Compass Minerals International (CMP) 10-Q 7 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	May 03, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-31921
Entity Registrant Name	Compass Minerals International, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-3972986
Entity Address, Address Line One	9900 West 109th Street
Entity Address, Address Line Two	Suite 100
Entity Address, City or Town	Overland Park
Entity Address, State or Province	KS
Entity Address, Postal Zip Code	66210
City Area Code	913
Local Phone Number	344-9200
Title of 12(b) Security	Common stock, $0.01 par value
Trading Symbol	CMP
Security Exchange Name	NYSE
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
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		34,001,181
Entity Central Index Key	0001227654
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 42.8	$ 10.6
Receivables, less allowance for doubtful accounts of $4.3 in 2021 and $3.9 in 2020	158.6	185.1
Inventories	219.9	299.9
Current assets held for sale	338.8	206.5
Other	49	55.1
Total current assets	809.1	757.2
Property, plant and equipment, net	845	851.7
Intangible assets, net	49.9	49.9
Goodwill	56.4	55.7
Noncurrent assets held for sale	0	404.1
Other	144.6	143.8
Total assets	1,905	2,262.4
Current liabilities:
Current portion of long-term debt	0	10
Accounts payable	104.6	82.6
Accrued salaries and wages	16	21.7
Income taxes payable	0.6	5.1
Accrued interest	14.1	9
Current liabilities held for sale	199.3	111.5
Accrued expenses and other current liabilities	58.8	56.4
Total current liabilities	393.4	296.3
Long-term debt, net of current portion	1,184	1,299.1
Deferred income taxes, net	60.8	60
Noncurrent liabilities held for sale	0	76.1
Other noncurrent liabilities	143.5	143.9
Commitments and contingencies (Note 9)
Stockholders’ equity:
Common stock: $0.01 par value, 200,000,000 authorized shares; 35,367,264 issued shares	0.4	0.4
Additional paid-in capital	131.3	127
Treasury stock, at cost — 1,390,182 shares at March 31, 2021 and 1,407,926 shares at December 31, 2020	(4.4)	(4.4)
Retained earnings	319.5	567.3
Accumulated other comprehensive loss	(323.5)	(303.3)
Total stockholders’ equity	123.3	387
Total liabilities and stockholders’ equity	$ 1,905	$ 2,262.4

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Allowance for doubtful accounts	$ 4.3	$ 3.9
Stockholders’ equity:
Common stock, par or stated value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	35,367,264	35,367,264
Treasury stock, shares (in shares)	1,390,182	1,407,926

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Sales	$ 426	$ 346.9
Gross profit	96	75.2
Selling, general and administrative expenses	32.4	29.8
Operating earnings	63.6	45.4
Other expense (income):
Interest expense	15.7	16.6
Loss (gain) on foreign exchange	2.1	(18)
Other expense, net	0.3	0.3
Earnings from continuing operations before income taxes	45.5	46.5
Income tax expense for continuing operations	12.6	12.6
Net earnings from continuing operations	32.9	33.9
Net loss from discontinued operations	(256.5)	(6.3)
Net (loss) earnings	$ (223.6)	$ 27.6
Basic net earnings from continuing operations per common share (in dollars per share)	$ 0.96	$ 0.99
Basic net loss from discontinued operations per common share (in dollars per share)	(7.55)	(0.19)
Basic net (loss) earnings per common share (in dollars per share)	(6.59)	0.80
Diluted net earnings from continuing operations per common share (in dollars per share)	0.95	0.99
Diluted net loss from discontinued operations per common share (in dollars per share)	(7.55)	(0.19)
Diluted net (loss) earnings per common share (in dollars per share)	$ (6.60)	$ 0.80
Weighted-average common shares outstanding (in thousands):
Basic (in shares)	33,974	33,892
Diluted (in shares)	34,012	33,892
Shipping and handling cost
Cost	$ 123.2	$ 98.5
Product cost
Cost	$ 206.8	$ 173.2

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net (loss) earnings	$ (223.6)	$ 27.6
Other comprehensive income (loss):
Unrealized gain from change in pension obligations, net of tax of $(0.1) in 2021 and $0.0 in 2020	0.2	0.2
Unrealized gain on cash flow hedges, net of tax of $0.0 in both 2021 and 2020	0.1	0.1
Cumulative translation adjustment	(20.5)	(173.5)
Comprehensive loss	$ (243.8)	$ (145.6)

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Unrealized gain from change in pension obligations, tax	$ (0.1)	$ 0
Unrealized gain on cash flow hedges, tax	$ 0	$ 0

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2019	$ 529.6	$ 0.4	$ 117.1	$ (3.2)	$ 607.4	$ (192.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(145.6)				27.6	(173.2)
Dividends on common stock	(24.8)		0.1		(24.9)
Shares issued for stock units, net of shares withheld for taxes	(0.1)			(0.1)
Stock-based compensation	2.4		2.4
Ending balance at Mar. 31, 2020	361.5	0.4	119.6	(3.3)	610.1	(365.3)
Beginning balance at Dec. 31, 2020	387	0.4	127	(4.4)	567.3	(303.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	(243.8)				(223.6)	(20.2)
Dividends on common stock	(24.1)		0.1		(24.2)
Stock options exercised, net of shares withheld for taxes	0.2		0.2
Stock-based compensation	4		4
Ending balance at Mar. 31, 2021	$ 123.3	$ 0.4	$ 131.3	$ (4.4)	$ 319.5	$ (323.5)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Cash dividends per share (in dollars per share)	$ 0.72	$ 0.72

