 2.2 94.1 614.0 1,360.0 (1,889.4 ) 180.9 Non-current assets held for sale — — — 3,989.6 — 3,989.6 Total other assets 5,207.3 5,203.7 7,770.1 7,784.2 (19,360.2 ) 6,605.1 Total assets $ 5,218.1 $ 5,205.5 $ 7,771.6 $ 9,807.9 $ (19,369.4 ) $ 8,633.7 Liabilities and Equity Current liabilities Accounts payable $ 1.4 $ — $ — $ 320.1 $ — $ 321.5 Employee compensation and benefits 0.4 — — 115.4 — 115.8 Other current liabilities 99.6 0.4 9.4 301.1 (9.2 ) 401.3 Current liabilities held for sale — — — 360.8 — 360.8 Total current liabilities 101.4 0.4 9.4 1,097.4 (9.2 ) 1,199.4 Other liabilities Long-term debt 48.4 — 2,652.8 628.9 (1,889.4 ) 1,440.7 Pension and other post-retirement compensation and benefits — — — 96.4 — 96.4 Deferred tax liabilities — — — 108.6 — 108.6 Other non-current liabilities 30.5 — — 183.3 — 213.8 Non-current liabilities held for sale — — — 537.0 — 537.0 Total liabilities 180.3 0.4 2,662.2 2,651.6 (1,898.6 ) 3,595.9 Equity 5,037.8 5,205.1 5,109.4 7,156.3 (17,470.8 ) 5,037.8 Total liabilities and equity $ 5,218.1 $ 5,205.5 $ 7,771.6 $ 9,807.9 $ (19,369.4 ) $ 8,633.7 Pentair plc and Subsidiaries Condensed Consolidating Statement of Cash Flows Year Ended December 31, 2017 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Operating activities Net cash provided by (used for) operating activities $ 678.3 $ 676.1 $ 656.2 $ 794.6 $ (2,185.0 ) $ 620.2 Investing activities Capital expenditures — — — (39.1 ) — (39.1 ) Proceeds from sale of property and equipment — — — 3.7 — 3.7 Proceeds from sale of businesses and other — — 2,765.6 (6.2 ) — 2,759.4 Acquisitions, net of cash acquired — — — (45.9 ) — (45.9 ) Net intercompany loan activity — (58.9 ) 103.7 172.5 (217.3 ) — Net cash provided by (used for) investing activities of continuing operations — (58.9 ) 2,869.3 85.0 (217.3 ) 2,678.1 Net cash provided by (used for) investing activities from discontinued operations — — — (47.7 ) — (47.7 ) Net cash provided by (used for) investing activities — (58.9 ) 2,869.3 37.3 (217.3 ) 2,630.4 Financing activities Net receipts (repayments) of commercial paper and revolving long-term debt — — (914.7 ) 1.6 — (913.1 ) Repayment of long-term debt — — (1,917.8 ) (91.5 ) — (2,009.3 ) Premium paid on early extinguishment of debt — — (86.0 ) (8.9 ) — (94.9 ) Net change in advances to subsidiaries (263.8 ) (617.2 ) (680.8 ) (840.5 ) 2,402.3 — Shares issued to employees, net of shares withheld 37.2 — — — — 37.2 Repurchases of ordinary shares (200.0 ) — — — — (200.0 ) Dividends paid (251.7 ) — — — — (251.7 ) Other — — — (0.8 ) — (0.8 ) Net cash provided by (used for) financing activities (678.3 ) (617.2 ) (3,599.3 ) (940.1 ) 2,402.3 (3,432.6 ) Change in cash held for sale — — — (5.4 ) — (5.4 ) Effect of exchange rate changes on cash and cash equivalents — — 73.8 (17.0 ) — 56.8 Change in cash and cash equivalents — — — (130.6 ) — (130.6 ) Cash and cash equivalents, beginning of year — — — 216.9 — 216.9 Cash and cash equivalents, end of year $ — $ — $ — $ 86.3 $ — $ 86.3 Pentair plc and Subsidiaries Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) Year Ended December 31, 2016 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Net sales $ — $ — $ — $ 2,780.6 $ — $ 2,780.6 Cost of goods sold — — — 1,821.5 — 1,821.5 Gross profit — — — 959.1 — 959.1 Selling, general and administrative 12.6 — 1.2 517.6 — 531.4 Research and development — — — 73.3 — 73.3 Operating (loss) income (12.6 ) — (1.2 ) 368.2 — 354.4 Loss (earnings) from continuing operations of investment in subsidiaries (189.4 ) (189.4 ) (301.5 ) — 680.3 — Other (income) expense: Loss on sale of businesses — — — 3.9 — 3.9 Net interest expense — — 110.9 29.2 — 140.1 Other income — — — (10.5 ) — (10.5 ) Income (loss) from continuing operations before income taxes 176.8 189.4 189.4 345.6 (680.3 ) 220.9 Provision (benefit) for income taxes (1.4 ) — — 44.1 — 42.7 Net income (loss) from continuing operations 178.2 189.4 189.4 301.5 (680.3 ) 178.2 Income from discontinued operations, net of tax — — — 343.4 — 343.4 Gain from sale of discontinued operations, net of tax — — — 0.6 — 0.6 Earnings (loss) from discontinued operations of investment in subsidiaries 344.0 344.0 344.0 — (1,032.0 ) — Net income (loss) $ 522.2 $ 533.4 $ 533.4 $ 645.5 $ (1,712.3 ) $ 522.2 Comprehensive income (loss), net of tax Net income (loss) $ 522.2 $ 533.4 $ 533.4 $ 645.5 $ (1,712.3 ) $ 522.2 Changes in cumulative translation adjustment (83.0 ) (83.0 ) (83.0 ) (83.0 ) 249.0 (83.0 ) Changes in market value of derivative financial instruments, net of tax (8.3 ) (8.3 ) (8.3 ) (8.3 ) 24.9 (8.3 ) Comprehensive income (loss) $ 430.9 $ 442.1 $ 442.1 $ 554.2 $ (1,438.4 ) $ 430.9 Pentair plc and Subsidiaries Condensed Consolidating Statement of Cash Flows Year Ended December 31, 2016 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Operating activities Net cash provided by (used for) operating activities $ 595.7 $ 541.7 $ 532.9 $ 903.4 $ (1,712.3 ) $ 861.4 Investing activities Capital expenditures — — — (43.3 ) — (43.3 ) Proceeds from sale of property and equipment — — — 18.8 — 18.8 Proceeds from sale of businesses and other — — — (5.1 ) — (5.1 ) Acquisitions, net of cash acquired — — — (25.0 ) — (25.0 ) Net intercompany loan activity — — 667.3 (191.0 ) (476.3 ) — Net cash provided by (used for) investing activities of continuing operations — — 667.3 (245.6 ) (476.3 ) (54.6 ) Net cash provided by (used for) investing activities of discontinued operations — — — (67.2 ) — (67.2 ) Net cash provided by (used for) investing activities — — 667.3 (312.8 ) (476.3 ) (121.8 ) Financing activities Net receipts (repayments) of commercial paper and revolving long-term debt — — (385.8 ) 0.5 — (385.3 ) Repayment of long-term debt — — — (0.7 ) — (0.7 ) Net change in advances to subsidiaries (372.8 ) (541.7 ) (842.3 ) (431.8 ) 2,188.6 — Shares issued to employees, net of shares withheld 20.7 — — — — 20.7 Dividends paid (243.6 ) — — — — (243.6 ) Other — — — 8.8 — 8.8 Net cash provided by (used for) financing activities (595.7 ) (541.7 ) (1,228.1 ) (423.2 ) 2,188.6 (600.1 ) Change in cash held for sale — — — 1.1 — 1.1 Effect of exchange rate changes on cash and cash equivalents — — 27.8 (55.1 ) — (27.3 ) Change in cash and cash equivalents — — (0.1 ) 113.4 — 113.3 Cash and cash equivalents, beginning of year — — 0.1 103.5 — 103.6 Cash and cash equivalents, end of year $ — $ — $ — $ 216.9 $ — $ 216.9

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Schedule II - Valuation and Qualifying Accounts	Schedule II — Valuation and Qualifying Accounts Pentair plc and Subsidiaries In millions Beginning balance Additions charged (reductions credited) to costs and expenses Deductions (1) Other changes (2) Ending balance Allowances for doubtful accounts Year ended December 31, 2018 $ 10.0 $ 1.1 $ 0.9 $ 2.4 $ 12.6 Year ended December 31, 2017 $ 9.0 $ 2.3 $ 2.2 $ 0.9 $ 10.0 Year ended December 31, 2016 $ 13.7 $ (1.2 ) $ 3.9 $ 0.4 $ 9.0 (1) Uncollectible accounts written off, net of recoveries (2) Result of foreign currency effects

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
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. 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 calendar quarter basis.
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, pension and other post-retirement benefits and the estimated impact of the new lease standard, discussed below. Actual results could differ from our estimates.
Revenue Recognition	Revenue recognition Revenue is recognized when control of the promised goods or services are transferred to our customers, in an amount that reflects the consideration we expect to be entitled to in exchange for transferring those goods or providing services. We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. When determining whether the customer has obtained control of the goods or services, we consider any future performance obligations. 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 Pentair has substantially accomplished what it must do to be entitled to the benefits represented by the revenue. Performance obligations A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account for purposes of revenue recognition. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The majority of our contracts have a single performance obligation as the promise to transfer the individual goods or services is not separately identifiable from other promises in the contracts and, therefore, not distinct. For contracts with multiple performance obligations, standalone selling price is generally readily observable. Our performance obligations are satisfied at a point in time or over time as work progresses. Revenue from goods and services transferred to customers at a point in time accounted for 92.5% , 92.4% and 94.0% of our revenue for the twelve months ended December 31, 2018, 2017 and 2016, respectively. Revenue on these contracts is recognized when obligations under the terms of the contract with our customer are satisfied; generally this occurs with the transfer of control upon shipment. Revenue from products and services transferred to customers over time accounted for 7.5% , 7.6% and 6.0% of our revenue for the twelve months ended December 31, 2018, 2017 and 2016, respectively. For the majority of our revenue recognized over time, we use an input measure to determine progress towards completion. Under this method, sales and gross profit are recognized as work is performed generally 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. Contract costs include labor, material, overhead and, when appropriate, general and administrative expenses. 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. For performance obligations related to long term contracts, when estimates of total costs to be incurred on a performance obligation exceed total estimates of revenue to be earned, a provision for the entire loss on the performance obligation is recognized in the period the loss is determined. On December 31, 2018, we had $57.2 million of remaining performance obligations on contracts with an original expected duration of one year or more. We expect to recognize the majority of our remaining performance obligations on these contracts within the next 12 to 18 months. Sales returns The right of return may exist explicitly or implicitly with our customers. 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. When the right of return exists, we adjust the transaction price for the estimated effect of returns. We estimate the expected returns based on 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 Our contracts may give customers the option to purchase additional goods or services priced at a discount. Options to acquire additional goods or services at a discount can come in many forms, such as customer programs and incentive offerings including pricing arrangements, promotions and other volume-based incentives. We reduce the transaction price for certain customer programs and incentive offerings including pricing arrangements, promotions and other volume-based incentives that represent variable consideration. Sales incentives given to our customers are recorded using either the expected value method or most likely amount approach for estimating the amount of consideration to which Pentair shall be entitled. The expected value is the sum of probability-weighted amounts in a range of possible consideration amounts. An expected value is an appropriate estimate of the amount of variable consideration when there are a large number of contracts with similar characteristics. The most likely amount is the single most likely amount in a range of possible consideration amounts (that is, the single most likely outcome of the contract). The most likely amount is an appropriate estimate of the amount of variable consideration if the contract has limited possible outcomes (for example, an entity either achieves a performance bonus or does not). 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. We use the expected value method to 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 of the transaction price. 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 determine the most likely amount of the rebate to be paid based on forecasted sales levels. These forecasts are updated at least quarterly for each customer, and the transaction price is reduced for the anticipated cost of the rebate. If the forecasted sales for a customer change, 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 activities after the customer obtains control are treated as a promised service performance obligation and recorded in Net sales in the accompanying Consolidated Statements of Operations and Comprehensive Income. Shipping and handling costs incurred by Pentair for the delivery of goods to customers are considered a cost to fulfill the contract and are included in Cost of goods sold in the accompanying Consolidated Statements of Operations and Comprehensive Income. Contract assets and liabilities Contract assets consist of unbilled amounts resulting from sales under long-term contracts when the cost-to-cost method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the customer, such as when the customer retains a small portion of the contract price until completion of the contract. We typically receive interim payments on sales under long-term contracts as work progresses, although for some contracts, we may be entitled to receive an advance payment. Contract liabilities consist of advanced payments, billings in excess of costs incurred and deferred revenue. Contract assets are recorded within Other current assets , and contract liabilities are recorded within Other current liabilities in the Consolidated Balance Sheets. Contract assets and liabilities consisted of the following: December 31 In millions 2018 2017 $ Change % Change Contract assets $ 36.5 $ 51.5 $ (15.0 ) (29.1 )% Contract liabilities 32.8 29.2 3.6 12.3 % Net contract assets $ 3.7 $ 22.3 $ (18.6 ) (83.4 )% The $18.6 million decrease in net contract assets from December 31, 2017 to December 31, 2018 was primarily the result of timing of milestone payments. Approximately 70% of our contract liabilities at December 31, 2017 were recognized in revenue during the twelve months ended December 31, 2018 . There were no impairment losses recognized on our contract assets for the twelve months ended December 31, 2018 . Practical expedients and exemptions We generally expense incremental costs of obtaining a contract when incurred because the amortization period would be less than one year. These costs primarily relate to sales commissions and are recorded in Selling, general and administrative expense in the Consolidated Statements of Operations and Comprehensive Income. We do not disclose the value of unsatisfied performance obligations for contracts with an original expected length of one year or less. Further, we do not adjust the promised amount of consideration for the effects of a significant financing component if we expect, at contract inception, that the period between when we transfer a promised good or service to a customer and when the customer pays for that good or service will be one year or less. Revenue by category We disaggregate our revenue from contracts with customers by segment, geographic location and vertical, as we believe these best depict how the nature, amount, timing and uncertainty of our revenue and cash flows are affected by economic factors.
Research and Development	Research and development We conduct research and development (“R&D”) activities primarily in our own facilities, which mostly consist of development of new products, product applications and manufacturing processes.
Cash Equivalents	Cash equivalents We consider highly liquid investments with original maturities of three months or less at the date of acquisition 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.
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.
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. The following table presents geographic Property, plant and equipment, net by region as of December 31: In millions 2018 2017 U.S. $ 156.9 $ 151.9 Western Europe 76.6 82.8 Developing (1) 28.8 33.0 Other Developed (2) 10.3 12.1 Consolidated (3) $ 272.6 $ 279.8 (1) Developing includes China, Eastern Europe, Latin America, the Middle East and Southeast Asia. (2) Other Developed includes Australia, Canada and Japan. (3) Property, plant and equipment, net held in Ireland, for each of the years presented, were not material. 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.
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 at least annually for impairment and is tested for impairment more frequently if events or changes in circumstances indicate that the asset might be impaired. We complete our annual goodwill impairment evaluation as of the first day of the fourth quarter. We last performed a two-step assessment of goodwill impairment as of October 1, 2017, referred to as a “step 1” approach. In the first step of the step 1 approach, 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 of the step 1 approach, 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. 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. 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. 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. As of October 1, 2018, we performed a qualitative assessment, referred to as a “step 0” approach, and determined that it was more likely than not that the fair value of the reporting units exceeded their respective carrying amounts. As a result, the Company was not required to proceed to a “step 1” impairment assessment. Factors considered included the 2017 “step 1” analysis and the calculated excess fair value over carrying amount, financial performance, forecasts and trends, market cap, regulatory and environmental issues, macro-economic conditions, industry and market considerations, raw material costs and management stability. We consider the extent to which each of the adverse events and circumstances identified affect the comparison of the respective reporting unit’s fair value with its carrying amount. We place more weight on the events and circumstances that most affect the respective reporting unit’s fair value or the carrying amount of its net assets. We consider positive and mitigating events and circumstances that may affect its determination of whether it is more likely than not that the fair value exceeds the carrying amount. We completed our annual goodwill impairment evaluation as of the first day of the fourth quarter of 2018, 2017 and 2016 with no indications of impairment. This non-recurring fair value measurement is a “Level 3” measurement under the fair value hierarchy described in Note 9. Identifiable intangible assets Our primary identifiable intangible assets include: customer relationships, trade names, proprietary technology and patents. 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. We complete our annual impairment test during the fourth quarter each year for those identifiable assets not subject to amortization. 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.
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. We maintain valuation allowances unless it is more likely than not that all or a portion of the deferred tax assets will 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 and expected returns on plan assets. These assumptions are updated annually and are disclosed in Note 11. 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, including service and interest costs and estimated return on plan assets, are recorded on a quarterly basis.
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.
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. Restricted share awards and units (“RSUs”) are recorded as compensation cost over the requisite service periods based on the market value on the date of grant. Performance share units (“PSUs”) are stock awards where the ultimate number of shares issued will be contingent on the Company’s performance against certain financial performance targets. The fair value of each PSU is based on the market value on the date of grant. We recognize expense related to the estimated vesting of our PSUs granted. The estimated vesting of the PSUs is based on the probability of achieving certain financial performance thresholds over the specified performance period.
Earnings (Loss) Per Common Share	Earnings per ordinary share We present two calculations of earnings per ordinary share (“EPS”). Basic EPS equals net income divided by the weighted-average number of ordinary shares outstanding during the period. Diluted EPS is computed by dividing net income by the sum of weighted-average number of ordinary shares outstanding plus 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, the effective portion of 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 are recognized in the Consolidated Statements of Operations and Comprehensive Income 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. Gains and losses on net investment hedges are included in AOCI as a separate component of equity in the Consolidated Balance Sheets. 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.
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 (Loss) and expense items are translated at average monthly rates of exchange. The resultant translation adjustments are included in AOCI, a component of equity.
New accounting standards	New accounting standards In February 2016, the Financial Accounting Standards Board issued ASU No. 2016-02, “Leases” (“the new lease standard” or “ASC 842”), which requires an entity to recognize both assets and liabilities arising from financing and operating leases, along with additional qualitative and quantitative disclosures. The new lease standard requirements are effective for annual reporting periods beginning after December 15, 2018, including interim periods within that reporting period. We adopted the new lease guidance as of January 1, 2019, using the transition method of adoption applied to those leases which were not completed as of that date. Under the transition method of adoption, comparative periods will not be restated for the new standard. We also elected the package of practical expedients permitted under the transition guidance, which among other things allowed us to carry forward the historical lease classification. In preparation for adoption of the new guidance, we have implemented appropriate changes to our business processes, systems and controls to support preparation of financial information and have reached conclusions on key accounting assessments related to the standard. As a result of these assessments, we anticipate the adoption of the new standard to increase assets and liabilities on the consolidated balance sheet by approximately $75.0 million as of the adoption date. We currently do not expect ASC 842 to have a material effect on either our consolidated statements of operations and comprehensive income or consolidated statements of cash flows. On January 1, 2018, we adopted ASU No. 2017-01, “Clarifying the Definition of a Business.” This ASU clarifies the definition of a business and provides guidance on whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The adoption of the new standard did not have a material impact on our consolidated financial statements. On January 1, 2018, we adopted ASU No. 2017-07, “Retirement Benefits-Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost.” As a result of the adoption, the interest cost, expected return on plan assets and net actuarial gain/loss components of net periodic pension and post-retirement benefit cost have been reclassified from Selling, general and administrative expense to Other (income) expense . Only the service cost component remains in Operating income and will be eligible for capitalization in assets on a prospective basis. The effect of the retrospective presentation change related to the net periodic cost of our defined benefit pension and other post-retirement plans on our Consolidated Statements of Operations and Comprehensive Income was a reclassification of expense of $13.9 million and income of $6.2 million for the years ended December 31, 2017 and 2016, respectively, from Selling, general and administrative expense to Other (income) expense . On January 1, 2018, we adopted ASU No. 2016-16, “Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory.” This ASU requires the tax effects of all intra-entity sales of assets other than inventory to be recognized in the period in which the transaction occurs. The adoption resulted in a $215.8 million cumulative-effect adjustment (of which $174.6 million related to nVent) recorded in retained earnings as of the beginning of 2018. The adjustment reflects a $254.3 million reduction of a prepaid long term tax asset, partially offset by the establishment of $38.5 million of deferred tax assets. On January 1, 2018, we adopted ASU No. 2014-09, “Revenue from Contracts with Customers” and the related amendments (“the new revenue standard”) using the modified retrospective method. The cumulative impact to our retained earnings at January 1, 2018 was not material. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. We expect the impact of the adoption of the new standard to be immaterial to our net income on an ongoing basis. A majority of our net sales continue to be recognized when products are shipped from our manufacturing facilities or delivery has occurred, depending on terms of the sale. Under the new revenue standard, timing for recognition of certain revenue may be accelerated such that a portion of revenue will be recognized prior to shipment or delivery dependent upon contract-specific terms.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Contract with Customer, Asset and Liability	Contract assets and liabilities consisted of the following: December 31 In millions 2018 2017 $ Change % Change Contract assets $ 36.5 $ 51.5 $ (15.0 ) (29.1 )% Contract liabilities 32.8 29.2 3.6 12.3 % Net contract assets $ 3.7 $ 22.3 $ (18.6 ) (83.4 )%
Disaggregation of Revenue	Geographic net sales information for continuing operations, based on geographic destination of the sale, was as follows: Years ended December 31 In millions 2018 2017 2016 U.S. $ 1,858.1 $ 1,752.7 $ 1,690.0 Western Europe 402.7 381.9 377.7 Developing (1) 476.5 478.2 492.0 Other Developed (2) 227.8 232.9 220.9 Consolidated net sales (3) $ 2,965.1 $ 2,845.7 $ 2,780.6 (1) Developing includes China, Eastern Europe, Latin America, the Middle East and Southeast Asia. (2) Other Developed includes Australia, Canada and Japan. (3) Net sales held in Ireland, for each of the years presented, were not material. Vertical net sales information was as follows: Years ended December 31 In millions 2018 2017 2016 Residential $ 1,665.9 $ 1,579.0 $ 1,498.7 Commercial 630.7 604.4 586.5 Industrial 668.5 662.3 695.4 Consolidated net sales $ 2,965.1 $ 2,845.7 $ 2,780.6
Property, Plant and Equipment	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
Long-lived Assets by Geographic Areas	The following table presents geographic Property, plant and equipment, net by region as of December 31: In millions 2018 2017 U.S. $ 156.9 $ 151.9 Western Europe 76.6 82.8 Developing (1) 28.8 33.0 Other Developed (2) 10.3 12.1 Consolidated (3) $ 272.6 $ 279.8 (1) Developing includes China, Eastern Europe, Latin America, the Middle East and Southeast Asia. (2) Other Developed includes Australia, Canada and Japan. (3) Property, plant and equipment, net held in Ireland, for each of the years presented, were not material.
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The cumulative effect of the changes made to our January 1, 2018 Consolidated Balance Sheet from the modified retrospective adoption of ASU 2016-16 and ASU 2014-09 was as follows: Consolidated Balance Sheets In millions Balance at December 31, 2017 Adjustments due to ASU 2016-16 Adjustments due to ASU 2014-09 Balance at January 1, 2018 Assets Accounts and notes receivable, net $ 483.1 $ — $ 2.7 $ 485.8 Inventories 356.9 — (1.6 ) 355.3 Other current assets 114.5 — 1.6 116.1 Current assets held for sale 708.0 — 3.8 711.8 Other non-current assets 180.9 (44.9 ) — 136.0 Non-current assets held for sale 3,989.6 (201.6 ) — 3,788.0 Liabilities Other current liabilities 401.3 — 2.7 404.0 Deferred tax liabilities 108.6 (3.7 ) 0.1 105.0 Non-current liabilities held for sale 537.0 (27.0 ) 0.4 510.4 Equity Retained Earnings 2,481.7 (215.8 ) 1.8 2,267.7

