A. O. Smith (AOS) 10-K 12 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 29, 2021	Jun. 30, 2020
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	1-475
Entity Registrant Name	A. O. Smith Corporation
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	39-0619790
Entity Address, Address Line One	11270 West Park Place
Entity Address, City or Town	Milwaukee
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	53224-9508
City Area Code	414
Local Phone Number	359-4000
Title of 12(b) Security	Common Stock (par value $1.00 per share)
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Documents Incorporated by Reference	1. Portions of the company’s definitive Proxy Statement for the 2021 Annual Meeting of Stockholders (to be filed with the Securities and Exchange Commission under Regulation 14A within 120 days after the end of the registrant’s fiscal year and, upon such filing, to be incorporated by reference in Part III).
Amendment Flag	false
Entity Central Index Key	0000091142
Document Fiscal Period Focus	FY
Trading Symbol	AOS
Document Fiscal Year Focus	2020
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		26,034,457
Entity Public Float			$ 42,461,387
Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		135,747,632
Entity Public Float			$ 6,241,019,639

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 573.1	$ 374
Marketable securities	116.5	177.4
Receivables	585	589.5
Inventories	300.1	303
Other current assets	43.3	56.5
Total Current Assets	1,618	1,500.4
Net property, plant and equipment	541.3	545.4
Goodwill	546.8	546
Other intangibles	323.9	338.4
Operating lease assets	41.6	46.9
Other assets	89.1	80.9
Total Assets	3,160.7	3,058
Current Liabilities
Trade payables	595.2	509.6
Accrued payroll and benefits	74.6	64.6
Accrued liabilities	161.9	143.7
Product warranties	47.8	41.8
Long-term debt due within one year	6.8	6.8
Total Current Liabilities	886.3	766.5
Long-term debt	106.4	277.2
Product warranties	94.5	92.4
Pension liabilities	13.6	27.8
Long-term operating lease liabilities	34.4	38.7
Other liabilities	177.2	188.6
Total Liabilities	1,312.4	1,391.2
Commitments and contingencies	0	0
Stockholders’ Equity
Preferred Stock	0	0
Capital in excess of par value	520.4	509
Retained earnings	2,509.6	2,323.4
Accumulated other comprehensive loss	(321.2)	(348.3)
Treasury stock at cost	(1,155.9)	(1,112.7)
Total Stockholders’ Equity	1,848.3	1,666.8
Total Liabilities and Stockholders’ Equity	3,160.7	3,058
Class A Common Stock
Stockholders’ Equity
Common Stock, value	130.8	130.9
Common Stock
Stockholders’ Equity
Common Stock, value	$ 164.6	$ 164.5

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Dec. 31, 2020	Dec. 31, 2019
Class A Common Stock
Common Stock, shares issued (in shares)	26,168,513	26,180,885
Common Stock
Common Stock, shares issued (in shares)	164,539,081	164,526,709

CONSOLIDATED STATEMENT OF EARNI

CONSOLIDATED STATEMENT OF EARNINGS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 2,895.3	$ 2,992.7	$ 3,187.9
Cost of products sold	1,787.1	1,812	1,882.4
Gross profit	1,108.2	1,180.7	1,305.5
Selling, general and administrative expenses	660.3	715.6	753.8
Severance, restructuring and impairment expenses	7.7	0	6.7
Interest expense	7.3	11	8.4
Other income - net	(11)	(18)	(21.2)
Earnings before provision for income taxes	443.9	472.1	557.8
Provision for income taxes	99	102.1	113.6
Net Earnings	$ 344.9	$ 370	$ 444.2
Net Earnings Per Share of Common Stock (in dollars per share)	$ 2.13	$ 2.24	$ 2.60
Diluted Net Earnings Per Share of Common Stock (in dollars per share)	$ 2.12	$ 2.22	$ 2.58

CONSOLIDATED STATEMENT OF COMPR

CONSOLIDATED STATEMENT OF COMPREHENSIVE EARNINGS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net Earnings	$ 344.9	$ 370	$ 444.2
Other comprehensive earnings (loss)
Foreign currency translation adjustments	18.1	(1.3)	(38.4)
Unrealized net gain on cash flow derivative instruments, less related income tax provision of $(0.1) in 2020, $(0.3) in 2019 and $(0.1) in 2018	0.4	0.9	0.2
Change in pension liability less related income tax (provision) benefit of $(2.8) in 2020, $(1.0) in 2019 and $4.3 in 2018	8.6	2.9	(13.1)
Comprehensive Earnings	$ 372	$ 372.5	$ 392.9

CONSOLIDATED STATEMENT OF COM_2

CONSOLIDATED STATEMENT OF COMPREHENSIVE EARNINGS (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Income tax provision on cash flow derivative instruments	$ (0.1)	$ (0.3)	$ (0.1)
Income tax (provision) benefit on change in pension liability	$ (2.8)	$ (1)	$ 4.3

CONSOLIDATED STATEMENT OF CASH

CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net Earnings	$ 344.9	$ 370	$ 444.2
Adjustments to reconcile earnings to cash provided by (used in) operating activities:
Depreciation and amortization	80	78.3	71.9
Stock based compensation expense	12.7	13.3	10.1
Net changes in operating assets and liabilities, net of acquisitions:
Current assets and liabilities	130.4	32.6	(40)
Noncurrent assets and liabilities	(5.9)	(38)	(37.3)
Cash Provided by Operating Activities	562.1	456.2	448.9
Investing Activities
Acquisition of business	0	(107)	0
Investments in marketable securities	(157.4)	(272.7)	(523.4)
Proceeds from sales of marketable securities	226	478	595.9
Capital expenditures	(56.8)	(64.4)	(85.2)
Cash Provided by (Used in) Investing Activities	11.8	33.9	(12.7)
Financing Activities
Long-term debt repaid	(170.8)		(189)
Long-term debt incurred		62.6
Common stock repurchases	(56.7)	(287.7)	(202.6)
Net proceeds (payments) from stock option activity	11.4	(0.5)	0.9
Payment of contingent consideration	0	(1)	(2.3)
Dividends paid	(158.7)	(149.2)	(130.1)
Cash Used in Financing Activities	(374.8)	(375.8)	(523.1)
Net increase (decrease) in cash and cash equivalents	199.1	114.3	(86.9)
Cash and cash equivalents-beginning of year	374	259.7	346.6
Cash and Cash Equivalents-End of Year	$ 573.1	$ 374	$ 259.7

CONSOLIDATED STATEMENT OF STOCK

CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common StockClass A Common Stock	Common StockCommon Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Foreign currency translation adjustments	Unrealized net gain on cash flow derivative instruments, less related income tax provision of $(0.1) in 2020 $(0.3) in 2019 and $(0.1) in 2018	Change in pension liability less related income tax benefit (provision) of $(2.8) in 2020, $(1.0) in 2019 and $4.3 in 2018	Treasury Stock
Balance at beginning of period at Dec. 31, 2017		$ 131.2	$ 164.5	$ 486.5	$ 1,788.7	$ (299.5)				$ (626.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class A Common Stock		(0.2)	0	0.2
Issuance of share units				(6)
Shares repurchased	$ (202.6)									(202.6)
Vesting of share units				(2.4)						2.5
Stock based compensation expense				10.1
Exercises of stock options				1.4						(0.7)
Stock incentives and directors' compensation				6.9						0.1
Net Earnings	444.2				444.2
Cash dividends on stock					(130.1)
Change in other comprehensive income (loss), less tax							$ (38.4)	$ 0.2	$ (13.1)
Balance at end of period at Dec. 31, 2018	1,717	131	164.5	496.7	2,102.8	(350.8)	(64.9)	(0.7)	(285.2)	(827.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class A Common Stock		(0.1)	0	0.1
Issuance of share units				(6.2)
Shares repurchased	(287.7)									(287.7)
Vesting of share units				(2.2)						2.2
Stock based compensation expense				12.9
Exercises of stock options				0.7						(0.2)
Stock incentives and directors' compensation				7						0.2
Net Earnings	370				370
Cash dividends on stock					(149.4)
Change in other comprehensive income (loss), less tax							(1.3)	0.9	2.9
Balance at end of period at Dec. 31, 2019	1,666.8	130.9	164.5	509	2,323.4	(348.3)	(66.2)	0.2	(282.3)	(1,112.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of Class A Common Stock		(0.1)	0.1	0.1
Issuance of share units				(6.7)
Shares repurchased	(56.7)									(56.7)
Vesting of share units				(1.8)						1.8
Stock based compensation expense				12.4
Exercises of stock options				0.1						11.3
Stock incentives and directors' compensation				7.3						0.4
Net Earnings	344.9				344.9
Cash dividends on stock					(158.7)
Change in other comprehensive income (loss), less tax							18.1	0.4	8.6
Balance at end of period at Dec. 31, 2020	$ 1,848.3	$ 130.8	$ 164.6	$ 520.4	$ 2,509.6	$ (321.2)	$ (48.1)	$ 0.6	$ (273.7)	$ (1,155.9)

CONSOLIDATED STATEMENT OF STO_2

CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unrealized net gain on cash flow derivative instruments, less related income tax provision of $(0.1) in 2020 $(0.3) in 2019 and $(0.1) in 2018
Income tax benefit (provision) on other comprehensive income (loss)	$ (0.1)	$ (0.3)	$ (0.1)
Change in pension liability less related income tax benefit (provision) of $(2.8) in 2020, $(1.0) in 2019 and $4.3 in 2018
Income tax benefit (provision) on other comprehensive income (loss)	$ (2.8)	$ (1)	$ 4.3
Treasury Stock
Shares surrendered as proceeds and to pay taxes (in shares)	35,467	87,918	54,180

Organization and Significant Ac

Organization and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Organization and Significant Accounting Policies	Organization and Significant Accounting Policies Organization. A. O. Smith Corporation (A. O. Smith or the Company) is comprised of two reporting segments: North America and Rest of World. The Rest of World segment is primarily comprised of China, Europe and India. Both segments manufacture and market comprehensive lines of residential and commercial gas and electric water heaters, boilers, tanks and water treatment products. Both segments primarily manufacture and market in their respective regions of the world. Consolidation. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of intercompany transactions. Use of estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S.) requires management to make estimates and assumptions that affect the amounts reported in the accompanying financial statements and notes. Actual results could differ from those estimates. Fair value of financial instruments. The carrying amounts of cash, cash equivalents, marketable securities, receivables, floating rate debt and trade payables approximated fair value as of December 31, 2020 and 2019, due to the short maturities or frequent rate resets of these instruments. The fair value of term notes with insurance companies was approximately $123.3 million as of December 31, 2020 compared with the carrying amount of $113.2 million for the same date. The fair value of term notes with insurance companies was approximately $122.1 million as of December 31, 2019 compared with the carrying amount of $120.0 million. Foreign currency translation. For all subsidiaries outside the U.S., with the exception of its Barbados, Hong Kong and Mexican companies and its non-operating companies in the Netherlands, the Company uses the local currency as the functional currency. For those operations using a functional currency other than the U.S. dollar, assets and liabilities were translated into U.S. dollars at year-end exchange rates, and revenues and expenses were translated at weighted-average exchange rates. The resulting translation adjustments were recorded as a separate component of stockholders’ equity. The Barbados, Hong Kong, Mexican and Netherlands companies use the U.S. dollar as the functional currency. Gains and losses from foreign currency transactions were included in net earnings and were not significant in 2020, 2019, or 2018. Cash and cash equivalents. The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. Marketable securities. The Company considers all highly liquid investments with maturities greater than 90 days when purchased to be marketable securities. At December 31, 2020, the Company’s marketable securities consisted of bank time deposits with original maturities ranging from 180 days to 12 months and were primarily located at investment grade rated banks in China. Inventory valuation. Inventories are carried at lower of cost and net realizable value. Cost is determined on the last-in, first-out (LIFO) method for a majority of the Company’s domestic inventories, which comprised 67 percent and 65 percent of the Company’s total inventory at December 31, 2020 and 2019, respectively. Inventories of foreign subsidiaries, the remaining domestic inventories and supplies were determined using the first-in, first-out (FIFO) method. Property, plant and equipment. Property, plant and equipment are stated at cost. Depreciation is computed primarily by the straight-line method. The estimated service lives used to compute depreciation are generally 25 to 50 years for buildings, three three Goodwill and other intangibles. Goodwill and indefinite-lived intangible assets are not amortized but are reviewed for impairment on an annual basis. Separable intangible assets, primarily comprised of customer relationships, that are not deemed to have an indefinite life are amortized on a straight-line basis over their estimated useful lives which range from five Impairment of long-lived and amortizable intangible assets. Property, plant and equipment and intangible assets subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If the sum of the expected undiscounted cash flows is less than the carrying value of the related asset or group of assets, a loss is recognized for the difference between the fair value and carrying value of the asset or group of assets. Such analyses necessarily involve significant judgment. Product warranties. The Company’s products carry warranties that generally range from one rates and estimated costs of product replacement. The variables used in the calculation of the provision are reviewed by the Company at least annually. At times, warranty issues may arise which are beyond the scope of the Company’s historical experience. The Company provides for any such warranty issues as they become known and estimable. The allocation of the warranty liability between current and long-term is based on expected warranty claims to be paid in the next year as determined by historical product failure rates. The following table presents the Company’s product warranty liability activity in 2020 and 2019: Years ended December 31 (dollars in millions) 2020 2019 Balance at beginning of year $ 134.3 $ 139.4 Expense 56.1 44.3 Claims settled (48.1) (49.4) Balance at end of year $ 142.3 $ 134.3 Derivative instruments. The Company utilizes certain derivative instruments to enhance its ability to manage currency as well as raw materials price risk. The Company does not enter into contracts for speculative purposes. The fair values of all derivatives are recorded in the consolidated balance sheets. The change in a derivative’s fair value is recorded each period in current earnings or accumulated other comprehensive loss (AOCL), depending on whether the derivative is designated as part of a hedge transaction and if so, the type of hedge transaction. See Note 14, “Derivative Instruments” of the notes to consolidated financial statements for disclosure of the Company’s derivative instruments and hedging activities. Fair Value Measurements. Accounting Standards Codification (ASC) 820 Fair Value Measurements , among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring basis or nonrecurring basis. ASC 820 clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: (Level 1) observable inputs such as quoted prices in active markets; (Level 2) inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and (Level 3) unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Assets and liabilities measured at fair value are based on the market approach which are prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. Assets measured at fair value on a recurring basis are as follows (dollars in millions): Fair Value Measurement Using December 31, 2020 December 31, 2019 Quoted prices in active markets for identical assets (Level 1) $ 116.5 $ 177.4 Significant other observable inputs (Level 2) (4.3) 6.9 There were no changes in the valuation techniques used to measure fair values on a recurring basis. Revenue recognition. Substantially all of the Company’s sales are from contracts with customers for the purchase of its products. Contracts and customer purchase orders are used to determine the existence of a sales contract. Shipping documents are used to verify shipment. For substantially all of its products, the Company transfers control of products to the customer at the point in time when title and risk are passed to the customer, which generally occurs upon shipment of the product. See Note 2, “Revenue Recognition” for disclosure of the Company’s revenue recognition activities. Advertising. The majority of advertising costs are charged to operations as incurred and totaled $97.0 million, $110.7 million and $132.1 million during 2020, 2019 and 2018, respectively. Included in total advertising costs are expenses associated with store displays for water heater, water treatment and air purification products in China that are amortized over 12 to 36 months which totaled $27.0 million, $28.5 million and $38.7 million during 2020, 2019 and 2018, respectively. Research and development. Research and development costs are charged to operations as incurred and amounted to $80.7 million, $87.9 million and $94.0 million during 2020, 2019 and 2018, respectively. Environmental costs. The Company accrues for costs associated with environmental obligations when such costs are probable and reasonably estimable. Costs of estimated future expenditures are not discounted to their present value. Recoveries of environmental costs from other parties are recorded as assets when their receipt is considered probable. The accruals are adjusted as facts and circumstances change. Stock-based compensation. Compensation cost is recognized using the straight-line method over the vesting period of the award and forfeitures are recognized as they occur. In accordance with amended ASC 718, the Company recognized $4.2 million, $2.3 million, and $2.4 million of discrete income tax benefits on settled stock based compensation awards during 2020, 2019, and 2018 respectively. Income taxes. The provision for income taxes is computed using the asset and liability method, in accordance with ASC 740 Income Taxes , under which deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial reporting and tax bases of assets and liabilities and for operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using the currently enacted tax rates that apply to taxable income in effect for the years in which those tax assets are expected to be realized or settled and are classified as noncurrent in the consolidated balance sheet. The Company records a valuation allowance to reduce deferred tax assets to the amount that is believed more likely than not to be realized. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position. The tax benefits recognized in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50 percent likelihood of being realized upon settlement. Earnings per share of common stock. The Company is not required to use the two-class method of calculating earnings per share since its Class A Common Stock and Common Stock have equal dividend rights. The numerator for the calculation of basic and diluted earnings per share is net earnings. The following table sets forth the computation of basic and diluted weighted-average shares used in the earnings per share calculations: 2020 2019 2018 Denominator for basic earnings per share - weighted-average shares outstanding 161,530,589 165,450,441 170,589,345 Effect of dilutive stock options, restricted stock and share units 1,073,560 1,260,456 1,604,695 Denominator for diluted earnings per share 162,604,149 166,710,897 172,194,040 Recent Accounting Pronouncements. In December 2019, the Financial Accounting Standards Board (FASB) amended Accounting Standards Codification (ASC) 740, Income Taxes (issued under Accounting Standards Update (ASU) 2019-12, “Simplifying the Accounting for Income Taxes”). This amendment removes certain exceptions to the general principles of ASC 740, and clarifies and amends existing guidance to improve consistent application. The amendment requires adoption on January 1, 2021. The Company does not expect that the adoption of ASU 2019-12 will have a material impact on its consolidated balance sheets, statements of earnings or statements of cash flows. In January 2017, the FASB amended ASC 350, Intangibles – Goodwill and Other (issued under ASU 2017-4, “Simplifying the Test for Goodwill Impairment”). This amendment simplifies the test for goodwill impairment by only requiring an entity to perform an annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount that the carrying amount exceeds the reporting unit’s fair value. Any loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The Company adopted the amendment on January 1, 2020 and the adoption did not have an impact on its consolidated balance sheets, statements of earnings or statements of cash flows. In June 2016, the FASB issued ASC 326, Financial Instruments – Credit Losses