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net (loss) earnings	$ (223.6)	$ 27.6
Adjustments to reconcile net (loss) earnings to net cash flows provided by operating activities:
Depreciation, depletion and amortization	34.6	33.1
Finance fee amortization	0.8	0.8
Stock-based compensation	4	2.4
Deferred income taxes	(1)	7.5
Unrealized foreign exchange loss (gain)	5.6	(18)
Loss on impairment of long-lived assets	253.1	0
Other, net	0.4	3.5
Changes in operating assets and liabilities:
Receivables	17.8	87.1
Inventories	73.6	36.6
Other assets	(1.9)	54.5
Accounts payable and accrued expenses and other current liabilities	37.2	(4.9)
Other liabilities	(0.4)	(1.6)
Net cash provided by operating activities	200.2	228.6
Net cash used in investing activities
Capital expenditures	(18.2)	(25.3)
Other, net	2	(0.6)
Net cash used in investing activities	(16.2)	(25.9)
Cash flows from financing activities:
Proceeds from revolving credit facility borrowings	6.3	46.2
Principal payments on revolving credit facility borrowings	(136.6)	(147.2)
Proceeds from issuance of long-term debt	69.8	22
Principal payments on long-term debt	(55.1)	(18.7)
Dividends paid	(24.1)	(24.8)
Deferred financing costs	(0.1)	(0.1)
Other, net	(0.5)	(0.2)
Net cash used in financing activities	(140.3)	(122.8)
Effect of exchange rate changes on cash and cash equivalents	(1.1)	(4.8)
Net change in cash and cash equivalents	42.6	75.1
Cash and cash equivalents, beginning of the year	21	34.7
Cash and cash equivalents, end of period	63.6	109.8
Less: cash and cash equivalents included in current assets held for sale	(20.8)	(15.8)
Cash and cash equivalents of continuing operations, end of period	42.8	94
Supplemental cash flow information:
Interest paid, net of amounts capitalized	10.5	11.3
Income taxes paid, net of refunds	$ 14.7	$ (37.7)