Acquisitions and Discontinued_2

Acquisitions and Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combination And Disposal Groups, Including Discontinued Operations, Disclosure [Abstract]
Schedule of Discontinued Operations	Operating results of discontinued operations are summarized below: Years ended December 31 In millions 2018 2017 2016 Net sales $ 693.9 $ 2,548.2 $ 3,755.4 Cost of goods sold 424.0 1,596.2 2,457.1 Gross profit 269.9 952.0 1,298.3 Selling, general and administrative 237.8 589.2 803.2 Research and development 14.6 48.3 59.0 Operating income $ 17.5 $ 314.5 $ 436.1 Income from discontinued operations before income taxes $ 31.8 $ 317.1 $ 418.5 Income tax provision (benefit) 6.1 (54.2 ) 75.1 Income from discontinued operations, net of tax $ 25.7 $ 371.3 $ 343.4 Gain from sale / impairment of discontinued operations before income taxes $ — $ 183.5 $ 0.6 Provision for income taxes — 2.4 — Gain from sale / impairment of discontinued operations, net of tax $ — $ 181.1 $ 0.6 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 2017 Cash and cash equivalents $ 27.0 Accounts receivable, net 348.5 Inventories 224.1 Other current assets 108.4 Current assets held for sale $ 708.0 Property, plant and equipment, net $ 265.8 Goodwill 2,238.2 Intangibles, net 1,236.6 Other non-current assets 249.0 Non-current assets held for sale $ 3,989.6 Accounts payable $ 174.1 Employee compensation and benefits 70.8 Other current liabilities 115.9 Current liabilities held for sale $ 360.8 Pension and other post-retirement compensation and benefits $ 189.2 Deferred tax liabilities 286.2 Other non-current liabilities 61.6 Non-current liabilities held for sale $ 537.0

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share, Basic and Diluted [Abstract]
Basic and Diluted Earnings (Loss) Per Share	Basic and diluted earnings per share were calculated as follows: Years ended December 31 In millions, except per share data 2018 2017 2016 Net income $ 347.4 $ 666.5 $ 522.2 Net income from continuing operations $ 321.7 $ 114.1 $ 178.2 Weighted average ordinary shares outstanding Basic 175.8 181.7 181.3 Dilutive impact of stock options and restricted stock awards 1.5 2.0 1.8 Diluted 177.3 183.7 183.1 Earnings per ordinary share Basic Continuing operations $ 1.83 $ 0.63 $ 0.98 Discontinued operations 0.15 3.04 1.90 Basic earnings per ordinary share $ 1.98 $ 3.67 $ 2.88 Diluted Continuing operations $ 1.81 $ 0.62 $ 0.97 Discontinued operations 0.15 3.01 1.88 Diluted earnings per ordinary share $ 1.96 $ 3.63 $ 2.85 Anti-dilutive stock options excluded from the calculation of diluted earnings per share 1.2 1.8 1.2

Restructuring (Tables)

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Restructuring Related Costs	Restructuring related costs included in Selling, general and administrative expenses in the Consolidated Statements of Operations and Comprehensive Income included costs for severance and other restructuring costs as follows: Years ended December 31 In millions 2018 2017 2016 Severance and related costs $ 13.2 $ 27.3 $ 12.2 Other 27.4 0.9 — Total restructuring costs $ 40.6 $ 28.2 $ 12.2
Restructuring Costs By Segment [Table Text Block]	Restructuring costs by reportable segment were as follows: Years ended December 31 In millions 2018 2017 2016 Aquatic Systems $ 15.3 $ 3.6 $ 1.8 Filtration Solutions 14.6 13.0 7.4 Flow Technologies 9.3 7.0 1.3 Other 1.4 4.6 1.7 Consolidated $ 40.6 $ 28.2 $ 12.2
Restructuring Accrual Activity Recorded on Consolidated Balance Sheets	Activity related to accrued severance and related costs recorded in Other current liabilities in the Consolidated Balance Sheets is summarized as follows: Years ended December 31 In millions 2018 2017 Beginning balance $ 34.5 $ 15.1 Costs incurred 13.2 27.3 Cash payments and other (20.6 ) (7.9 ) Ending balance $ 27.1 $ 34.5

Goodwill and Other Identifiab_2

Goodwill and Other Identifiable Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill by Segment	The changes in the carrying amount of goodwill for the years ended December 31, 2018 and 2017 by reportable segment were as follows: In millions December 31, 2017 Foreign currency December 31, 2018 Aquatic Systems $ 973.1 $ (7.2 ) $ 965.9 Filtration Solutions 667.6 (24.1 ) 643.5 Flow Technologies 472.1 (8.8 ) 463.3 Total goodwill $ 2,112.8 $ (40.1 ) $ 2,072.7 In millions December 31, 2016 Acquisitions/ Foreign currency December 31, 2017 Aquatic Systems $ 918.7 $ — $ 54.4 $ 973.1 Filtration Solutions 630.2 27.3 10.1 667.6 Flow Technologies 445.7 — 26.4 472.1 Total goodwill $ 1,994.6 $ 27.3 $ 90.9 $ 2,112.8
Identifiable Intangible Assets	Identifiable intangible assets consisted of the following at December 31: 2018 2017 In millions Cost Accumulated amortization Net Cost Accumulated amortization Net Definite-life intangibles Customer relationships $ 347.1 $ (247.9 ) $ 99.2 $ 360.9 $ (229.9 ) $ 131.0 Trade names 0.4 (0.4 ) — 1.5 (1.4 ) 0.1 Proprietary technology and patents 86.2 (68.4 ) 17.8 117.0 (89.3 ) 27.7 Total finite-life intangibles 433.7 (316.7 ) 117.0 479.4 (320.6 ) 158.8 Indefinite-life intangibles Trade names 159.3 — 159.3 163.0 — 163.0 Total intangibles $ 593.0 $ (316.7 ) $ 276.3 $ 642.4 $ (320.6 ) $ 321.8
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 2019 2020 2021 2022 2023 Estimated amortization expense $ 27.4 $ 22.4 $ 17.3 $ 10.1 $ 7.8

Supplemental Balance Sheet In_2

Supplemental Balance Sheet Information (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure Supplemental Balance Sheet Information [Abstract]
Supplemental Balance Sheet Information	December 31 In millions 2018 2017 Inventories Raw materials and supplies $ 191.3 $ 190.8 Work-in-process 64.0 57.9 Finished goods 132.2 108.2 Total inventories $ 387.5 $ 356.9 Other current assets Cost in excess of billings $ 36.5 $ 51.5 Prepaid expenses 36.7 51.4 Prepaid income taxes 8.5 7.8 Other current assets 7.7 3.8 Total other current assets $ 89.4 $ 114.5 Property, plant and equipment, net Land and land improvements $ 33.5 $ 33.5 Buildings and leasehold improvements 178.9 184.3 Machinery and equipment 593.8 609.6 Construction in progress 35.7 23.7 Total property, plant and equipment 841.9 851.1 Accumulated depreciation and amortization 569.3 571.3 Total property, plant and equipment, net $ 272.6 $ 279.8 Other non-current assets Prepaid income taxes $ — $ 52.8 Deferred income taxes 26.2 29.0 Deferred compensation plan assets 20.9 23.2 Other non-current assets 98.4 75.9 Total other non-current assets $ 145.5 $ 180.9 Other current liabilities Dividends payable $ 30.8 $ 63.1 Accrued warranty 33.9 38.1 Accrued rebates 55.7 49.8 Billings in excess of cost 21.3 20.1 Income taxes payable 10.4 39.7 Accrued restructuring 27.1 34.5 Other current liabilities 149.2 156.0 Total other current liabilities $ 328.4 $ 401.3 Other non-current liabilities Income taxes payable $ 46.8 $ 61.3 Self-insurance liabilities 47.7 48.3 Deferred compensation plan liabilities 20.9 23.2 Foreign currency contract liabilities 30.6 47.2 Other non-current liabilities 22.2 33.8 Total other non-current liabilities $ 168.2 $ 213.8

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Components of Accumulated Other Comprehensive Income (Loss)	Components of Accumulated Other Comprehensive Loss consist of the following: December 31 In millions 2018 2017 Cumulative translation adjustments $ (211.4 ) $ (221.4 ) Market value of derivative financial instruments, net of tax (17.2 ) (22.0 ) Accumulated other comprehensive loss $ (228.6 ) $ (243.4 )

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Debt and Average Interest Rates on Debt Outstanding	Debt and the average interest rates on debt outstanding were as follows: In millions Average Maturity year December 31 December 31, 2018 2018 2017 Commercial paper 3.248% 2023 $ 76.0 $ 34.0 Revolving credit facilities 3.703% 2023 26.2 28.4 Senior notes - fixed rate (1) 2.900% 2018 — 255.3 Senior notes - fixed rate (1) 2.650% 2019 250.0 250.0 Senior notes - fixed rate - Euro (1) 2.450% 2019 155.1 594.4 Senior notes - fixed rate (1) 3.625% 2020 74.0 74.0 Senior notes - fixed rate (1) 5.000% 2021 103.8 103.8 Senior notes - fixed rate (1) 3.150% 2022 88.3 88.3 Senior notes - fixed rate (1) 4.650% 2025 19.3 19.3 Unamortized issuance costs and discounts N/A N/A (5.1 ) (6.8 ) Total debt $ 787.6 $ 1,440.7 (1) Senior notes guaranteed as to payment by Pentair plc and PISG (“the Notes”)
Debt Outstanding Matures on Calendar Year Basis	Debt outstanding, excluding unamortized issuance costs and discounts , at December 31, 2018 matures on a calendar year basis as follows: In millions 2019 2020 2021 2022 2023 Thereafter Total Contractual debt obligation maturities $ 405.1 $ 74.0 $ 103.8 $ 88.3 $ 102.1 $ 19.4 $ 792.7

Derivatives and Financial Ins_2

Derivatives and Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Recorded Amounts and Estimated Fair Values of Long-term Debt and Derivative Financial Instruments	The recorded amounts and estimated fair values of total debt, excluding unamortized issuance costs and discounts , at December 31 were as follows: 2018 2017 In millions Recorded Fair Value Recorded Fair Value Variable rate debt $ 102.2 $ 102.2 $ 62.4 $ 62.4 Fixed rate debt 690.5 691.8 1,385.1 1,424.0 Total debt $ 792.7 $ 794.0 $ 1,447.5 $ 1,486.4
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, 2018 In millions Level 1 Level 2 Level 3 NAV Total Foreign currency contract liabilities $ — $ (30.6 ) $ — $ — $ (30.6 ) Deferred compensation plan assets 17.6 — — 3.3 20.9 Total recurring fair value measurements $ 17.6 $ (30.6 ) $ — $ 3.3 $ (9.7 ) Recurring fair value measurements December 31, 2017 In millions Level 1 Level 2 Level 3 NAV Total Foreign currency contract assets $ — $ 0.6 $ — $ — $ 0.6 Foreign currency contract liabilities — (47.2 ) — — (47.2 ) Deferred compensation plan assets 18.7 — — 4.5 23.2 Total recurring fair value measurements $ 18.7 $ (46.6 ) $ — $ 4.5 $ (23.4 ) Nonrecurring fair value measurements (1)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income (loss) before income taxes and noncontrolling interest	Income from continuing operations before income taxes consisted of the following: Years ended December 31 In millions 2018 2017 2016 Federal (1) $ (24.6 ) $ (34.1 ) $ (25.6 ) International (2) 404.4 206.9 246.5 Income from continuing operations before income taxes $ 379.8 $ 172.8 $ 220.9 (1) “Federal” reflects United Kingdom (“U.K.”) income from continuing operations before income taxes. (2) “International” reflects non-U.K. income from continuing operations before income taxes.
Provision for Income Taxes	The provision for income taxes consisted of the following: Years ended December 31 In millions 2018 2017 2016 Currently payable (receivable) Federal (1) $ (0.1 ) $ — $ — International (2) 62.3 76.7 41.5 Total current taxes 62.2 76.7 41.5 Deferred Federal (1) — — — International (2) (4.1 ) (18.0 ) 1.2 Total deferred taxes (4.1 ) (18.0 ) 1.2 Total provision for income taxes $ 58.1 $ 58.7 $ 42.7 (1) “Federal” represents U.K. taxes. (2) “International” represents non-U.K. taxes.
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 2018 2017 2016 U.K. federal statutory income tax rate 19.0 % 19.3 % 20.0 % Tax effect of international operations (1) (12.0 ) (20.8 ) (26.5 ) Change in valuation allowances 7.9 27.6 22.1 Withholding taxes 0.3 0.4 1.8 Interest limitations 1.8 1.7 1.5 Excess tax benefits on stock-based compensation (1.7 ) (4.5 ) — Tax effect of U.S. tax reform (0.9 ) 1.3 — Tax effect of early extinguishment of debt 0.9 9.0 — Other — — 0.4 Effective tax rate 15.3 % 34.0 % 19.3 % (1) The tax effect of international operations consists of non-U.K. jurisdictions.
Reconciliations of Gross Unrecognized Tax Benefits	conciliations of the beginning and ending gross unrecognized tax benefits were as follows: Years ended December 31 In millions 2018 2017 2016 Beginning balance $ 13.8 $ 46.3 $ 25.0 Gross increases for tax positions in prior periods 44.0 4.7 26.9 Gross decreases for tax positions in prior periods (4.4 ) (3.4 ) (2.2 ) Gross increases based on tax positions related to the current year 0.9 0.7 0.8 Gross decreases related to settlements with taxing authorities (1.8 ) (33.6 ) (3.4 ) Reductions due to statute expiration (1.1 ) (0.9 ) (0.8 ) Ending balance $ 51.4 $ 13.8 $ 46.3 W
Deferred Taxes	ferred taxes were recorded in the Consolidated Balance Sheets as follows: December 31 In millions 2018 2017 Other non-current assets $ 26.2 $ 29.0 Deferred tax liabilities 105.9 108.6 Net deferred tax liabilities $ 79.7 $ 79.6 T
Tax Effects of Major Items Recorded as Deferred Tax Assets and Liabilities	e tax effects of the major items recorded as deferred tax assets and liabilities were as follows: December 31 In millions 2018 2017 Deferred tax assets Accrued liabilities and reserves $ 42.9 $ 43.9 Pension and other post-retirement compensation and benefits 25.2 35.7 Employee compensation and benefits 21.8 39.2 Tax loss and credit carryforwards 724.7 670.5 Other assets 4.4 — Total deferred tax assets 819.0 789.3 Valuation allowance 711.9 656.2 Deferred tax assets, net of valuation allowance 107.1 133.1 Deferred tax liabilities Property, plant and equipment 7.1 3.7 Goodwill and other intangibles 179.7 190.6 Other liabilities — 18.4 Total deferred tax liabilities 186.8 212.7 Net deferred tax liabilities $ 79.7 $ 79.6 In