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Substantially all of the Company’s sales are from contracts with customers for the purchase of its products. Contracts and customer purchase orders are used to determine the existence of a sales contract. Shipping documents are used to verify shipment. For substantially all of its products, the Company transfers control of products to the customer at the point in time when title and risk are passed to the customer, which generally occurs upon shipment of the product. Each unit sold is considered an independent, unbundled performance obligation. The Company’s sales arrangements do not include other performance obligations that are material in the context of the contract. The nature, timing and amount of revenue for a respective performance obligation are consistent for each customer. The Company measures the sales transaction price based upon the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. Sales and value added taxes are excluded from the measurement of transaction price. The Company’s payment terms for the majority of its customers are 30 to 90 days from shipment. Additionally, certain customers in China pay the Company prior to the shipment of products resulting in a customer deposits liability of $90.0 million and $49.6 million at December 31, 2020 and December 31, 2019, respectively. Customer deposit liabilities are short-term in nature and are recognized into revenue within one year of receipt. The Company assesses the collectability of customer receivables based on the creditworthiness of a customer as determined by credit checks and analysis, as well as the customer’s payment history. In determining the allowance for doubtful accounts, the Company also considers various factors including the aging of customer accounts and historical write-offs. In addition, the Company monitors other risk factors including forward-looking information when establishing adequate allowances for doubtful accounts, which reflects the current estimate of credit losses expected to be incurred over the life of the receivables. The Company’s allowance for doubtful accounts was $5.6 million at December 31, 2020 and $6.7 million at December 31, 2019. Rebates and incentives are based on pricing agreements and are tied to sales volume. The amount of revenue is reduced for variable consideration related to customer rebates which are calculated using expected values and are based on program specific factors such as expected rebate percentages based on expected volumes. In situations where the customer has the right to return eligible products, the Company reduces revenue for its estimates of expected product returns, which are primarily based on an analysis of historical experience. Changes in such accruals may be required if actual sales volume differs from estimated sales volume or if future returns differ from historical experience. Shipping and handling costs billed to customers are included in net sales and the related costs are included in cost of products sold and are activities performed to fulfill the promise to transfer products. Disaggregation of Net Sales The Company is comprised of two reporting segments: North America and Rest of World. The Rest of World segment is primarily comprised of China, Europe and India. Both segments manufacture and market comprehensive lines of residential and commercial gas and electric water heaters, boilers, tanks and water treatment products. Both segments primarily manufacture and market in their respective regions of the world. As each segment manufactures and markets products in its respective region of the world, the Company has determined that geography is the primary factor in reporting its sales. The Company further disaggregates its North America segment sales by major product line as each of North America’s major product lines is sold through distinct distribution channels and these product lines may be impacted differently by certain economic factors. Within the Rest of World segment, particularly in China and India, the Company’s major customers purchase across the Company’s product lines, utilizing the same distribution channels regardless of product type. In addition, the impact of economic factors is unlikely to be differentiated by product line in the Rest of World segment. The North America segment major product lines are defined as the following: Water heaters The Company’s water heaters are open water heating systems that heat potable water. Typical applications for water heaters include residences, restaurants, hotels and motels, office buildings, laundries, car washes and small businesses. The Company sells residential and commercial water heater products and related parts through its wholesale distribution channel, which includes more than 1,200 independent wholesale plumbing distributors. The Company also sells residential water heaters and related parts through retail and maintenance, repair and operations (MRO) channels. A significant portion of the Company’s water heater sales in the North America segment is derived from the replacement of existing products. Boilers The Company’s boilers are closed loop water heating systems used primarily for space heating or hydronic heating. The Company’s boilers are primarily used in applications in commercial settings for hospitals, schools, hotels and other large commercial buildings while residential boilers are used in homes, apartments and condominiums. The Company’s boiler distribution channel is comprised primarily of manufacturer representative firms, with the remainder of its boilers distributed through wholesale channels. The Company’s boiler sales in the North America segment are derived from a combination of replacement of existing products and new construction. Water treatment products The Company’s water treatment products range from point-of-entry water softeners, solutions for problem well water, and whole-home water filtration products to on-the-go filtration bottles and point-of-use carbon and reverse osmosis products. Typical applications for the Company’s water treatment products include residences, restaurants, hotels and offices. The Company sells water treatment products through its retail and wholesale distribution channels, similar to water heater products and related parts. The Company’s water treatment products are also sold through independent water quality dealers as well as directly to consumers including through internet sales channels. A portion of the Company’s sales of water treatment products in the North America segment is comprised of replacement filters. The following table disaggregates the Company’s net sales by segment. As described above, the Company’s North America segment sales are further disaggregated by major product line. In addition, the Company’s Rest of World segment sales are disaggregated by China and all other Rest of World. Years ended December 31 (dollars in millions) 2020 2019 2018 North America Water heaters and related parts $ 1,753.9 $ 1,742.6 $ 1,757.0 Boilers and related parts 187.2 199.5 200.4 Water treatment products (1) 177.2 141.4 87.3 Total North America 2,118.3 2,083.5 2,044.7 Rest of World China $ 701.0 $ 827.2 $ 1,070.4 All other Rest of World 99.3 108.6 103.2 Total Rest of World 800.3 935.8 1,173.6 Inter-segment sales (23.3) (26.6) (30.4) Total Net Sales $ 2,895.3 $ 2,992.7 $ 3,187.9 (1) Includes the results of Water-Right, Inc. and its affiliated entities (Water-Right) from April 8, 2019, the date of acquisition.

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisition	Acquisition On April 8, 2019, the Company acquired 100 percent of the shares of Water-Right, a Wisconsin-based water treatment company. With the addition of Water-Right, the Company grew its North America water treatment platform. Water-Right is included in the Company’s North America segment. The Company paid an aggregate cash purchase price of $107.0 million, net of cash acquired. In addition, the Company established a $4.0 million escrow to satisfy any potential obligations of the former owners of Water-Right, should they arise. During 2020, the Company released $3.9 million of the escrow to the previous owners of Water-Right. The remaining balance of $0.1 million is scheduled to be disbursed in the second quarter of 2021. The following table summarizes the allocation of the fair value of the assets acquired and liabilities assumed at the date of acquisition of Water-Right for purposes of allocating the purchase price. Significant assumptions used to estimate the fair value of intangible assets acquired include discount rates and certain assumptions that form the basis of the forecasted results, including revenue growth rates, attrition rates and royalty rates. The $60.4 million of acquired identifiable intangible assets was comprised of the following: $40.2 million of customer relationships being amortized over 20 years, $19.0 million of trademarks not subject to amortization, and $1.2 million of non-compete agreements being amortized over 7.5 years. April 8, 2019 (dollars in millions) Current assets, net of cash acquired $ 9.7 Property, plant and equipment 8.6 Intangible assets 60.4 Goodwill 31.0 Total assets acquired 109.7 Current liabilities (2.7) Net assets acquired $ 107.0 As required under ASC 805 Business Combinations , Water-Right’s results of operations have been included in the Company’s consolidated financial statements from April 8, 2019, the date of acquisition.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases The Company’s lease portfolio consists of operating leases for buildings and equipment, such as forklifts and copiers, primarily in the United States and China. The Company defines a lease as a contract that gives the Company the right to control the use of a physical asset for a stated term. The Company pays the lessor for that right, with a series of payments defined in the contract and a corresponding right of use operating lease asset and liability are recorded. The Company has elected not to record leases with an initial term of 12 months or less on its consolidated balance sheet. To determine balance sheet amounts, required legal payments are discounted using the Company’s incremental borrowing rate as of the inception of the lease. The incremental borrowing rate is the rate of interest that the Company would incur if it were to borrow, on a collateralized basis, an amount equal to the value of the leased item over a similar term, in a similar economic environment. Variable lease components not based on an index or rate are excluded from the measurement of the lease asset and liability and expensed as incurred for all asset classes. Certain leases include one or more options to renew or terminate. Renewal terms can extend the lease term from one Supplemental balance sheet information related to leases is as follows: (dollars in millions) December 31, 2020 December 31, 2019 Liabilities Short term: Accrued liabilities $ 11.1 $ 12.0 Long term: Operating lease liabilities 34.4 38.7 Total operating lease liabilities $ 45.5 $ 50.7 Less: Rent incentives and deferrals (3.9) (3.8) Assets Operating lease assets $ 41.6 $ 46.9 Lease Term and Discount Rate December 31, 2020 Weighted-average remaining lease term 10 years Weighted-average discount rate 3.49% The components of lease expense were as follows: (dollars in millions) Lease Expense (1) Classification Year ended December 31, 2020 Year ended December 31, 2019 Operating lease expense Cost of products sold $ 3.1 $ 3.0 Selling, general and administrative expenses 16.0 17.6 (1) Includes short-term lease expense of $1.8 million for the year ended December 31, 2020. Includes variable lease cost of $1.6 million for the year ended December 31, 2020. Includes short-term lease expense of $2.0 million for the year ended December 31, 2019. Includes variable lease cost of $2.1 million for the year ended December 31, 2019. Rent expense, including payments under operating leases was $24.0 million in 2018. Maturities of lease liabilities were as follows: (dollars in millions) December 31, 2020 2021 $ 12.4 2022 10.2 2023 5.6 2024 4.6 2025 2.9 After 2025 21.0 Total lease payments 56.7 Less: imputed interest (11.2) Present value of operating lease liabilities $ 45.5

Severance, Restructuring and Im

Severance, Restructuring and Impairment Expenses	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Severance, Restructuring and Impairment Expenses	Severance, Restructuring and Impairment Expenses To align its business to current market conditions, the Company recognized $7.7 million of pre-tax severance and restructuring expenses during the year ended December 31, 2020. These expenses were comprised of $6.8 million severance costs and $0.9 million of other restructuring expenses, as well as a corresponding $1.4 million tax benefit. Of the $7.7 million expense recognized during the year ended December 31, 2020, $2.7 million was related to the North America segment and $5.0 million was related to the Rest of World segment. The Company’s severance and restructuring actions were completed in 2020. On March 21, 2018, the Company announced a move of manufacturing operations from its Renton, Washington facility to other U.S. facilities. The Company recognized $6.7 million of restructuring and impairment expenses, comprised of $4.0 million of severance and compensation related costs, lease exit costs of $2.1 million and impairment charges related to long-lived assets totaling $0.6 million, as well as a corresponding $1.7 million tax benefit related to the charges. As of December 31, 2019, the consolidation of the Renton facility to other U.S. facilities was complete. The following table presents an analysis of the Company’s restructuring reserve for the years ended December 31, 2020, 2019, and 2018: (dollars in millions) Severance Restructuring Expenses Fixed Assets Total Balance at January 1, 2018 $ — $ — $ — $ — Charges 4.0 2.1 0.6 6.7 Cash payments and disposals (3.8) (0.8) (0.6) (5.2) Balance at December 31, 2018 0.2 1.3 — 1.5 Cash payments and disposals (0.2) (0.8) — (1.0) Balance at December 31, 2019 — 0.5 — 0.5 Charges 6.8 0.9 — 7.7 Cash payments and disposals (5.1) (1.4) — (6.5) Balance at December 31, 2020 $ 1.7 $ — $ — $ 1.7

Statement of Cash Flows

Statement of Cash Flows	12 Months Ended
	Dec. 31, 2020
Supplemental Cash Flow Elements [Abstract]
Statement of Cash Flows	Statement of Cash Flows Supplemental cash flow information is as follows: Years ended December 31 (dollars in millions) 2020 2019 2018 Net change in current assets and liabilities, net of acquisitions: Receivables $ 4.5 $ 62.4 $ (54.6) Inventories 2.9 6.3 (7.7) Other current assets 4.7 (4.8) 10.0 Trade payables 85.6 (35.4) 8.8 Accrued liabilities, including payroll and benefits 29.3 14.2 (3.5) Income taxes 3.4 (10.1) 7.0 $ 130.4 $ 32.6 $ (40.0)

Inventories

Inventories	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventories	Inventories December 31 (dollars in millions) 2020 2019 Finished products $ 143.4 $ 136.8 Work in process 21.8 21.7 Raw materials 159.2 168.3 Inventories, at FIFO cost 324.4 326.8 LIFO reserve (24.3) (23.8) $ 300.1 $ 303.0 The Company recognized after-tax LIFO income of $(0.2) million, $(0.7) million and $(0.4) million in 2020, 2019 and 2018, respectively.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment December 31 (dollars in millions) 2020 2019 Land $ 11.6 $ 11.6 Buildings 349.2 334.1 Equipment 729.7 686.9 Software 132.1 124.3 1,222.6 1,156.9 Accumulated depreciation and amortization (681.3) (611.5) $ 541.3 $ 545.4

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Changes in the carrying amount of goodwill during the years ended December 31, 2020 and 2019 consisted of the following: (dollars in millions) North America Rest of World Total Balance at December 31, 2018 $ 453.9 $ 59.1 $ 513.0 Acquisition 31.0 — 31.0 Currency translation adjustment 2.0 — 2.0 Balance at December 31, 2019 486.9 59.1 546.0 Currency translation adjustment 0.8 — 0.8 Balance at December 31, 2020 $ 487.7 $ 59.1 $ 546.8 The carrying amount of other intangible assets consisted of the following: 2020 2019 December 31 (dollars in millions) Gross Accumulated Net Gross Accumulated Net Amortizable intangible assets: Patents $ 3.7 $ (3.7) $ — $ 3.7 $ (3.5) $ 0.2 Customer lists 278.0 (138.1) 139.9 278.0 (123.6) 154.4 Total amortizable intangible assets 281.7 (141.8) 139.9 281.7 (127.1) 154.6 Indefinite-lived intangible assets: Trade names 184.0 — 184.0 183.8 — 183.8 Total intangible assets $ 465.7 $ (141.8) $ 323.9 $ 465.5 $ (127.1) $ 338.4 Amortization expenses of other intangible assets of $14.5 million, $15.8 million, and $14.3 million were recorded in 2020, 2019 and 2018, respectively. In the future, excluding the impact of any future acquisitions, the Company expects amortization expense of approximately $12.2 million annually and the intangible assets will be amortized over a weighted-average period of 13 years. The Company concluded that no goodwill impairment existed at the time of the annual impairment tests which were performed in the fourth quarters of 2020, 2019 and 2018. No impairments of other intangible assets were recorded in 2020, 2019 and 2018.

Debt

Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Debt	Debt December 31 (dollars in millions) 2020 2019 Bank credit lines, average year-end interest rates of —% for 2020 and 2.4% for 2019 $ — $ 4.7 Revolving credit agreement borrowings, average year-end interest rates of —% for 2020 and 2.8% for 2019 — 85.0 Commercial paper, average year-end interest rates of —% for 2020 and 2.2% for 2019 — 74.3 Term notes with insurance companies, expiring 2029-2034, average year-end interest rates of 3.3% for 2020 and 3.3% for 2019 113.2 120.0 113.2 284.0 Long-term debt due within one year (6.8) (6.8) Long-term debt $ 106.4 $ 277.2 In December 2016, the Company completed a $500 million multi-year multi-currency revolving credit agreement with a group of nine banks, which expires on December 15, 2021. The facility has an accordion provision which allows it to be increased up to $700 million if certain conditions (including lender approval) are satisfied. Borrowings under the Company’s bank credit lines and commercial paper borrowings are supported by the revolving credit agreement. As a result of the long-term nature of this facility, the commercial paper and credit line borrowings are classified as long-term debt at December 31, 2019. As of December 31, 2020 there were no commercial paper or credit line borrowings. At its option, the Company either maintains cash balances or pays fees for bank credit and services. The company has fixed-rate interest expense obligations of $22.2 million on outstanding debt as of December 31, 2020. Scheduled maturities of long-term debt within each of the five years subsequent to December 31, 2020 are as follows: Years ending December 31 (dollars in millions) Amount 2021 $ 6.8 2022 6.8 2023 10.0 2024 10.0 2025 10.0

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity The Company’s authorized capital consists of three million shares of Preferred Stock $1 par value, 27 million shares of Class A Common Stock $5 par value, and 240 million shares of Common Stock $1 par value. The Common Stock has equal dividend rights with Class A Common Stock and is entitled, as a class, to elect one-third of the Board of Directors and has 1/10th vote per share on all other matters. Class A Common Stock is convertible to Common Stock on a one for one basis. There were 12,372 shares during 2020, 10,442 shares during 2019 and 48,232 shares during 2018, of Class A Common Stock converted into Common Stock. Regular dividends paid on the A. O. Smith Corporation Class A Common Stock and Common Stock amounted to $0.98, $0.90 and $0.76 per share in 2020, 2019 and 2018, respectively. In the second quarter of 2019, the Company's Board of Directors approved adding three million shares of Common Stock to an existing discretionary share repurchase authority. Under the share repurchase program, the Common Stock may be purchased through a combination of Rule 10b5-1 automatic trading plan and discretionary purchases in accordance with applicable securities laws. The number of shares purchased and the timing of the purchases will depend on a number of factors, including share price, trading volume and general market conditions, as well as working capital requirements, general business conditions and other factors, including alternative investment opportunities. The stock repurchase authorization remains effective until terminated by the Board of Directors which may occur at any time, subject to the parameters of any Rule 10b5-1 automatic trading plan that the Company may then have in effect. Due to the uncertainty surrounding the impact of the global COVID-19 pandemic, the Company suspended its share repurchases on March 18, 2020. In 2020, the Company repurchased 1,348,391 shares at an average price of $42.02 per share and at a total cost of $56.7 million. As of December 31, 2020, there were 1,613,824 shares remaining on the existing repurchase authorization. In 2019, the Company repurchased 6,113,038 shares at a cost of $287.7 million. In 2018, the Company repurchased 3,797,800 shares at a cost of $202.6 million. At December 31, 2020, a total of 130,380 and 28,807,455 shares of Class A Common Stock and Common Stock, respectively, were held as treasury stock. At December 31, 2019, a total of 130,380 and 28,205,806 shares of Class A Common Stock and Common Stock, respectively, were held as treasury stock. Changes to accumulated other comprehensive loss by component are as follows: (dollars in millions) Years ended December 31, 2020 2019 Cumulative foreign currency translation Balance at beginning of period $ (66.2) $ (64.9) Other comprehensive gain (loss) before reclassifications 18.1 (1.3) Balance at end of period (48.1) (66.2) Unrealized net gain (loss) on cash flow derivatives Balance at beginning of period 0.2 (0.7) Other comprehensive gain (loss) before reclassifications 1.7 (0.3) Realized (gains) losses on derivatives reclassified to cost of products sold (net of tax provision (benefit) of $0.4 and $(0.5) in 2020 and 2019, respectively) (1) (1.3) 1.2 Balance at end of period 0.6 0.2 Pension liability Balance at beginning of period (282.3) (285.2) Other comprehensive (loss) before reclassifications (6.3) (9.5) Amounts reclassified from accumulated other comprehensive loss (1) 14.9 12.4 Balance at end of period (273.7) (282.3) Total accumulated other comprehensive loss, end of period $ (321.2) $ (348.3) (1) Amounts reclassified from accumulated other comprehensive loss: Realized (gains) loss on derivatives reclassified to cost of products sold $ (1.7) $ 1.7 Tax provision (benefit) 0.4 (0.5) Reclassification net of tax $ (1.3) $ 1.2 Amortization of pension items: Actuarial losses $ 20.2 (2) $ 16.8 (2) Prior year service cost (0.4) (2) (0.5) (2) 19.8 16.3 Tax benefit (4.9) (3.9) Reclassification net of tax $ 14.9 $ 12.4 (2) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 13 “Pensions and Other Post-retirement Benefits” for additional details.