Accounting Policies and Basis o

Accounting Policies and Basis of Presentation	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Accounting Policies and Basis of Presentation	Accounting Policies and Basis of Presentation: Compass Minerals International, Inc. (“CMI”), through its subsidiaries (collectively, the “Company”), is a leading producer of essential minerals focused on safely delivering where and when it matters to help solve nature’s challenges for customers and communities. The Company’s salt products help keep roadways safe during winter weather and are used in numerous other consumer, industrial and agricultural applications. Its plant nutrition products improve the quality and yield of crops, while supporting sustainable agriculture. The Company’s principal products are salt, consisting of sodium chloride and magnesium chloride and plant nutrients, consisting of sulfate of potash (“SOP”). The Company’s production sites are located in the United States (“U.S.”), Canada and the United Kingdom (“U.K.”). The Company also provides records management services to businesses located in the U.K. Except where otherwise noted, references to North America include only the continental U.S. and Canada, and references to the U.K. include only England, Scotland and Wales. References to “Compass Minerals,” “our,” “us” and “we” refer to CMI and its consolidated subsidiaries. CMI is a holding company with no significant operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMI and its wholly-owned domestic and foreign subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company for the year ended December 31, 2020, as filed with the Securities and Exchange Commission (“SEC”) in its Annual Report on Form 10-K on February 26, 2021. In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation, have been included. The Company experiences a substantial amount of seasonality in its sales, including its deicing salt product sales. As a result, Salt segment sales and operating earnings are generally higher in the first and fourth quarters and lower during the second and third quarters of each year. In particular, sales of highway and consumer deicing salt and magnesium chloride products vary based on the severity of the winter conditions in areas where the products are used. Following industry practice in North America and the U.K., the Company seeks to stockpile sufficient quantities of deicing salt throughout the second, third and fourth quarters to meet the estimated requirements for the winter season. Production of deicing salt can also vary based on the severity or mildness of the preceding winter season. Due to the seasonal nature of the deicing product lines, operating results for the interim periods are not necessarily indicative of the results that may be expected for the full fiscal year. Significant Accounting Policies The Company’s significant accounting policies are detailed in “Note 2 – Summary of Significant Accounting Policies” within Part II, Item 8 of its Annual Report on Form 10-K for the year ended December 31, 2020. The Company reports its financial results from discontinued operations and continuing operations separately to recognize the financial impact of disposal transactions from ongoing operations. Discontinued operations reporting occurs when a component or a group of components of an entity has been disposed of or classified as held for sale and represents a strategic shift that has a major effect on the entity’s operations and financial results. In the Company’s Consolidated Statements of Cash Flows, the cash flows from discontinued operations are not separately classified. The Company has reclassified certain prior year amounts, including the results of discontinued operations, assets and liabilities held for sale and reportable segment information, to conform to the current year presentation. Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations. See Note 2 for information on discontinued operations and Note 10 for information on the Company’s reportable segments. Recent Accounting Pronouncements The Company has evaluated all of the recently issued, but not yet effective, accounting standards that have been issued or proposed by the FASB or other standards-setting bodies through the filing date of these unaudited consolidated financial statements and does not believe the future adoption of any such pronouncements will have a material impact on its consolidated financial statements. Strategic Evaluation and Plan to Sell Businesses During 2020, the Company initiated an evaluation of the strategic fit of certain of the Company’s businesses. On February 16, 2021, the Company announced its plan to restructure its former Plant Nutrition South America segment to enable targeted and separate sales processes for each portion of the former segment, including its chemicals and specialty plant nutrition businesses along with the Company’s equity method investment in Fermavi Eletroquímica Ltda. (“Fermavi”). Concurrently, to optimize its asset base in North America, the Company evaluated the strategic fit of its North America micronutrient product business. On March 16, 2021, the Board of the Directors of the Company approved a plan to sell the Company’s South America chemicals and specialty plant nutrition businesses, investment in Fermavi and North America micronutrient product business (collectively, the “Specialty Businesses”) with the goal of reducing the Company’s leverage and enabling increased focus on optimizing the Company’s core businesses. The South America chemicals and specialty plant nutrition businesses and investment in Fermavi were previously reported as the Company’s Plant Nutrition South America segment. The North America micronutrient product business was previously included as part of the Company’s Plant Nutrition North America segment, which has been renamed as the Plant Nutrition segment. The Company now has two reportable segments, Salt and Plant Nutrition, as discussed further in Note 10 . The Company concluded that the Specialty Businesses met the criteria for classification as held for sale upon receiving approval from its Board of Directors to sell the Specialty Businesses in the first quarter of 2021. In addition, the Company believes there is a single disposal plan representing a strategic shift that will have a material effect on its operations and financial results. Consequently, the Specialty Businesses qualify for presentation as assets and liabilities held for sale and discontinued operations in accordance with U.S. GAAP . Accordingly, current and noncurrent assets and liabilities of the Specialty Businesses are presented in the Consolidated Balance Sheets as assets and liabilities held for sale for both periods presented and their results of operations are presented as discontinued operations in the Consolidated Statements of Operations for each period presented. Interest expense attributed to discontinued operations represents interest expense for loans in Brazil by the Company’s South America chemicals and specialty plant nutrition businesses, which are expected to be fully repaid from proceeds received from the Company’s sale of its South America specialty plant nutrition business. As described further in Note 2 , on March 23, 2021, and April 7, 2021, the Company entered into definitive agreements to sell its South America specialty plant nutrition business and a component of its North America micronutrient business, respectively. The Company continues to actively pursue the sales of the remaining South America chemicals business and its investment in Fermavi, and the Company believes these sales are probable to occur within the next twelve months.