Benefit Plans (Tables)

Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
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, 2018 and 2017 : Pension plans Other post-retirement plans In millions 2018 2017 2018 2017 Change in benefit obligations Benefit obligation beginning of year $ 473.8 $ 423.8 $ 17.5 $ 18.9 Service cost 4.1 11.7 — — Interest cost 11.5 16.4 0.6 0.7 Actuarial loss (gain) (23.6 ) 41.4 (1.4 ) (0.1 ) Foreign currency translation (0.2 ) 0.6 — — Benefits paid (187.7 ) (20.1 ) (1.8 ) (2.0 ) Benefit obligation end of year $ 277.9 $ 473.8 $ 14.9 $ 17.5 Change in plan assets Fair value of plan assets beginning of year $ 382.8 $ 352.3 $ — $ — Actual return on plan assets (21.4 ) 42.4 — — Company contributions 7.1 6.3 1.8 2.0 Foreign currency translation (0.1 ) 1.9 — — Benefits paid (187.7 ) (20.1 ) (1.8 ) (2.0 ) Fair value of plan assets end of year $ 180.7 $ 382.8 $ — $ — Funded status Benefit obligations in excess of the fair value of plan assets $ (97.2 ) $ (91.0 ) $ (14.9 ) $ (17.5 )
Amounts Recognized in Consolidated Balance Sheets	Amounts recorded in the Consolidated Balance Sheets were as follows: Pension plans Other post-retirement plans In millions 2018 2017 2018 2017 Current liabilities $ (28.3 ) $ (6.1 ) $ (1.7 ) $ (1.9 ) Non-current liabilities (68.9 ) (84.9 ) (13.2 ) (15.6 ) Benefit obligations in excess of the fair value of plan assets $ (97.2 ) $ (91.0 ) $ (14.9 ) $ (17.5 )
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 exceeds the fair value of plan assets Accumulated benefit obligation exceeds the fair value of plan assets In millions 2018 2017 2018 2017 Projected benefit obligation $ 277.9 $ 473.8 $ 270.6 $ 464.9 Fair value of plan assets 180.7 382.8 173.7 374.5 Accumulated benefit obligation N/A N/A 268.3 462.3
Components of Net Periodic Benefit Cost	Components of net periodic benefit expense for our pension plans for the years ended December 31 were as follows: In millions 2018 2017 2016 Service cost $ 4.1 $ 11.7 $ 12.8 Interest cost 11.5 16.4 16.5 Expected return on plan assets (7.6 ) (11.6 ) (11.5 ) Net actuarial loss (gain) 5.2 8.4 (11.5 ) Net periodic benefit expense $ 13.2 $ 24.9 $ 6.3
Weighted-Average Assumptions used to Determine Domestic Benefit Obligations and Domestic Net Periodic Benefit Cost	The following table provides the weighted-average assumptions used to determine benefit obligations and net periodic benefit cost as they pertain to our pension and other post-retirement plans. Pension plans Other post-retirement 2018 2017 2016 2018 2017 2016 Benefit obligation assumptions (1) Discount rate 3.73 % 4.00 % 3.92 % 3.95 % 3.40 % 3.80 % Rate of compensation increase 3.77 % 3.96 % 3.95 % NA NA NA Net periodic benefit expense assumptions Discount rate 4.00 % 3.94 % 4.12 % 3.40 % 3.80 % 3.95 % Expected long-term return on plan assets 4.17 % 4.05 % 4.19 % NA NA NA Rate of compensation increase 3.96 % 3.96 % 3.93 % NA NA NA (1) The benefit obligation for the Salaried Plan as of December 31, 2018 and 2017 were determined using assumptions reflecting the termination of the plan. As a result, the weighted-average assumptions for the pension plans reflected in the table above do not include the Salaried Plan.
Assumed Health Care Cost Trend Rates	The assumed healthcare cost trend rates for other post-retirement plans as of December 31 were as follows: 2018 2017 Healthcare cost trend rate assumed for following year 6.2 % 6.6 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 4.4 % 4.4 % Year the cost trend rate reaches the ultimate trend rate 2038 2038
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, 2018 : One Percentage Point In millions Increase Decrease Increase (decrease) in annual service and interest cost $ — $ — Increase (decrease) in other post-retirement benefit obligations 0.6 (0.5 )
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 pension plans as compared to our investment policy goals as of December 31 was as follows: Actual Target 2018 2017 2018 2017 Fixed income 87 % 98 % 95 % 97 % Alternative 5 % 2 % 5 % 3 % Cash 8 % — % — % — %
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, 2018 and December 31, 2017 were as follows: December 31, 2018 In millions Level 1 Level 2 Level 3 Total Cash and cash equivalents $ — $ 12.0 $ — $ 12.0 Fixed income: Corporate and non U.S. government — 102.3 — 102.3 U.S. treasuries — 18.7 — 18.7 Other — 16.5 — 16.5 Other investments — — 9.3 9.3 Total investments at fair value $ — $ 149.5 $ 9.3 $ 158.8 Investments measured at NAV 21.9 Total $ 180.7 December 31, 2017 In millions Level 1 Level 2 Level 3 Total Fixed income: Corporate and non U.S. government $ — $ 262.8 $ — $ 262.8 U.S. treasuries — 43.2 — 43.2 Mortgage-backed securities — 3.3 — 3.3 Other — 37.0 — 37.0 Other investments — — 9.4 9.4 Total investments at fair value $ — $ 346.3 $ 9.4 $ 355.7 Investments measured at NAV 27.1 Total $ 382.8
Expected Future Service to Be Paid by Plans	The following benefit payments, which reflect expected future service or payout from termination, as appropriate, are expected to be paid by the plans for the years ended December 31 as follows: In millions Pension Plans Other post- retirement plans 2019 $ 183.0 $ 1.7 2020 7.2 1.6 2021 7.2 1.6 2022 7.3 1.5 2023 6.8 1.4 Thereafter 36.2 5.4

Share Plans (Tables)

Share Plans (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Compensation Cost	Total share-based compensation expense for 2018 , 2017 and 2016 was as follows: December 31 In millions 2018 2017 2016 Restricted stock units $ 8.9 $ 17.5 $ 17.3 Stock options 4.6 10.5 10.4 Performance share units 7.4 11.6 6.5 Total share-based compensation expense $ 20.9 $ 39.6 $ 34.2
Stock Option Activity	The following table summarizes stock option activity under all plans for the year ended December 31, 2018 : Shares and intrinsic value in millions Number of shares Weighted- average exercise price Weighted- average remaining contractual life (years) Aggregate intrinsic value Outstanding as of January 1, 2018 5.2 $ 28.80 Granted 0.5 45.42 Exercised (0.8 ) 23.52 Forfeited (0.1 ) 43.77 Spin-off adjustment (0.7 ) — Outstanding as of December 31, 2018 4.1 $ 35.77 5.2 $ 20.6 Options exercisable as of December 31, 2018 3.0 $ 33.93 4.0 $ 19.5 Options expected to vest as of December 31, 2018 1.1 $ 40.55 8.2 $ 1.2
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 2018 2017 2016 Risk-free interest rate 2.58 % 1.65 % 1.56 % Expected dividend yield 1.56 % 2.35 % 2.49 % Expected share price volatility 24.8 % 26.9 % 27.3 % Expected term (years) 6.1 6.3 5.9
Restricted Stock Activity	The following table summarizes restricted stock unit activity under all plans for the year ended December 31, 2018 : Shares in millions Number of shares Weighted average grant date fair value Outstanding as of January 1, 2018 0.6 $ 39.44 Granted 0.2 45.46 Vested (0.6 ) 43.89 Conversion of PSUs 0.5 — Spin-off adjustment (0.2 ) — Outstanding as of December 31, 2018 0.5 $ 41.74
Performance Shares Award Outstanding Activity	The following table summarizes performance share unit activity under all plans for the year ended December 31, 2018 : Shares in millions Number of shares Weighted average grant date fair value Outstanding as of January 1, 2018 0.5 $ 29.53 Granted 0.1 45.42 Conversion to RSUs (0.5 ) — Outstanding as of December 31, 2018 0.1 $ 45.42

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Financial Information by Reportable Business Segment	Financial information by reportable segment is included in the following summary: 2018 2017 2016 2018 2017 2016 In millions Net sales Segment income (loss) Aquatic Systems $ 1,026.1 $ 939.6 $ 877.8 $ 277.6 $ 254.1 $ 217.4 Filtration Solutions 1,001.0 990.6 976.3 168.5 154.5 138.4 Flow Technologies 936.7 914.2 923.5 145.6 140.6 141.6 Other 1.3 1.3 3.0 (54.9 ) (52.7 ) (56.0 ) Consolidated (1) $ 2,965.1 $ 2,845.7 $ 2,780.6 $ 536.8 $ 496.5 $ 441.4 (1) One customer in the Aquatic Systems segment, Pool Corporation, represented approximately 15% of our consolidated net sales in 2018 , 2017 and 2016 . 2018 2017 2016 2018 2017 2016 2018 2017 2016 In millions Identifiable assets (1) Capital expenditures Depreciation Aquatic Systems $ 1,304.2 $ 1,323.0 $ 1,238.0 $ 10.6 $ 9.6 $ 12.0 $ 8.1 $ 10.6 $ 9.8 Filtration Solutions 1,232.4 1,333.3 1,362.4 16.6 19.2 17.8 23.2 21.6 23.7 Flow Technologies 1,003.6 1,010.8 865.2 10.3 7.3 11.0 13.1 13.4 13.3 Other 266.3 4,966.6 8,069.2 10.7 3.0 2.5 5.3 5.2 6.2 Consolidated $ 3,806.5 $ 8,633.7 $ 11,534.8 $ 48.2 $ 39.1 $ 43.3 $ 49.7 $ 50.8 $ 53.0 (1) All cash and cash equivalents and assets held for sale are included in “Other.”
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	The following table presents a reconciliation of consolidated segment income to consolidated income from continuing operations before income taxes: In millions 2018 2017 2016 Segment income $ 536.8 $ 496.5 $ 441.4 Restructuring and other (31.8 ) (28.2 ) (7.8 ) Intangible amortization (34.9 ) (36.4 ) (35.4 ) Pension and other post-retirement mark-to-market (loss) gain (3.6 ) (8.5 ) 12.0 Trade name and other impairment (12.0 ) (15.6 ) — Loss on sale of businesses (7.3 ) (4.2 ) (3.9 ) Loss on early extinguishment of debt (17.1 ) (101.4 ) — Interest expense, net (32.6 ) (87.3 ) (140.1 ) Corporate allocations (11.0 ) (36.7 ) (39.4 ) Deal related costs and expenses (2.0 ) — — Other expense (4.7 ) (5.4 ) (5.9 ) Income from continuing operations before income taxes $ 379.8 $ 172.8 $ 220.9

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Net rental expense	Net rental expense under operating leases was as follows: Years ended December 31 In millions 2018 2017 2016 Gross rental expense $ 30.4 $ 29.7 $ 29.0 Sublease rental income (0.4 ) (0.2 ) (0.5 ) Net rental expense $ 30.0 $ 29.5 $ 28.5
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, 2018 were as follows: In millions 2019 2020 2021 2022 2023 Thereafter Total Minimum lease payments $ 23.2 $ 17.6 $ 13.3 $ 11.1 $ 9.5 $ 13.8 $ 88.5 Minimum sublease rentals (0.7 ) (0.6 ) (0.6 ) (0.6 ) (0.6 ) (0.6 ) (3.7 ) Net future minimum lease commitments $ 22.5 $ 17.0 $ 12.7 $ 10.5 $ 8.9 $ 13.2 $ 84.8
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, 2018 , 2017 and 2016 were as follows: Years ended December 31 In millions 2018 2017 2016 Beginning balance $ 38.1 $ 36.3 $ 44.6 Service and product warranty provision 50.8 60.8 55.2 Payments (54.6 ) (59.6 ) (64.2 ) Foreign currency translation (0.4 ) 0.6 0.7 Ending balance $ 33.9 $ 38.1 $ 36.3

Selected Quarterly Data (Tables

Selected Quarterly Data (Tables)	12 Months Ended
	Dec. 31, 2018
Selected Quarterly Financial Information [Abstract]
Quarterly Financial Information	The following tables present 2018 and 2017 quarterly financial information: 2018 In millions, except per-share data First Quarter Second Quarter Third Quarter Fourth Quarter Full Year Net sales $ 732.6 $ 780.6 $ 711.4 $ 740.5 $ 2,965.1 Gross profit 253.3 282.6 243.8 268.0 1,047.7 Operating income 92.7 122.6 108.4 113.0 436.7 Net income from continuing operations 58.4 77.9 (1) 91.2 94.2 321.7 Income (loss) from discontinued operations, net of tax 44.5 (36.4 ) 18.9 (1.3 ) 25.7 Net income 102.9 41.5 110.1 92.9 347.4 Earnings (loss) per ordinary share (2) Basic Continuing operations $ 0.33 $ 0.44 $ 0.52 $ 0.55 $ 1.83 Discontinued operations 0.24 (0.21 ) 0.11 (0.01 ) 0.15 Basic earnings per ordinary share $ 0.57 $ 0.23 $ 0.63 $ 0.54 $ 1.98 Diluted Continuing operations $ 0.32 $ 0.44 $ 0.52 $ 0.54 $ 1.81 Discontinued operations 0.25 (0.21 ) 0.11 (0.01 ) 0.15 Diluted earnings per ordinary share $ 0.57 $ 0.23 $ 0.63 $ 0.53 $ 1.96 (1) Includes decrease of $17.1 million related to loss on early extinguishment of debt. (2) 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. 2017 In millions, except per-share data First Quarter Second Quarter Third Quarter Fourth Quarter Full Year Net sales $ 683.3 $ 754.0 $ 687.6 $ 720.8 $ 2,845.7 Gross profit 223.7 273.6 236.5 253.7 987.5 Operating income 61.9 129.2 101.8 85.4 378.3 Net income (loss) from continuing operations 12.7 (3.4 ) (1) 49.0 55.8 (2) 114.1 Income from discontinued operations, net of tax 75.0 66.5 78.2 151.6 371.3 Gain (loss) from sale of discontinued operations, net of tax — 200.6 (1.7 ) (17.8 ) 181.1 Net income 87.7 263.7 125.5 189.6 666.5 Earnings (loss) per ordinary share (3) Basic Continuing operations $ 0.07 $ (0.02 ) $ 0.27 $ 0.32 $ 0.63 Discontinued operations 0.41 1.47 0.42 0.73 3.04 Basic earnings per ordinary share $ 0.48 $ 1.45 $ 0.69 $ 1.05 $ 3.67 Diluted Continuing operations $ 0.07 $ (0.02 ) $ 0.27 $ 0.30 $ 0.62 Discontinued operations 0.41 1.45 0.41 0.74 3.01 Diluted earnings per ordinary share $ 0.48 $ 1.43 $ 0.68 $ 1.04 $ 3.63 (1) Includes decrease of $101.4 million related to loss on early extinguishment of debt. (2) Includes decrease of $15.6 million due to trade name and other impairment and $8.5 million related to a “mark-to-market” actuarial loss on pension and other post-retirement benefit plans. (3) 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.