Stock Based Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock Based Compensation	Stock Based Compensation The Company adopted the A. O. Smith Combined Incentive Compensation Plan (the Plan) effective January 1, 2007. The Plan was most recently reapproved by stockholders on April 15, 2020. The Plan is a continuation of the A. O. Smith Combined Executive Incentive Compensation Plan which was originally approved by stockholders in 2002. The number of shares available for granting of options or share units at December 31, 2020, was 3,395,216 which includes 2,400,000 additional shares that were authorized on April 15, 2020 at the Company's annual meeting of stockholders. Upon stock option exercise or share unit vesting, shares are issued from treasury stock. Total stock based compensation expense recognized in 2020, 2019 and 2018 was $12.7 million, $13.3 million and $10.1 million, respectively. Stock Options The stock options granted in 2020, 2019 and 2018 have three year pro rata vesting from the date of grant. Stock options are issued at exercise prices equal to the fair value of the Company’s Common Stock on the date of grant. For active employees, all options granted in 2020, 2019 and 2018 expire ten years after the date of grant. The Company’s stock options are expensed ratably over the three year vesting period. Included in stock option expense for 2020, 2019 and 2018 was $6.2 million, $6.4 million and $4.4 million, respectively. Included in the stock option expense recognized in 2020, 2019 and 2018 is expense associated with the accelerated vesting of stock option awards for certain employees who either are retirement eligible or become retirement eligible during the vesting period. Changes in options, all of which relate to the Company’s Common Stock, were as follows: Years Ended December 31 2020 2019 2018 Number of Weighted Number of Weighted Number of Weighted Number of shares under options: Outstanding at beginning of year 2,728,350 $ 37.64 2,432,689 $ 33.05 2,263,126 $ 27.73 Granted 798,970 42.50 557,045 49.49 373,220 61.62 Exercised (1) (662,215) 19.59 (249,840) 18.55 (176,302) 22.93 Forfeited (79,451) 48.98 (11,544) 54.02 (27,355) 47.95 Outstanding at end of year (2) 2,785,654 43.01 2,728,350 37.64 2,432,689 33.05 Exercisable at end of year (3) 1,529,464 40.35 1,820,743 30.07 1,665,184 24.52 (1) The total intrinsic value of options exercised in 2020, 2019 and 2018 was $21.3 million, $7.7 million and $6.8 million, respectively. (2) The weighted average remaining contractual life of options outstanding was 8 years at December 31, 2020, and 7 years at December 31, 2019, and December 31, 2018, respectively. The aggregate intrinsic value of options outstanding at December 31, 2020 was $35.3 million. (3) The weighted average remaining contractual life of options exercisable was 6 years at December 31, 2020, December 31, 2019 and December 31, 2018. The aggregate intrinsic value of options exercisable at December 31, 2020 was $23.7 million. Number of Options Weighted Avg. Per Nonvested options at beginning of year 907,607 $ 52.82 Granted 798,970 42.50 Vested (416,432) 53.20 Forfeited (33,955) 49.06 Nonvested options at end of year 1,256,190 46.23 The weighted-average fair value per option at the date of grant during 2020, 2019 and 2018, using the Black-Scholes option-pricing model, was $8.17, $10.83 and $14.80, respectively. Assumptions were as follows: 2020 2019 2018 Expected life (years) 5.7 5.5 5.7 Risk-free interest rate 1.5 % 2.7 % 2.9 % Dividend yield 2.1 % 1.6 % 1.0 % Expected volatility 23.7 % 22.8 % 22.1 % The expected lives of options for purposes of these models are based on historical exercise behavior. The risk free interest rates for purposes of these models are based on the U.S. Treasury yield curve in effect on the date of grant for the respective expected lives of the option. The expected dividend yields for purposes of these models are based on the dividends paid in the preceding four quarters divided by the grant date market value of the Common Stock. The expected volatility for purposes of these models are based on the historical volatility of the Common Stock. Restricted Stock and Share Units Participants may also be awarded shares of restricted stock or share units under the Plan. Share units vest three years after the date of grant. The Company granted 174,420, 140,102 and 106,581 share units under the plan in 2020, 2019 and 2018, respectively. The share units were valued at $7.4 million, $6.9 million and $6.6 million at the date of issuance in 2020, 2019 and 2018, respectively, based on the price of the Company’s Common Stock at the date of grant. The share units are recognized as compensation expense ratably over the three-year vesting period; however, included in share unit expense was expense associated with accelerated vesting of share unit awards for certain employees who are retirement eligible or will become retirement eligible during the vesting period. Stock based compensation expense of $6.5 million, $6.9 million and $5.7 million was recognized in 2020, 2019 and 2018, respectively. Certain non-U.S.-based employees receive the cash value of the share price at the vesting date in lieu of shares. Unvested cash-settled awards are remeasured at each reporting period. A summary of share unit activity under the plan is as follows: Number of Units Weighted-Average Issued and unvested at January 1, 2020 366,102 $ 49.92 Granted 174,420 42.64 Vested (100,735) 49.21 Forfeited (13,001) 51.25 Issued and unvested at December 31, 2020 426,786 46.99

Pension and Other Post-retireme

Pension and Other Post-retirement Benefits	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Pension and Other Post-retirement Benefits	Pension and Other Post-retirement Benefits The Company provides retirement benefits for all U.S. employees including benefits for employees of previously owned businesses which were earned up to the date of sale. The Company also has two foreign pension plans, neither of which is material to the Company’s financial position. The Company has a defined contribution plan which matches 100 percent of the first one percent of contributions made by participating employees and matches 50 percent of the next five percent of employee contributions. The Company also has defined contribution plans for certain hourly employees which provide for matching Company contributions. The Company also has a defined benefit plan for salaried employees and its non-union hourly workforce. In 2009, the Company announced U.S. employees hired after January 1, 2010, would not participate in the defined benefit plan, and benefit accruals for the majority of current salaried and hourly employees sunset on December 31, 2014. An additional Company contribution is made to the defined contribution plan in lieu of benefits earned in a defined benefit plan. The Company also has defined benefit and contribution plans for certain union hourly employees. The Company has unfunded defined-benefit post-retirement plans covering certain hourly and salaried employees that provide medical and life insurance benefits from retirement to age 65. Certain hourly employees retiring after January 1, 1996, are subject to a maximum annual benefit and salaried employees hired after December 31, 1993, are not eligible for post-retirement medical benefits. Obligations and Funded Status Pension and Post-retirement Disclosure Information under ASC 715, Compensation – Retirement Benefits (ASC 715) The following tables present the changes in benefit obligations, plan assets and funded status for domestic pension and post-retirement plans and the components of net periodic benefit costs. Pension Benefits Post-retirement Benefits Years ended December 31 (dollars in millions) 2020 2019 2020 2019 Accumulated benefit obligation (ABO) at December 31 $ 869.0 $ 868.7 N/A N/A Change in projected benefit obligations (PBO) PBO at beginning of year $ (869.3) $ (833.8) $ (8.0) $ (7.0) Service cost (1.5) (1.6) — (0.1) Interest cost (23.0) (31.6) (0.1) (0.3) Participant contributions — — (0.1) (0.1) Plan amendments — — 2.0 — Actuarial loss including assumption changes (63.8) (98.6) (0.8) (1.2) Benefits paid 87.8 96.3 1.1 0.7 PBO at end of year $ (869.8) $ (869.3) $ (5.9) $ (8.0) Change in fair value of plan assets Plan assets at beginning of year $ 832.4 $ 777.5 $ — $ — Actual return on plan assets 104.1 143.4 — — Contribution by the Company 10.1 7.8 0.5 0.5 Participant contributions — — 0.1 0.1 Benefits paid (87.8) (96.3) (0.6) (0.6) Plan assets at end of year $ 858.8 $ 832.4 $ — $ — Funded status $ (11.0) $ (36.9) $ (5.9) $ (8.0) Amount recognized in the balance sheet Noncurrent assets $ 3.0 $ — $ — $ — Current liabilities (0.6) (9.3) (0.5) (0.5) Non-current liabilities (13.4) (27.6) (5.4) (7.5) Net pension liability at end of year $ (11.0) * $ (36.9) * $ (5.9) $ (8.0) Amounts recognized in accumulated other comprehensive loss before tax Net actuarial loss (gain) $ 452.0 $ 463.1 $ 0.6 $ (0.2) Prior service cost 1.0 0.5 (3.3) (1.8) Total recognized in accumulated other comprehensive loss $ 453.0 $ 463.6 $ (2.7) $ (2.0) *In addition, the Company has a liability for a foreign pension plan of $0.2 million at December 31, 2020 and 2019. The actuarial loss in the current year for both the pension and post-retirement benefit plans was primarily due to the change in the discount rate. Pension Benefits Post-retirement Benefits Years ended December 31 (dollars in millions) 2020 2019 2018 2020 2019 2018 Net periodic (benefit) cost Service cost $ 1.5 $ 1.6 $ 2.0 $ — $ 0.1 $ 0.1 Interest cost 23.0 31.6 28.9 0.1 0.3 0.3 Expected return on plan assets (51.9) (57.3) (58.1) — — — Amortization of unrecognized: Net actuarial loss 20.2 16.8 19.0 — — — Prior service cost (0.4) (0.5) (0.5) (0.5) (0.4) (0.4) Defined-benefit plan income (7.6) (7.8) (8.7) (0.4) — $ — Curtailment and other one-time charges 2.5 1.6 — (0.5) — — Various U.S. defined contribution plans cost 14.4 13.3 12.2 — — — $ 9.3 $ 7.1 $ 3.5 $ (0.9) $ — $ — Other changes in plan assets and projected benefit obligation recognized in other comprehensive loss Net actuarial loss (gain) $ 11.7 $ 12.6 $ 36.1 $ 0.8 $ 1.2 $ (0.6) Amortization of net actuarial loss (22.8) (18.4) (19.0) — — — Prior service credit — — — (2.0) — — Amortization of prior service cost 0.4 0.5 0.5 0.5 0.4 0.4 Total recognized in other comprehensive loss (10.7) (5.3) 17.6 (0.7) 1.6 (0.2) Total recognized in net periodic (benefit) cost and other comprehensive loss $ (15.8) $ (11.5) $ 8.9 $ (1.6) $ 1.6 $ (0.2) The 2020 and 2019 after tax adjustments for additional minimum pension liability resulted in other comprehensive gain of $8.6 million and $2.9 million, respectively. Actuarial assumptions used to determine benefit obligations at December 31 are as follows: Pension Benefits Post-retirement Benefits 2020 2019 2020 2019 Discount rate 2.44 % 3.18 % 2.04 % 3.40 % Actuarial assumptions used to determine net periodic benefit cost for the year ended December 31 are as follows: Pension Benefits Post-retirement Benefits Years ended December 31 2020 2019 2018 2020 2019 2018 Discount rate 3.18 % 4.32 % 3.65 % 2.95 % 4.45 % 3.79 % Expected long-term return on plan assets 6.75 % 7.15 % 7.15 % n/a n/a n/a Rate of compensation increase 4.00 % 4.00 % 4.00 % 4.00 % 4.00 % 4.00 % Assumed health care cost trend rates Assumed health care cost trend rates as of December 31 are as follows: 2020 2019 Health care cost trend rate assumed for next year 7.40 % 7.70 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate 2029 2029 Plan Assets The Company’s pension plan weighted asset allocations as of December 31 by asset category are as follows: Asset Category 2020 2019 Equity securities 44 % 42 % Debt securities 46 47 Real estate 9 10 Private equity 1 1 100 % 100 % The following tables present the fair value measurement of the Company’s plan assets as of December 31, 2020 and 2019 (dollars in millions): December 31, 2020 Asset Category Total Quoted Prices in Significant Other Significant Non- Short-term investments $ 13.7 $ — $ 13.7 $ — Equity securities Common stocks 136.5 136.5 — — Commingled equity funds 132.0 — 132.0 — Fixed income securities U.S. Treasury securities 44.3 44.3 — — Other fixed income securities 229.1 — 229.1 — Commingled fixed income funds 119.5 — 119.5 — Options (8.1) — (8.1) — Other types of investments Mutual funds 105.6 — 105.6 — Real estate funds 79.8 — — 79.8 Private equity 4.9 — — 4.9 Total fair value of plan asset investments $ 857.3 $ 180.8 $ 591.8 $ 84.7 Non-investment plan assets 1.5 Total plan assets $ 858.8 December 31, 2019 Asset Category Total Quoted Prices in Significant Other Significant Non- Short-term investments $ 14.6 $ 2.8 $ 11.8 $ — Equity securities Common stocks 127.0 127.0 — — Commingled equity funds 113.4 — 113.4 — Fixed income securities U.S. Treasury securities 49.8 49.8 — — Other fixed income securities 225.1 — 225.1 — Commingled fixed income funds 114.0 — 114.0 — Options (10.8) (10.8) Other types of investments Mutual funds 104.9 — 104.9 — Real estate funds 82.3 — — 82.3 Private equity 8.6 — — 8.6 Total fair value of plan asset investments $ 828.9 $ 179.6 $ 558.4 $ 90.9 Non-investment plan assets 3.4 Total plan assets $ 832.3 The short-term investments included in the Company’s plan assets consist of cash and cash equivalents. The fair value of the remaining categories of the Company’s plan assets are valued as follows: equity securities are valued using the closing stock price on a national securities exchange, which reflects the last reported sales price on the last business day of the year; fixed income securities are valued using institutional bond quotes, which are based on various market and industry inputs; mutual funds and real estate funds are valued using the net asset value of the fund, which is based on the fair value of the underlying securities; Options are valued using the closings market value on the last day of the year; and private equity investments are valued at the estimated fair value at the previous quarter end, which is based on the proportionate share of the underlying portfolio investments. The following table presents a reconciliation of the fair value measurements using significant unobservable inputs (Level 3) as of December 31, 2020 and 2019 (dollars in millions): Real estate Private Total Balance at December 31, 2018 $ 80.4 $ 13.2 $ 93.6 Actual return (loss) on plan assets: Relating to assets still held at the reporting date 1.9 — 1.9 Relating to assets sold during the period — (1.4) (1.4) Purchases, sales and settlements — (3.2) (3.2) Balance at December 31, 2019 82.3 8.6 90.9 Actual (loss) return on plan assets: Relating to assets still held at the reporting date (2.5) (2.2) (4.7) Relating to assets sold during the period — (0.1) (0.1) Purchases, sales and settlements — (1.4) (1.4) Balance at December 31, 2020 $ 79.8 $ 4.9 $ 84.7 The Company’s investment policies employ an approach whereby a diversified blend of equity and bond investments is used to maximize the long-term return of plan assets for a prudent level of risk. Equity investments are diversified across domestic and non-domestic stocks, as well as growth, value, and small to large capitalizations. Bond investments include corporate and government issues, with short-, mid- and long-term maturities, with a focus on investment grade when purchased. The Company’s target allocation to equity managers is between 30 to 60 percent with the remainder allocated primarily to bonds, real estate, private equity managers and cash. Investment and market risks are measured and monitored on an ongoing basis through regular investment portfolio reviews, annual liability measurements and periodic asset/liability studies. The Company’s actual asset allocations are in line with target allocations. The Company regularly reviews its actual asset allocation and periodically rebalances its investments to the targeted allocation when considered appropriate. There was no Company stock included in plan assets at December 31, 2020. Cash Flows The Company was not required to and did not make any contributions in 2020. The Company is not required to make a contribution in 2021. Estimated Future Payments The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid: Years ended December 31 (dollars in millions) Pension Benefits Post-retirement 2021 $ 56.7 $ 0.5 2022 56.6 0.5 2023 55.8 0.5 2024 54.8 0.5 2025 54.0 0.5 2026 – 2030 264.0 2.0

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments The Company utilizes certain derivative instruments to enhance its ability to manage currency exposure as well as raw materials price risk. Derivative instruments are entered into for periods consistent with the related underlying exposures and do not constitute positions independent of those exposures. The Company does not enter into contracts for speculative purposes. The contracts are executed with major financial institutions with no credit loss anticipated for failure of the counterparties to perform. Cash Flow Hedges With the exception of its net investment hedges, the Company designates all of its hedging instruments as cash flow hedges. For derivative instruments that are designated and qualify as a cash flow hedge (i.e., hedging the exposure to variability in expected future cash flows that is attributable to a particular risk), gains or losses on the derivative instrument are reported as a component of other comprehensive loss, net of tax, and are reclassified into earnings in the same line item associated with the forecasted transaction and in the same period or periods during which the hedged transaction affects earnings. Foreign Currency Forward Contracts The Company is exposed to foreign currency exchange risk as a result of transactions in currencies other than the functional currency of certain subsidiaries. The Company utilizes foreign currency forward purchase and sale contracts to manage the volatility associated with foreign currency purchases, sales and certain intercompany transactions in the normal course of business. Principal currencies for which the Company utilizes foreign currency forward contracts include the British pound, Canadian dollar, Euro and Mexican peso. Gains and losses on these instruments are recorded in accumulated other comprehensive loss, net of tax, until the underlying transaction is recorded in earnings. When the hedged item is realized, gains or losses are reclassified from accumulated other comprehensive loss to the consolidated statement of earnings. The assessment of effectiveness for forward contracts is based on changes in the forward rates. These hedges have been determined to be effective. The majority of the amounts in accumulated other comprehensive loss for cash flow hedges are expected to be reclassified into earnings within one year. The following table summarizes, by currency, the contractual amounts of the Company’s foreign currency forward contracts that are designated as cash flow hedges: December 31 (dollars in millions) 2020 2019 Buy Sell Buy Sell British pound $ — $ 1.0 $ — $ 1.3 Canadian dollar — 79.7 — 49.7 Euro 32.7 — 36.0 — Mexican peso 16.5 — 18.6 — Total $ 49.2 $ 80.7 $ 54.6 $ 51.0 Commodity Futures Contracts In addition to entering into supply arrangements in the normal course of business, the Company also enters into futures contracts to fix the cost of certain raw material purchases, principally steel, with the objective of minimizing changes in cost due to market price fluctuations. The hedging strategy for achieving this objective is to purchase steel futures contracts on the New York Metals Exchange (NYMEX) and copper futures contracts on the open market of the London Metals Exchange (LME) or over the counter contracts based on the LME. With NYMEX, the Company is required to make cash deposits on unrealized losses on steel derivative contracts. There were no outstanding commodity futures contracts as of December 31, 2020 and 2019. Net Investment Hedges The Company enters into certain foreign currency forward contracts to hedge the exposure to a portion of the Company’s net investments in certain non-U.S. subsidiaries against the effect of exchange rate fluctuations on the translation of foreign currency balances to the U.S. dollar. For the derivative instruments that are designated and qualify as net investment hedges, gains and losses are reported in other comprehensive loss where they offset gains and losses recorded on the Company’s net investments in its non-U.S. subsidiaries. These hedges are determined to be effective. The Company recognized $(3.1) million and $— million of after-tax losses associated with hedges of a net investment in non-U.S. subsidiaries in currency translation adjustment in other comprehensive income in 2020 and 2019, respectively. The contractual amount of the Company’s foreign currency forward contracts that are designated as net investment hedges is $100.0 million as of December 31, 2020. The following tables present the impact of derivative contracts on the Company’s financial statements. Fair value of derivatives designated as hedging instruments under ASC 815: Fair Value December 31 (dollars in millions) Balance Sheet Location 2020 2019 Foreign currency contracts Other current assets $ 2.7 $ 8.4 Accrued liabilities (7.0) (1.5) Total derivatives designated as hedging instruments $ (4.3) $ 6.9 The effect of cash flow hedges on the condensed consolidated statement of earnings: Years ended December 31 (dollars in millions) Derivatives in ASC 815 cash flow Amount of gain (loss) Location of gain (loss) Amount of gain 2020 2019 2020 2019 Foreign currency contracts $ 2.3 $ 0.2 Cost of products sold $ 1.9 $ (0.2) Commodities contracts — (0.5) Cost of products sold (0.2) (1.5) $ 2.3 $ (0.3) $ 1.7 $ (1.7)