Discontinued Operations

Discontinued Operations	3 Months Ended
	Mar. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations: On March 23, 2021, the Company entered into a definitive agreement to sell its South America specialty plant nutrition business to ICL Brasil Ltda., a subsidiary of ICL Group Ltd., for R$1.11 billion Brazilian reais plus an amount that will be set at closing to equal $198.3 million U.S. dollars, subject to certain adjustments for net debt and working capital. The terms of the agreement provide for an additional earn-out payment of up to R$88 million Brazilian reais, payable in 2022 and which will be calculated on a sliding scale if the South America specialty plant nutrition business achieves certain full-year 2021 earnings before interest, taxes, depreciation and amortization (“EBITDA”) performance targets. The transaction is expected to close in the third quarter of 2021, subject to customary closing conditions and required antitrust approval in Brazil. The Company and ICL Brasil Ltda. have also agreed to enter into a Reverse Transition Services Agreement, which will govern the parties respective rights and obligations with respect to the provision of certain transition services to the Company’s Brazil subsidiaries after closing. The Reverse Transition Services Agreement has a term of 18 months and allows the Company’s remaining Brazil subsidiaries to assign their rights and obligations with respect to the transition services to any buyer of a sufficient portion of their assets. On April 7, 2021, the Company entered into a definitive agreement to sell a component of its North America micronutrient business to Koch Agronomic Services, LLC, a subsidiary of Koch Industries, for approximately $60.25 million, subject to a closing working capital adjustment. The transaction closed on May 4, 2021. In measuring the assets and liabilities held for sale at fair value less estimated costs to sell, the Company completed an impairment analysis when its Board of Directors committed to a plan to sell the Specialty Businesses. Management evaluated indicators of fair value of each of the Specialty Businesses, including the net proceeds expected to be realized at closing of the transactions described above to sell its South America specialty plant nutrition business and a component of its North America micronutrient business, in addition to indications of fair value received from third parties in connection with the marketing of the remaining South America chemicals business and the investment in Fermavi. A significant portion of the Company’s foreign currency translation adjustment (“CTA”) balance as of March 31, 2021, is related to the foreign exchange translation of the Specialty Businesses’ balance sheet. The CTA loss balance of the Specialty Businesses was considered in the Company’s determination of the impairment loss. The Company recognized a total impairment loss of $255.2 million included in its loss from discontinued operations in its Consolidated Statement of Operations for the three months ended March 31, 2021. The impairment is due primarily to the translation of the net assets of the Company’s Brazil subsidiaries from Brazilian reais to U.S. dollars, which has been reported in CTA. The impairment loss for its South America chemicals and specialty plant nutrition businesses was $92.7 million and $154.5 million, respectively, inclusive of CTA. The amount recorded in CTA will not be eliminated until there is a substantial liquidation of the applicable foreign entity. The Company also recognized an impairment loss of $8.0 million on its investment in Fermavi. There was no impairment for its North America micronutrient product business. As described above, the Company has entered into definitive agreements to sell its South America specialty plant nutrition business and a component of its North America micronutrient business on March 23, 2021, and April 7, 2021, respectively. The Company’s determination of the net proceeds to be realized at closing of each transaction involves certain estimates and judgments based on, among other items: (i) management’s interpretation and application of key terms of each definitive agreement, (ii) certain balance sheet amounts of the business or asset group as of March 31, 2021, and (iii) certain projections of costs to be incurred through an estimated future closing date. The balances of net working capital, cash and debt, and deductions, are subject to future change based on the operations of the business from March 31, 2021, through the closing date, and estimated costs to sell the business could differ from actual results. As such, a change in the impairment loss associated with the Specialty Businesses could occur in a future period, including upon closing of the transactions described above or thereafter. In addition to calculating an estimate of net proceeds expected to be realized at closing, as described above, certain additional judgments, estimates and other reporting matters related to discontinued operations include matters discussed in the following paragraphs. As discussed in Note 1 , the North America micronutrient product business was previously reported in the Company’s Plant Nutrition North America segment (which is now known as the Plant Nutrition segment), which aligns with the Plant Nutrition North America reporting unit for purposes of evaluating goodwill. Based on the Company’s assessment of the estimated relative fair values of the North America micronutrient product business and the remaining business from the former Plant Nutrition North America reporting unit, the Company performed an allocation of goodwill between the North America micronutrient product business classified as held for sale and the business being retained, which resulted in $6.9 million and $6.8 million of goodwill allocated to the North America micronutrient product business as of March 31, 2021, and December 31, 2020, respectively. See Note 6 for additional details. An allocation of goodwill related to the former Plant Nutrition South America segment was not required as of March 31, 2021, as the entire segment and related goodwill is classified as held for sale at March 31, 2021, and December 31, 2020. The information below sets forth selected financial information related to operating results of the Specialty Businesses classified as discontinued operations. While the reclassification of revenue and expenses related to discontinued operations from prior periods have no impact upon previously reported results, the Consolidated Balance Sheets present the assets and liabilities that were reclassified from the specified line items to assets and liabilities held for sale and the Consolidated Statements of Operations present the revenue and expenses that were reclassified from the specified line items to discontinued operations. The following table represents summarized balance sheet information of assets and liabilities held for sale (in millions): March 31, December 31, Cash and cash equivalents $ 20.8 $ 10.5 Receivables, less allowance for doubtful accounts of $6.7 in 2021 and $7.1 in 2020 111.4 111.5 Inventories 72.5 70.7 Property, plant and equipment, net 103.3 — Goodwill 207.6 — Loss recognized on held for sale classification (255.2) — Other 78.4 13.8 Current assets held for sale $ 338.8 $ 206.5 Property, plant and equipment, net $ — $ 113.2 Goodwill — 225.5 Other — 65.4 Noncurrent assets held for sale $ — $ 404.1 Current portion of long-term debt $ 94.3 $ 53.7 Accounts payable 48.9 34.3 Accrued expenses and other current liabilities 56.1 23.5 Current liabilities held for sale $ 199.3 $ 111.5 Long-term debt, net of current portion $ — $ 38.6 Other noncurrent liabilities — 37.5 Noncurrent liabilities held for sale $ — $ 76.1 The following table represents summarized statements of operations information of discontinued operations (in millions): Three Months Ended 2021 2020 Sales $ 85.4 $ 67.0 Shipping and handling cost 3.8 3.3 Product cost 62.8 51.6 Gross profit 18.8 12.1 Selling, general and administrative expenses 13.5 13.3 Operating earnings (loss) 5.3 (1.2) Interest expense 1.7 2.4 Loss on foreign exchange 4.3 3.7 Loss on impairment 255.2 — Other income, net (0.4) (0.1) Loss from discontinued operations before income taxes (255.5) (7.2) Income tax expense (benefit) 1.0 (0.9) Net loss from discontinued operations $ (256.5) $ (6.3) The significant components included in our Consolidated Statements of Cash Flows for the discontinued operations are as follows (in millions): Three Months Ended 2021 2020 Depreciation, depletion and amortization $ 4.7 $ 5.7 Loss on impairment of long-lived assets 253.1 — Capital expenditures 1.6 1.4 Proceeds from issuance of long-term debt 21.0 22.0 Principal payments on long-term debt (10.9) (16.2)