Supplemental Guarantor Inform_2

Supplemental Guarantor Information (Tables)	12 Months Ended
	Dec. 31, 2018
Condensed Financial Information Disclosure [Abstract]
Condensed Consolidating Statement of Operations and Comprehensive Income (Loss)	Pentair plc and Subsidiaries Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) Year Ended December 31, 2018 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Net sales $ — $ — $ — $ 2,965.1 $ — $ 2,965.1 Cost of goods sold — — — 1,917.4 — 1,917.4 Gross profit — — — 1,047.7 — 1,047.7 Selling, general and administrative 11.8 0.9 1.2 520.4 — 534.3 Research and development — — — 76.7 — 76.7 Operating (loss) income (11.8 ) (0.9 ) (1.2 ) 450.6 — 436.7 Loss (earnings) from continuing operations of investment in subsidiaries (333.5 ) (333.4 ) (376.5 ) — 1,043.4 — Other (income) expense: Loss on sale of businesses — — — 7.3 — 7.3 Loss on early extinguishment of debt — — 17.1 — — 17.1 Net interest (income) expense — (1.0 ) 24.8 8.8 — 32.6 Other income — — — (0.1 ) — (0.1 ) Income (loss) from continuing operations before income taxes 321.7 333.5 333.4 434.6 (1,043.4 ) 379.8 Provision for income taxes — — — 58.1 — 58.1 Net income (loss) from continuing operations 321.7 333.5 333.4 376.5 (1,043.4 ) 321.7 Income from discontinued operations, net of tax — — — 25.7 — 25.7 Earnings (loss) from discontinued operations of investment in subsidiaries 25.7 25.7 25.7 — (77.1 ) — Net income (loss) $ 347.4 $ 359.2 $ 359.1 $ 402.2 $ (1,120.5 ) $ 347.4 Comprehensive income (loss), net of tax Net income (loss) $ 347.4 $ 359.2 $ 359.1 $ 402.2 $ (1,120.5 ) $ 347.4 Changes in cumulative translation adjustment 10.0 10.0 10.0 10.0 (30.0 ) 10.0 Changes in market value of derivative financial instruments, net of tax 4.8 4.8 4.8 4.8 (14.4 ) 4.8 Comprehensive income (loss) $ 362.2 $ 374.0 $ 373.9 $ 417.0 $ (1,164.9 ) $ 362.2 Pentair plc and Subsidiaries Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) Year Ended December 31, 2017 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Net sales $ — $ — $ — $ 2,845.7 $ — $ 2,845.7 Cost of goods sold — — — 1,858.2 — 1,858.2 Gross profit — — — 987.5 — 987.5 Selling, general and administrative 9.0 0.6 — 526.4 — 536.0 Research and development — — — 73.2 — 73.2 Operating (loss) income (9.0 ) (0.6 ) — 387.9 — 378.3 Loss (earnings) from continuing operations of investment in subsidiaries (122.2 ) (122.2 ) (283.4 ) — 527.8 — Other (income) expense: Loss on sale of businesses — — — 4.2 — 4.2 Loss on early extinguishment of debt — — 91.0 10.4 — 101.4 Net interest (income) expense — (0.6 ) 70.7 17.2 — 87.3 Other expense — — — 12.6 — 12.6 Income (loss) from continuing operations before income taxes 113.2 122.2 121.7 343.5 (527.8 ) 172.8 Provision (benefit) for income taxes (0.9 ) — — 59.6 — 58.7 Net income (loss) from continuing operations 114.1 122.2 121.7 283.9 (527.8 ) 114.1 Income from discontinued operations, net of tax — — — 371.3 — 371.3 Gain from sale of discontinued operations, net of tax — — — 181.1 — 181.1 Earnings (loss) from discontinued operations of investment in subsidiaries 552.4 552.4 552.4 — (1,657.2 ) — Net income (loss) $ 666.5 $ 674.6 $ 674.1 $ 836.3 $ (2,185.0 ) $ 666.5 Comprehensive income (loss), net of tax Net income (loss) $ 666.5 $ 674.6 $ 674.1 $ 836.3 $ (2,185.0 ) $ 666.5 Changes in cumulative translation adjustment 497.5 497.5 497.5 497.5 (1,492.5 ) 497.5 Changes in market value of derivative financial instruments, net of tax (4.6 ) (4.6 ) (4.6 ) (4.6 ) 13.8 (4.6 ) Comprehensive income (loss) $ 1,159.4 $ 1,167.5 $ 1,167.0 $ 1,329.2 $ (3,663.7 ) $ 1,159.4 Pentair plc and Subsidiaries Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) Year Ended December 31, 2016 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Net sales $ — $ — $ — $ 2,780.6 $ — $ 2,780.6 Cost of goods sold — — — 1,821.5 — 1,821.5 Gross profit — — — 959.1 — 959.1 Selling, general and administrative 12.6 — 1.2 517.6 — 531.4 Research and development — — — 73.3 — 73.3 Operating (loss) income (12.6 ) — (1.2 ) 368.2 — 354.4 Loss (earnings) from continuing operations of investment in subsidiaries (189.4 ) (189.4 ) (301.5 ) — 680.3 — Other (income) expense: Loss on sale of businesses — — — 3.9 — 3.9 Net interest expense — — 110.9 29.2 — 140.1 Other income — — — (10.5 ) — (10.5 ) Income (loss) from continuing operations before income taxes 176.8 189.4 189.4 345.6 (680.3 ) 220.9 Provision (benefit) for income taxes (1.4 ) — — 44.1 — 42.7 Net income (loss) from continuing operations 178.2 189.4 189.4 301.5 (680.3 ) 178.2 Income from discontinued operations, net of tax — — — 343.4 — 343.4 Gain from sale of discontinued operations, net of tax — — — 0.6 — 0.6 Earnings (loss) from discontinued operations of investment in subsidiaries 344.0 344.0 344.0 — (1,032.0 ) — Net income (loss) $ 522.2 $ 533.4 $ 533.4 $ 645.5 $ (1,712.3 ) $ 522.2 Comprehensive income (loss), net of tax Net income (loss) $ 522.2 $ 533.4 $ 533.4 $ 645.5 $ (1,712.3 ) $ 522.2 Changes in cumulative translation adjustment (83.0 ) (83.0 ) (83.0 ) (83.0 ) 249.0 (83.0 ) Changes in market value of derivative financial instruments, net of tax (8.3 ) (8.3 ) (8.3 ) (8.3 ) 24.9 (8.3 ) Comprehensive income (loss) $ 430.9 $ 442.1 $ 442.1 $ 554.2 $ (1,438.4 ) $ 430.9
Condensed Consolidating Balance Sheet	Pentair plc and Subsidiaries Condensed Consolidating Balance Sheet December 31, 2018 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Assets Current assets Cash and cash equivalents $ 0.1 $ — $ 0.1 $ 74.1 $ — $ 74.3 Accounts and notes receivable, net 4.6 — — 483.6 — 488.2 Inventories — — — 387.5 — 387.5 Other current assets 3.4 — 2.2 99.2 (15.4 ) 89.4 Total current assets 8.1 — 2.3 1,044.4 (15.4 ) 1,039.4 Property, plant and equipment, net — — — 272.6 — 272.6 Other assets Investments in subsidiaries 1,903.8 2,036.1 2,675.7 — (6,615.6 ) — Goodwill — — — 2,072.7 — 2,072.7 Intangibles, net — — — 276.3 — 276.3 Other non-current assets 23.3 — 696.1 729.7 (1,303.6 ) 145.5 Total other assets 1,927.1 2,036.1 3,371.8 3,078.7 (7,919.2 ) 2,494.5 Total assets $ 1,935.2 $ 2,036.1 $ 3,374.1 $ 4,395.7 $ (7,934.6 ) $ 3,806.5 Liabilities and Equity Current liabilities Accounts payable $ 0.9 $ — $ — $ 377.7 $ — $ 378.6 Employee compensation and benefits 0.2 — — 111.5 — 111.7 Other current liabilities 47.6 1.5 4.4 290.3 (15.4 ) 328.4 Total current liabilities 48.7 1.5 4.4 779.5 (15.4 ) 818.7 Other liabilities Long-term debt 29.9 130.8 1,333.9 596.6 (1,303.6 ) 787.6 Pension and other post-retirement compensation and benefits — — — 90.0 — 90.0 Deferred tax liabilities — — — 105.9 — 105.9 Other non-current liabilities 20.5 — — 147.7 — 168.2 Total liabilities 99.1 132.3 1,338.3 1,719.7 (1,319.0 ) 1,970.4 Equity 1,836.1 1,903.8 2,035.8 2,676.0 (6,615.6 ) 1,836.1 Total liabilities and equity $ 1,935.2 $ 2,036.1 $ 3,374.1 $ 4,395.7 $ (7,934.6 ) $ 3,806.5 Pentair plc and Subsidiaries Condensed Consolidating Balance Sheet December 31, 2017 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Assets Current assets Cash and cash equivalents $ — $ — $ — $ 86.3 $ — $ 86.3 Accounts and notes receivable, net — — — 483.1 — 483.1 Inventories — — — 356.9 — 356.9 Other current assets 10.8 1.8 1.5 109.6 (9.2 ) 114.5 Current assets held for sale — — — 708.0 — 708.0 Total current assets 10.8 1.8 1.5 1,743.9 (9.2 ) 1,748.8 Property, plant and equipment, net — — — 279.8 — 279.8 Other assets Investments in subsidiaries 5,205.1 5,109.6 7,156.1 — (17,470.8 ) — Goodwill — — — 2,112.8 — 2,112.8 Intangibles, net — — — 321.8 — 321.8 Other non-current assets 2.2 94.1 614.0 1,360.0 (1,889.4 ) 180.9 Non-current assets held for sale — — — 3,989.6 — 3,989.6 Total other assets 5,207.3 5,203.7 7,770.1 7,784.2 (19,360.2 ) 6,605.1 Total assets $ 5,218.1 $ 5,205.5 $ 7,771.6 $ 9,807.9 $ (19,369.4 ) $ 8,633.7 Liabilities and Equity Current liabilities Accounts payable $ 1.4 $ — $ — $ 320.1 $ — $ 321.5 Employee compensation and benefits 0.4 — — 115.4 — 115.8 Other current liabilities 99.6 0.4 9.4 301.1 (9.2 ) 401.3 Current liabilities held for sale — — — 360.8 — 360.8 Total current liabilities 101.4 0.4 9.4 1,097.4 (9.2 ) 1,199.4 Other liabilities Long-term debt 48.4 — 2,652.8 628.9 (1,889.4 ) 1,440.7 Pension and other post-retirement compensation and benefits — — — 96.4 — 96.4 Deferred tax liabilities — — — 108.6 — 108.6 Other non-current liabilities 30.5 — — 183.3 — 213.8 Non-current liabilities held for sale — — — 537.0 — 537.0 Total liabilities 180.3 0.4 2,662.2 2,651.6 (1,898.6 ) 3,595.9 Equity 5,037.8 5,205.1 5,109.4 7,156.3 (17,470.8 ) 5,037.8 Total liabilities and equity $ 5,218.1 $ 5,205.5 $ 7,771.6 $ 9,807.9 $ (19,369.4 ) $ 8,633.7
Condensed Consolidating Statement of Cash Flows	Pentair plc and Subsidiaries Condensed Consolidating Statement of Cash Flows Year Ended December 31, 2018 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Operating activities Net cash provided by (used for) operating activities $ 266.3 $ 362.1 $ 370.6 $ 637.7 $ (1,197.6 ) $ 439.1 Investing activities Capital expenditures — — — (48.2 ) — (48.2 ) Proceeds from sale of property and equipment — — — 0.2 — 0.2 Payments due to sale of businesses and other — — — (12.8 ) — (12.8 ) Acquisitions, net of cash acquired — — — (0.9 ) — (0.9 ) Net intercompany loan activity — 94.1 181.0 1,655.7 (1,930.8 ) — Net cash provided by (used for) investing activities of continuing operations — 94.1 181.0 1,594.0 (1,930.8 ) (61.7 ) Net cash provided by (used for) investing activities of discontinued operations — — — (7.1 ) — (7.1 ) Net cash provided by (used for) investing activities — 94.1 181.0 1,586.9 (1,930.8 ) (68.8 ) Financing activities Net receipts (repayments) of commercial paper and revolving long-term debt — — 41.9 (2.2 ) — 39.7 Repayment of long-term debt — — (675.1 ) — — (675.1 ) Premium paid on early extinguishment of debt — — (16.0 ) — — (16.0 ) Transfer of cash to nVent — — — (74.2 ) — (74.2 ) Distribution of cash from nVent — — 993.6 — — 993.6 Net change in advances to subsidiaries 407.7 (456.2 ) (874.6 ) (2,205.3 ) 3,128.4 — Shares issued to employees, net of shares withheld 13.3 — — — — 13.3 Repurchases of ordinary shares (500.0 ) — — — — (500.0 ) Dividends paid (187.2 ) — — — — (187.2 ) Other — — (2.0 ) — — (2.0 ) Net cash provided by (used for) financing activities (266.2 ) (456.2 ) (532.2 ) (2,281.7 ) 3,128.4 (407.9 ) Change in cash held for sale — — — 27.0 — 27.0 Effect of exchange rate changes on cash and cash equivalents — — (19.3 ) 17.9 — (1.4 ) Change in cash and cash equivalents 0.1 — 0.1 (12.2 ) — (12.0 ) Cash and cash equivalents, beginning of year — — — 86.3 — 86.3 Cash and cash equivalents, end of year $ 0.1 $ — $ 0.1 $ 74.1 $ — $ 74.3 Pentair plc and Subsidiaries Condensed Consolidating Statement of Cash Flows Year Ended December 31, 2017 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Operating activities Net cash provided by (used for) operating activities $ 678.3 $ 676.1 $ 656.2 $ 794.6 $ (2,185.0 ) $ 620.2 Investing activities Capital expenditures — — — (39.1 ) — (39.1 ) Proceeds from sale of property and equipment — — — 3.7 — 3.7 Proceeds from sale of businesses and other — — 2,765.6 (6.2 ) — 2,759.4 Acquisitions, net of cash acquired — — — (45.9 ) — (45.9 ) Net intercompany loan activity — (58.9 ) 103.7 172.5 (217.3 ) — Net cash provided by (used for) investing activities of continuing operations — (58.9 ) 2,869.3 85.0 (217.3 ) 2,678.1 Net cash provided by (used for) investing activities from discontinued operations — — — (47.7 ) — (47.7 ) Net cash provided by (used for) investing activities — (58.9 ) 2,869.3 37.3 (217.3 ) 2,630.4 Financing activities Net receipts (repayments) of commercial paper and revolving long-term debt — — (914.7 ) 1.6 — (913.1 ) Repayment of long-term debt — — (1,917.8 ) (91.5 ) — (2,009.3 ) Premium paid on early extinguishment of debt — — (86.0 ) (8.9 ) — (94.9 ) Net change in advances to subsidiaries (263.8 ) (617.2 ) (680.8 ) (840.5 ) 2,402.3 — Shares issued to employees, net of shares withheld 37.2 — — — — 37.2 Repurchases of ordinary shares (200.0 ) — — — — (200.0 ) Dividends paid (251.7 ) — — — — (251.7 ) Other — — — (0.8 ) — (0.8 ) Net cash provided by (used for) financing activities (678.3 ) (617.2 ) (3,599.3 ) (940.1 ) 2,402.3 (3,432.6 ) Change in cash held for sale — — — (5.4 ) — (5.4 ) Effect of exchange rate changes on cash and cash equivalents — — 73.8 (17.0 ) — 56.8 Change in cash and cash equivalents — — — (130.6 ) — (130.6 ) Cash and cash equivalents, beginning of year — — — 216.9 — 216.9 Cash and cash equivalents, end of year $ — $ — $ — $ 86.3 $ — $ 86.3 Pentair plc and Subsidiaries Condensed Consolidating Statement of Cash Flows Year Ended December 31, 2016 In millions Parent Company Guarantor Subsidiary Guarantor Subsidiary Issuer Non-guarantor Subsidiaries Eliminations Consolidated Total Operating activities Net cash provided by (used for) operating activities $ 595.7 $ 541.7 $ 532.9 $ 903.4 $ (1,712.3 ) $ 861.4 Investing activities Capital expenditures — — — (43.3 ) — (43.3 ) Proceeds from sale of property and equipment — — — 18.8 — 18.8 Proceeds from sale of businesses and other — — — (5.1 ) — (5.1 ) Acquisitions, net of cash acquired — — — (25.0 ) — (25.0 ) Net intercompany loan activity — — 667.3 (191.0 ) (476.3 ) — Net cash provided by (used for) investing activities of continuing operations — — 667.3 (245.6 ) (476.3 ) (54.6 ) Net cash provided by (used for) investing activities of discontinued operations — — — (67.2 ) — (67.2 ) Net cash provided by (used for) investing activities — — 667.3 (312.8 ) (476.3 ) (121.8 ) Financing activities Net receipts (repayments) of commercial paper and revolving long-term debt — — (385.8 ) 0.5 — (385.3 ) Repayment of long-term debt — — — (0.7 ) — (0.7 ) Net change in advances to subsidiaries (372.8 ) (541.7 ) (842.3 ) (431.8 ) 2,188.6 — Shares issued to employees, net of shares withheld 20.7 — — — — 20.7 Dividends paid (243.6 ) — — — — (243.6 ) Other — — — 8.8 — 8.8 Net cash provided by (used for) financing activities (595.7 ) (541.7 ) (1,228.1 ) (423.2 ) 2,188.6 (600.1 ) Change in cash held for sale — — — 1.1 — 1.1 Effect of exchange rate changes on cash and cash equivalents — — 27.8 (55.1 ) — (27.3 ) Change in cash and cash equivalents — — (0.1 ) 113.4 — 113.3 Cash and cash equivalents, beginning of year — — 0.1 103.5 — 103.6 Cash and cash equivalents, end of year $ — $ — $ — $ 216.9 $ — $ 216.9

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Basis of Presentation (Details)	Dec. 31, 2018
Minimum
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	20.00%
Maximum
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	50.00%

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Revenue, Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues, percent	92.50%	92.40%	94.00%
Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues, percent	7.50%	7.60%	6.00%

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies - Performance Obligations (Detail) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 $ in Millions	Dec. 31, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 57.2
Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation period	12 months
Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation period	18 months

Basis of Presentation and Sum_7

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Contract Assets and Liabilities (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Contract assets	$ 36,500,000	$ 51,500,000
Contract liabilities	32,800,000	29,200,000
Net contract assets	3,700,000	$ 22,300,000
$ Change
Contract assets	(15,000,000)
Contract liabilities	3,600,000
Net contract assets	$ (18,600,000)
% Change
Contract assets	(29.10%)
Contract liabilities	12.30%
Net contract assets	(83.40%)
Percent of contract liabilities		70.00%
Impairment losses on contract assets	$ 0

Basis of Presentation and Sum_8

Basis of Presentation and Summary of Significant Accounting Policies - Net Sales Information (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Net sales	[1]	$ 2,965.1	$ 2,845.7	$ 2,780.6
Residential
Disaggregation of Revenue [Line Items]
Net sales		1,665.9	1,579	1,498.7
Commercial
Disaggregation of Revenue [Line Items]
Net sales		630.7	604.4	586.5
Industrial
Disaggregation of Revenue [Line Items]
Net sales		668.5	662.3	695.4
U.S.
Disaggregation of Revenue [Line Items]
Net sales		1,858.1	1,752.7	1,690
Western Europe
Disaggregation of Revenue [Line Items]
Net sales		402.7	381.9	377.7
Developing
Disaggregation of Revenue [Line Items]
Net sales		476.5	478.2	492
Other Developed
Disaggregation of Revenue [Line Items]
Net sales		$ 227.8	$ 232.9	$ 220.9
[1]	(1) One customer in the Aquatic Systems segment, Pool Corporation, represented approximately 15% of our consolidated net sales in 2018, 2017 and 2016.