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of the provision (benefit) for income taxes consisted of the following: Years ended December 31 (dollars in millions) 2020 2019 2018 Current: Federal $ 67.1 $ 66.4 $ 60.1 State 17.4 14.8 15.6 International 25.8 19.9 38.6 Deferred: Federal 5.6 0.4 (1.7) State 2.3 1.8 1.5 International (19.2) (1.2) (0.5) $ 99.0 $ 102.1 $ 113.6 The provision for income taxes differs from the U.S. federal statutory rate due to the following items: Years ended December 31 2020 2019 2018 Provision at U.S. federal statutory rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 3.5 2.8 2.4 International income tax rate differential—China (0.6) (1.3) (2.3) International income tax rate differential—other 0.2 0.4 1.1 Research tax credits (0.5) (0.4) (0.5) Excess tax benefit on stock compensation (0.9) (0.5) (0.4) Other (0.4) (0.4) (0.9) 22.3 % 21.6 % 20.4 % U.S. Tax Reform was enacted on December 22, 2017 and significantly changed U.S. corporate income tax laws. Among other things, U.S. Tax Reform reduced the U.S. corporate income tax rate to 21 percent commencing on January 1, 2018, implemented a territorial tax system and levied a one-time mandatory tax on undistributed earnings of foreign subsidiaries of U.S. companies. The Company completed its accounting for the income tax effects of U.S. Tax Reform as of December 31, 2018 and determined that there was no material adjustment necessary to the provisional amounts it recorded in 2017. As allowed under ASU 2018-02 Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income , the Company has elected not to reclassify the income tax effects of U.S. Tax Reform from accumulated other comprehensive losses to retained earnings. Components of earnings before income taxes were as follows: Years ended December 31 (dollars in millions) 2020 2019 2018 U.S. $ 407.3 $ 400.3 $ 376.0 International 36.6 71.8 181.8 $ 443.9 $ 472.1 $ 557.8 Total income taxes paid by the Company amounted to $114.1 million, $116.6 million, and $116.4 million in 2020, 2019 and 2018, respectively. As of December 31, 2020, the Company has $9.8 million accrued for its estimate of withholding taxes due upon repatriation of undistributed foreign earnings it considers to be not permanently reinvested. As of December 31, 2020, $524.2 million of cash and cash equivalents and marketable securities were held by its foreign subsidiaries. The tax effects of temporary differences of assets and liabilities between income tax and financial reporting are as follows: December 31 (dollars in millions) 2020 2019 Assets Liabilities Assets Liabilities Employee benefits $ 21.6 $ — $ 27.3 $ — Product liability and warranties 42.5 — 39.7 — Inventories 1.5 — — 0.3 Accounts receivable 16.3 — 16.3 — Property, plant and equipment — 36.3 — 34.9 Intangibles — 66.2 — 61.3 Environmental liabilities 1.9 — 1.9 — Undistributed foreign earnings — 9.8 — 20.8 Tax loss and credit carryovers 20.3 — 15.2 — All other 9.9 — 7.7 — Valuation allowance (13.0) — (11.9) — $ 101.0 $ 112.3 $ 96.2 $ 117.3 Net liability $ 11.3 $ 21.1 The Company believes it is more likely than not that it will realize its net deferred tax assets through the reduction of future taxable income. The Company considered historical operating results in determining the probability of the realization of the deferred tax assets. A reconciliation of the beginning and ending amounts of tax loss carryovers, credit carryovers and valuation allowances is as follows: Net Operating Losses and Tax Credits Valuation Allowances December 31 (dollars in millions) 2020 2019 2020 2019 Beginning balance $ 15.2 $ 17.5 $ 11.9 $ 13.1 Increases / (Reductions) 5.1 (2.3) 1.1 (1.2) Ending balance $ 20.3 $ 15.2 $ 13.0 $ 11.9 The Company has foreign net operating loss carryovers that expire in 2021 through 2028 and state and local net operating loss carryovers that expire between 2029 and 2030. A reconciliation of the beginning and ending amount of unrecognized benefits is as follows: (Dollars in millions) 2020 2019 Balance at January 1 $ 9.7 $ 8.3 Additions / (Reductions) for tax positions of prior years (0.7) 1.4 Balance at December 31 $ 9.0 $ 9.7 The amount of unrecognized tax benefits that, if recognized, would affect the effective income tax rate is $0.5 million. The Company recognizes potential interest and penalties related to unrecognized tax benefits as a component of income tax expense. At December 31, 2020, there was an immaterial amount of interest and penalties accrued. The Company anticipates that there will not be a material decrease in the total amount of unrecognized tax benefits in 2021. The Company’s U.S. federal income tax returns and its U.S. state and local income tax returns are subject to audit for the years 2017-2020 and 2003-2020, respectively. The Company is subject to non-U.S. income tax audits for the years 2014-2020.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Environmental Contingencies The Company is a potentially responsible party in judicial and administrative proceedings seeking to clean up sites which have been environmentally impacted. In each case, the Company has established reserves, insurance proceeds and/or a potential recovery from third parties. The Company believes any environmental claims will not have a material effect on its financial position or results of operations. Product Liability The Company is subject to various claims and pending lawsuits for product liability and other matters arising out of the conduct of the Company’s business. With respect to product liability claims, the Company has self-insured a portion of its product liability loss exposure for many years. The Company has established reserves and has insurance coverage, which it believes are adequate to cover incurred claims. For the years ended December 31, 2020 and 2019, the Company had $125 million of product liability insurance for individual losses in excess of $7.5 million. The Company periodically reevaluates its exposure on claims and lawsuits and makes adjustments to its reserves as appropriate. The Company believes, based on current knowledge, consultation with counsel, adequate reserves and insurance coverage that the outcome of such claims and lawsuits will not have a material adverse effect on the Company’s financial position, results of operations or cash flows. Purchase Obligations The Company utilizes blanket purchase orders to communicate expected annual requirements to many suppliers. Requirements under blanket purchase orders generally do not become committed until several weeks prior to the scheduled unit production. The purchase obligations the Company considers firm as of December 31, 2020 is $157.2 million, most of which will be ordered in 2021. Inventory Repurchase Arrangements The Company maintains a commercial relationship with a supply-chain service provider (the Provider) in connection with the Company’s business in China. In this capacity, the Provider offers order-entry, warehousing and logistics support. The Provider also offers asset-backed financing to certain of the Company’s distributors in China to facilitate their working capital needs. To facilitate its financing support business, the Provider has collateralized lending facilities in place with multiple Chinese banks under which the Company has agreed to repurchase inventory if both requested by the banks and certain defined conditions are met, primarily related to the aging of the distributors’ notes. The Provider is required to indemnify the Company for any losses the Company would incur in the event of an inventory repurchase under these arrangements. Potential losses under the repurchase arrangements represent the difference between the repurchase price and net proceeds from the resale of product plus costs incurred in the process, less related distributor rebates.

Operations by Segment

Operations by Segment	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Operations by Segment	Operations by Segment The Company is comprised of two reporting segments: North America and Rest of World. The Rest of World segment is primarily comprised of China, Europe and India. Both segments manufacture and market comprehensive lines of residential and commercial gas and electric water heaters, boilers, tanks and water treatment products. Both segments primarily manufacture and market in their respective regions of the world. The accounting policies of the reportable segments are the same as those described in the “Summary of Significant Accounting Policies” outlined in Note 1. Segment earnings, defined by the Company as earnings before interest, taxes, general corporate and corporate research and development expenses, were used to measure the performance of the segments. Net Sales Earnings Years ended December 31 (dollars in millions) 2020 2019 2018 2020 2019 2018 North America (1) (2) $ 2,118.3 $ 2,083.5 $ 2,044.7 $ 503.5 $ 488.9 $ 464.1 Rest of World (3) 800.3 935.8 1,173.6 — 40.2 149.3 Inter-segment (23.3) (26.6) (30.4) (0.3) — — Total segments – sales, segment earnings $ 2,895.3 $ 2,992.7 $ 3,187.9 $ 503.2 $ 529.1 $ 613.4 Corporate expenses (52.0) (46.0) (47.2) Interest expense (7.3) (11.0) (8.4) Earnings before income taxes 443.9 472.1 557.8 Provision for income taxes (99.0) (102.1) (113.6) Net earnings $ 344.9 $ 370.0 $ 444.2 (1) In 2020, the Company recognized $2.7 of severance and restructuring expenses in connection with the Company's alignment of the business to current market conditions. For additional information, see Note 5 “Severance, Restructuring and Impairment Expenses.” (2) In 2018, the Company recognized $6.7 of restructuring and impairment expenses in connection with the move of manufacturing operations from its Renton, Washington facility to other U.S. facilities. For additional information, see Note 5 “Severance, Restructuring and Impairment Expenses.” (3) In 2020, the Company recognized $5.0 of severance and restructuring expenses in connection with its alignment of its business to current market conditions. For additional information, see Note 5 “Severance, Restructuring and Impairment Expenses.” In 2020, sales to the North America segment’s two largest customers were $471.9 million and $349.9 million which represented 16 percent and 12 percent of the Company’s net sales, respectively. In 2019, sales to the North America segment’s two largest customers were $421.1 million and $378.9 million which represented 14 percent and 13 percent of the Company’s net sales, respectively. In 2018, sales to the North America segment’s two largest customers were $425.3 million and $355.6 million which represented 13 percent and 11 percent of the Company’s net sales, respectively. Assets, depreciation and capital expenditures by segment Total Assets (December 31) Depreciation and Amortization (Years Ended December 31) Capital Expenditures (Years Ended December 31) (dollars in millions) 2020 2019 2018 2020 2019 2018 2020 2019 2018 North America $ 1,759.1 $ 1,742.8 $ 1,653.6 $ 51.5 $ 49.3 $ 45.5 $ 41.7 $ 47.6 $ 45.8 Rest of World 664.9 709.1 721.6 27.9 27.9 25.2 14.9 15.9 32.3 Corporate 736.7 606.1 696.3 0.6 1.1 1.2 0.2 0.9 7.1 Total $ 3,160.7 $ 3,058.0 $ 3,071.5 $ 80.0 $ 78.3 $ 71.9 $ 56.8 $ 64.4 $ 85.2 The majority of corporate assets consist of cash, cash equivalents, marketable securities and deferred income taxes. Net sales and long-lived assets by geographic location The following data by geographic area includes net sales based on product shipment destination and long-lived assets based on physical location. Long-lived assets include net property, plant and equipment, operating lease assets and other long-term assets. Long-lived Assets (December 31) Net Sales (Years Ended December 31) (dollars in millions) 2020 2019 2018 2020 2019 2018 United States $ 355.8 $ 360.2 $ 327.3 United States $ 1,904.9 $ 1,868.7 $ 1,820.8 China 268.3 266.7 252.6 China 695.6 825.4 1,071.2 Canada 4.5 4.2 3.1 Canada 175.0 168.5 175.0 Other Foreign 43.4 42.1 42.9 Other Foreign 119.8 130.1 120.9 Total $ 672.0 $ 673.2 $ 625.9 Total $ 2,895.3 $ 2,992.7 $ 3,187.9

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	Quarterly Results of Operations (Unaudited) (dollars in millions, except per share amounts) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter 2020 2019 2020 2019 2020 2019 2020 2019 Net sales $ 636.9 $ 748.2 $ 663.9 $ 765.4 $ 760.0 $ 728.2 $ 834.5 $ 750.9 Gross profit 239.5 292.8 247.5 308.7 297.1 284.2 324.1 295.0 Net earnings 51.7 89.3 67.8 102.1 105.4 87.3 120.0 91.3 Basic earnings per share 0.32 0.53 0.42 0.61 0.65 0.53 0.74 0.56 Diluted earnings per share 0.32 0.53 0.42 0.61 0.65 0.53 0.74 0.56 Common dividends declared 0.24 0.22 0.24 0.22 0.24 0.22 0.26 0.24 Net earnings per share are computed separately for each period, and therefore, the sum of such quarterly per share amounts may differ from the total for the year. In 2020, the Company recorded $7.7 million of severance and restructuring expenses associated with the alignment of its business to current market conditions. These charges reduced after-tax earnings by $6.3 million or $0.04 per share.

SCHEDULE II - VALUATION AND QUA

SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS	A. O. SMITH CORPORATION SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Dollars in millions) Years ended December 31, 2020, 2019 and 2018 Description Balance at Charged to Acquisition Deductions Balance at 2020: Valuation allowance for trade and notes receivable $ 6.6 $ 0.8 $ — $ (1.8) $ 5.6 Valuation allowance for deferred tax assets 11.9 1.1 — — 13.0 2019: Valuation allowance for trade and notes receivable $ 6.4 $ 0.3 $ — $ (0.1) $ 6.6 Valuation allowance for deferred tax assets 13.1 — — (1.2) 11.9 2018: Valuation allowance for trade and notes receivable $ 5.3 $ 1.5 $ — $ (0.4) $ 6.4 Valuation allowance for deferred tax assets 15.0 — — (1.9) 13.1

Organization and Significant _2

Organization and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Organization	Organization. A. O. Smith Corporation (A. O. Smith or the Company) is comprised of two reporting segments: North America and Rest of World. The Rest of World segment is primarily comprised of China, Europe and India. Both segments manufacture and market comprehensive lines of residential and commercial gas and electric water heaters, boilers, tanks and water treatment products. Both segments primarily manufacture and market in their respective regions of the world.
Consolidation	Consolidation. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries after elimination of intercompany transactions.
Use of estimates	Use of estimates. The preparation of financial statements in conformity with accounting principles generally accepted in the United States (U.S.) requires management to make estimates and assumptions that affect the amounts reported in the accompanying financial statements and notes. Actual results could differ from those estimates.
Fair value of financial instruments	Fair value of financial instruments. The carrying amounts of cash, cash equivalents, marketable securities, receivables, floating rate debt and trade payables approximated fair value as of December 31, 2020 and 2019, due to the short maturities or frequent rate resets of these instruments.
Foreign currency translation	Foreign currency translation. For all subsidiaries outside the U.S., with the exception of its Barbados, Hong Kong and Mexican companies and its non-operating companies in the Netherlands, the Company uses the local currency as the functional currency. For those operations using a functional currency other than the U.S. dollar, assets and liabilities were translated into U.S. dollars at year-end exchange rates, and revenues and expenses were translated at weighted-average exchange rates. The resulting translation adjustments were recorded as a separate component of stockholders’ equity. The Barbados, Hong Kong, Mexican and Netherlands companies use the U.S. dollar as the functional currency. Gains and losses from foreign currency transactions were included in net earnings and were not significant in 2020, 2019, or 2018.
Cash and cash equivalents	Cash and cash equivalents. The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents.
Marketable securities	Marketable securities. The Company considers all highly liquid investments with maturities greater than 90 days when purchased to be marketable securities. At December 31, 2020, the Company’s marketable securities consisted of bank time deposits with original maturities ranging from 180 days to 12 months and were primarily located at investment grade rated banks in China.
Inventory valuation	Inventory valuation. Inventories are carried at lower of cost and net realizable value. Cost is determined on the last-in, first-out (LIFO) method for a majority of the Company’s domestic inventories, which comprised 67 percent and 65 percent of the Company’s total inventory at December 31, 2020 and 2019, respectively. Inventories of foreign subsidiaries, the remaining domestic inventories and supplies were determined using the first-in, first-out (FIFO) method.
Property, plant and equipment	Property, plant and equipment. Property, plant and equipment are stated at cost. Depreciation is computed primarily by the straight-line method. The estimated service lives used to compute depreciation are generally 25 to 50 years for buildings, three three
Goodwill and other intangibles	Goodwill and other intangibles. Goodwill and indefinite-lived intangible assets are not amortized but are reviewed for impairment on an annual basis. Separable intangible assets, primarily comprised of customer relationships, that are not deemed to have an indefinite life are amortized on a straight-line basis over their estimated useful lives which range from five
Impairment of long-lived and amortizable intangible assets	Impairment of long-lived and amortizable intangible assets. Property, plant and equipment and intangible assets subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. If the sum of the expected undiscounted cash flows is less than the carrying value of the related asset or group of assets, a loss is recognized for the difference between the fair value and carrying value of the asset or group of assets. Such analyses necessarily involve significant judgment.
Product warranties	Product warranties. The Company’s products carry warranties that generally range from one
Derivative instruments	Derivative instruments. The Company utilizes certain derivative instruments to enhance its ability to manage currency as well as raw materials price risk. The Company does not enter into contracts for speculative purposes. The fair values of all derivatives are recorded in the consolidated balance sheets. The change in a derivative’s fair value is recorded each period in current earnings or accumulated other comprehensive loss (AOCL), depending on whether the derivative is designated as part of a hedge transaction and if so, the type of hedge transaction. See Note 14, “Derivative Instruments” of the notes to consolidated financial statements for disclosure of the Company’s derivative instruments and hedging activities.
Fair Value Measurements	Fair Value Measurements. Accounting Standards Codification (ASC) 820 Fair Value Measurements , among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring basis or nonrecurring basis. ASC 820 clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: (Level 1) observable inputs such as quoted prices in active markets; (Level 2) inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and (Level 3) unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.
Revenue recognition	Revenue recognition. Substantially all of the Company’s sales are from contracts with customers for the purchase of its products. Contracts and customer purchase orders are used to determine the existence of a sales contract. Shipping documents are used to verify shipment. For substantially all of its products, the Company transfers control of products to the customer at the point in time when title and risk are passed to the customer, which generally occurs upon shipment of the product. See Note 2, “Revenue Recognition” for disclosure of the Company’s revenue recognition activities.
Advertising	Advertising. The majority of advertising costs are charged to operations as incurred and totaled $97.0 million, $110.7 million and $132.1 million during 2020, 2019 and 2018, respectively. Included in total advertising costs are expenses associated with store displays for water heater, water treatment and air purification products in China that are amortized over 12 to 36 months which totaled $27.0 million, $28.5 million and $38.7 million during 2020, 2019 and 2018, respectively.
Research and development	Research and development. Research and development costs are charged to operations as incurred and amounted to $80.7 million, $87.9 million and $94.0 million during 2020, 2019 and 2018, respectively.
Environmental costs	Environmental costs. The Company accrues for costs associated with environmental obligations when such costs are probable and reasonably estimable. Costs of estimated future expenditures are not discounted to their present value.
Stock-based compensation	Stock-based compensation. Compensation cost is recognized using the straight-line method over the vesting period of the award and forfeitures are recognized as they occur.
Income taxes	Income taxes. The provision for income taxes is computed using the asset and liability method, in accordance with ASC 740 Income Taxes , under which deferred tax assets and liabilities are recognized for the expected future tax consequences of temporary differences between the financial reporting and tax bases of assets and liabilities and for operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using the currently enacted tax rates that apply to taxable income in effect for the years in which those tax assets are expected to be realized or settled and are classified as noncurrent in the consolidated balance sheet. The Company records a valuation allowance to reduce deferred tax assets to the amount that is believed more likely than not to be realized.
Earnings per share of common stock	Earnings per share of common stock. The Company is not required to use the two-class method of calculating earnings per share since its Class A Common Stock and Common Stock have equal dividend rights. The numerator for the calculation of basic and diluted earnings per share is net earnings.
Recent Accounting Pronouncements	Recent Accounting Pronouncements. In December 2019, the Financial Accounting Standards Board (FASB) amended Accounting Standards Codification (ASC) 740, Income Taxes (issued under Accounting Standards Update (ASU) 2019-12, “Simplifying the Accounting for Income Taxes”). This amendment removes certain exceptions to the general principles of ASC 740, and clarifies and amends existing guidance to improve consistent application. The amendment requires adoption on January 1, 2021. The Company does not expect that the adoption of ASU 2019-12 will have a material impact on its consolidated balance sheets, statements of earnings or statements of cash flows. In January 2017, the FASB amended ASC 350, Intangibles – Goodwill and Other (issued under ASU 2017-4, “Simplifying the Test for Goodwill Impairment”). This amendment simplifies the test for goodwill impairment by only requiring an entity to perform an annual or interim goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount and recognize an impairment charge for the amount that the carrying amount exceeds the reporting unit’s fair value. Any loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. The Company adopted the amendment on January 1, 2020 and the adoption did not have an impact on its consolidated balance sheets, statements of earnings or statements of cash flows. In June 2016, the FASB issued ASC 326, Financial Instruments – Credit Losses