Revenues

Revenues	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenues: Nature of Products and Services The Company’s Salt segment products include salt and magnesium chloride for use in road deicing and dust control, food processing, water softeners, and agricultural and industrial applications and the Company’s Plant Nutrition segment products include various grades of SOP. In the U.K., the Company operates a records management business utilizing excavated areas of the Winsford salt mine with one other location in London, England. Identifying the Contract The Company accounts for a customer contract when there is approval and commitment from both parties, the rights of the parties and payment terms are identified, the contract has commercial substance and collectability of consideration is probable. Identifying the Performance Obligations At contract inception, the Company assesses the goods and services it has promised to its customers and identifies a performance obligation for each promise to transfer to the customer a distinct good or service (or bundle of goods or services). Determining whether products and services are considered distinct performance obligations that should be accounted for separately or aggregated together may require significant judgment. Identifying and Allocating the Transaction Price The Company’s revenues are measured based on consideration specified in the customer contract, net of any sales incentives and amounts collected on behalf of third parties such as sales taxes. In certain cases, the Company’s customer contracts may include promises to transfer multiple products and services to a customer. For multiple-element arrangements, the Company generally allocates the transaction price to each performance obligation in proportion to its stand-alone selling price. When Performance Obligations Are Satisfied The vast majority of the Company’s revenues are recognized at a point in time when the performance obligations are satisfied based upon transfer of control of the product or service to a customer. To determine when the control of goods is transferred, the Company typically assesses, among other things, the shipping terms of the contract, as shipping is an indicator of transfer of control. Some of the Company’s products are sold when the control of the goods transfers to the customer at the time of shipment. There are also instances when the Company provides shipping services to deliver its products. Shipping and handling costs that occur before the customer obtains control of the goods are deemed to be fulfillment activities and are accounted for as fulfillment costs. The Company recognizes shipping and handling costs that are incurred after the customer obtains control of the goods as fulfillment costs which are accrued at the time of revenue recognition. Significant Payment Terms The customer contract states the final terms of the sale, including the description, quantity and price of each product or service purchased. Payment is typically due in full within 30 days of delivery. The Company does not adjust the consideration for the effects of a significant financing component if the Company expects, at contract inception, that the period between when the good or service is transferred to the customer and when the customer pays for that good or service will be one year or less. Refunds, Returns and Warranties The Company’s products are generally not sold with a right of return and the Company does not generally provide credits or incentives, which may be required to be accounted for as variable consideration when estimating the amount of revenue to be recognized. The Company uses historical experience to estimate accruals for refunds due to manufacturing or other defects. See Note 10 for disaggregation of sales by segment, type and geographical region.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Inventories	Inventories: Inventories consist of the following (in millions): March 31, December 31, Finished goods $ 168.8 $ 252.1 Raw materials and supplies 51.1 47.8 Total inventories $ 219.9 $ 299.9

Property, Plant and Equipment,

Property, Plant and Equipment, Net	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net: Property, plant and equipment, net, consists of the following (in millions): March 31, December 31, Land, buildings and structures, and leasehold improvements $ 547.8 $ 544.5 Machinery and equipment 1,041.7 1,035.4 Office furniture and equipment 54.2 50.7 Mineral interests 168.9 172.4 Construction in progress 59.7 43.7 1,872.3 1,846.7 Less: accumulated depreciation and depletion (1,027.3) (995.0) Property, plant and equipment, net $ 845.0 $ 851.7