Basis of Presentation and Sum_9

Basis of Presentation and Summary of Significant Accounting Policies - Research and Development (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Research and development	$ 76.7	$ 73.2	$ 73.3

Basis of Presentation and Su_10

Basis of Presentation and Summary of Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2018
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

Basis of Presentation and Su_11

Basis of Presentation and Summary of Significant Accounting Policies - Property, Plant and Equipment by Geographic Location (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 272,600,000	$ 279,800,000
Impairment of long-lived assets	0	0	$ 0
U.S.
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	156,900,000	151,900,000
Western Europe
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	76,600,000	82,800,000
Developing
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	28,800,000	33,000,000
Other Developed
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 10,300,000	$ 12,100,000

Basis of Presentation and Su_12

Basis of Presentation and Summary of Significant Accounting Policies - Goodwill and identifiable intangible assets (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill planning period	6 years
Growth rate period	6 years
Impairment charges, related to trade names	$ 0	$ 8,800,000	$ 0	$ 0

Basis of Presentation and Su_13

Basis of Presentation and Summary of Significant Accounting Policies - Insurance Subsidiary (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for policy claims	$ 60.9	$ 61.5
Other Current Liabilities
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for policy claims	13.2	13.2
Other Noncurrent Liabilities
Liability for Claims and Claims Adjustment Expense [Line Items]
Reserve for policy claims	$ 47.7	$ 48.3

Basis of Presentation and Su_14

Basis of Presentation and Summary of Significant Accounting Policies - New Accounting Standards (Detail) - USD ($) $ in Millions	Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets		$ 3,806.5	$ 8,633.7	$ 11,534.8
Liabilities		1,970.4	3,595.9
Net periodic benefit cost		$ 13.2	24.9	6.3
Reclassification from AOCI to retained earnings	$ 215.8
Reduction in prepaid long-term asset	254.3
Deferred tax asset, income tax expense	38.5
nVent
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification from AOCI to retained earnings	$ 174.6
Effect of Change | Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic benefit cost			$ 13.9	$ (6.2)
Subsequent Event | Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Assets					$ 75
Liabilities					$ 75

Basis of Presentation and Su_15

Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Impact of ASUs on the Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Accounts and notes receivable, net	$ 488.2	$ 485.8	$ 483.1
Inventories	387.5	355.3	356.9
Other current assets	89.4	116.1	114.5
Current assets held for sale	0	711.8	708
Other non-current assets	145.5	136	180.9
Non-current assets held for sale	0	3,788	3,989.6
Liabilities
Other current liabilities	328.4	404	401.3
Deferred tax liabilities	105.9	105	108.6
Non-current liabilities held for sale	0	510.4	537
Equity
Retained earnings	$ 169.2	2,267.7	2,481.7
Accounting Standards Update 2016-16
Assets
Accounts and notes receivable, net		0
Inventories		0
Other current assets		0
Current assets held for sale		0
Other non-current assets		(44.9)
Non-current assets held for sale		(201.6)
Liabilities
Other current liabilities		0
Deferred tax liabilities		(3.7)
Non-current liabilities held for sale		(27)
Equity
Retained earnings		(215.8)
Balances without adoption of ASC 606
Assets
Accounts and notes receivable, net			483.1
Inventories			356.9
Other current assets			114.5
Other non-current assets			180.9
Liabilities
Other current liabilities			401.3
Deferred tax liabilities			108.6
Equity
Retained earnings			$ 2,481.7
Effect of Change | Accounting Standards Update 2014-09
Assets
Accounts and notes receivable, net		2.7
Inventories		(1.6)
Other current assets		1.6
Current assets held for sale		3.8
Other non-current assets		0
Non-current assets held for sale		0
Liabilities
Other current liabilities		2.7
Deferred tax liabilities		0.1
Non-current liabilities held for sale		0.4
Equity
Retained earnings		$ 1.8

Acquisitions and Discontinued_3

Acquisitions and Discontinued Operations - Acquisitions (Details) - USD ($) $ in Millions	Feb. 13, 2019	Feb. 12, 2019	Nov. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Acquisitions, net of cash acquired			$ 25	$ 0.9	$ 45.9	$ 25
Finite-lived intangible assets acquired					$ 19.1
Useful life					11 years
Aquion | Subsequent Event
Business Acquisition [Line Items]
Payments to acquire businesses	$ 160
Pelican | Subsequent Event
Business Acquisition [Line Items]
Payments to acquire businesses		$ 120

Acquisitions and Discontinued_4

Acquisitions and Discontinued Operations - Discontinued Operations (Details) - USD ($)	1 Months Ended	3 Months Ended				12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Proceeds from divestiture of businesses	$ 993,600,000					$ 993,600,000	$ 0	$ 0
Gain from sale / impairment of discontinued operations, net of tax		$ (17,800,000)	$ (1,700,000)	$ 200,600,000	$ 0	0	181,100,000	600,000
Discontinued Operations, Disposed of by Sale
Business Acquisition [Line Items]
Proceeds from divestiture of businesses							3,150,000,000
Discontinued Operations
Business Acquisition [Line Items]
Separation costs						$ 84,200,000	39,300,000	$ 0
Business exit costs							$ 56,400,000

Acquisitions and Discontinued_5

Acquisitions and Discontinued Operations - Components of Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Business Combination And Disposal Groups, Including Discontinued Operations, Disclosure [Abstract]
Cash and cash equivalents	$ 27					$ 27
Net sales					$ 693.9	2,548.2	$ 3,755.4
Cost of goods sold					424	1,596.2	2,457.1
Gross profit					269.9	952	1,298.3
Selling, general and administrative					237.8	589.2	803.2
Research and development					14.6	48.3	59
Operating income					17.5	314.5	436.1
Income from discontinued operations before income taxes					31.8	317.1	418.5
Income tax provision (benefit)					6.1	(54.2)	75.1
Income from discontinued operations, net of tax					25.7	371.3	343.4
Gain from sale / impairment of discontinued operations before income taxes					0	(183.5)	(0.6)
Provision for income taxes					0	2.4	0
Gain from sale / impairment of discontinued operations, net of tax	17.8	$ 1.7	$ (200.6)	$ 0	0	(181.1)	$ (0.6)
Accounts receivable, net	348.5					348.5
Inventories	224.1					224.1
Other current assets	108.4					108.4
Current assets held for sale	708				0	708		$ 711.8
Property, plant and equipment, net	265.8					265.8
Goodwill	2,238.2					2,238.2
Intangibles, net	1,236.6					1,236.6
Other non-current assets	249					249
Non-current assets held for sale	3,989.6				0	3,989.6		3,788
Accounts payable	174.1					174.1
Employee compensation and benefits	70.8					70.8
Other current liabilities	115.9					115.9
Current liabilities held for sale	360.8				0	360.8
Pension and other post-retirement compensation and benefits	189.2					189.2
Deferred tax liabilities	286.2					286.2
Other non-current liabilities	61.6					61.6
Non-current liabilities held for sale	$ 537				$ 0	$ 537		$ 510.4

Earnings (Loss) Per Share - Add

Earnings (Loss) Per Share - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																12 Months Ended
	Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Computation Of Earnings Per Share Line Items
Net income	$ 92.9		$ 110.1		$ 41.5		$ 102.9		$ 189.6		$ 125.5		$ 263.7		$ 87.7		$ 347.4		$ 666.5		$ 522.2
Net income from continuing operations																	$ 321.7		$ 114.1		$ 178.2
Weighted average common shares outstanding
Basic (shares)																	175.8		181.7		181.3
Dilutive impact of stock options and restricted stock awards (shares)																	1.5		2		1.8
Diluted (shares)																	177.3		183.7		183.1
Earnings per ordinary share
Continuing operations (USD per share)	$ 0.55		$ 0.52		$ 0.44		$ 0.33		$ 0.32		$ 0.27		$ (0.02)		$ 0.07		$ 1.83		$ 0.63		$ 0.98
Discontinued operations (USD per share)	(0.01)		0.11		(0.21)		0.24		0.73		0.42		1.47		0.41		0.15		3.04		1.90
Basic earnings (loss) per common share (USD per share)	0.54	[1]	0.63	[1]	0.23	[1]	0.57	[1]	1.05	[2]	0.69	[2]	1.45	[2]	0.48	[2]	1.98	[1]	3.67	[2]	2.88
Continuing operations (USD per share)	0.54		0.52		0.44		0.32		0.30		0.27		(0.02)		0.07		1.81		0.62		0.97
Discontinued operations (USD per share)	(0.01)		0.11		(0.21)		0.25		0.74		0.41		1.45		0.41		0.15		3.01		1.88
Diluted earnings (loss) per common share (USD per share)	$ 0.53	[1]	$ 0.63	[1]	$ 0.23	[1]	$ 0.57	[1]	$ 1.04	[2]	$ 0.68	[2]	$ 1.43	[2]	$ 0.48	[2]	$ 1.96	[1]	$ 3.63	[2]	$ 2.85
Anti-dilutive stock options excluded from the calculation of diluted earnings per share																	1.2		1.8		1.2
Retained earnings
Computation Of Earnings Per Share Line Items
Net income																	$ 347.4		$ 666.5		$ 522.2
[1]	(2) 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.
[2]	(3) 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 Info

Restructuring - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)Person	Dec. 31, 2017USD ($)Person	Dec. 31, 2016USD ($)Person
Restructuring Cost and Reserve [Line Items]
Number of employees | Person	300	250	300
Restructuring costs	$ 40.6	$ 28.2	$ 12.2
Aquatic Systems
Restructuring Cost and Reserve [Line Items]
Restructuring costs	15.3	3.6	1.8
Filtration Solutions
Restructuring Cost and Reserve [Line Items]
Restructuring costs	14.6	13	7.4
Flow Technologies
Restructuring Cost and Reserve [Line Items]
Restructuring costs	9.3	7	1.3
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 1.4	$ 4.6	$ 1.7

Restructuring - Costs Included

Restructuring - Costs Included in Selling, General & Administrative expenses on Consolidated Statements of Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 40.6	$ 28.2	$ 12.2
Severance and related costs
Restructuring Cost and Reserve [Line Items]
Restructuring costs	13.2	27.3	12.2
Other
Restructuring Cost and Reserve [Line Items]
Restructuring costs	$ 27.4	$ 0.9	$ 0

Restructuring - Accrual Activit

Restructuring - Accrual Activity recorded on Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Beginning balance	$ 34.5	$ 15.1
Costs incurred	13.2	27.3
Cash payments and other	(20.6)	(7.9)
Ending balance	$ 27.1	$ 34.5

Restructuring - Restructuring C

Restructuring - Restructuring Costs by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 40.6	$ 28.2	$ 12.2
Other
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 1.4	$ 4.6	$ 1.7

Goodwill and Other Identifiab_3

Goodwill and Other Identifiable Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Amortization and Impairment
Accumulated goodwill impairment losses			$ 200,500,000
Amortization	$ 34,900,000	$ 36,400,000	35,400,000
Impairment charges, related to trade names	$ 0	$ 8,800,000	$ 0	$ 0

Goodwill and Other Identifiab_4

Goodwill and Other Identifiable Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Beginning Balance	$ 2,112.8	$ 1,994.6
Acquisitions/ divestitures		27.3
Foreign currency translation/other	(40.1)	90.9
Ending Balance	2,072.7	2,112.8
Aquatic Systems
Goodwill [Roll Forward]
Beginning Balance	973.1	918.7
Acquisitions/ divestitures		0
Foreign currency translation/other	(7.2)	54.4
Ending Balance	965.9	973.1
Filtration Solutions
Goodwill [Roll Forward]
Beginning Balance	667.6	630.2
Acquisitions/ divestitures		27.3
Foreign currency translation/other	(24.1)	10.1
Ending Balance	643.5	667.6
Flow Technologies
Goodwill [Roll Forward]
Beginning Balance	472.1	445.7
Acquisitions/ divestitures		0
Foreign currency translation/other	(8.8)	26.4
Ending Balance	$ 463.3	$ 472.1

Goodwill and Other Identifiab_5

Goodwill and Other Identifiable Intangible Assets - Identifiable Intangible Assets (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Acquired Intangible Assets by Major Class [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)	$ 0	$ 8,800,000	$ 0	$ 0
Finite-life intangibles, cost	433,700,000	479,400,000
Accumulated amortization	(316,700,000)	(320,600,000)
Finite-life intangibles, net	117,000,000	158,800,000
Indefinite-life intangibles	159,300,000	163,000,000
Total intangibles, cost	593,000,000	642,400,000
Total intangibles, net	276,300,000	321,800,000
Customer relationships
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	347,100,000	360,900,000
Accumulated amortization	(247,900,000)	(229,900,000)
Finite-life intangibles, net	99,200,000	131,000,000
Trade names
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	400,000	1,500,000
Accumulated amortization	(400,000)	(1,400,000)
Finite-life intangibles, net	0	100,000
Patented Technology [Member]
Acquired Intangible Assets by Major Class [Line Items]
Finite-life intangibles, cost	86,200,000	117,000,000
Accumulated amortization	(68,400,000)	(89,300,000)
Finite-life intangibles, net	$ 17,800,000	$ 27,700,000

Goodwill and Other Identifiab_6

Goodwill and Other Identifiable Intangible Assets - Estimated Future Amortization Expense for Identifiable Intangible Assets (Detail) $ in Millions	Dec. 31, 2018USD ($)
Expected Amortization Expense
Estimated amortization expense 2019	$ 27.4
Estimated amortization expense 2020	22.4
Estimated amortization expense 2021	17.3
Estimated amortization expense 2022	10.1
Estimated amortization expense 2023	$ 7.8

Supplemental Balance Sheet In_3

Supplemental Balance Sheet Information (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016
Inventories
Raw materials and supplies	$ 191.3		$ 190.8
Work-in-process	64		57.9
Finished goods	132.2		108.2
Total inventories	387.5	$ 355.3	356.9
Other current assets
Cost in excess of billings	36.5		51.5
Prepaid expenses	36.7		51.4
Deferred income taxes	8.5		7.8
Other Current Assets	7.7		3.8
Total other current assets	89.4	116.1	114.5
Property, plant and equipment, net
Land and land improvements	33.5		33.5
Buildings and leasehold improvements	178.9		184.3
Machinery and equipment	593.8		609.6
Construction in progress	35.7		23.7
Total property, plant and equipment	841.9		851.1
Accumulated depreciation and amortization	569.3		571.3
Total property, plant and equipment, net	272.6		279.8
prepaid taxes long term	26.2		29
Other non-current assets
Prepaid Taxes, Noncurrent	0		52.8
Deferred Compensation Plan Assets	20.9		23.2
Other non-current assets	98.4		75.9
Total other non-current assets	145.5	136	180.9
Other current liabilities
Dividends payable	30.8		63.1
Accrued warranty	33.9		38.1
Accrued Exchange Fee Rebate	55.7		49.8
Billings in excess of cost	21.3		20.1
Taxes Payable	10.4		39.7
Restructuring Reserve	27.1		34.5	$ 15.1
Other current liabilities	149.2		156
Total other current liabilities	328.4	$ 404	401.3
Other non-current liabilities
Taxes payable	46.8		61.3
Self Insurance Reserve, Noncurrent	47.7		48.3
Deferred Compensation Liability, Current	20.9		23.2
Foreign Currency Contracts, Liability, Fair Value Disclosure	30.6		47.2
Other non-current liabilities	22.2		33.8
Total other non-current liabilities	$ 168.2		$ 213.8

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Components of AOCI (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative translation adjustments	$ (211.4)	$ (221.4)
Market value of derivative financial instruments, net of tax	(17.2)	(22)
Accumulated other comprehensive income (loss)	$ (228.6)	$ (243.4)

Debt - Debt Outstanding and Ave

Debt - Debt Outstanding and Average Interest Rates (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt, gross	$ 792.7
Unamortized issuance costs and discounts	(5.1)	$ (6.8)
Total debt	$ 787.6	1,440.7
Commercial Paper
Debt Instrument [Line Items]
Average interest rate at end of period	3.248%
Debt, gross	$ 76	34
Line of Credit | Revolving credit facilities
Debt Instrument [Line Items]
Average interest rate at end of period	3.703%
Debt, gross	$ 26.2	28.4
Senior Notes | Senior notes 2.900% due 2018
Debt Instrument [Line Items]
Average interest rate at end of period	2.90%
Debt, gross	$ 0	255.3
Total debt		255.3
Senior Notes | Senior Notes 2.650% due 2019
Debt Instrument [Line Items]
Average interest rate at end of period	2.65%
Debt, gross	$ 250	250
Senior Notes | Senior Notes 2.450% due 2019
Debt Instrument [Line Items]
Average interest rate at end of period	2.45%
Debt, gross	$ 155.1	594.4
Senior Notes | Senior Notes 3.625% due 2020
Debt Instrument [Line Items]
Average interest rate at end of period	3.625%
Debt, gross	$ 74	74
Senior Notes | Senior Notes, 5.000% Due 2021
Debt Instrument [Line Items]
Average interest rate at end of period	5.00%
Debt, gross	$ 103.8	103.8
Senior Notes | Senior Notes 3.150% due 2022
Debt Instrument [Line Items]
Average interest rate at end of period	3.15%
Debt, gross	$ 88.3	88.3
Senior Notes | Senior Notes 4.650%
Debt Instrument [Line Items]
Average interest rate at end of period	4.65%
Debt, gross	$ 19.3	$ 19.3

Debt - Debt Outstanding Amounts

Debt - Debt Outstanding Amounts Maturing (Detail) $ in Millions	Dec. 31, 2018USD ($)
Debt Disclosure [Abstract]
2,019	$ 405.1
2,020	74
2,021	103.8
2,022	88.3
2,023	102.1
Thereafter	19.4
Total debt	$ 792.7

Debt - Additional Information (

Debt - Additional Information (Details) € in Millions	Apr. 25, 2018USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2018EUR (€)	May 31, 2017USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2018
Debt Instrument [Line Items]
Commercial paper					$ 76,000,000	$ 34,000,000
Proceeds from divestiture of businesses		$ 993,600,000			993,600,000	0	$ 0
Long-term debt					787,600,000	1,440,700,000
Loss on early extinguishment of debt					17,100,000	101,400,000	$ 0
Other Credit Facilities
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity					21,100,000
Line of credit facility, amount outstanding					0
Line of Credit | Revolving credit facilities
Debt Instrument [Line Items]
Debt term	5 years
Credit facility maximum borrowing capacity	$ 800,000,000
Line of credit increase limit	$ 300,000,000
Remaining borrowing capacity					697,800,000
Line of Credit | Revolving credit facilities | Minimum
Debt Instrument [Line Items]
Covenant, unrestricted cash					$ 5,000,000
Leverage ratio covenant					3.75
EBITDA ratio covenant					1
Line of Credit | Revolving credit facilities | Maximum
Debt Instrument [Line Items]
Covenant, unrestricted cash					$ 250,000,000
Leverage ratio covenant					1
EBITDA ratio covenant					3
Senior Notes
Debt Instrument [Line Items]
Repayments of debt				$ 1,659,300,000
Loss on early extinguishment of debt				$ (6,500,000)
Senior Notes | Senior notes 2.900% due 2018
Debt Instrument [Line Items]
Long-term debt						$ 255,300,000
Debt, interest rate								2.90%
Senior Notes | Senior Notes 2.450% due 2019
Debt Instrument [Line Items]
Debt, interest rate								2.45%
Cash tender offer | €			€ 363.4
Loss on extinguishment of debt, before write off of debt issuance cost		16,000,000
Write off of deferred debt issuance cost		$ 1,100,000
Senior Notes | Senior Notes Maturing In 2019
Debt Instrument [Line Items]
Long-term debt					$ 405,100,000

Derivatives and Financial Ins_3

Derivatives and Financial Instruments - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2018EUR (€)
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Gain (Loss) on Derivative Used in Net Investment Hedge, after Tax	$ 0.8	$ 29.6
Cross Currency Interest Rate Contract [Member]
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative Liability, Notional Amount	$ 331.4
Derivative, Notional Amount		$ 481.4
Senior Notes 2.450% due 2019 | Senior Notes
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Derivative, Amount of Hedged Item | €			€ 136,600,000

Derivatives and Financial Ins_4

Derivatives and Financial Instruments - Recorded Amounts and Estimated Fair Values of Long-term Debt and Derivative Financial Instruments (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Total debt		$ 787.6	$ 1,440.7
Carrying (Reported) Amount, Fair Value Disclosure
Derivative [Line Items]
Variable rate debt		102.2	62.4
Fixed rate debt		690.5	1,385.1
Total debt		792.7	1,447.5
Estimate of Fair Value, Fair Value Disclosure
Derivative [Line Items]
Variable rate debt		102.2	62.4
Fixed rate debt		691.8	1,424
Total debt		$ 794	$ 1,486.4
Senior Notes 2.450% due 2019 | Senior Notes
Derivative [Line Items]
Tender Offer	$ 363.4

Derivatives and Financial Ins_5

Derivatives and Financial Instruments - Assets and Liabilities Measured at Fair Value (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract liabilities	$ (30,600,000)	$ (47,200,000)
Impairment of Intangible Assets (Excluding Goodwill)	0	8,800,000	$ 0	$ 0
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets		600,000
Foreign currency contract liabilities	(30,600,000)	(47,200,000)
Deferred compensation plan assets	20,900,000	23,200,000
Total recurring fair value measurements	(9,700,000)	(23,400,000)
Fair Value, Inputs, Level 1 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets		0
Foreign currency contract liabilities	0	0
Deferred compensation plan assets	17,600,000	18,700,000
Total recurring fair value measurements	17,600,000	18,700,000
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		600,000
Foreign currency contract liabilities	(30,600,000)	(47,200,000)
Deferred compensation plan assets	0	0
Total recurring fair value measurements	(30,600,000)	(46,600,000)
Fair Value, Inputs, Level 3 | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets		0
Foreign currency contract liabilities	0	0
Deferred compensation plan assets	0	0
Total recurring fair value measurements	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contract assets		0
Foreign currency contract liabilities	0	0
Deferred compensation plan assets	3,300,000	4,500,000
Total recurring fair value measurements	$ 3,300,000	$ 4,500,000

Derivatives and Financial Ins_6

Derivatives and Financial Instruments - Assets and Liabilities Measured at Fair Value Additional Information (Detail) $ in Millions	3 Months Ended
	Dec. 31, 2017USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of intangible assets after impairment	$ 10.8

Income Taxes - Income (Loss) Be

Income Taxes - Income (Loss) Before Income Taxes and Noncontrolling Interest (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Federal	[1]	$ (24.6)	$ (34.1)	$ (25.6)
International	[2]	404.4	206.9	246.5
Income from continuing operations before income taxes		$ 379.8	$ 172.8	$ 220.9
Federal statutory income tax rate		19.00%	19.30%	20.00%
[1]	(1) “Federal” reflects United Kingdom (“U.K.”) income from continuing operations before income taxes.
[2]	(2) “International” reflects non-U.K. income from continuing operations before income taxes.