Organization and Significant _3

Organization and Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Product Warranty Liability Activity	The following table presents the Company’s product warranty liability activity in 2020 and 2019: Years ended December 31 (dollars in millions) 2020 2019 Balance at beginning of year $ 134.3 $ 139.4 Expense 56.1 44.3 Claims settled (48.1) (49.4) Balance at end of year $ 142.3 $ 134.3
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets measured at fair value on a recurring basis are as follows (dollars in millions): Fair Value Measurement Using December 31, 2020 December 31, 2019 Quoted prices in active markets for identical assets (Level 1) $ 116.5 $ 177.4 Significant other observable inputs (Level 2) (4.3) 6.9
Schedule of Computation of Basic and Diluted Weighted Average Shares Used in EPS Calculations	The following table sets forth the computation of basic and diluted weighted-average shares used in the earnings per share calculations: 2020 2019 2018 Denominator for basic earnings per share - weighted-average shares outstanding 161,530,589 165,450,441 170,589,345 Effect of dilutive stock options, restricted stock and share units 1,073,560 1,260,456 1,604,695 Denominator for diluted earnings per share 162,604,149 166,710,897 172,194,040

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Net Sales Disaggregated by Segment and Major Product Line	The following table disaggregates the Company’s net sales by segment. As described above, the Company’s North America segment sales are further disaggregated by major product line. In addition, the Company’s Rest of World segment sales are disaggregated by China and all other Rest of World. Years ended December 31 (dollars in millions) 2020 2019 2018 North America Water heaters and related parts $ 1,753.9 $ 1,742.6 $ 1,757.0 Boilers and related parts 187.2 199.5 200.4 Water treatment products (1) 177.2 141.4 87.3 Total North America 2,118.3 2,083.5 2,044.7 Rest of World China $ 701.0 $ 827.2 $ 1,070.4 All other Rest of World 99.3 108.6 103.2 Total Rest of World 800.3 935.8 1,173.6 Inter-segment sales (23.3) (26.6) (30.4) Total Net Sales $ 2,895.3 $ 2,992.7 $ 3,187.9 (1) Includes the results of Water-Right, Inc. and its affiliated entities (Water-Right) from April 8, 2019, the date of acquisition.

Acquisition (Tables)

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Summary of Allocation of Fair Value of Assets Acquired and Liabilities Assumed at Date of Acquisition	The following table summarizes the allocation of the fair value of the assets acquired and liabilities assumed at the date of acquisition of Water-Right for purposes of allocating the purchase price. Significant assumptions used to estimate the fair value of intangible assets acquired include discount rates and certain assumptions that form the basis of the forecasted results, including revenue growth rates, attrition rates and royalty rates. The $60.4 million of acquired identifiable intangible assets was comprised of the following: $40.2 million of customer relationships being amortized over 20 years, $19.0 million of trademarks not subject to amortization, and $1.2 million of non-compete agreements being amortized over 7.5 years. April 8, 2019 (dollars in millions) Current assets, net of cash acquired $ 9.7 Property, plant and equipment 8.6 Intangible assets 60.4 Goodwill 31.0 Total assets acquired 109.7 Current liabilities (2.7) Net assets acquired $ 107.0

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Supplemental Balance Sheet Information Related To Leases	Supplemental balance sheet information related to leases is as follows: (dollars in millions) December 31, 2020 December 31, 2019 Liabilities Short term: Accrued liabilities $ 11.1 $ 12.0 Long term: Operating lease liabilities 34.4 38.7 Total operating lease liabilities $ 45.5 $ 50.7 Less: Rent incentives and deferrals (3.9) (3.8) Assets Operating lease assets $ 41.6 $ 46.9 Lease Term and Discount Rate December 31, 2020 Weighted-average remaining lease term 10 years Weighted-average discount rate 3.49%
Schedule of Components of Lease Expense	The components of lease expense were as follows: (dollars in millions) Lease Expense (1) Classification Year ended December 31, 2020 Year ended December 31, 2019 Operating lease expense Cost of products sold $ 3.1 $ 3.0 Selling, general and administrative expenses 16.0 17.6 (1) Includes short-term lease expense of $1.8 million for the year ended December 31, 2020. Includes variable lease cost of $1.6 million for the year ended December 31, 2020. Includes short-term lease expense of $2.0 million for the year ended December 31, 2019. Includes variable lease cost of $2.1 million for the year ended December 31, 2019.
Schedule of Maturities of Lease Liabilities	Maturities of lease liabilities were as follows: (dollars in millions) December 31, 2020 2021 $ 12.4 2022 10.2 2023 5.6 2024 4.6 2025 2.9 After 2025 21.0 Total lease payments 56.7 Less: imputed interest (11.2) Present value of operating lease liabilities $ 45.5

Severance, Restructuring and _2

Severance, Restructuring and Impairment Expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Restructuring and Related Activities [Abstract]
Analysis of Company's Restructuring Reserve	The following table presents an analysis of the Company’s restructuring reserve for the years ended December 31, 2020, 2019, and 2018: (dollars in millions) Severance Restructuring Expenses Fixed Assets Total Balance at January 1, 2018 $ — $ — $ — $ — Charges 4.0 2.1 0.6 6.7 Cash payments and disposals (3.8) (0.8) (0.6) (5.2) Balance at December 31, 2018 0.2 1.3 — 1.5 Cash payments and disposals (0.2) (0.8) — (1.0) Balance at December 31, 2019 — 0.5 — 0.5 Charges 6.8 0.9 — 7.7 Cash payments and disposals (5.1) (1.4) — (6.5) Balance at December 31, 2020 $ 1.7 $ — $ — $ 1.7

Statement of Cash Flows (Tables

Statement of Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2020
Supplemental Cash Flow Elements [Abstract]
Schedule of Supplemental Cash Flow Information	Supplemental cash flow information is as follows: Years ended December 31 (dollars in millions) 2020 2019 2018 Net change in current assets and liabilities, net of acquisitions: Receivables $ 4.5 $ 62.4 $ (54.6) Inventories 2.9 6.3 (7.7) Other current assets 4.7 (4.8) 10.0 Trade payables 85.6 (35.4) 8.8 Accrued liabilities, including payroll and benefits 29.3 14.2 (3.5) Income taxes 3.4 (10.1) 7.0 $ 130.4 $ 32.6 $ (40.0)

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventories	December 31 (dollars in millions) 2020 2019 Finished products $ 143.4 $ 136.8 Work in process 21.8 21.7 Raw materials 159.2 168.3 Inventories, at FIFO cost 324.4 326.8 LIFO reserve (24.3) (23.8) $ 300.1 $ 303.0

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property Plant and Equipment	December 31 (dollars in millions) 2020 2019 Land $ 11.6 $ 11.6 Buildings 349.2 334.1 Equipment 729.7 686.9 Software 132.1 124.3 1,222.6 1,156.9 Accumulated depreciation and amortization (681.3) (611.5) $ 541.3 $ 545.4

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill	Changes in the carrying amount of goodwill during the years ended December 31, 2020 and 2019 consisted of the following: (dollars in millions) North America Rest of World Total Balance at December 31, 2018 $ 453.9 $ 59.1 $ 513.0 Acquisition 31.0 — 31.0 Currency translation adjustment 2.0 — 2.0 Balance at December 31, 2019 486.9 59.1 546.0 Currency translation adjustment 0.8 — 0.8 Balance at December 31, 2020 $ 487.7 $ 59.1 $ 546.8
Schedule of Indefinite-Lived Intangible Assets	The carrying amount of other intangible assets consisted of the following: 2020 2019 December 31 (dollars in millions) Gross Accumulated Net Gross Accumulated Net Amortizable intangible assets: Patents $ 3.7 $ (3.7) $ — $ 3.7 $ (3.5) $ 0.2 Customer lists 278.0 (138.1) 139.9 278.0 (123.6) 154.4 Total amortizable intangible assets 281.7 (141.8) 139.9 281.7 (127.1) 154.6 Indefinite-lived intangible assets: Trade names 184.0 — 184.0 183.8 — 183.8 Total intangible assets $ 465.7 $ (141.8) $ 323.9 $ 465.5 $ (127.1) $ 338.4
Schedule of Finite-Lived Intangible Assets	The carrying amount of other intangible assets consisted of the following: 2020 2019 December 31 (dollars in millions) Gross Accumulated Net Gross Accumulated Net Amortizable intangible assets: Patents $ 3.7 $ (3.7) $ — $ 3.7 $ (3.5) $ 0.2 Customer lists 278.0 (138.1) 139.9 278.0 (123.6) 154.4 Total amortizable intangible assets 281.7 (141.8) 139.9 281.7 (127.1) 154.6 Indefinite-lived intangible assets: Trade names 184.0 — 184.0 183.8 — 183.8 Total intangible assets $ 465.7 $ (141.8) $ 323.9 $ 465.5 $ (127.1) $ 338.4

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of Debt	December 31 (dollars in millions) 2020 2019 Bank credit lines, average year-end interest rates of —% for 2020 and 2.4% for 2019 $ — $ 4.7 Revolving credit agreement borrowings, average year-end interest rates of —% for 2020 and 2.8% for 2019 — 85.0 Commercial paper, average year-end interest rates of —% for 2020 and 2.2% for 2019 — 74.3 Term notes with insurance companies, expiring 2029-2034, average year-end interest rates of 3.3% for 2020 and 3.3% for 2019 113.2 120.0 113.2 284.0 Long-term debt due within one year (6.8) (6.8) Long-term debt $ 106.4 $ 277.2
Schedule of Maturities of Long Term Debt	Scheduled maturities of long-term debt within each of the five years subsequent to December 31, 2020 are as follows: Years ending December 31 (dollars in millions) Amount 2021 $ 6.8 2022 6.8 2023 10.0 2024 10.0 2025 10.0

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Changes in Accumulated Other Comprehensive Loss by Component	Changes to accumulated other comprehensive loss by component are as follows: (dollars in millions) Years ended December 31, 2020 2019 Cumulative foreign currency translation Balance at beginning of period $ (66.2) $ (64.9) Other comprehensive gain (loss) before reclassifications 18.1 (1.3) Balance at end of period (48.1) (66.2) Unrealized net gain (loss) on cash flow derivatives Balance at beginning of period 0.2 (0.7) Other comprehensive gain (loss) before reclassifications 1.7 (0.3) Realized (gains) losses on derivatives reclassified to cost of products sold (net of tax provision (benefit) of $0.4 and $(0.5) in 2020 and 2019, respectively) (1) (1.3) 1.2 Balance at end of period 0.6 0.2 Pension liability Balance at beginning of period (282.3) (285.2) Other comprehensive (loss) before reclassifications (6.3) (9.5) Amounts reclassified from accumulated other comprehensive loss (1) 14.9 12.4 Balance at end of period (273.7) (282.3) Total accumulated other comprehensive loss, end of period $ (321.2) $ (348.3) (1) Amounts reclassified from accumulated other comprehensive loss: Realized (gains) loss on derivatives reclassified to cost of products sold $ (1.7) $ 1.7 Tax provision (benefit) 0.4 (0.5) Reclassification net of tax $ (1.3) $ 1.2 Amortization of pension items: Actuarial losses $ 20.2 (2) $ 16.8 (2) Prior year service cost (0.4) (2) (0.5) (2) 19.8 16.3 Tax benefit (4.9) (3.9) Reclassification net of tax $ 14.9 $ 12.4 (2) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost. See Note 13 “Pensions and Other Post-retirement Benefits” for additional details.

Stock Based Compensation (Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Changes in Option Shares	Changes in options, all of which relate to the Company’s Common Stock, were as follows: Years Ended December 31 2020 2019 2018 Number of Weighted Number of Weighted Number of Weighted Number of shares under options: Outstanding at beginning of year 2,728,350 $ 37.64 2,432,689 $ 33.05 2,263,126 $ 27.73 Granted 798,970 42.50 557,045 49.49 373,220 61.62 Exercised (1) (662,215) 19.59 (249,840) 18.55 (176,302) 22.93 Forfeited (79,451) 48.98 (11,544) 54.02 (27,355) 47.95 Outstanding at end of year (2) 2,785,654 43.01 2,728,350 37.64 2,432,689 33.05 Exercisable at end of year (3) 1,529,464 40.35 1,820,743 30.07 1,665,184 24.52 (1) The total intrinsic value of options exercised in 2020, 2019 and 2018 was $21.3 million, $7.7 million and $6.8 million, respectively. (2) The weighted average remaining contractual life of options outstanding was 8 years at December 31, 2020, and 7 years at December 31, 2019, and December 31, 2018, respectively. The aggregate intrinsic value of options outstanding at December 31, 2020 was $35.3 million. (3) The weighted average remaining contractual life of options exercisable was 6 years at December 31, 2020, December 31, 2019 and December 31, 2018. The aggregate intrinsic value of options exercisable at December 31, 2020 was $23.7 million.
Schedule of Share-based Payment Arrangement, Performance Shares, Activity	Number of Options Weighted Avg. Per Nonvested options at beginning of year 907,607 $ 52.82 Granted 798,970 42.50 Vested (416,432) 53.20 Forfeited (33,955) 49.06 Nonvested options at end of year 1,256,190 46.23
Schedule of Weighted Average Fair Value per Option at Date of Grant	Assumptions were as follows: 2020 2019 2018 Expected life (years) 5.7 5.5 5.7 Risk-free interest rate 1.5 % 2.7 % 2.9 % Dividend yield 2.1 % 1.6 % 1.0 % Expected volatility 23.7 % 22.8 % 22.1 %
Schedule of Share Unit Activity Under Plan	A summary of share unit activity under the plan is as follows: Number of Units Weighted-Average Issued and unvested at January 1, 2020 366,102 $ 49.92 Granted 174,420 42.64 Vested (100,735) 49.21 Forfeited (13,001) 51.25 Issued and unvested at December 31, 2020 426,786 46.99

Pension and Other Post-retire_2

Pension and Other Post-retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Schedule of Changes in Benefit Obligation, Plan Assets and Funded Status of Defined Benefit Pension and Post Retirement Benefit Plans	The following tables present the changes in benefit obligations, plan assets and funded status for domestic pension and post-retirement plans and the components of net periodic benefit costs. Pension Benefits Post-retirement Benefits Years ended December 31 (dollars in millions) 2020 2019 2020 2019 Accumulated benefit obligation (ABO) at December 31 $ 869.0 $ 868.7 N/A N/A Change in projected benefit obligations (PBO) PBO at beginning of year $ (869.3) $ (833.8) $ (8.0) $ (7.0) Service cost (1.5) (1.6) — (0.1) Interest cost (23.0) (31.6) (0.1) (0.3) Participant contributions — — (0.1) (0.1) Plan amendments — — 2.0 — Actuarial loss including assumption changes (63.8) (98.6) (0.8) (1.2) Benefits paid 87.8 96.3 1.1 0.7 PBO at end of year $ (869.8) $ (869.3) $ (5.9) $ (8.0) Change in fair value of plan assets Plan assets at beginning of year $ 832.4 $ 777.5 $ — $ — Actual return on plan assets 104.1 143.4 — — Contribution by the Company 10.1 7.8 0.5 0.5 Participant contributions — — 0.1 0.1 Benefits paid (87.8) (96.3) (0.6) (0.6) Plan assets at end of year $ 858.8 $ 832.4 $ — $ — Funded status $ (11.0) $ (36.9) $ (5.9) $ (8.0) Amount recognized in the balance sheet Noncurrent assets $ 3.0 $ — $ — $ — Current liabilities (0.6) (9.3) (0.5) (0.5) Non-current liabilities (13.4) (27.6) (5.4) (7.5) Net pension liability at end of year $ (11.0) * $ (36.9) * $ (5.9) $ (8.0) Amounts recognized in accumulated other comprehensive loss before tax Net actuarial loss (gain) $ 452.0 $ 463.1 $ 0.6 $ (0.2) Prior service cost 1.0 0.5 (3.3) (1.8) Total recognized in accumulated other comprehensive loss $ 453.0 $ 463.6 $ (2.7) $ (2.0) *In addition, the Company has a liability for a foreign pension plan of $0.2 million at December 31, 2020 and 2019.
Schedule of Net Periodic Benefit Cost	Pension Benefits Post-retirement Benefits Years ended December 31 (dollars in millions) 2020 2019 2018 2020 2019 2018 Net periodic (benefit) cost Service cost $ 1.5 $ 1.6 $ 2.0 $ — $ 0.1 $ 0.1 Interest cost 23.0 31.6 28.9 0.1 0.3 0.3 Expected return on plan assets (51.9) (57.3) (58.1) — — — Amortization of unrecognized: Net actuarial loss 20.2 16.8 19.0 — — — Prior service cost (0.4) (0.5) (0.5) (0.5) (0.4) (0.4) Defined-benefit plan income (7.6) (7.8) (8.7) (0.4) — $ — Curtailment and other one-time charges 2.5 1.6 — (0.5) — — Various U.S. defined contribution plans cost 14.4 13.3 12.2 — — — $ 9.3 $ 7.1 $ 3.5 $ (0.9) $ — $ — Other changes in plan assets and projected benefit obligation recognized in other comprehensive loss Net actuarial loss (gain) $ 11.7 $ 12.6 $ 36.1 $ 0.8 $ 1.2 $ (0.6) Amortization of net actuarial loss (22.8) (18.4) (19.0) — — — Prior service credit — — — (2.0) — — Amortization of prior service cost 0.4 0.5 0.5 0.5 0.4 0.4 Total recognized in other comprehensive loss (10.7) (5.3) 17.6 (0.7) 1.6 (0.2) Total recognized in net periodic (benefit) cost and other comprehensive loss $ (15.8) $ (11.5) $ 8.9 $ (1.6) $ 1.6 $ (0.2)
Schedule of Actuarial Assumptions Used To Determine Benefit Obligations and Net Periodic Benefit Cost	Actuarial assumptions used to determine benefit obligations at December 31 are as follows: Pension Benefits Post-retirement Benefits 2020 2019 2020 2019 Discount rate 2.44 % 3.18 % 2.04 % 3.40 % Actuarial assumptions used to determine net periodic benefit cost for the year ended December 31 are as follows: Pension Benefits Post-retirement Benefits Years ended December 31 2020 2019 2018 2020 2019 2018 Discount rate 3.18 % 4.32 % 3.65 % 2.95 % 4.45 % 3.79 % Expected long-term return on plan assets 6.75 % 7.15 % 7.15 % n/a n/a n/a Rate of compensation increase 4.00 % 4.00 % 4.00 % 4.00 % 4.00 % 4.00 %
Schedule of Health Care Cost Trend Rates	Assumed health care cost trend rates as of December 31 are as follows: 2020 2019 Health care cost trend rate assumed for next year 7.40 % 7.70 % Rate to which the cost trend rate is assumed to decline (the ultimate trend rate) 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate 2029 2029
Schedule of Weighted Asset Allocations by Asset Category	The Company’s pension plan weighted asset allocations as of December 31 by asset category are as follows: Asset Category 2020 2019 Equity securities 44 % 42 % Debt securities 46 47 Real estate 9 10 Private equity 1 1 100 % 100 %
Schedule of Fair Value Measurement of Plan Assets	The following tables present the fair value measurement of the Company’s plan assets as of December 31, 2020 and 2019 (dollars in millions): December 31, 2020 Asset Category Total Quoted Prices in Significant Other Significant Non- Short-term investments $ 13.7 $ — $ 13.7 $ — Equity securities Common stocks 136.5 136.5 — — Commingled equity funds 132.0 — 132.0 — Fixed income securities U.S. Treasury securities 44.3 44.3 — — Other fixed income securities 229.1 — 229.1 — Commingled fixed income funds 119.5 — 119.5 — Options (8.1) — (8.1) — Other types of investments Mutual funds 105.6 — 105.6 — Real estate funds 79.8 — — 79.8 Private equity 4.9 — — 4.9 Total fair value of plan asset investments $ 857.3 $ 180.8 $ 591.8 $ 84.7 Non-investment plan assets 1.5 Total plan assets $ 858.8 December 31, 2019 Asset Category Total Quoted Prices in Significant Other Significant Non- Short-term investments $ 14.6 $ 2.8 $ 11.8 $ — Equity securities Common stocks 127.0 127.0 — — Commingled equity funds 113.4 — 113.4 — Fixed income securities U.S. Treasury securities 49.8 49.8 — — Other fixed income securities 225.1 — 225.1 — Commingled fixed income funds 114.0 — 114.0 — Options (10.8) (10.8) Other types of investments Mutual funds 104.9 — 104.9 — Real estate funds 82.3 — — 82.3 Private equity 8.6 — — 8.6 Total fair value of plan asset investments $ 828.9 $ 179.6 $ 558.4 $ 90.9 Non-investment plan assets 3.4 Total plan assets $ 832.3
Schedule of Reconciliation of Fair Value Measurements Using Significant Unobservable Inputs	The following table presents a reconciliation of the fair value measurements using significant unobservable inputs (Level 3) as of December 31, 2020 and 2019 (dollars in millions): Real estate Private Total Balance at December 31, 2018 $ 80.4 $ 13.2 $ 93.6 Actual return (loss) on plan assets: Relating to assets still held at the reporting date 1.9 — 1.9 Relating to assets sold during the period — (1.4) (1.4) Purchases, sales and settlements — (3.2) (3.2) Balance at December 31, 2019 82.3 8.6 90.9 Actual (loss) return on plan assets: Relating to assets still held at the reporting date (2.5) (2.2) (4.7) Relating to assets sold during the period — (0.1) (0.1) Purchases, sales and settlements — (1.4) (1.4) Balance at December 31, 2020 $ 79.8 $ 4.9 $ 84.7
Schedule of Estimated Future Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid: Years ended December 31 (dollars in millions) Pension Benefits Post-retirement 2021 $ 56.7 $ 0.5 2022 56.6 0.5 2023 55.8 0.5 2024 54.8 0.5 2025 54.0 0.5 2026 – 2030 264.0 2.0