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, Net	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, Net	Goodwill and Intangible Assets, Net: Amounts related to the Company’s amortization of intangible assets are as follows (in millions): Three Months Ended 2021 2020 Aggregate amortization expense $ 0.4 $ 0.4 Amounts related to the Company’s goodwill are as follows (in millions): March 31, December 31, Plant Nutrition Segment $ 50.3 $ 49.6 Other 6.1 6.1 Total $ 56.4 $ 55.7 The change in goodwill between December 31, 2020, and March 31, 2021 was due to the impact from translating foreign-denominated amounts to U.S. dollars. As of March 31, 2021, there were no indicators necessitating an interim impairment test of the Company’s operating segments based on the Company’s review of operating performance. See Note 2 for a discussion of the Company’s evaluation of interim impairment indicators related to discontinued operations.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes: The Company’s effective income tax rate differs from the U.S. statutory federal income tax rate primarily due to U.S. statutory depletion, state income taxes (net of federal tax benefit), foreign income, mining and withholding taxes, global intangible low-taxed income and interest expense recognition differences for book and tax purposes. As of March 31, 2021, and December 31, 2020, the Company had $3.4 million of gross foreign federal net operating loss (“NOL”) carryforwards that have no expiration date, $0 and $0.1 million, respectively, of gross foreign federal NOL carryforwards which expire beginning in 2033, and $0.2 million of net operating tax-effected state NOL carryforwards which expire beginning in 2027. Canadian provincial tax authorities have challenged tax positions claimed by one of the Company’s Canadian subsidiaries and have issued tax reassessments for years 2002-2015. The reassessments are a result of ongoing audits and to tal $157.0 million, including interest, through March 31, 2021. The Company disputes these reassessments and will continue to work with th e appropriate authorities in Canada to resolve the dispute. There is a reasonable possibility that the ultimate resolution of this dispute, and any related disputes for other open tax years, may be materially higher or lower than the amounts the Company has reserved for such di sputes. In connection with this dispute, local regulations require the Company to post security with the tax authority until the dispute is resolved. The Company has posted collateral in the form of a $121.7 million performance bond and has paid $39.5 million to the Canadian tax authorities (most of which is recorded in other assets i n the Consolidated Balance Sheets at March 31, 2021, and December 31, 2020), which is necessary to proceed with future appeals or litigation. The Company expects that it will be required by local regulations to provide security for additional interest on the above unresolved disputed amounts and for any future reassessments issued by these Canadian tax authorities in the form of cash, letters of credit, performance bonds, asset liens or other arrangements agreeable with the tax authorities until the disputes are resolved. The Company expects that the ultimate outcome of these matters will not have a material impact on its results of operations or financial condition. However, the Company can provide no assurance as to the ultimate outcome of these matters, and the impact could be material if they are not resolved in the Company’s favor. As of March 31, 2021, the Company believes it has adequately reserved for these reassessments. Additionally, the Company has other uncertain tax positions as well as assessments and disputed positions with taxing authorities in its various jurisdictions, which are consistent with those matters disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. Settlements In 2017, the Company, the Canadian Revenue Authority (“CRA”) and the U.S. Internal Revenue Service (“IRS”) reached a settlement agreement on transfer pricing issues for the Company’s 2007-2012 tax years. During 2018, in accordance with the agreement, the Company’s U.S. subsidiary made intercompany cash payments of $85.7 million to its Canadian subsidiary and tax payments were made t o Canadian taxing authorities of $17.5 million. Additional tax payments of $5.3 million were made during 2019 with the remaining liability of $1.4 million expected to be paid in 2021. Corresponding tax refunds of $22.3 million have been received through March 31, 2021, from U.S. taxing authorities, with the remaining refund of approximately $0.7 million ex pected in 2021 (recorded in other current assets in the Consolidated Balance Shee ts). In 2018, the Company, the CRA and the IRS reached a settlement agreement on transfer pricing and management fees as part of an advanced pricing agreement that covers tax years 2013-2021. During 2019, in accordance with the settlement agreement, the Company’ s U.S. subsidiary made intercompany cash payments of $106.1 million to its Canadian subsidiary and tax payments to Canadian taxing authorities of $29.9 million, with the remaining $1.4 million balance paid during 2020. Corresponding tax refunds of $60.0 million ha ve been received through March 31, 2021, from U.S. taxing authorities, with the remaining $1.7 million e xpected in 2021 (recorded in other current assets in the Consolidated Balance Sheets).