Income Taxes - Provision for In

Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Currently payable
Federal	[1]	$ (0.1)	$ 0	$ 0
International	[2]	62.3	76.7	41.5
Total current taxes		62.2	76.7	41.5
Deferred
Federal	[1]	0	0	0
International	[2]	(4.1)	(18)	1.2
Total deferred taxes		(4.1)	(18)	1.2
Total provision (benefit) for income taxes		$ 58.1	$ 58.7	$ 42.7
[1]	(1) “Federal” represents U.K. taxes.
[2]	(2) “International” represents non-U.K. taxes.

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate (Detail)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal statutory income tax rate		19.00%	19.30%	20.00%
Tax effect of international operations	[1]	(12.00%)	(20.80%)	(26.50%)
Change in valuation allowances		7.90%	27.60%	22.10%
Withholding taxes		0.30%	0.40%	1.80%
Interest limitations		1.80%	1.70%	1.50%
Excess tax benefits on stock-based compensation		(1.70%)	(4.50%)	0.00%
Tax effect of U.S. tax reform		(0.90%)	1.30%	0.00%
Tax effect of early extinguishment of debt		0.90%	9.00%	0.00%
Other		0.00%	0.00%	0.40%
Effective tax rate		15.30%	34.00%	19.30%
[1]	(1) The tax effect of international operations consists of non-U.K. jurisdictions.

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Federal Statutory Income Tax Rate to Effective Tax Rate Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Federal statutory income tax rate	19.00%	19.30%	20.00%

Income Taxes - Reconciliations

Income Taxes - Reconciliations of Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 13.8	$ 46.3
Gross increases for tax positions in prior periods	44	4.7	$ 26.9
Gross decreases for tax positions in prior periods	(4.4)	(3.4)	(2.2)
Gross increases based on tax positions related to the current year	0.9	0.7	0.8
Gross decreases related to settlements with taxing authorities	(1.8)	(33.6)	(3.4)
Reductions due to statute expiration	(1.1)	(0.9)	(0.8)
Ending balance	$ 51.4	$ 13.8	$ 46.3

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Income Taxes [Line Items]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			19.00%	19.30%	20.00%
Gross unrecognized tax benefits		$ 13.8	$ 51.4	$ 13.8	$ 46.3	$ 25
Amount of tax benefits that, if recognized, would impact the effective tax rate			50.3
Payment of penalties		0.3	0.5	0.3
Payment of interest expense		2.9	3.6	$ 2.9
Foreign credit carryforwards			29.6
Tax loss carryforwards			2,911.9
Deferred tax assets, valuation allowance			692.3
Deferred Tax Assets, Operating Loss Carryforwards, Foreign			2,818.2
Deferred Tax Assets, Operating Loss Carryforwards, Foreign (jurisdictions with unlimited tax loss carryforward periods)			2,345.7
Deferred Tax Assets, Operating Loss Carryforwards, Domestic			93.7
State tax losses available for carry forward			56.1
Tax Cuts and Jobs Act of 2017, Corporate Federal Tax Rate				21.00%
Provisional income tax expense		$ 2.2
Measurement period adjustment	$ 3.6
Income tax decrease			1.4
Decrease of income tax expense related to remeasurement of deferred tax assets and liabilities			28
Transition tax expense			26.6
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			$ 8.1

Income Taxes - Deferred Taxes (

Income Taxes - Deferred Taxes (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Other non-current assets	$ 26.2		$ 29
Deferred tax liabilities	105.9	$ 105	108.6
Total deferred tax liabilities	$ 79.7		$ 79.6

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets
Accrued liabilities and reserves	$ 42.9	$ 43.9
Pension and other post-retirement compensation and benefits	25.2	35.7
Employee compensation and benefits	21.8	39.2
Tax loss and credit carryforwards	724.7	670.5
Other assets	4.4	0
Total deferred tax assets	819	789.3
Valuation allowance	711.9	656.2
Deferred tax assets, net of valuation allowance	107.1	133.1
Deferred tax liabilities
Property, plant and equipment	7.1	3.7
Goodwill and other intangibles	179.7	190.6
Other liabilities	0	18.4
Deferred Tax Liabilities, Gross	186.8	212.7
Total deferred tax liabilities	$ 79.7	$ 79.6

Benefit Plans - Pension and Oth

Benefit Plans - Pension and Other Post-retirement Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets	$ 180.7	$ 382.8
Pension plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation	277.9	473.8	$ 423.8
Plan assets	180.7	$ 382.8	$ 352.3
Pension plans | Salaried Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Lump-sum payments	$ 171.9
Period of annuity purchase	120 days
Benefit obligation	$ 175.9
Plan assets	$ 153.7

Benefit Plans - Obligations and

Benefit Plans - Obligations and Funded Status (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in benefit obligations
Service cost	$ 4.1	$ 11.7	$ 12.8
Interest cost	11.5	16.4	16.5
Change in plan assets
Fair value of plan assets beginning of year	382.8
Fair value of plan assets end of year	180.7	382.8
Pension plans
Change in benefit obligations
Benefit obligation beginning of year	473.8	423.8
Service cost	4.1	11.7
Interest cost	11.5	16.4
Actuarial loss	(23.6)	41.4
Translation (gain) loss	(0.2)	0.6
Benefits paid	187.7	20.1
Benefit obligation end of year	277.9	473.8	423.8
Change in plan assets
Fair value of plan assets beginning of year	382.8	352.3
Actual return on plan assets	(21.4)	42.4
Company contributions	7.1	6.3
Translation gain (loss)	(0.1)	1.9
Benefits paid	187.7	20.1
Fair value of plan assets end of year	180.7	382.8	352.3
Funded status
Plan assets less than benefit obligation	(97.2)	(91)
Other post-retirement plans
Change in benefit obligations
Benefit obligation beginning of year	17.5	18.9
Service cost	0	0
Interest cost	0.6	0.7
Actuarial loss	(1.4)	(0.1)
Translation (gain) loss	0	0
Benefits paid	1.8	2
Benefit obligation end of year	14.9	17.5	18.9
Change in plan assets
Fair value of plan assets beginning of year	0	0
Actual return on plan assets	0	0
Company contributions	1.8	2
Translation gain (loss)	0	0
Benefits paid	1.8	2
Fair value of plan assets end of year	0	0	$ 0
Funded status
Plan assets less than benefit obligation	$ (14.9)	$ (17.5)

Benefit Plans - Amounts Recorde

Benefit Plans - Amounts Recorded in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Non-current liabilities	$ (90)	$ (96.4)
Accumulated benefit obligation	275	470.4
Pension plans
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(28.3)	(6.1)
Non-current liabilities	(68.9)	(84.9)
Benefit obligations in excess of the fair value of plan assets	(97.2)	(91)
Other post-retirement plans
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(1.7)	(1.9)
Non-current liabilities	(13.2)	(15.6)
Benefit obligations in excess of the fair value of plan assets	$ (14.9)	$ (17.5)

Benefit Plans - Pension Plans w

Benefit Plans - Pension Plans with Accumulated Benefit Obligation or Projected Benefit Obligation in Excess of Plan Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Pension plans with a projected benefit obligation in excess of plan assets:
Projected benefit obligation	$ 277.9	$ 473.8
Fair value of plan assets	180.7	382.8
Pension plans with an accumulated benefit obligation in excess of plan assets:
Projected benefit obligation	270.6	464.9
Fair value of plan assets	173.7	374.5
Accumulated benefit obligation	$ 268.3	$ 462.3

Benefit Plans - Components of N

Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Service cost	$ 4.1	$ 11.7	$ 12.8
Interest cost	11.5	16.4	16.5
Expected return on plan assets	(7.6)	(11.6)	(11.5)
Net actuarial loss (gain)	5.2	8.4	(11.5)
Net periodic benefit expense	$ 13.2	$ 24.9	$ 6.3

Benefit Plans - Schedule of Ass

Benefit Plans - Schedule of Assumptions (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension plans
Benefit obligation assumptions
Discount rate	3.73%	4.00%	3.92%
Rate of compensation increase	3.77%	3.96%	3.95%
Net periodic benefit expense assumptions
Discount rate	4.00%	3.94%	4.12%
Expected long-term return on plan assets	4.17%	4.05%	4.19%
Rate of compensation increase	3.96%	3.96%	3.93%
Other post-retirement plans
Benefit obligation assumptions
Discount rate	3.95%	3.40%	3.80%
Net periodic benefit expense assumptions
Discount rate	3.40%	3.80%	3.95%

Benefit Plans - Expected Rates

Benefit Plans - Expected Rates of Return (Details)	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Pension plan assets yielded returns	(5.60%)	12.00%	7.40%

Benefit Plans - Assumed Health

Benefit Plans - Assumed Health Care Cost Trend Rates (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Healthcare cost trend rate assumed for following year	6.20%	6.60%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.40%	4.40%
Year the cost trend rate reaches the ultimate trend rate	2,038	2,038

Benefit Plans - Effect of One-P

Benefit Plans - Effect of One-Percentage-Point Change in Assumed Healthcare Cost Trend Rates (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Retirement Benefits [Abstract]
Effect on total annual service and interest cost	$ 0
Effect on other post-retirement benefit obligations	0.6
Effect on total annual service and interest cost	0
Effect on other post-retirement benefit obligations	$ (0.5)

Benefit Plans - Actual Overall

Benefit Plans - Actual Overall Asset Allocation for U.S. And Non-U.S. Plans as Compared to Investment Policy Goals (Detail)	Dec. 31, 2018	Dec. 31, 2017
Fixed income
Plan Assets
Asset allocation	87.00%	98.00%
Target Allocation
Asset allocation	95.00%	97.00%
Other securities
Plan Assets
Asset allocation	5.00%	2.00%
Target Allocation
Asset allocation	5.00%	3.00%
Cash
Plan Assets
Asset allocation	8.00%	0.00%
Target Allocation
Asset allocation	0.00%	0.00%

Benefit Plans - Plan Assets Usi

Benefit Plans - Plan Assets Using Fair Value Methodologies (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 180.7	$ 382.8
Total
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	158.8	355.7
Total | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12
Total | Fixed income | Foreign Government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	102.3	262.8
Total | Fixed income | US Treasury Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18.7	43.2
Total | Fixed income | Collateralized Mortgage Backed Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3.3
Total | Fixed income | Other securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.5	37
Total | Other Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.3	9.4
Fair Value, Inputs, Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Fair Value, Inputs, Level 1 | Fixed income | Foreign Government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 | Fixed income | US Treasury Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 | Fixed income | Collateralized Mortgage Backed Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Fair Value, Inputs, Level 1 | Fixed income | Other securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 1 | Other Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	149.5	346.3
Fair Value, Inputs, Level 2 | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12
Fair Value, Inputs, Level 2 | Fixed income | Foreign Government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	102.3	262.8
Fair Value, Inputs, Level 2 | Fixed income | US Treasury Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	18.7	43.2
Fair Value, Inputs, Level 2 | Fixed income | Collateralized Mortgage Backed Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3.3
Fair Value, Inputs, Level 2 | Fixed income | Other securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.5	37
Fair Value, Inputs, Level 2 | Other Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.3	9.4
Fair Value, Inputs, Level 3 | Cash
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Fair Value, Inputs, Level 3 | Fixed income | Foreign Government
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fair Value, Inputs, Level 3 | Fixed income | US Treasury Securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	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	0
Fair Value, Inputs, Level 3 | Other Investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.3	9.4
Investments measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 21.9	$ 27.1

Benefit Plans - Cash Flows, Con

Benefit Plans - Cash Flows, Contributions (Details) - Pension plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions	$ 7.1	$ 6.3
Expected contribution	$ 29.9

Benefit Plans - Estimated futur

Benefit Plans - Estimated future benefit payments (Detail) $ in Millions	Dec. 31, 2018USD ($)
Pension plans
Defined Benefit Plan Disclosure [Line Items]
2,019	$ 183
2,020	7.2
2,021	7.2
2,022	7.3
2,023	6.8
Thereafter	36.2
Other post-retirement plans
Defined Benefit Plan Disclosure [Line Items]
2,019	1.7
2,020	1.6
2,021	1.6
2,022	1.5
2,023	1.4
Thereafter	$ 5.4

Benefit Plans - Savings Plan (D

Benefit Plans - Savings Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annual eligible compensation percentage	1.50%
Other accrued retirement compensation	$ 28.2	$ 29.6
First 1%
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Matching contribution to eligible employee contributions	100.00%	100.00%
Percent of eligible compensation		1.00%
Next 5%
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Matching contribution to eligible employee contributions		50.00%
Percent of eligible compensation	5.00%	5.00%
Flow 401(K) Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
401(k) plan and ESOP combined expenses	$ 23.4	$ 27.9	$ 27.1

Shareholder's Equity - Addition

Shareholder's Equity - Additional Information (Detail) - USD ($)	May 08, 2018	Dec. 06, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 19, 2017	Dec. 31, 2014
Shareholders Equity
Common stock, shares authorized			426,000,000	426,000,000
Common stock, par value (per share)			$ 0.01	$ 0.01
Common stock shares repurchased, shares			10,200,000
Stock Repurchased During Period, Value			$ 500,000,000		$ 200,000,000
Dividends payable amount per share						$ 0.18
ApprovedNotDeclaredlDividends		$ 0.72
Dividends payable			$ 30,800,000	$ 63,100,000
Dividends paid per common share			$ 1.05	$ 1.38	$ 1.34
December 2014 Share Repurchase Program [Member] [Domain]
Shareholders Equity
Authorized amount to repurchase shares of common stock							$ 1,000,000,000
May 2018 Share Repurchase Program [Member]
Shareholders Equity
Authorized amount to repurchase shares of common stock	$ 750,000,000
Stock Repurchase Program Expiration Date	May 31, 2021
Common stock shares repurchased, shares			8,000,000
Stock Repurchased During Period, Value			$ 350,000,000
Remaining authorized repurchase amount			$ 400,000,120
December 2014 Share Repurchase Program [Member]
Shareholders Equity
Common stock shares repurchased, shares			2,200,000	3,000,000
Stock Repurchased During Period, Value			$ 150,000,000	$ 200,000,000

Share Plans - Share-based compe

Share Plans - Share-based compensation expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 20.9	$ 39.6	$ 34.2
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	8.9	17.5	17.3
Equity Option
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	4.6	10.5	10.4
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based compensation	$ 7.4	$ 11.6	$ 6.5

Share Plans - Additional Inform

Share Plans - Additional Information (Detail) - USD ($)	May 09, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Sep. 28, 2012
Share-based compensation expense
Share-based compensation		$ 3,400,000	$ 7,600,000	$ 11,500,000
Share Incentive Plans
Vesting period		3 years
Fair value of options granted
Weighted average grant date fair value of options granted		$ 10.92	$ 12.59	$ 9.74
Total intrinsic value of options exercised		$ 18,200,000	$ 34,300,000	$ 27,100,000
Unrecognized compensation cost related to stock options		7,800,000
Cash received from option exercises		19,500,000	46,000,000	31,600,000
Tax benefit realized for tax deductions from option exercises		$ 5,600,000	7,800,000	5,500,000
Stock Options
Share Incentive Plans
Vesting period		3 years
Expiration period		10 years
Weighted average grant date fair value
Weighted average period to recognize compensation cost		2 years 1 month
Stock Options | Tranche 1
Share Incentive Plans
Vesting percentage		33.33%
Stock Options | Tranche 2
Share Incentive Plans
Vesting percentage		33.33%
Stock Options | Tranche 3
Share Incentive Plans
Vesting percentage		33.33%
Restricted Stock and Restricted Stock Units (RSUs)
Share Incentive Plans
Vesting period		3 years
Restricted Stock and Restricted Stock Units (RSUs) | Tranche 1
Share Incentive Plans
Vesting percentage		33.33%
Restricted Stock and Restricted Stock Units (RSUs) | Tranche 2
Share Incentive Plans
Vesting percentage		33.33%
Restricted Stock and Restricted Stock Units (RSUs) | Tranche 3
Share Incentive Plans
Vesting percentage		33.33%
Restricted Stock Units
Weighted average grant date fair value
Unrecognized compensation cost related to restricted stock units		$ 18,400,000
Weighted average period to recognize compensation cost		1 year
Total fair value of shares vested		$ 24,400,000	$ 21,700,000	$ 27,200,000
Tax benefit realized for tax deductions from option exercises		$ 700,000
Spin-off transaction, equity interests issued per ordinary predecessor share (in share)	1
Stock Appreciation Rights (SARs)
Share Incentive Plans
Vesting period		3 years
Performance Shares
Weighted average grant date fair value
Unrecognized compensation cost related to restricted stock units		$ 4,300,000
Weighted average period to recognize compensation cost		2 years 2 months
Tax benefit realized for tax deductions from option exercises		$ 200,000
Performance Shares | Grant Date 2016
Weighted average grant date fair value
Conversion rate of target	125.00%
Performance Shares | Grant Date 2017
Weighted average grant date fair value
Conversion rate of target	100.00%
2012 Stock and Incentive Plan
Share Incentive Plans
Number of shares authorized for issuance					9,000,000

Share Plans - Stock Option Acti

Share Plans - Stock Option Activity (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016
Shares
Beginning balance	5.2
Granted	0.5
Exercised	(0.8)	(1)
Forfeited	(0.1)
Spin-off adjustment	(0.7)
Ending balance	4.1
Options exercisable	3
Options expected to vest at end of period	1.1
Weighted Average Exercise Price
Beginning balance (USD per share)	$ 28.80
Granted (USD per share)	45.42
Exercised (USD per share)	23.52
Forfeited (USD per share)	43.77
Expired (USD per share)	0
Ending Balance (USD per share)	35.77
Options exercisable at end of period (USD per share)	33.93
Options expected to vest at end of period (USD per share)	$ 40.55
Weighted Average Remaining Contractual Life
Ending balance	5 years 2 months
Options exercisable at end of period	4 years
Options expected to vest at end of period	8 years 2 months
Aggregate Intrinsic value
Balance at end of period	$ 20.6
Options exercisable at end of period	19.5
Options expected to vest at end of period	$ 1.2