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Summary by Currency of Foreign Currency Forward Contracts	The following table summarizes, by currency, the contractual amounts of the Company’s foreign currency forward contracts that are designated as cash flow hedges: December 31 (dollars in millions) 2020 2019 Buy Sell Buy Sell British pound $ — $ 1.0 $ — $ 1.3 Canadian dollar — 79.7 — 49.7 Euro 32.7 — 36.0 — Mexican peso 16.5 — 18.6 — Total $ 49.2 $ 80.7 $ 54.6 $ 51.0
Schedule of Impact of Cash Flow Hedges on Company's Financial Statements	The following tables present the impact of derivative contracts on the Company’s financial statements. Fair value of derivatives designated as hedging instruments under ASC 815: Fair Value December 31 (dollars in millions) Balance Sheet Location 2020 2019 Foreign currency contracts Other current assets $ 2.7 $ 8.4 Accrued liabilities (7.0) (1.5) Total derivatives designated as hedging instruments $ (4.3) $ 6.9
Schedule of effect of cash flow hedges on the condensed consolidated statement of earnings	The effect of cash flow hedges on the condensed consolidated statement of earnings: Years ended December 31 (dollars in millions) Derivatives in ASC 815 cash flow Amount of gain (loss) Location of gain (loss) Amount of gain 2020 2019 2020 2019 Foreign currency contracts $ 2.3 $ 0.2 Cost of products sold $ 1.9 $ (0.2) Commodities contracts — (0.5) Cost of products sold (0.2) (1.5) $ 2.3 $ (0.3) $ 1.7 $ (1.7)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components of Provision for Income Taxes	The components of the provision (benefit) for income taxes consisted of the following: Years ended December 31 (dollars in millions) 2020 2019 2018 Current: Federal $ 67.1 $ 66.4 $ 60.1 State 17.4 14.8 15.6 International 25.8 19.9 38.6 Deferred: Federal 5.6 0.4 (1.7) State 2.3 1.8 1.5 International (19.2) (1.2) (0.5) $ 99.0 $ 102.1 $ 113.6
Difference Between Provision for Income Taxes and U.S. Federal Statutory Rate	The provision for income taxes differs from the U.S. federal statutory rate due to the following items: Years ended December 31 2020 2019 2018 Provision at U.S. federal statutory rate 21.0 % 21.0 % 21.0 % State taxes, net of federal benefit 3.5 2.8 2.4 International income tax rate differential—China (0.6) (1.3) (2.3) International income tax rate differential—other 0.2 0.4 1.1 Research tax credits (0.5) (0.4) (0.5) Excess tax benefit on stock compensation (0.9) (0.5) (0.4) Other (0.4) (0.4) (0.9) 22.3 % 21.6 % 20.4 %
Components of Earnings Before Income Taxes	Components of earnings before income taxes were as follows: Years ended December 31 (dollars in millions) 2020 2019 2018 U.S. $ 407.3 $ 400.3 $ 376.0 International 36.6 71.8 181.8 $ 443.9 $ 472.1 $ 557.8
Tax Effects of Temporary Differences of Assets and Liabilities	The tax effects of temporary differences of assets and liabilities between income tax and financial reporting are as follows: December 31 (dollars in millions) 2020 2019 Assets Liabilities Assets Liabilities Employee benefits $ 21.6 $ — $ 27.3 $ — Product liability and warranties 42.5 — 39.7 — Inventories 1.5 — — 0.3 Accounts receivable 16.3 — 16.3 — Property, plant and equipment — 36.3 — 34.9 Intangibles — 66.2 — 61.3 Environmental liabilities 1.9 — 1.9 — Undistributed foreign earnings — 9.8 — 20.8 Tax loss and credit carryovers 20.3 — 15.2 — All other 9.9 — 7.7 — Valuation allowance (13.0) — (11.9) — $ 101.0 $ 112.3 $ 96.2 $ 117.3 Net liability $ 11.3 $ 21.1
Reconciliation of Tax Loss Carryovers, Credit Carryovers and Valuation Allowances	A reconciliation of the beginning and ending amounts of tax loss carryovers, credit carryovers and valuation allowances is as follows: Net Operating Losses and Tax Credits Valuation Allowances December 31 (dollars in millions) 2020 2019 2020 2019 Beginning balance $ 15.2 $ 17.5 $ 11.9 $ 13.1 Increases / (Reductions) 5.1 (2.3) 1.1 (1.2) Ending balance $ 20.3 $ 15.2 $ 13.0 $ 11.9
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amount of unrecognized benefits is as follows: (Dollars in millions) 2020 2019 Balance at January 1 $ 9.7 $ 8.3 Additions / (Reductions) for tax positions of prior years (0.7) 1.4 Balance at December 31 $ 9.0 $ 9.7

Operations by Segment (Tables)

Operations by Segment (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Schedule of Reporting Information by Segment	Net Sales Earnings Years ended December 31 (dollars in millions) 2020 2019 2018 2020 2019 2018 North America (1) (2) $ 2,118.3 $ 2,083.5 $ 2,044.7 $ 503.5 $ 488.9 $ 464.1 Rest of World (3) 800.3 935.8 1,173.6 — 40.2 149.3 Inter-segment (23.3) (26.6) (30.4) (0.3) — — Total segments – sales, segment earnings $ 2,895.3 $ 2,992.7 $ 3,187.9 $ 503.2 $ 529.1 $ 613.4 Corporate expenses (52.0) (46.0) (47.2) Interest expense (7.3) (11.0) (8.4) Earnings before income taxes 443.9 472.1 557.8 Provision for income taxes (99.0) (102.1) (113.6) Net earnings $ 344.9 $ 370.0 $ 444.2 (1) In 2020, the Company recognized $2.7 of severance and restructuring expenses in connection with the Company's alignment of the business to current market conditions. For additional information, see Note 5 “Severance, Restructuring and Impairment Expenses.” (2) In 2018, the Company recognized $6.7 of restructuring and impairment expenses in connection with the move of manufacturing operations from its Renton, Washington facility to other U.S. facilities. For additional information, see Note 5 “Severance, Restructuring and Impairment Expenses.” (3) In 2020, the Company recognized $5.0 of severance and restructuring expenses in connection with its alignment of its business to current market conditions. For additional information, see Note 5 “Severance, Restructuring and Impairment Expenses.” Total Assets (December 31) Depreciation and Amortization (Years Ended December 31) Capital Expenditures (Years Ended December 31) (dollars in millions) 2020 2019 2018 2020 2019 2018 2020 2019 2018 North America $ 1,759.1 $ 1,742.8 $ 1,653.6 $ 51.5 $ 49.3 $ 45.5 $ 41.7 $ 47.6 $ 45.8 Rest of World 664.9 709.1 721.6 27.9 27.9 25.2 14.9 15.9 32.3 Corporate 736.7 606.1 696.3 0.6 1.1 1.2 0.2 0.9 7.1 Total $ 3,160.7 $ 3,058.0 $ 3,071.5 $ 80.0 $ 78.3 $ 71.9 $ 56.8 $ 64.4 $ 85.2
Schedule of Net Sales and Long-lived Assets, by Geographical Location	The following data by geographic area includes net sales based on product shipment destination and long-lived assets based on physical location. Long-lived assets include net property, plant and equipment, operating lease assets and other long-term assets. Long-lived Assets (December 31) Net Sales (Years Ended December 31) (dollars in millions) 2020 2019 2018 2020 2019 2018 United States $ 355.8 $ 360.2 $ 327.3 United States $ 1,904.9 $ 1,868.7 $ 1,820.8 China 268.3 266.7 252.6 China 695.6 825.4 1,071.2 Canada 4.5 4.2 3.1 Canada 175.0 168.5 175.0 Other Foreign 43.4 42.1 42.9 Other Foreign 119.8 130.1 120.9 Total $ 672.0 $ 673.2 $ 625.9 Total $ 2,895.3 $ 2,992.7 $ 3,187.9

Quarterly Results of Operatio_2

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Results of Operations	(dollars in millions, except per share amounts) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter 2020 2019 2020 2019 2020 2019 2020 2019 Net sales $ 636.9 $ 748.2 $ 663.9 $ 765.4 $ 760.0 $ 728.2 $ 834.5 $ 750.9 Gross profit 239.5 292.8 247.5 308.7 297.1 284.2 324.1 295.0 Net earnings 51.7 89.3 67.8 102.1 105.4 87.3 120.0 91.3 Basic earnings per share 0.32 0.53 0.42 0.61 0.65 0.53 0.74 0.56 Diluted earnings per share 0.32 0.53 0.42 0.61 0.65 0.53 0.74 0.56 Common dividends declared 0.24 0.22 0.24 0.22 0.24 0.22 0.26 0.24

Organization and Significant _4

Organization and Significant Accounting Policies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of reporting segments | segment	2
Fair value of term notes	$ 123.3	$ 122.1
Carrying amount of term notes	$ 113.2	$ 120
Percentage of (LIFO) inventory	67.00%	65.00%
Advertising costs charged to operations	$ 97	$ 110.7	$ 132.1
Amortization of total advertising costs	27	28.5	38.7
Research and development costs	80.7	87.9	94
Income tax benefits on settled stock based compensation awards	$ 4.2	$ 2.3	$ 2.4
Minimum percentage of amount likely to be realized upon ultimate settlement to recognize tax benefits	50.00%
Minimum
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, maturity period	180 days
Product warranty period	1 year
Amortization of total advertising costs, months	12 months
Minimum | Customer Relationships
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets estimated useful lives	5 years
Minimum | Buildings
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated service lives used to compute depreciation	25 years
Minimum | Equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated service lives used to compute depreciation	3 years
Minimum | Software
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated service lives used to compute depreciation	3 years
Maximum
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, maturity period	12 months
Product warranty period	10 years
Amortization of total advertising costs, months	36 months
Maximum | Customer Relationships
Organization And Summary Of Significant Accounting Policies [Line Items]
Intangible assets estimated useful lives	25 years
Maximum | Buildings
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated service lives used to compute depreciation	50 years
Maximum | Equipment
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated service lives used to compute depreciation	20 years
Maximum | Software
Organization And Summary Of Significant Accounting Policies [Line Items]
Estimated service lives used to compute depreciation	15 years

Organization and Significant _5

Organization and Significant Accounting Policies - Company's Product Warranty Liability Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance at beginning of year	$ 134.3	$ 139.4
Expense	56.1	44.3
Claims settled	(48.1)	(49.4)
Balance at end of year	$ 142.3	$ 134.3

Organization and Significant _6

Organization and Significant Accounting Policies - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis	$ 116.5	$ 177.4
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets measured at fair value on recurring basis		$ 6.9
Liabilities measured at fair value on recurring basis	$ (4.3)

Organization and Significant _7

Organization and Significant Accounting Policies - Schedule of Computation of Basic and Diluted Weighted-Average Shares Used in Earnings per Share Calculations (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Denominator for basic earnings per share - weighted-average shares outstanding (in shares)	161,530,589	165,450,441	170,589,345
Effect of dilutive stock options, restricted stock and share units (in shares)	1,073,560	1,260,456	1,604,695
Denominator for diluted earnings per share (in shares)	162,604,149	166,710,897	172,194,040

Revenue Recognition - Narrative

Revenue Recognition - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)segmentdistributor	Dec. 31, 2019USD ($)
Disaggregation of Revenue [Line Items]
Customer deposits liability	$ 90	$ 49.6
Allowance for doubtful accounts	$ 5.6	$ 6.7
Number of reporting segments | segment	2
Water Heaters | North America
Disaggregation of Revenue [Line Items]
Number of wholesale distributors | distributor	1,200
Minimum
Disaggregation of Revenue [Line Items]
Payment terms	30 days
Maximum
Disaggregation of Revenue [Line Items]
Payment terms	90 days

Revenue Recognition - Segment S

Revenue Recognition - Segment Sales Disaggregated by Major Product Line (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 834.5	$ 760	$ 663.9	$ 636.9	$ 750.9	$ 728.2	$ 765.4	$ 748.2	$ 2,895.3	$ 2,992.7	$ 3,187.9
China
Disaggregation of Revenue [Line Items]
Net sales									695.6	825.4	1,071.2
Operating Segments | North America
Disaggregation of Revenue [Line Items]
Net sales									2,118.3	2,083.5	2,044.7
Operating Segments | North America | Water heaters and related parts
Disaggregation of Revenue [Line Items]
Net sales									1,753.9	1,742.6	1,757
Operating Segments | North America | Boilers and related parts
Disaggregation of Revenue [Line Items]
Net sales									187.2	199.5	200.4
Operating Segments | North America | Water treatment products
Disaggregation of Revenue [Line Items]
Net sales									177.2	141.4	87.3
Operating Segments | Rest of World
Disaggregation of Revenue [Line Items]
Net sales									800.3	935.8	1,173.6
Operating Segments | Rest of World | China
Disaggregation of Revenue [Line Items]
Net sales									701	827.2	1,070.4
Operating Segments | Rest of World | All other Rest of World
Disaggregation of Revenue [Line Items]
Net sales									99.3	108.6	103.2
Inter-segment sales
Disaggregation of Revenue [Line Items]
Net sales									$ (23.3)	$ (26.6)	$ (30.4)

Acquisition - Narrative (Detail

Acquisition - Narrative (Details) - USD ($) $ in Millions	Apr. 08, 2019	Jun. 30, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Aggregate cash purchase price, net of cash acquired			$ 0	$ 107	$ 0
Acquired intangible assets, amortization period, in years			13 years
Water-Right, Inc
Business Acquisition [Line Items]
Percentage of ownership interest acquired	100.00%
Aggregate cash purchase price, net of cash acquired	$ 107
Acquired intangible assets	60.4
Water-Right, Inc | Trademarks
Business Acquisition [Line Items]
Acquired intangible assets, not subject to amortization	19
Water-Right, Inc | Customer relationships
Business Acquisition [Line Items]
Acquired intangible assets, subject to amortization	$ 40.2
Acquired intangible assets, amortization period, in years	20 years
Water-Right, Inc | Noncompete agreements
Business Acquisition [Line Items]
Acquired intangible assets, subject to amortization	$ 1.2
Acquired intangible assets, amortization period, in years	7 years 6 months
Water-Right, Inc | Escrow Deposit
Business Acquisition [Line Items]
Escrow to satisfy any potential obligations to the former owners	$ 4
Release of escrow			$ 3.9
Water-Right, Inc | Escrow Deposit | Forecast
Business Acquisition [Line Items]
Release of escrow		$ 0.1

Acquisition - Schedule of Preli

Acquisition - Schedule of Preliminary Allocation of Fair Value of Assets Acquired and Liabilities Assumed at Date of Acquisition (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Apr. 08, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 546.8	$ 546		$ 513
Water-Right, Inc
Business Acquisition [Line Items]
Current assets, net of cash acquired			$ 9.7
Property, plant and equipment			8.6
Intangible assets			60.4
Goodwill			31
Total assets acquired			109.7
Current liabilities			(2.7)
Net assets acquired			$ 107

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease termination period	1 year
Rent expense, including payments under operating leases		$ 24
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, renewal term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, renewal term	5 years

Leases - Supplemental balance s

Leases - Supplemental balance sheet (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Liabilities
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesCurrent	us-gaap:AccruedLiabilitiesCurrent
Short term: Accrued liabilities	$ 11.1	$ 12
Long term: Operating lease liabilities	34.4	38.7
Total operating lease liabilities	45.5	50.7
Less: Rent incentives and deferrals	(3.9)	(3.8)
Assets
Operating lease assets	$ 41.6	$ 46.9
Lease Term and Discount Rate
Weighted-average remaining lease term	10 years
Weighted-average discount rate	3.49%