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt: Long-term debt consists of the following (in millions): March 31, December 31, 4.875% Senior Notes due July 2024 $ 250.0 $ 250.0 Term Loan due January 2025 345.8 390.0 Revolving Credit Facility due January 2025 — 130.3 6.75% Senior Notes due December 2027 500.0 500.0 AR Securitization Facility expires June 2023 100.0 51.2 1,195.8 1,321.5 Less unamortized debt issuance costs (11.8) (12.4) Total debt 1,184.0 1,309.1 Less: current portion — (10.0) Long-term debt $ 1,184.0 $ 1,299.1 In the first quarter of 2021, the Company made a $41.7 million required prepayment of its term loan for 2020 Excess Cash Flow (as such term is defined in the credit agreement). This prepayment will reduce the future required term loan payments. As such, the Company will not have a scheduled term loan payment until June 2023. As of March 31, 2021, the term loan and revolving credit facility under the Company’s credit agreement were secured by substantially all existing and future U.S. assets of the Company, the Goderich mine in Ontario, Canada and capital stock of certain subsidiaries. As of March 31, 2021, t he weighted average interest rate on all borrowings outstanding under the term loan and revolving credit facility under the Company’s credit agreement was approxi mately 2.1%. Securitization On June 30, 2020, certain of the Company’s U.S. subsidiaries entered into a three-year committed revolving accounts receivable financing facility (the “AR Facility”) of up to $100 million with PNC Bank, National Association (“PNC”), as administrative agent and lender, and PNC Capital Markets, LLC, as structuring agent. In connection with the AR Facility, two of the Company’s U.S. subsidiaries, from time to time, sell and contribute receivables and certain related assets to a special purposes entity and wholly-owned U.S. subsidiary of the Company (the “SPE”). The SPE finances its acquisition of the receivables by obtaining secured loans from PNC and the other lenders party to a receivables financing agreement. A U.S. subsidiary of the Company services the receivables on behalf of t he SPE for a fee. In addition, the Company has agreed to guarantee the performance by its subsidiaries. The Company and its subsidiaries do not guarantee the loan principal or interest under the receivables financing agreement or the collectability of the receivables under the AR Facility. The purchase price for the sale of receivables consists of cash available to the SPE from loans under the AR Facility and from collections on previously sold receivables and, to the extent the SPE does not have funds available to pay the purchase price due on any day in cash, through an increase in the principal amount of a subordinated intercompany loan. The SPE pays monthly interest and fees with respect to amounts advanced by the lenders under the AR Facility. The SPE’s sole business consists of the purchase or acceptance through capital contributions of the receivables and the subsequent granting of a security interest in these receivables and related rights to PNC on behalf of the lenders under the AR Facility. The SPE is a separate legal entity with its own separate creditors who will be entitled, upon its liquidation, to be satisfied out of the SPE’s assets prior to any assets or value in the SPE becoming available to the Company and the assets of the SPE are not available to pay creditors of the Company or any of its affiliates other than the SPE.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies:The Wisconsin Department of Agriculture, Trade and Consumer Protection (“DATCP”) and the Wisconsin Department of Natural Resources (“DNR”) have information indicating that agricultural chemicals are present within the subsurface area of the Company’s property located in Kenosha, Wisconsin. The agricultural chemicals were used by previous owners and operators of the site. None of the identified chemicals have been used in association with the Company’s operations since it acquired the property in 2002. DATCP and DNR have directed the Company to conduct further investigations into the environmental conditions at the Kenosha property. The Company continues on-property investigations and has provided the findings to DATCP and DNR as they have become available. All investigations and mitigation activities to date, and any potential future remediation work, are being conducted under the Wisconsin Agricultural Chemical Cleanup Program, which provides for reimbursement of some of the costs. The Company conducts business operations in several countries and is subject to various federal and local labor, social security, environmental and tax laws. While the Company believes it complies with such laws, they are complex and subject to interpretation. In addition to the tax assessments discussed in Note 7 , the Company’s Brazilian subsidiaries are party to administrative tax proceedings and claims which totaled $7.5 million and $7.9 million as of March 31, 2021 and December 31, 2020, respectively, and relate primarily to value added tax, state tax (ICMS) and social security tax (PIS and COFINS) assessments. The Company has assessed the likelihood of a loss at less than probable and therefore, has not established a reserve for these matters. The Company also assumed liabilities for labor-related matters in connection with the acquisition of Compass Minerals América do Sul Indústria e Comércio Ltda., which are primarily related to compensation, labor benefits and consequential tax claims that totaled $2.8 million and $3.5 million as of March 31, 2021 and December 31, 2020, respectively. The Company believes the maximum exposure for these other labor matters totaled approximately $13 million and $16 million as of March 31, 2021 and December 31, 2020, respectively. Amounts recorded are included in liabilities held for sale on the Consolidated Balance Sheets. The Division of Enforcement of the SEC is investigating the Company’s disclosures primarily concerning the operation of the Goderich mine. The Company has cooperated with this investigation and will continue to do so. While it is not possible to predict the timing or the outcome of the SEC inquiry, the Company believes that this matter will not have a material impact on its results of operation, cash flows or financial position. The Company is also involved in legal and administrative proceedings and claims of various types from the ordinary course of the Company’s business. Management cannot predict the outcome of legal claims and proceedings with certainty. Nevertheless, management believes the outcome of legal proceedings and claims, which are pending or known to be threatened, even if determined adversely, will not, individually or in the aggregate, have a material adverse effect on the Company’s results of operations, cash flows or financial position.