Share Plans - Stock Option Fair

Share Plans - Stock Option Fair Value Assumptions (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Risk-free interest rate	2.58%	1.65%	1.56%
Expected dividend yield	1.56%	2.35%	2.49%
Expected share price volatility	24.80%	26.90%	27.30%
Expected term (years)	6 years 1 month	6 years 3 months	5 years 11 months

Share Plans - Restricted Stock

Share Plans - Restricted Stock Units (Detail) - Restricted Stock Units shares in Millions	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Number of shares
Beginning balance (in shares) | shares	0.6
Granted (in shares) | shares	0.2
Vested (in shares) | shares	(0.6)
Conversion of PSUs (in shares) | shares	0.5
Spin-off adjustment (in shares) | shares	(0.2)
Ending Balance (in shares) | shares	0.5
Weighted average grant date fair value
Beginning balance (USD per share) | $ / shares	$ 39.44
Granted (USD per share) | $ / shares	45.46
Vested (USD per share) | $ / shares	43.89
Conversion of PSUs (USD per share) | $ / shares	0
Spin-off adjustment (USD per share) | $ / shares	0
Ending balance (USD per share) | $ / shares	$ 41.74

Share Plans - Performance Stock

Share Plans - Performance Stock units (Details) - Performance Shares shares in Millions	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Number of shares
Beginning balance (in shares) | shares	0.5
Granted (in shares) | shares	0.1
Conversion to RSUs (in shares) | shares	(0.5)
Ending Balance (in shares) | shares	0.1
Weighted average grant date fair value
Beginning balance (USD per share) | $ / shares	$ 29.53
Granted (USD per share) | $ / shares	45.42
Conversion to RSUs (USD per share) | $ / shares	0
Ending balance (USD per share) | $ / shares	$ 45.42

Segment Information - Financial

Segment Information - Financial Information By Reportable Segment (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net sales	[1]	$ 2,965.1	$ 2,845.7	$ 2,780.6
Segment Income (Loss)		536.8	496.5	441.4
Identifiable assets		3,806.5	8,633.7	11,534.8
Capital expenditures		48.2	39.1	43.3
Depreciation		$ 49.7	$ 50.8	53
Segment Reporting, Disclosure of Major Customers		1	1
Segment Reporting, Net sales associated with Major Customer (percent)		15.00%	15.00%
Aquatic Systems
Segment Reporting Information [Line Items]
Net sales		$ 1,026.1	$ 939.6	877.8
Segment Income (Loss)		277.6	254.1	217.4
Identifiable assets		1,304.2	1,323	1,238
Capital expenditures		10.6	9.6	12
Depreciation		8.1	10.6	9.8
Filtration Solutions
Segment Reporting Information [Line Items]
Net sales		1,001	990.6	976.3
Segment Income (Loss)		168.5	154.5	138.4
Identifiable assets		1,232.4	1,333.3	1,362.4
Capital expenditures		16.6	19.2	17.8
Depreciation		23.2	21.6	23.7
Flow Technologies
Segment Reporting Information [Line Items]
Net sales		936.7	914.2	923.5
Segment Income (Loss)		145.6	140.6	141.6
Identifiable assets		1,003.6	1,010.8	865.2
Capital expenditures		10.3	7.3	11
Depreciation		13.1	13.4	13.3
Other
Segment Reporting Information [Line Items]
Net sales		1.3	1.3	3
Segment Income (Loss)		(54.9)	(52.7)	(56)
Identifiable assets	[2]	266.3	4,966.6	8,069.2
Capital expenditures		10.7	3	2.5
Depreciation		$ 5.3	$ 5.2	$ 6.2
[1]	(1) One customer in the Aquatic Systems segment, Pool Corporation, represented approximately 15% of our consolidated net sales in 2018, 2017 and 2016.
[2]	(1) All cash and cash equivalents and assets held for sale are included in “Other.”

Segment Information Reconciliat

Segment Information Reconciliation of Income from Continuing Operations from Segments to Consolidated (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Income (Loss)	$ 536.8	$ 496.5	$ 441.4
Restructuring costs	(40.6)	(28.2)	(12.2)
Impairment of trade names	(12)	(15.6)	0
Gain (Loss) on Disposition of Business	(7.3)	(4.2)	(3.9)
Loss on early extinguishment of debt	(17.1)	(101.4)	0
Other Expenses		(12.6)
Income from continuing operations before income taxes	379.8	172.8	220.9
Segment Reconciling Items [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Segment Income (Loss)	536.8	496.5	441.4
Restructuring costs	(31.8)	(28.2)	(7.8)
Amortization	(34.9)	(36.4)	(35.4)
Mark-to-market actuarial gains (losses) on pension and post-retirement benefit plans	(3.6)	(8.5)	12
Impairment of trade names	(12)	(15.6)	0
Gain (Loss) on Disposition of Business	(7.3)	(4.2)	(3.9)
Loss on early extinguishment of debt	(17.1)	(101.4)	0
Interest Revenue (Expense), Net	(32.6)	(87.3)	(140.1)
Corporate allocations	(11)	(36.7)	(39.4)
Deal related costs and expenses	(2)	0	0
Other Expenses	(4.7)	(5.4)	(5.9)
Income from continuing operations before income taxes	$ 379.8	$ 172.8	$ 220.9

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Outstanding Value Of Letters Of Credit	$ 123.6	$ 129.2

Commitments and Contingencies_2

Commitments and Contingencies - Net Rental Expense Under Operating Leases (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Leased Assets [Line Items]
Gross rental expense	$ 30.4	$ 29.7	$ 29
Sublease rental income	(0.4)	(0.2)	(0.5)
Net rental expense	$ 30	$ 29.5	$ 28.5

Commitments and Contingencies_3

Commitments and Contingencies - Future Minimum Lease Commitments Under Non-Cancelable Operating Leases (Detail) $ in Millions	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
2,019	$ (22.5)
2,020	(17)
2,021	(12.7)
2,022	(10.5)
2,022	(8.9)
Thereafter	(13.2)
Total	(84.8)
Minimum lease payments
Operating Leased Assets [Line Items]
2,019	(23.2)
2,020	(17.6)
2,021	(13.3)
2,022	(11.1)
2,022	(9.5)
Thereafter	(13.8)
Total	(88.5)
Minimum sublease rentals
Operating Leased Assets [Line Items]
2,019	(0.7)
2,020	(0.6)
2,021	(0.6)
2,022	(0.6)
2,022	(0.6)
Thereafter	(0.6)
Total	$ (3.7)

Commitments and Contingencies_4

Commitments and Contingencies - Warranty Reserve Rollforward (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Movement in Standard Product Warranty Accrual [Roll Forward]
Beginning balance	$ 38.1	$ 36.3	$ 44.6
Service and product warranty provision	50.8	60.8	55.2
Payments	(54.6)	(59.6)	(64.2)
Foreign currency translation	(0.4)	0.6	0.7
Ending balance	$ 33.9	$ 38.1	$ 36.3

Selected Quarterly Data (unau_2

Selected Quarterly Data (unaudited) - Quarterly Financial Information (Detail) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended																12 Months Ended
		Dec. 31, 2018		Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2017		Sep. 30, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Quarterly Financial Information [Line Items]
Loss on early extinguishment of debt																		$ 17.1		$ 101.4		$ 0
Net sales		$ 740.5		$ 711.4		$ 780.6		$ 732.6		$ 720.8		$ 687.6		$ 754		$ 683.3
Net sales	[1]																	2,965.1		2,845.7		2,780.6
Gross profit		268		243.8		282.6		253.3		253.7		236.5		273.6		223.7		1,047.7		987.5		959.1
Operating income		113		108.4		122.6		92.7		85.4		101.8		129.2		61.9		436.7		378.3		354.4
Net income from continuing operations		94.2		91.2		77.9	[2]	58.4		55.8	[3]	49		(3.4)	[4]	12.7		321.7		114.1		178.2
Income (loss) from discontinued operations, net of tax		(1.3)		18.9		(36.4)		44.5		151.6		78.2		66.5		75		25.7		371.3		343.4
Gain from sale / impairment of discontinued operations, net of tax										(17.8)		(1.7)		200.6		0		0		181.1		0.6
Net income		$ 92.9		$ 110.1		$ 41.5		$ 102.9		$ 189.6		$ 125.5		$ 263.7		$ 87.7		$ 347.4		$ 666.5		$ 522.2
Earnings per ordinary share
Continuing operations (USD per share)		$ 0.55		$ 0.52		$ 0.44		$ 0.33		$ 0.32		$ 0.27		$ (0.02)		$ 0.07		$ 1.83		$ 0.63		$ 0.98
Discontinued operations (USD per share)		(0.01)		0.11		(0.21)		0.24		0.73		0.42		1.47		0.41		0.15		3.04		1.90
Earnings Per Share, Basic (USD per share)		0.54	[5]	0.63	[5]	0.23	[5]	0.57	[5]	1.05	[6]	0.69	[6]	1.45	[6]	0.48	[6]	1.98	[5]	3.67	[6]	2.88
Continuing operations (USD per share)		0.54		0.52		0.44		0.32		0.30		0.27		(0.02)		0.07		1.81		0.62		0.97
Discontinued operations (USD per share)		(0.01)		0.11		(0.21)		0.25		0.74		0.41		1.45		0.41		0.15		3.01		1.88
Diluted		$ 0.53	[5]	$ 0.63	[5]	$ 0.23	[5]	$ 0.57	[5]	$ 1.04	[6]	$ 0.68	[6]	$ 1.43	[6]	$ 0.48	[6]	$ 1.96	[5]	$ 3.63	[6]	$ 2.85
Impairment of trade names																		$ 12		$ 15.6		$ 0
Segment Reconciling Items [Member]
Quarterly Financial Information [Line Items]
Loss on early extinguishment of debt																		17.1		101.4		0
Earnings per ordinary share
Impairment of trade names																		12		15.6		0
Mark-to-market actuarial gains (losses) on pension and post-retirement benefit plans																		3.6		8.5		(12)
Retained earnings
Quarterly Financial Information [Line Items]
Net income																		$ 347.4		$ 666.5		$ 522.2
[1]	(1) One customer in the Aquatic Systems segment, Pool Corporation, represented approximately 15% of our consolidated net sales in 2018, 2017 and 2016.
[2]	(1) Includes decrease of $17.1 million related to loss on early extinguishment of debt.
[3]	(2) Includes decrease of $15.6 million due to trade name and other impairment and $8.5 million related to a “mark-to-market” actuarial loss on pension and other post-retirement benefit plans.
[4]	(1) Includes decrease of $101.4 million related to loss on early extinguishment of debt.
[5]	(2) 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.
[6]	(3) 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.

Supplemental Guarantor Inform_3

Supplemental Guarantor Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018
Parent Company Guarantor
Condensed Financial Statements, Captions [Line Items]
Ownership percentage	100.00%
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Ownership percentage	100.00%

Supplemental Guarantor Inform_4

Supplemental Guarantor Information - Condensed Consolidating Statement of Operations and Comprehensive Income (Loss) (Detail) - USD ($) $ in Millions		3 Months Ended											12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018		Mar. 31, 2018	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017		Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net sales	[1]												$ 2,965.1	$ 2,845.7	$ 2,780.6
Cost of goods sold													1,917.4	1,858.2	1,821.5
Gross profit		$ 268	$ 243.8	$ 282.6		$ 253.3	$ 253.7		$ 236.5	$ 273.6		$ 223.7	1,047.7	987.5	959.1
Selling, general and administrative													534.3	536	531.4
Research and development													76.7	73.2	73.3
Operating income		113	108.4	122.6		92.7	85.4		101.8	129.2		61.9	436.7	378.3	354.4
Loss (earnings) from investment in subsidiaries													0	0	0
Other (income) expense:
Loss on sale of businesses													7.3	4.2	3.9
Loss on early extinguishment of debt													17.1	101.4	0
Net interest expense													32.6	87.3	140.1
Other expense (income)													0.1		10.5
Other expense														12.6
Income from continuing operations before income taxes													379.8	172.8	220.9
Provision for income taxes													58.1	58.7	42.7
Net income from continuing operations		94.2	91.2	77.9	[2]	58.4	55.8	[3]	49	(3.4)	[4]	12.7	321.7	114.1	178.2
Income (loss) from discontinued operations, net of tax		(1.3)	18.9	(36.4)		44.5	151.6		78.2	66.5		75	25.7	371.3	343.4
Gain from sale / impairment of discontinued operations, net of tax							(17.8)		(1.7)	200.6		0	0	181.1	0.6
Earnings (loss) from discontinued operations of investment in subsidiaries													0	0	0
Net income		$ 92.9	$ 110.1	$ 41.5		$ 102.9	$ 189.6		$ 125.5	$ 263.7		$ 87.7	347.4	666.5	522.2
Net income (loss) from continuing operations before noncontrolling interest													347.4	666.5	522.2
Comprehensive income, net of tax
Changes in cumulative translation adjustment (inclusive of divestiture of business reclassified to gain from sale of $374.2 for the year ended December 31, 2017)													10	497.5	(83)
Changes in market value of derivative financial instruments													4.8	(4.6)	(8.3)
Comprehensive income													362.2	1,159.4	430.9
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
Operating income													0	0	0
Loss (earnings) from investment in subsidiaries													1,043.4	527.8	680.3
Other (income) expense:
Loss on sale of businesses													0	0	0
Loss on early extinguishment of debt													0	0	0
Net interest expense													0	0	0
Other expense (income)													0		0
Other expense														0
Income from continuing operations before income taxes													(1,043.4)	(527.8)	(680.3)
Provision for income taxes													0	0	0
Net income from continuing operations													(1,043.4)	(527.8)	(680.3)
Income (loss) from discontinued operations, net of tax													0	0	0
Gain from sale / impairment of discontinued operations, net of tax														0	0
Earnings (loss) from discontinued operations of investment in subsidiaries													(77.1)	(1,657.2)	(1,032)
Net income													(1,120.5)	(2,185)	(1,712.3)
Net income (loss) from continuing operations before noncontrolling interest													(1,120.5)	(2,185)	(1,712.3)
Comprehensive income, net of tax
Changes in cumulative translation adjustment (inclusive of divestiture of business reclassified to gain from sale of $374.2 for the year ended December 31, 2017)													(30)	(1,492.5)	249
Changes in market value of derivative financial instruments													(14.4)	13.8	24.9
Comprehensive income													(1,164.9)	(3,663.7)	(1,438.4)
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													11.8	9	12.6
Research and development													0	0	0
Operating income													(11.8)	(9)	(12.6)
Loss (earnings) from investment in subsidiaries													(333.5)	(122.2)	(189.4)
Other (income) expense:
Loss on sale of businesses													0	0	0
Loss on early extinguishment of debt													0	0	0
Net interest expense													0	0	0
Other expense (income)													0		0
Other expense														0
Income from continuing operations before income taxes													321.7	113.2	176.8
Provision for income taxes													0	(0.9)	(1.4)
Net income from continuing operations													321.7	114.1	178.2
Income (loss) from discontinued operations, net of tax													0	0	0
Gain from sale / impairment of discontinued operations, net of tax														0	0
Earnings (loss) from discontinued operations of investment in subsidiaries													25.7	552.4	344
Net income													347.4	666.5	522.2
Net income (loss) from continuing operations before noncontrolling interest													347.4	666.5	522.2
Comprehensive income, net of tax
Changes in cumulative translation adjustment (inclusive of divestiture of business reclassified to gain from sale of $374.2 for the year ended December 31, 2017)													10	497.5	(83)
Changes in market value of derivative financial instruments													4.8	(4.6)	(8.3)
Comprehensive income													362.2	1,159.4	430.9
Subsidiary 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													0.9	0.6	0
Research and development													0	0	0
Operating income													(0.9)	(0.6)	0
Loss (earnings) from investment in subsidiaries													(333.4)	(122.2)	(189.4)
Other (income) expense:
Loss on sale of businesses													0	0	0
Loss on early extinguishment of debt													0	0	0
Net interest expense													(1)	(0.6)	0
Other expense (income)													0		0
Other expense														0
Income from continuing operations before income taxes													333.5	122.2	189.4
Provision for income taxes													0	0	0
Net income from continuing operations													333.5	122.2	189.4
Income (loss) from discontinued operations, net of tax													0	0	0
Gain from sale / impairment of discontinued operations, net of tax														0	0
Earnings (loss) from discontinued operations of investment in subsidiaries													25.7	552.4	344
Net income													359.2	674.6	533.4
Net income (loss) from continuing operations before noncontrolling interest													359.2	674.6	533.4
Comprehensive income, net of tax
Changes in cumulative translation adjustment (inclusive of divestiture of business reclassified to gain from sale of $374.2 for the year ended December 31, 2017)													10	497.5	(83)
Changes in market value of derivative financial instruments													4.8	(4.6)	(8.3)
Comprehensive income													374	1,167.5	442.1
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													1.2	0	1.2
Research and development													0	0	0
Operating income													(1.2)	0	(1.2)
Loss (earnings) from investment in subsidiaries													(376.5)	(283.4)	(301.5)
Other (income) expense:
Loss on sale of businesses													0	0	0
Loss on early extinguishment of debt													17.1	91	0
Net interest expense													24.8	70.7	110.9
Other expense (income)													0		0
Other expense														0
Income from continuing operations before income taxes													333.4	121.7	189.4
Provision for income taxes													0	0	0
Net income from continuing operations													333.4	121.7	189.4
Income (loss) from discontinued operations, net of tax													0	0	0
Gain from sale / impairment of discontinued operations, net of tax														0	0
Earnings (loss) from discontinued operations of investment in subsidiaries													25.7	552.4	344
Net income													359.1	674.1	533.4
Net income (loss) from continuing operations before noncontrolling interest													359.1	674.1	533.4
Comprehensive income, net of tax
Changes in cumulative translation adjustment (inclusive of divestiture of business reclassified to gain from sale of $374.2 for the year ended December 31, 2017)													10	497.5	(83)
Changes in market value of derivative financial instruments													4.8	(4.6)	(8.3)
Comprehensive income													373.9	1,167	442.1
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales													2,965.1	2,845.7	2,780.6
Cost of goods sold													1,917.4	1,858.2	1,821.5
Gross profit													1,047.7	987.5	959.1
Selling, general and administrative													520.4	526.4	517.6
Research and development													76.7	73.2	73.3
Operating income													450.6	387.9	368.2
Loss (earnings) from investment in subsidiaries													0	0	0
Other (income) expense:
Loss on sale of businesses													7.3	4.2	3.9
Loss on early extinguishment of debt													0	10.4	0
Net interest expense													8.8	17.2	29.2
Other expense (income)													0.1		10.5
Other expense														12.6
Income from continuing operations before income taxes													434.6	343.5	345.6
Provision for income taxes													58.1	59.6	44.1
Net income from continuing operations													376.5	283.9	301.5
Income (loss) from discontinued operations, net of tax													25.7	371.3	343.4
Gain from sale / impairment of discontinued operations, net of tax														181.1	0.6
Earnings (loss) from discontinued operations of investment in subsidiaries													0	0	0
Net income													402.2	836.3	645.5
Net income (loss) from continuing operations before noncontrolling interest													402.2	836.3	645.5
Comprehensive income, net of tax
Changes in cumulative translation adjustment (inclusive of divestiture of business reclassified to gain from sale of $374.2 for the year ended December 31, 2017)													10	497.5	(83)
Changes in market value of derivative financial instruments													4.8	(4.6)	(8.3)
Comprehensive income													$ 417	$ 1,329.2	$ 554.2
[1]	(1) One customer in the Aquatic Systems segment, Pool Corporation, represented approximately 15% of our consolidated net sales in 2018, 2017 and 2016.
[2]	(1) Includes decrease of $17.1 million related to loss on early extinguishment of debt.
[3]	(2) Includes decrease of $15.6 million due to trade name and other impairment and $8.5 million related to a “mark-to-market” actuarial loss on pension and other post-retirement benefit plans.
[4]	(1) Includes decrease of $101.4 million related to loss on early extinguishment of debt.