Leases - Components of lease ex

Leases - Components of lease expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Short-term lease expense	$ 1.8	$ 2
Variable lease cost	1.6	2.1
Cost of products sold
Lessee, Lease, Description [Line Items]
Operating lease expense	3.1	3
Selling, general and administrative expenses
Lessee, Lease, Description [Line Items]
Operating lease expense	$ 16	$ 17.6

Leases - Maturities of lease li

Leases - Maturities of lease liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 12.4
2022	10.2
2023	5.6
2024	4.6
2025	2.9
After 2025	21
Total lease payments	56.7
Less: imputed interest	(11.2)
Present value of operating lease liabilities	$ 45.5	$ 50.7

Severance, Restructuring and _3

Severance, Restructuring and Impairment Expenses - Narrative (Details) - USD ($) $ in Millions	Mar. 21, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Severance, restructuring and impairment expenses	$ 6.7	$ 7.7	$ 0	$ 6.7
Severance costs	4	6.8
Other Restructuring Costs		0.9
Tax benefit		(99)	$ (102.1)	(113.6)
Lease exit cost	2.1
Impairment of long-lived assets	0.6
North America
Restructuring Cost and Reserve [Line Items]
Severance, restructuring and impairment expenses		2.7		$ 6.7
Rest of World
Restructuring Cost and Reserve [Line Items]
Severance, restructuring and impairment expenses		5
Restructuring and Impairment Charges
Restructuring Cost and Reserve [Line Items]
Tax benefit	$ 1.7	$ 1.4

Severance, Restructuring and _4

Severance, Restructuring and Impairment Expenses - Schedule of Analysis of Company's Restructuring Reserve (Details) - USD ($) $ in Millions	Mar. 21, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Reserve [Roll Forward]
Beginning balance		$ 0.5	$ 1.5	$ 0
Charges	$ 6.7	7.7	0	6.7
Cash payments and disposals		(6.5)	(1)	(5.2)
Ending balance		1.7	0.5	1.5
Severance Costs
Restructuring Reserve [Roll Forward]
Beginning balance		0	0.2	0
Charges		6.8		4
Cash payments and disposals		(5.1)	(0.2)	(3.8)
Ending balance		1.7	0	0.2
Restructuring Expenses
Restructuring Reserve [Roll Forward]
Beginning balance		0.5	1.3	0
Charges		0.9		2.1
Cash payments and disposals		(1.4)	(0.8)	(0.8)
Ending balance		0	0.5	1.3
Fixed Assets Impairment
Restructuring Reserve [Roll Forward]
Beginning balance		0	0	0
Charges		0		0.6
Cash payments and disposals		0	0	(0.6)
Ending balance		$ 0	$ 0	$ 0

Statement of Cash Flows - Sched

Statement of Cash Flows - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net change in current assets and liabilities, net of acquisitions:
Receivables	$ 4.5	$ 62.4	$ (54.6)
Inventories	2.9	6.3	(7.7)
Other current assets	4.7	(4.8)	10
Trade payables	85.6	(35.4)	8.8
Accrued liabilities, including payroll and benefits	29.3	14.2	(3.5)
Income taxes	3.4	(10.1)	7
Current assets and liabilities	$ 130.4	$ 32.6	$ (40)

Inventories - Schedule of Inven

Inventories - Schedule of Inventories (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Finished products	$ 143.4	$ 136.8
Work in process	21.8	21.7
Raw materials	159.2	168.3
Inventories, at FIFO cost	324.4	326.8
LIFO reserve	(24.3)	(23.8)
Net inventory	$ 300.1	$ 303

Inventories - Narrative (Detail

Inventories - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
After-tax LIFO income	$ (0.2)	$ (0.7)	$ (0.4)

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,222.6	$ 1,156.9
Accumulated depreciation and amortization	(681.3)	(611.5)
Net property, plant and equipment	541.3	545.4
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	11.6	11.6
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	349.2	334.1
Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	729.7	686.9
Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 132.1	$ 124.3

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Schedule of Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Beginning balance	$ 546	$ 513
Acquisition		31
Currency translation adjustment	0.8	2
Ending balance	546.8	546
North America
Goodwill [Roll Forward]
Beginning balance	486.9	453.9
Acquisition		31
Currency translation adjustment	0.8	2
Ending balance	487.7	486.9
Rest of World
Goodwill [Roll Forward]
Beginning balance	59.1	59.1
Acquisition		0
Currency translation adjustment	0	0
Ending balance	$ 59.1	$ 59.1

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Schedule of Carrying Amount of Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 281.7	$ 281.7
Accumulated Amortization	(141.8)	(127.1)
Net	139.9	154.6
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	465.7	465.5
Accumulated Amortization	(141.8)	(127.1)
Net	323.9	338.4
Trade names
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	184	183.8
Patents
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3.7	3.7
Accumulated Amortization	(3.7)	(3.5)
Net	0	0.2
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	(3.7)	(3.5)
Customer lists
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	278	278
Accumulated Amortization	(138.1)	(123.6)
Net	139.9	154.4
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Accumulated Amortization	$ (138.1)	$ (123.6)

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Other Intangibles [Line Items]
Amortization expenses of other intangible assets	$ 14,500,000	$ 15,800,000	$ 14,300,000
Amortization of intangible assets, weighted average period, years	13 years
Goodwill impairment	$ 0	0	0
Other intangible asset impairments	0	$ 0	$ 0
Annually
Goodwill And Other Intangibles [Line Items]
Amortization expenses of other intangible assets	$ 12,200,000

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Debt	$ 113,200,000	$ 284,000,000
Long-term debt due within one year	(6,800,000)	(6,800,000)
Long-term debt	$ 106,400,000	$ 277,200,000
Revolving Credit Agreement Borrowings
Debt Instrument [Line Items]
Line of credit facility, average year-end interest rate	0.00%	2.80%
Debt	$ 0	$ 85,000,000
Bank Credit Lines
Debt Instrument [Line Items]
Line of credit facility, average year-end interest rate	0.00%	2.40%
Debt	$ 0	$ 4,700,000
Commercial Paper
Debt Instrument [Line Items]
Line of credit facility, average year-end interest rate	0.00%	2.20%
Debt	$ 0	$ 74,300,000
Term Notes With Insurance Companies
Debt Instrument [Line Items]
Line of credit facility, average year-end interest rate	3.30%	3.30%
Debt	$ 113,200,000	$ 120,000,000

Debt - Narrative (Details)

Debt - Narrative (Details)	12 Months Ended
	Dec. 31, 2016USD ($)bank	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Multi-currency revolving credit agreement	$ 500,000,000
Number of banks involved in multi-year multi-currency revolving credit agreement | bank	9
Multi-currency revolving credit agreement, maximum amount	$ 700,000,000
Amount outstanding		$ 113,200,000	$ 284,000,000
Fixed-rate interest expense obligation		22,200,000
Commercial Paper
Debt Instrument [Line Items]
Amount outstanding		0	74,300,000
Bank Credit Lines
Debt Instrument [Line Items]
Amount outstanding		$ 0	$ 4,700,000

Debt - Schedule of Maturities o

Debt - Schedule of Maturities of Long Term Debt (Details) $ in Millions	Dec. 31, 2020USD ($)
Debt Disclosure [Abstract]
2021	$ 6.8
2022	6.8
2023	10
2024	10
2025	$ 10

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)vote$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Jun. 30, 2019shares
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)	3,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 1
Common stock, voting rights, allowable percentage of Board of Directors to elect	33.33%
Common stock, voting rights, matters other than election of Board of Directors, vote per share | vote	0.1
Common stock, conversion basis, ratio	1
Dividends paid (in dollars per share) | $ / shares	$ 0.98	$ 0.90	$ 0.76
Stock repurchase program number of shares authorized to repurchase (in shares)				3,000,000
Shares repurchased (in shares)	1,348,391	6,113,038	3,797,800
Shares repurchased, price per share (in dollars per share) | $ / shares	$ 42.02
Shares repurchased, value | $	$ 56.7	$ 287.7	$ 202.6
Remaining authorization stock repurchase (in shares)	1,613,824
Class A Common Stock
Class of Stock [Line Items]
Common Stock, shares authorized (in shares)	27,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 5
Shares converted into Common Stock (in shares)	12,372	10,442	48,232
Treasury stock, number of shares held (in shares)	130,380	130,380
Common Stock
Class of Stock [Line Items]
Common Stock, shares authorized (in shares)	240,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 1
Treasury stock, number of shares held (in shares)	28,807,455	28,205,806

Stockholders' Equity - Changes

Stockholders' Equity - Changes in Accumulated Other Comprehensive Loss by Component (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 1,666.8	$ 1,717
Balance at end of period	1,848.3	1,666.8
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(348.3)	(350.8)
Balance at end of period	(321.2)	(348.3)
Cumulative foreign currency translation
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(66.2)	(64.9)
Other comprehensive gain (loss) before reclassifications	18.1	(1.3)
Balance at end of period	(48.1)	(66.2)
Unrealized net gain (loss) on cash flow derivatives
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	0.2	(0.7)
Other comprehensive gain (loss) before reclassifications	1.7	(0.3)
Amounts reclassified, net of tax	(1.3)	1.2
Balance at end of period	0.6	0.2
Tax provision (benefit)	0.4	(0.5)
Reclassification, before income tax	(1.7)	1.7
Pension liability
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(282.3)	(285.2)
Other comprehensive gain (loss) before reclassifications	(6.3)	(9.5)
Amounts reclassified, net of tax	14.9	12.4
Balance at end of period	(273.7)	(282.3)
Tax provision (benefit)	(4.9)	(3.9)
Reclassification, before income tax	19.8	16.3
Actuarial losses
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification, before income tax	20.2	16.8
Prior year service cost
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Reclassification, before income tax	$ (0.4)	$ (0.5)

Stock Based Compensation - Narr

Stock Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 15, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock based compensation cost recognized		$ 12.7	$ 13.3	$ 10.1
Stock option compensation expense recognized		$ 6.2	$ 6.4	$ 4.4
Weighted-average fair value per option at the date of grant (in dollars per share)		$ 8.17	$ 10.83	$ 14.80
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years	3 years	3 years
Award expiration period		10 years	10 years	10 years
Restricted Stock And Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Number of share units granted (in shares)		174,420	140,102	106,581
Value of share units granted		$ 7.4	$ 6.9	$ 6.6
Share based compensation expense attributable to share units		$ 6.5	$ 6.9	$ 5.7
A.O. Smith Combined Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for granting of options, restricted stock or share units (in shares)		3,395,216
Additional shares authorized (in shares)	2,400,000

Stock Based Compensation - Chan

Stock Based Compensation - Changes in Option Awards All of Which Related to Common Stock (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Options
Outstanding at beginning of year (in shares)	2,728,350	2,432,689	2,263,126
Granted (in shares)	798,970	557,045	373,220
Exercised (in shares)	(662,215)	(249,840)	(176,302)
Forfeited (in shares)	(79,451)	(11,544)	(27,355)
Outstanding at end of year (in shares)	2,785,654	2,728,350	2,432,689
Number of options, Exercisable at End of year (in shares)	1,529,464	1,820,743	1,665,184
Weighted Avg. Per Share Exercise Price
Outstanding at beginning of year (in dollars per share)	$ 37.64	$ 33.05	$ 27.73
Granted (in dollars per share)	42.50	49.49	61.62
Exercised (in dollars per share)	19.59	18.55	22.93
Forfeited (in dollars per share)	48.98	54.02	47.95
Outstanding at end of year (in dollars per share)	43.01	37.64	33.05
Weighted-Avg. Per Share Exercise Price, Exercisable at end of year (in dollars per share)	$ 40.35	$ 30.07	$ 24.52
Intrinsic value of options exercised	$ 21.3	$ 7.7	$ 6.8
Weighted average remaining contractual life of options outstanding	8 years	7 years	7 years
Aggregate intrinsic value of options outstanding	$ 35.3
Weighted average remaining contractual life of options exercisable	6 years	6 years	6 years
Aggregate intrinsic value of options exercisable	$ 23.7

Stock Based Compensation - Nonv

Stock Based Compensation - Nonvested Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Options
Nonvested options at beginning of year (in shares)	907,607
Granted (in shares)	798,970	557,045	373,220
Vested (in shares)	(416,432)
Forfeited (in shares)	(33,955)
Nonvested options at end of year (in shares)	1,256,190	907,607
Weighted Avg. Per Share Exercise Price
Nonvested options at beginning of year (in dollars per share)	$ 52.82
Granted (in dollars per share)	42.50	$ 49.49	$ 61.62
Vested (in dollars per share)	53.20
Forfeited (in dollars per share)	49.06
Nonvested options at end of year (in dollars per share)	$ 46.23	$ 52.82

Stock Based Compensation - Sche

Stock Based Compensation - Schedule of Weighted-Average Fair Value per Option at Date of Grant (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Payment Arrangement [Abstract]
Expected life (years)	5 years 8 months 12 days	5 years 6 months	5 years 8 months 12 days
Risk-free interest rate	1.50%	2.70%	2.90%
Dividend yield	2.10%	1.60%	1.00%
Expected volatility	23.70%	22.80%	22.10%

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Share Unit Activity Under Plan (Details) - Restricted Stock And Share Units - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Units
Issued and unvested at beginning of year (in shares)	366,102
Granted (in shares)	174,420	140,102	106,581
Vested (in shares)	(100,735)
Forfeited (in shares)	(13,001)
Issued and unvested at end of year (in shares)	426,786	366,102
Weighted-Average Grant Date Value
Issued and unvested at beginning of year (in dollars per share)	$ 49.92
Granted (in dollars per share)	42.64
Vested (in dollars per share)	49.21
Forfeited (in dollars per share)	51.25
Issued and unvested at end of year (in dollars per share)	$ 46.99	$ 49.92

Pensions and Other Post-retirem

Pensions and Other Post-retirement Benefits - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Percentage match of the first one percent of contributions made by participating employees	100.00%
Percentage match of the next five percent of contributions made by participating employees	50.00%
Medical and life insurance maximum participant coverage age, in years	65 years
Other comprehensive gain for after tax adjustment for additional minimum pension liability	$ 8,600,000	$ 2,900,000	$ (13,100,000)
Employer contributions in 2020	0
Expected employer contributions in 2021	$ 0
Minimum | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation to equity managers	30.00%
Maximum | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation to equity managers		60.00%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Other comprehensive gain for after tax adjustment for additional minimum pension liability	$ 10,700,000	$ 5,300,000	(17,600,000)
Employer contributions in 2020	10,100,000	7,800,000
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Other comprehensive gain for after tax adjustment for additional minimum pension liability	700,000	(1,600,000)	$ 200,000
Employer contributions in 2020	$ 500,000	$ 500,000

Pension and Other Post-retire_3

Pension and Other Post-retirement Benefits - Schedule of Changes in Benefit Obligations, Plan Assets and Funded Status of Defined Benefit Pension and Post-Retirement Benefit Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in fair value of plan assets
Plan assets at beginning of year	$ 828,900,000
Contribution by the Company	0
Plan assets at end of year	857,300,000	$ 828,900,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation (ABO) at December 31	869,000,000	868,700,000
Change in projected benefit obligations (PBO)
PBO at beginning of year	(869,300,000)	(833,800,000)
Service cost	(1,500,000)	(1,600,000)	$ (2,000,000)
Interest cost	(23,000,000)	(31,600,000)	(28,900,000)
Participant contributions	0	0
Plan amendments	0	0
Actuarial loss including assumption changes	(63,800,000)	(98,600,000)
Benefits paid	87,800,000	96,300,000
PBO at end of year	(869,800,000)	(869,300,000)	(833,800,000)
Change in fair value of plan assets
Plan assets at beginning of year	832,400,000	777,500,000
Actual return on plan assets	104,100,000	143,400,000
Contribution by the Company	10,100,000	7,800,000
Participant contributions	0	0
Benefits paid	(87,800,000)	(96,300,000)
Plan assets at end of year	858,800,000	832,400,000	777,500,000
Funded status	(11,000,000)	(36,900,000)
Noncurrent assets	3,000,000	0
Current liabilities	(600,000)	(9,300,000)
Non-current liabilities	(13,400,000)	(27,600,000)
Net pension liability at end of year	(11,000,000)	(36,900,000)
Net actuarial loss (gain)	452,000,000	463,100,000
Prior service cost	1,000,000	500,000
Total recognized in accumulated other comprehensive loss	453,000,000	463,600,000
Pension Benefits | Foreign plan
Change in fair value of plan assets
Net pension liability at end of year	(200,000)	(200,000)
Post-retirement Benefits
Change in projected benefit obligations (PBO)
PBO at beginning of year	(8,000,000)	(7,000,000)
Service cost	0	(100,000)	(100,000)
Interest cost	(100,000)	(300,000)	(300,000)
Participant contributions	(100,000)	(100,000)
Plan amendments	2,000,000	0
Actuarial loss including assumption changes	(800,000)	(1,200,000)
Benefits paid	1,100,000	700,000
PBO at end of year	(5,900,000)	(8,000,000)	(7,000,000)
Change in fair value of plan assets
Plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Contribution by the Company	500,000	500,000
Participant contributions	100,000	100,000
Benefits paid	(600,000)	(600,000)
Plan assets at end of year	0	0	$ 0
Funded status	(5,900,000)	(8,000,000)
Noncurrent assets	0	0
Current liabilities	(500,000)	(500,000)
Non-current liabilities	(5,400,000)	(7,500,000)
Net pension liability at end of year	(5,900,000)	(8,000,000)
Net actuarial loss (gain)	600,000	(200,000)
Prior service cost	(3,300,000)	(1,800,000)
Total recognized in accumulated other comprehensive loss	$ (2,700,000)	$ (2,000,000)

Pension and Other Post-retire_4

Pension and Other Post-retirement Benefits - Components of Company's Net Pension Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other changes in plan assets and projected benefit obligation recognized in other comprehensive loss
Total recognized in other comprehensive loss	$ (8.6)	$ (2.9)	$ 13.1
Pension Benefits
Net periodic (benefit) cost
Service cost	1.5	1.6	2
Interest cost	23	31.6	28.9
Expected return on plan assets	(51.9)	(57.3)	(58.1)
Net actuarial loss	20.2	16.8	19
Prior service cost	(0.4)	(0.5)	(0.5)
Defined-benefit plan income	(7.6)	(7.8)	(8.7)
Curtailment and other one-time charges	2.5	1.6	0
Various U.S. defined contribution plans cost	14.4	13.3	12.2
Total defined benefit plan and defined contribution plan periodic benefit cost	9.3	7.1	3.5
Other changes in plan assets and projected benefit obligation recognized in other comprehensive loss
Net actuarial loss (gain)	11.7	12.6	36.1
Amortization of net actuarial loss	(22.8)	(18.4)	(19)
Prior service credit	0	0	0
Amortization of prior service cost	0.4	0.5	0.5
Total recognized in other comprehensive loss	(10.7)	(5.3)	17.6
Total recognized in net periodic (benefit) cost and other comprehensive loss	(15.8)	(11.5)	8.9
Post-retirement Benefits
Net periodic (benefit) cost
Service cost	0	0.1	0.1
Interest cost	0.1	0.3	0.3
Expected return on plan assets	0	0	0
Net actuarial loss	0	0	0
Prior service cost	(0.5)	(0.4)	(0.4)
Defined-benefit plan income	(0.4)	0	0
Curtailment and other one-time charges	(0.5)	0	0
Total defined benefit plan and defined contribution plan periodic benefit cost	(0.9)	0	0
Other changes in plan assets and projected benefit obligation recognized in other comprehensive loss
Net actuarial loss (gain)	0.8	1.2	(0.6)
Amortization of net actuarial loss	0	0	0
Prior service credit	(2)	0	0
Amortization of prior service cost	0.5	0.4	0.4
Total recognized in other comprehensive loss	(0.7)	1.6	(0.2)
Total recognized in net periodic (benefit) cost and other comprehensive loss	$ (1.6)	$ 1.6	$ (0.2)

Pension and Other Post-retire_5

Pension and Other Post-retirement Benefits - Actuarial Assumptions Used to Determine Benefit Obligations (Details)	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.44%	3.18%
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.04%	3.40%

Pension and Other Post-retire_6

Pension and Other Post-retirement Benefits - Assumptions Used to Determine Net Periodic Benefit Cost (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.18%	4.32%	3.65%
Expected long-term return on plan assets	6.75%	7.15%	7.15%
Rate of compensation increase	4.00%	4.00%	4.00%
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.95%	4.45%	3.79%
Rate of compensation increase	4.00%	4.00%	4.00%

Pension and Other Post-retire_7

Pension and Other Post-retirement Benefits - Health Care Cost Trend Rates (Details)	Dec. 31, 2020	Dec. 31, 2019
Pension And Other Post-Retirement Benefits
Health care cost trend rate assumed for next year	7.40%	7.70%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%

Pension and Other Post-retire_8

Pension and Other Post-retirement Benefits - Weighted Asset Allocations by Asset Category (Details)	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Average assets allocation	100.00%	100.00%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Average assets allocation	44.00%	42.00%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Average assets allocation	46.00%	47.00%
Real estate
Defined Benefit Plan Disclosure [Line Items]
Average assets allocation	9.00%	10.00%
Private equity
Defined Benefit Plan Disclosure [Line Items]
Average assets allocation	1.00%	1.00%

Pension and Other Post-retire_9

Pension and Other Post-retirement Benefits - Fair Value Measurement of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	$ 857.3	$ 828.9
Non-investment plan assets	1.5	3.4
Total plan assets	858.8	832.3
Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	13.7	14.6
Common stocks
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	136.5	127
Commingled equity funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	132	113.4
U.S. Treasury securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	44.3	49.8
Other fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	229.1	225.1
Commingled fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	119.5	114
Options
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	(8.1)	(10.8)
Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	105.6	104.9
Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	79.8	82.3
Private equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	4.9	8.6
Quoted Prices in Active Markets for Identical Contracts (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	180.8	179.6
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	2.8
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Common stocks
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	136.5	127
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Commingled equity funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Quoted Prices in Active Markets for Identical Contracts (Level 1) | U.S. Treasury securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	44.3	49.8
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Other fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Commingled fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Options
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Quoted Prices in Active Markets for Identical Contracts (Level 1) | Private equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	591.8	558.4
Significant Other Observable Inputs (Level 2) | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	13.7	11.8
Significant Other Observable Inputs (Level 2) | Common stocks
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Other Observable Inputs (Level 2) | Commingled equity funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	132	113.4
Significant Other Observable Inputs (Level 2) | U.S. Treasury securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Other Observable Inputs (Level 2) | Other fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	229.1	225.1
Significant Other Observable Inputs (Level 2) | Commingled fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	119.5	114
Significant Other Observable Inputs (Level 2) | Options
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	(8.1)	(10.8)
Significant Other Observable Inputs (Level 2) | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	105.6	104.9
Significant Other Observable Inputs (Level 2) | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Other Observable Inputs (Level 2) | Private equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	84.7	90.9	$ 93.6
Significant Non- observable Inputs (Level 3) | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3) | Common stocks
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3) | Commingled equity funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3) | U.S. Treasury securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3) | Other fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3) | Commingled fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3) | Options
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0
Significant Non- observable Inputs (Level 3) | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	0	0
Significant Non- observable Inputs (Level 3) | Real estate funds
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	79.8	82.3	80.4
Significant Non- observable Inputs (Level 3) | Private equity
Defined Benefit Plan Disclosure [Line Items]
Total fair value of plan asset investments	$ 4.9	$ 8.6	$ 13.2

Pension and Other Post-retir_10

Pension and Other Post-retirement Benefits - Reconciliation of Fair Value Measurements Using Significant Unobservable Inputs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at beginning of year	$ 828.9
Plan assets at end of year	857.3	$ 828.9
Real estate
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at beginning of year	82.3
Plan assets at end of year	79.8	82.3
Private equity
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at beginning of year	8.6
Plan assets at end of year	4.9	8.6
Significant Non- observable Inputs (Level 3)
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at beginning of year	90.9	93.6
Relating to assets still held at the reporting date	(4.7)	1.9
Relating to assets sold during the period	(0.1)	(1.4)
Purchases, sales and settlements	(1.4)	(3.2)
Plan assets at end of year	84.7	90.9
Significant Non- observable Inputs (Level 3) | Real estate
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at beginning of year	82.3	80.4
Relating to assets still held at the reporting date	(2.5)	1.9
Relating to assets sold during the period	0	0
Purchases, sales and settlements	0	0
Plan assets at end of year	79.8	82.3
Significant Non- observable Inputs (Level 3) | Private equity
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Plan assets at beginning of year	8.6	13.2
Relating to assets still held at the reporting date	(2.2)	0
Relating to assets sold during the period	(0.1)	(1.4)
Purchases, sales and settlements	(1.4)	(3.2)
Plan assets at end of year	$ 4.9	$ 8.6

Pension and Other Post-retir_11

Pension and Other Post-retirement Benefits - Estimated Future Payments (Details) $ in Millions	Dec. 31, 2020USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
2021	$ 56.7
2022	56.6
2023	55.8
2024	54.8
2025	54
2026 – 2030	264
Post-retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
2021	0.5
2022	0.5
2023	0.5
2024	0.5
2025	0.5
2026 – 2030	$ 2

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Trading Activity, Gains and Losses, Net [Line Items]
Foreign currency translation adjustments	$ 18.1	$ (1.3)	$ (38.4)
Net Investment Hedging | Non-US
Trading Activity, Gains and Losses, Net [Line Items]
Foreign currency translation adjustments	(3.1)	$ 0
Net Investment Hedging | Non-US | Foreign currency forward contracts
Trading Activity, Gains and Losses, Net [Line Items]
Contractual amounts of foreign currency forward contracts	$ 100
Commodity Futures Contracts
Trading Activity, Gains and Losses, Net [Line Items]
Reclassification period for effective portion of contract, in years	1 year

Derivative Instruments - Schedu

Derivative Instruments - Schedule of Summary by Currency of Foreign Currency Forward Contracts (Details) - Foreign currency forward contracts - Cash Flow Hedging - Designated as Hedging Instrument - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Buy
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Contractual amounts of foreign currency forward contracts	$ 49.2	$ 54.6
Buy | Euro
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Contractual amounts of foreign currency forward contracts	32.7	36
Buy | Mexican peso
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Contractual amounts of foreign currency forward contracts	16.5	18.6
Sell
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Contractual amounts of foreign currency forward contracts	80.7	51
Sell | British pound
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Contractual amounts of foreign currency forward contracts	1	1.3
Sell | Canadian dollar
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Contractual amounts of foreign currency forward contracts	$ 79.7	$ 49.7

Derivative Instruments - Impact

Derivative Instruments - Impact of Derivative Contracts on Company's Financial Statements (Details) - Designated as Hedging Instrument - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Total derivatives designated as hedging instruments	$ (4.3)	$ 6.9
Foreign currency contracts | Other current assets
Derivatives, Fair Value [Line Items]
Fair value of derivative instruments, assets	2.7	8.4
Foreign currency contracts | Accrued liabilities
Derivatives, Fair Value [Line Items]
Fair value of derivative instruments, liabilities	$ (7)	$ (1.5)

Derivative Instruments - Sche_2

Derivative Instruments - Schedule of Effect of Derivatives Instruments on Consolidated Statement of Earnings (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Amount of gain (loss) recognized in other comprehensive loss on derivatives	$ 2.3	$ (0.3)
Amount of gain (loss) reclassified from accumulated other comprehensive loss into earnings	1.7	(1.7)
Foreign currency contracts
Derivative [Line Items]
Amount of gain (loss) recognized in other comprehensive loss on derivatives	2.3	0.2
Foreign currency contracts | Cost of products sold
Derivative [Line Items]
Amount of gain (loss) reclassified from accumulated other comprehensive loss into earnings	1.9	(0.2)
Commodities contracts
Derivative [Line Items]
Amount of gain (loss) recognized in other comprehensive loss on derivatives	0	(0.5)
Commodities contracts | Cost of products sold
Derivative [Line Items]
Amount of gain (loss) reclassified from accumulated other comprehensive loss into earnings	$ (0.2)	$ (1.5)

Income Taxes - Components of Pr

Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ 67.1	$ 66.4	$ 60.1
State	17.4	14.8	15.6
International	25.8	19.9	38.6
Deferred:
Federal	5.6	0.4	(1.7)
State	2.3	1.8	1.5
International	(19.2)	(1.2)	(0.5)
Provision for income taxes	$ 99	$ 102.1	$ 113.6

Income Taxes - Difference Betwe

Income Taxes - Difference Between Provision For Income Taxes And U.S. Federal Statutory Rate (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Statutory Federal Tax Rate [Line Items]
Provision at U.S. federal statutory rate	21.00%	21.00%	21.00%
State taxes, net of federal benefit	3.50%	2.80%	2.40%
Research tax credits	(0.50%)	(0.40%)	(0.50%)
Excess tax benefit on stock compensation	(0.90%)	(0.50%)	(0.40%)
Other	(0.40%)	(0.40%)	(0.90%)
Effective income tax rate	22.30%	21.60%	20.40%
State Administration of Taxation, China
Reconciliation of Statutory Federal Tax Rate [Line Items]
International income tax rate differential	(0.60%)	(1.30%)	(2.30%)
Other
Reconciliation of Statutory Federal Tax Rate [Line Items]
International income tax rate differential	0.20%	0.40%	1.10%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Total taxes paid	$ 114.1	$ 116.6	$ 116.4
Additional income tax accrual	9.8
Cash and cash equivalents and marketable securities were held by foreign subsidiaries	524.2
Unrecognized tax benefits that would affect the effective tax rate, if recognized	$ 0.5

Income Taxes - Components of Ea

Income Taxes - Components of Earning Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S.	$ 407.3	$ 400.3	$ 376
International	36.6	71.8	181.8
Earnings before provision for income taxes	$ 443.9	$ 472.1	$ 557.8

Income Taxes - Tax Effects of T

Income Taxes - Tax Effects of Temporary Differences of Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets
Employee benefits	$ 21.6	$ 27.3
Product liability and warranties	42.5	39.7
Inventories	1.5
Accounts receivable	16.3	16.3
Environmental liabilities	1.9	1.9
Tax loss and credit carryovers	20.3	15.2
All other	9.9	7.7
Valuation allowance	(13)	(11.9)	$ (13.1)
Assets	101	96.2
Liabilities
Inventories		0.3
Property, plant and equipment	36.3	34.9
Intangibles	66.2	61.3
Undistributed foreign earnings	9.8	20.8
Liabilities	112.3	117.3
Net liability	$ 11.3	$ 21.1

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Net Operating Losses, Tax Credit and Valuation Allowances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation Of Net Operating Losses And Tax Credits [Roll Forward]
Net Operating Losses and Tax Credits, Beginning balance	$ 15.2	$ 17.5
Increases / (Reductions)	5.1	(2.3)
Net Operating Losses and Tax Credits, Ending balance	20.3	15.2
Reconciliation Of Valuation Allowance, Deferred Tax Asset [Roll Forward]
Balance at Beginning of Year	11.9	13.1
Increases / (Reductions)	1.1	(1.2)
Balance at End of Year	$ 13	$ 11.9

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at January 1	$ 9.7	$ 8.3
Reductions for tax positions of prior years	(0.7)
Additions for tax positions of prior years		1.4
Balance at December 31	$ 9	$ 9.7

Commitment and Contingencies -

Commitment and Contingencies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Commitments and Contingencies [Line Items]
Product liability insurance for individual losses in excess of accrual amount	$ 125,000,000	$ 125,000,000
Amounts in excess to be covered by third party insurance	7,500,000	7,500,000
Purchase obligation	157,200,000
Distributor rebate accruals	5,400,000	14,100,000
Repurchase Of Inventory
Commitments and Contingencies [Line Items]
Other commitment	$ 6,500,000	$ 23,100,000

Operations by Segment - Schedul

Operations by Segment - Schedule of Segment Earnings (Details) - USD ($) $ in Millions	Mar. 21, 2018	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net sales		$ 834.5	$ 760	$ 663.9	$ 636.9	$ 750.9	$ 728.2	$ 765.4	$ 748.2	$ 2,895.3	$ 2,992.7	$ 3,187.9
Segment earnings										503.2	529.1	613.4
Other income (expense)										11	18	21.2
Interest expense										(7.3)	(11)	(8.4)
Earnings before provision for income taxes										443.9	472.1	557.8
Provision for income taxes										(99)	(102.1)	(113.6)
Net Earnings		$ 120	$ 105.4	$ 67.8	$ 51.7	$ 91.3	$ 87.3	$ 102.1	$ 89.3	344.9	370	444.2
Severance, restructuring and impairment expenses	$ 6.7									7.7	0	6.7
Inter-segment sales
Segment Reporting Information [Line Items]
Net sales										(23.3)	(26.6)	(30.4)
Segment earnings										(0.3)	0	0
Corporate
Segment Reporting Information [Line Items]
Other income (expense)										(52)	(46)	(47.2)
North America
Segment Reporting Information [Line Items]
Severance, restructuring and impairment expenses										2.7		6.7
North America | Operating Segments
Segment Reporting Information [Line Items]
Net sales										2,118.3	2,083.5	2,044.7
Segment earnings										503.5	488.9	464.1
Rest of World
Segment Reporting Information [Line Items]
Severance, restructuring and impairment expenses										5
Rest of World | Operating Segments
Segment Reporting Information [Line Items]
Net sales										800.3	935.8	1,173.6
Segment earnings										$ 0	$ 40.2	$ 149.3

Operations by Segment - Narrati

Operations by Segment - Narrative (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of reporting segments | segment									2
Sales to a largest customer	$ 834.5	$ 760	$ 663.9	$ 636.9	$ 750.9	$ 728.2	$ 765.4	$ 748.2	$ 2,895.3	$ 2,992.7	$ 3,187.9
North America | Geographic Concentration Risk | Customer One
Segment Reporting Information [Line Items]
Sales to a largest customer									471.9	421.1	425.3
North America | Geographic Concentration Risk | Customer Two
Segment Reporting Information [Line Items]
Sales to a largest customer									$ 349.9	$ 378.9	$ 355.6
North America | Sales Revenue, Net | Geographic Concentration Risk | Customer One
Segment Reporting Information [Line Items]
Concentration risk percentage									16.00%	14.00%	13.00%
North America | Sales Revenue, Net | Geographic Concentration Risk | Customer Two
Segment Reporting Information [Line Items]
Concentration risk percentage									12.00%	13.00%	11.00%

Operations by Segment - Assets,

Operations by Segment - Assets, Depreciation And Capital Expenditure By Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total Assets	$ 3,160.7	$ 3,058	$ 3,071.5
Depreciation and amortization	80	78.3	71.9
Capital expenditures	56.8	64.4	85.2
Corporate
Segment Reporting Information [Line Items]
Total Assets	736.7	606.1	696.3
Depreciation and amortization	0.6	1.1	1.2
Capital expenditures	0.2	0.9	7.1
North America | Operating Segments
Segment Reporting Information [Line Items]
Total Assets	1,759.1	1,742.8	1,653.6
Depreciation and amortization	51.5	49.3	45.5
Capital expenditures	41.7	47.6	45.8
Rest of World | Operating Segments
Segment Reporting Information [Line Items]
Total Assets	664.9	709.1	721.6
Depreciation and amortization	27.9	27.9	25.2
Capital expenditures	$ 14.9	$ 15.9	$ 32.3

Operations by Segment - Net Sal

Operations by Segment - Net Sales and Long-Lived Assets by Geographic Location (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 672				$ 673.2				$ 672	$ 673.2	$ 625.9
Net sales	834.5	$ 760	$ 663.9	$ 636.9	750.9	$ 728.2	$ 765.4	$ 748.2	2,895.3	2,992.7	3,187.9
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	355.8				360.2				355.8	360.2	327.3
Net sales									1,904.9	1,868.7	1,820.8
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	268.3				266.7				268.3	266.7	252.6
Net sales									695.6	825.4	1,071.2
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	4.5				4.2				4.5	4.2	3.1
Net sales									175	168.5	175
Other Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 43.4				$ 42.1				43.4	42.1	42.9
Net sales									$ 119.8	$ 130.1	$ 120.9

Quarterly Results of Operatio_3

Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 834.5	$ 760	$ 663.9	$ 636.9	$ 750.9	$ 728.2	$ 765.4	$ 748.2	$ 2,895.3	$ 2,992.7	$ 3,187.9
Gross profit	324.1	297.1	247.5	239.5	295	284.2	308.7	292.8	1,108.2	1,180.7	1,305.5
Net Earnings	$ 120	$ 105.4	$ 67.8	$ 51.7	$ 91.3	$ 87.3	$ 102.1	$ 89.3	$ 344.9	$ 370	$ 444.2
Basic net earnings per share of common stock (in dollars per share)	$ 0.74	$ 0.65	$ 0.42	$ 0.32	$ 0.56	$ 0.53	$ 0.61	$ 0.53	$ 2.13	$ 2.24	$ 2.60
Diluted net earnings per share of common stock (in dollars per share)	0.74	0.65	0.42	0.32	0.56	0.53	0.61	0.53	$ 2.12	$ 2.22	$ 2.58
Common dividends declared (in dollars per share)	$ 0.26	$ 0.24	$ 0.24	$ 0.24	$ 0.24	$ 0.22	$ 0.22	$ 0.22

Quarterly Results of Operatio_4

Quarterly Results of Operations (Unaudited) - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 21, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Severance, restructuring and impairment expenses	$ 6.7	$ 7.7	$ 0	$ 6.7
Restructuring and Impairment Charges
Restructuring Cost and Reserve [Line Items]
Reduction in after-tax earnings		$ 6.3
Reduction in after-tax earnings per share (in dollars per share)		$ 0.04

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Valuation Allowance For Trade And Notes Receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ 6.6	$ 6.4	$ 5.3
Charged to Costs and Expenses	0.8	0.3	1.5
Acquisition of Businesses	0	0	0
Deductions	(1.8)	(0.1)	(0.4)
Balance at End of Year	5.6	6.6	6.4
Valuation Allowance For Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	11.9	13.1	15
Charged to Costs and Expenses	1.1	0	0
Acquisition of Businesses	0	0	0
Deductions	0	(1.2)	(1.9)
Balance at End of Year	$ 13	$ 11.9	$ 13.1