Supplemental Guarantor Inform_5

Supplemental Guarantor Information - Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 74.3		$ 86.3	$ 216.9	$ 103.6	$ 103.6
Accounts and notes receivable, net	488.2	$ 485.8	483.1
Inventories	387.5	355.3	356.9
Other current assets	89.4	116.1	114.5
Current assets held for sale	0	711.8	708
Total current assets	1,039.4		1,748.8
Property, plant and equipment, net	272.6		279.8
Other assets
Investments in subsidiaries	0		0
Goodwill	2,072.7		2,112.8	1,994.6
Intangibles, net	276.3		321.8
Long-term intercompany debt			0
Other non-current assets	145.5	136	180.9
Non-current assets held for sale	0	3,788	3,989.6
Total other assets	2,494.5		6,605.1
Total assets	3,806.5		8,633.7	11,534.8
Current liabilities
Accounts payable	378.6		321.5
Employee compensation and benefits	111.7		115.8
Other current liabilities	328.4	404	401.3
Current liabilities held for sale	0		360.8
Total current liabilities	818.7		1,199.4
Other liabilities
Long-term debt	787.6		1,440.7
Pension and other post-retirement compensation and benefits	90		96.4
Deferred tax liabilities	105.9	105	108.6
Other non-current liabilities	168.2		213.8
Non-current liabilities held for sale	0	$ 510.4	537
Total liabilities	1,970.4		3,595.9
Equity
Total equity	1,836.1		5,037.8	4,254.4	4,008.8
Total liabilities and equity	3,806.5		8,633.7
Eliminations
Current assets
Cash and cash equivalents	0		0	0	0
Accounts and notes receivable, net	0		0
Inventories	0		0
Other current assets	(15.4)		(9.2)
Current assets held for sale			0
Total current assets	(15.4)		(9.2)
Property, plant and equipment, net	0		0
Other assets
Investments in subsidiaries	(6,615.6)		(17,470.8)
Goodwill	0		0
Intangibles, net	0		0
Long-term intercompany debt			0
Other non-current assets	(1,303.6)		(1,889.4)
Non-current assets held for sale			0
Total other assets	(7,919.2)		(19,360.2)
Total assets	(7,934.6)		(19,369.4)
Current liabilities
Accounts payable	0		0
Employee compensation and benefits	0		0
Other current liabilities	(15.4)		(9.2)
Current liabilities held for sale			0
Total current liabilities	(15.4)		(9.2)
Other liabilities
Long-term debt	(1,303.6)		(1,889.4)
Pension and other post-retirement compensation and benefits	0		0
Deferred tax liabilities	0		0
Other non-current liabilities	0		0
Non-current liabilities held for sale			0
Total liabilities	(1,319)		(1,898.6)
Equity
Total equity	(6,615.6)		(17,470.8)
Total liabilities and equity	(7,934.6)		(19,369.4)
Parent Company Guarantor
Current assets
Cash and cash equivalents	0.1		0	0	0
Accounts and notes receivable, net	4.6		0
Inventories	0		0
Other current assets	3.4		10.8
Current assets held for sale			0
Total current assets	8.1		10.8
Property, plant and equipment, net	0		0
Other assets
Investments in subsidiaries	1,903.8		5,205.1
Goodwill	0		0
Intangibles, net	0		0
Long-term intercompany debt			0
Other non-current assets	23.3		2.2
Non-current assets held for sale			0
Total other assets	1,927.1		5,207.3
Total assets	1,935.2		5,218.1
Current liabilities
Accounts payable	0.9		1.4
Employee compensation and benefits	0.2		0.4
Other current liabilities	47.6		99.6
Current liabilities held for sale			0
Total current liabilities	48.7		101.4
Other liabilities
Long-term debt	29.9		48.4
Pension and other post-retirement compensation and benefits	0		0
Deferred tax liabilities	0		0
Other non-current liabilities	20.5		30.5
Non-current liabilities held for sale			0
Total liabilities	99.1		180.3
Equity
Total equity	1,836.1		5,037.8
Total liabilities and equity	1,935.2		5,218.1
Subsidiary Guarantor
Current assets
Cash and cash equivalents	0		0	0	0
Accounts and notes receivable, net	0		0
Inventories	0		0
Other current assets	0		1.8
Current assets held for sale			0
Total current assets	0		1.8
Property, plant and equipment, net	0		0
Other assets
Investments in subsidiaries	2,036.1		5,109.6
Goodwill	0		0
Intangibles, net	0		0
Long-term intercompany debt			0
Other non-current assets	0		94.1
Non-current assets held for sale			0
Total other assets	2,036.1		5,203.7
Total assets	2,036.1		5,205.5
Current liabilities
Accounts payable	0		0
Employee compensation and benefits	0		0
Other current liabilities	1.5		0.4
Current liabilities held for sale			0
Total current liabilities	1.5		0.4
Other liabilities
Long-term debt	130.8		0
Pension and other post-retirement compensation and benefits	0		0
Deferred tax liabilities	0		0
Other non-current liabilities	0		0
Non-current liabilities held for sale			0
Total liabilities	132.3		0.4
Equity
Total equity	1,903.8		5,205.1
Total liabilities and equity	2,036.1		5,205.5
Subsidiary Issuer
Current assets
Cash and cash equivalents	0.1		0	0	0.1
Accounts and notes receivable, net	0		0
Inventories	0		0
Other current assets	2.2		1.5
Current assets held for sale			0
Total current assets	2.3		1.5
Property, plant and equipment, net	0		0
Other assets
Investments in subsidiaries	2,675.7		7,156.1
Goodwill	0		0
Intangibles, net	0		0
Long-term intercompany debt			0
Other non-current assets	696.1		614
Non-current assets held for sale			0
Total other assets	3,371.8		7,770.1
Total assets	3,374.1		7,771.6
Current liabilities
Accounts payable	0		0
Employee compensation and benefits	0		0
Other current liabilities	4.4		9.4
Current liabilities held for sale			0
Total current liabilities	4.4		9.4
Other liabilities
Long-term debt	1,333.9		2,652.8
Pension and other post-retirement compensation and benefits	0		0
Deferred tax liabilities	0		0
Other non-current liabilities	0		0
Non-current liabilities held for sale			0
Total liabilities	1,338.3		2,662.2
Equity
Total equity	2,035.8		5,109.4
Total liabilities and equity	3,374.1		7,771.6
Non-Guarantor Subsidiaries
Current assets
Cash and cash equivalents	74.1		86.3	$ 216.9	$ 103.5
Accounts and notes receivable, net	483.6		483.1
Inventories	387.5		356.9
Other current assets	99.2		109.6
Current assets held for sale			708
Total current assets	1,044.4		1,743.9
Property, plant and equipment, net	272.6		279.8
Other assets
Investments in subsidiaries	0		0
Goodwill	2,072.7		2,112.8
Intangibles, net	276.3		321.8
Long-term intercompany debt			0
Other non-current assets	729.7		1,360
Non-current assets held for sale			3,989.6
Total other assets	3,078.7		7,784.2
Total assets	4,395.7		9,807.9
Current liabilities
Accounts payable	377.7		320.1
Employee compensation and benefits	111.5		115.4
Other current liabilities	290.3		301.1
Current liabilities held for sale			360.8
Total current liabilities	779.5		1,097.4
Other liabilities
Long-term debt	596.6		628.9
Pension and other post-retirement compensation and benefits	90		96.4
Deferred tax liabilities	105.9		108.6
Other non-current liabilities	147.7		183.3
Non-current liabilities held for sale			537
Total liabilities	1,719.7		2,651.6
Equity
Total equity	2,676		7,156.3
Total liabilities and equity	$ 4,395.7		$ 9,807.9

Supplemental Guarantor Inform_6

Supplemental Guarantor Information - Condensed Consolidating Statement of Cash Flows (Detail) - USD ($) $ in Millions	1 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Nov. 30, 2016	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Operating activities
Net cash provided by (used for) operating activities				$ 439.1	$ 620.2	$ 861.4
Investing activities
Capital expenditures				(48.2)	(39.1)	(43.3)
Proceeds from sale of property and equipment				0.2	3.7	18.8
(Payments due to) proceeds from sale of businesses and other			$ 2,759.4	(12.8)	2,759.4	(5.1)	$ (5.1)
Acquisitions, net of cash acquired		$ (25)		(0.9)	(45.9)	(25)
Net intercompany loan activity				0	0	0
Net cash provided by (used for) investing activities of continuing operations				(61.7)	2,678.1	(54.6)
Net cash used for investing activities of discontinued operations				(7.1)	(47.7)	(67.2)
Net cash provided by (used for) investing activities				(68.8)	2,630.4	(121.8)
Financing activities
Net receipts (repayments) of commercial paper and revolving long-term debt				39.7	(913.1)	(385.3)
Proceeds from long-term debt						0
Repayment of long-term debt				(675.1)	(2,009.3)	(0.7)
Debt issuance costs						0
Premium paid on early extinguishment of debt				(16)	(94.9)	0
Transfer of cash to nVent				(74.2)	0	0
Distribution of cash from nVent	$ 993.6			993.6	0	0
Net change in advances to subsidiaries				0	0	0
Excess tax benefits from share-based compensation						0
Shares issued to employees, net of shares withheld				13.3	37.2	20.7
Repurchases of ordinary shares				(500)	(200)	0
Dividends paid				(187.2)	(251.7)	(243.6)
Other				(2)	(0.8)	8.8
Net cash provided by (used for) financing activities of continuing operations				(407.9)	(3,432.6)	(600.1)
Change in cash held for sale				27	(5.4)	1.1
Effect of exchange rate changes on cash and cash equivalents				(1.4)	56.8	(27.3)
Change in cash and cash equivalents				(12)	(130.6)	113.3
Cash and cash equivalents, beginning of year			216.9	86.3	216.9	103.6
Cash and cash equivalents, end of year				74.3	86.3	216.9	$ 103.6
Eliminations
Operating activities
Net cash provided by (used for) operating activities				(1,197.6)	(2,185)	(1,712.3)
Investing activities
Capital expenditures				0	0	0
Proceeds from sale of property and equipment				0	0	0
(Payments due to) proceeds from sale of businesses and other				0	0	0
Acquisitions, net of cash acquired				0	0	0
Net intercompany loan activity				(1,930.8)	(217.3)	(476.3)
Net cash provided by (used for) investing activities of continuing operations				(1,930.8)	(217.3)	(476.3)
Net cash used for investing activities of discontinued operations				0	0	0
Net cash provided by (used for) investing activities				(1,930.8)	(217.3)	(476.3)
Financing activities
Net receipts (repayments) of commercial paper and revolving long-term debt				0	0	0
Proceeds from long-term debt						0
Repayment of long-term debt				0	0	0
Debt issuance costs						0
Premium paid on early extinguishment of debt				0	0
Transfer of cash to nVent				0
Distribution of cash from nVent				0
Net change in advances to subsidiaries				3,128.4	2,402.3	2,188.6
Excess tax benefits from share-based compensation						0
Shares issued to employees, net of shares withheld				0	0	0
Repurchases of ordinary shares				0	0	0
Dividends paid				0	0	0
Other				0	0	0
Net cash provided by (used for) financing activities of continuing operations				3,128.4	2,402.3	2,188.6
Change in cash held for sale				0	0	0
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	0
Cash and cash equivalents, end of year				0	0	0
Parent Company Guarantor
Operating activities
Net cash provided by (used for) operating activities				266.3	678.3	595.7
Investing activities
Capital expenditures				0	0	0
Proceeds from sale of property and equipment				0	0	0
(Payments due to) proceeds from sale of businesses and other				0	0	0
Acquisitions, net of cash acquired				0	0	0
Net intercompany loan activity				0	0	0
Net cash provided by (used for) investing activities of continuing operations				0	0	0
Net cash used for investing activities of discontinued operations				0	0	0
Net cash provided by (used for) investing activities				0	0	0
Financing activities
Net receipts (repayments) of commercial paper and revolving long-term debt				0	0	0
Proceeds from long-term debt						0
Repayment of long-term debt				0	0	0
Debt issuance costs						0
Premium paid on early extinguishment of debt				0	0
Transfer of cash to nVent				0
Distribution of cash from nVent				0
Net change in advances to subsidiaries				407.7	(263.8)	(372.8)
Excess tax benefits from share-based compensation						0
Shares issued to employees, net of shares withheld				13.3	37.2	20.7
Repurchases of ordinary shares				(500)	(200)	0
Dividends paid				(187.2)	(251.7)	(243.6)
Other				0	0	0
Net cash provided by (used for) financing activities of continuing operations				(266.2)	(678.3)	(595.7)
Change in cash held for sale				0	0	0
Effect of exchange rate changes on cash and cash equivalents				0	0	0
Change in cash and cash equivalents				0.1	0	0
Cash and cash equivalents, beginning of year			0	0	0	0
Cash and cash equivalents, end of year				0.1	0	0
Subsidiary Guarantor
Operating activities
Net cash provided by (used for) operating activities				362.1	676.1	541.7
Investing activities
Capital expenditures				0	0	0
Proceeds from sale of property and equipment				0	0	0
(Payments due to) proceeds from sale of businesses and other				0	0	0
Acquisitions, net of cash acquired				0	0	0
Net intercompany loan activity				94.1	(58.9)	0
Net cash provided by (used for) investing activities of continuing operations				94.1	(58.9)	0
Net cash used for investing activities of discontinued operations				0	0	0
Net cash provided by (used for) investing activities				94.1	(58.9)	0
Financing activities
Net receipts (repayments) of commercial paper and revolving long-term debt				0	0	0
Proceeds from long-term debt						0
Repayment of long-term debt				0	0	0
Debt issuance costs						0
Premium paid on early extinguishment of debt				0	0
Transfer of cash to nVent				0
Distribution of cash from nVent				0
Net change in advances to subsidiaries				(456.2)	(617.2)	(541.7)
Excess tax benefits from share-based compensation						0
Shares issued to employees, net of shares withheld				0	0	0
Repurchases of ordinary shares				0	0	0
Dividends paid				0	0	0
Other				0	0	0
Net cash provided by (used for) financing activities of continuing operations				(456.2)	(617.2)	(541.7)
Change in cash held for sale				0	0	0
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	0
Cash and cash equivalents, end of year				0	0	0
Subsidiary Issuer
Operating activities
Net cash provided by (used for) operating activities				370.6	656.2	532.9
Investing activities
Capital expenditures				0	0	0
Proceeds from sale of property and equipment				0	0	0
(Payments due to) proceeds from sale of businesses and other				0	2,765.6	0
Acquisitions, net of cash acquired				0	0	0
Net intercompany loan activity				181	103.7	667.3
Net cash provided by (used for) investing activities of continuing operations				181	2,869.3	667.3
Net cash used for investing activities of discontinued operations				0	0	0
Net cash provided by (used for) investing activities				181	2,869.3	667.3
Financing activities
Net receipts (repayments) of commercial paper and revolving long-term debt				41.9	(914.7)	(385.8)
Proceeds from long-term debt
Repayment of long-term debt				(675.1)	(1,917.8)	0
Debt issuance costs
Premium paid on early extinguishment of debt				(16)	(86)
Transfer of cash to nVent				0
Distribution of cash from nVent				993.6
Net change in advances to subsidiaries				(874.6)	(680.8)	(842.3)
Excess tax benefits from share-based compensation						0
Shares issued to employees, net of shares withheld				0	0	0
Repurchases of ordinary shares				0	0	0
Dividends paid				0	0	0
Other				(2)	0	0
Net cash provided by (used for) financing activities of continuing operations				(532.2)	(3,599.3)	(1,228.1)
Change in cash held for sale				0	0	0
Effect of exchange rate changes on cash and cash equivalents				(19.3)	73.8	27.8
Change in cash and cash equivalents				0.1	0	(0.1)
Cash and cash equivalents, beginning of year			0	0	0	0.1
Cash and cash equivalents, end of year				0.1	0	0
Non-Guarantor Subsidiaries
Operating activities
Net cash provided by (used for) operating activities				637.7	794.6	903.4
Investing activities
Capital expenditures				(48.2)	(39.1)	(43.3)
Proceeds from sale of property and equipment				0.2	3.7	18.8
(Payments due to) proceeds from sale of businesses and other				(12.8)	(6.2)	(5.1)
Acquisitions, net of cash acquired				(0.9)	(45.9)	(25)
Net intercompany loan activity				1,655.7	172.5	(191)
Net cash provided by (used for) investing activities of continuing operations				1,594	85	(245.6)
Net cash used for investing activities of discontinued operations				(7.1)	(47.7)	(67.2)
Net cash provided by (used for) investing activities				1,586.9	37.3	(312.8)
Financing activities
Net receipts (repayments) of commercial paper and revolving long-term debt				(2.2)	1.6	0.5
Proceeds from long-term debt						0
Repayment of long-term debt				0	(91.5)	(0.7)
Debt issuance costs						0
Premium paid on early extinguishment of debt				0	(8.9)
Transfer of cash to nVent				(74.2)
Distribution of cash from nVent				0
Net change in advances to subsidiaries				(2,205.3)	(840.5)	(431.8)
Excess tax benefits from share-based compensation						0
Shares issued to employees, net of shares withheld				0	0	0
Repurchases of ordinary shares				0	0	0
Dividends paid				0	0	0
Other				0	(0.8)	8.8
Net cash provided by (used for) financing activities of continuing operations				(2,281.7)	(940.1)	(423.2)
Change in cash held for sale				27	(5.4)	1.1
Effect of exchange rate changes on cash and cash equivalents				17.9	(17)	(55.1)
Change in cash and cash equivalents				(12.2)	(130.6)	113.4
Cash and cash equivalents, beginning of year			$ 216.9	86.3	216.9	103.5
Cash and cash equivalents, end of year				$ 74.1	$ 86.3	$ 216.9

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts - Disclosure Table (Detail) - Allowance for Doubtful Accounts - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning balance		$ 10	$ 9	$ 13.7
Additions charged to costs and expenses		1.1	2.3
Reductions credited				(1.2)
Deductions	[1]	0.9	2.2	3.9
Other changes	[2]	2.4	0.9	0.4
Ending balance		$ 12.6	$ 10	$ 9
[1]	Uncollectible accounts written off, net of recoveries
[2]	Result of foreign currency effects