Operating Segments

Operating Segments	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Operating Segments	Operating Segments: The Company’s reportable segments are strategic business units that offer different products and services, and each business requires different technology and marketing strategies. In connection with the planned disposals discussed in Note 1 , the Company has identified two reportable segments. The Specialty Businesses that comprised the Company’s former Plant Nutrition South America reportable segment and the North America micronutrient product business previously reported within the former Plant Nutrition North America reportable segment were classified as discontinued operations for all periods presented. As part of the Company’s strategic shift, the Company has renamed the former Plant Nutrition North America segment as the Plant Nutrition segment. For the three months ended March 31, 2021 and 2020, the Company has presented two reportable segments: Salt and Plant Nutrition. The Salt segment produces and markets salt, consisting of sodium chloride and magnesium chloride, for use in road deicing for winter roadway safety and for dust control, food processing, water softeners and other consumer, agricultural and industrial applications. The Plant Nutrition segment produces and markets plant nutrients, including various grades of SOP. Segment information is as follows (in millions): Three Months Ended March 31, 2021 Salt Plant Corporate & Other (a) Total Sales to external customers $ 369.0 $ 54.2 $ 2.8 $ 426.0 Intersegment sales — 0.5 (0.5) — Shipping and handling cost 115.5 7.7 — 123.2 Operating earnings (loss) 80.1 4.4 (20.9) 63.6 Depreciation, depletion and amortization 18.0 8.8 3.1 29.9 Total assets (as of end of period) 892.9 481.9 191.4 1,566.2 Three Months Ended March 31, 2020 Salt Plant Corporate & Other (a) Total Sales to external customers $ 287.8 $ 56.4 $ 2.7 $ 346.9 Intersegment sales — 0.3 (0.3) — Shipping and handling cost 89.9 8.6 — 98.5 Operating earnings (loss) 56.9 6.6 (18.1) 45.4 Depreciation, depletion and amortization 14.6 9.8 3.0 27.4 Total assets (as of end of period) 956.5 528.4 32.2 1,517.1 Disaggregated revenue by product type is as follows (in millions): Three Months Ended March 31, 2021 Salt Plant Corporate & Other (a) Total Highway Deicing Salt $ 291.3 $ — $ — $ 291.3 Consumer & Industrial Salt 77.7 — — 77.7 SOP — 54.7 — 54.7 Eliminations & Other — (0.5) 2.8 2.3 Sales to external customers $ 369.0 $ 54.2 $ 2.8 $ 426.0 Three Months Ended March 31, 2020 Salt Plant Corporate & Other (a) Total Highway Deicing Salt $ 215.1 $ — $ — $ 215.1 Consumer & Industrial Salt 72.7 — — 72.7 SOP — 56.7 — 56.7 Eliminations & Other — (0.3) 2.7 2.4 Sales to external customers $ 287.8 $ 56.4 $ 2.7 $ 346.9 (a) Corporate and other includes corporate entities, records management operations and other incidental operations and eliminations. Operating earnings (loss) for corporate and other includes indirect corporate overhead, including costs for general corporate governance and oversight, as well as costs for the human resources, information technology, legal and finance functions. Corporate assets in 2021 include assets under the Company’s A/R Facility. The Company’s revenue by geographic area is as follows (in millions): Three Months Ended Revenue 2021 2020 United States (a) $ 316.0 $ 257.7 Canada 70.8 77.4 United Kingdom 34.9 11.8 Other 4.3 — Total revenue $ 426.0 $ 346.9 (a) United States sales exclude product sold to foreign customers at U.S. ports.

Stockholders' Equity and Equity

Stockholders' Equity and Equity Instruments	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity and Equity Instruments	Stockholders’ Equity and Equity Instruments: In May 2020, the Company’s stockholders approved the 2020 Incentive Award Plan (the “2020 Plan”), which authorizes the issuance of 2,977,933 shares of Company common stock. Since the date the 2020 Plan was approved, the Company ceased issuing equity awards under the 2015 Incentive Award Plan (as amended, the “2015 Plan”). Since the approval of the 2015 Plan in May 2015, the Company ceased issuing equity awards under the 2005 Incentive Award Plan (as amended, the “2005 Plan”). The 2005 Plan, the 2015 Plan and the 2020 Plan allow for grants of equity awards to executive officers, other employees and directors, including restricted stock units (“RSUs”), performance stock units (“PSUs”), stock options and deferred stock units. Options Substantially all of the stock options granted vest ratably, in tranches, over a four-year service period. Unexercised options expire after seven years. Options do not have dividend or voting rights. Upon vesting, each option can be exercised to purchase one share of the Company’s common stock. The exercise price of options is equal to the closing stock price on the grant date. To estimate the fair value of options on the grant date, the Company uses the Black-Scholes option valuation model. Award recipients are grouped according to expected exercise behavior. Unless better information is available to estimate the expected term of the options, the estimate is based on historical exercise experience. The risk-free rate, using U.S. Treasury yield curves in effect at the time of grant, is selected based on the expected term of each group. The Company’s historical stock price is used to estimate expected volatility. The fair value and inputs used to calculate fair value for options granted for the three months ended March 31, 2021, are included in the table below: Fair value of options granted $13.46 Exercise price $63.14 Expected term (years) 4.75 Expected volatility 36.1% Dividend yield 3.7% Risk-free rate of return 0.4% RSUs Typically, the RSUs granted under the 2015 Plan and the 2020 Plan vest after one PSUs Substantially all of the PSUs granted under the 2015 Plan and the 2020 Plan are either total stockholder return PSUs (“TSR PSUs”), return on invested capital PSUs (“ROIC PSUs”) or EBITDA growth PSUs (“EBITDA Growth PSUs”). The actual number of shares of the Company’s common stock that may be earned with respect to TSR PSUs is calculated by comparing the Company’s total stockholder return to the total stockholder return for each company comprising the Company’s peer group over the three-year performance period and may range from 0% to 200% of the target number of shares based upon the attainment of these performance conditions. The actual number of shares of common stock that may be earned with respect to ROIC PSUs is calculated based on the average of the Company’s annual return on invested capital for each year in the three-year performance period and may range from 0% to 200% of the target number of shares based upon the attainment of these performance conditions. The actual number of shares of common stock that may be earned with respect to EBITDA Growth PSUs is calculated based on the attainment of EBITDA growth during the performance period and may range from 0% to 300% of the target number of shares based upon the attainment of these performance conditions. PSUs represent a target number of shares of the Company’s common stock that may be earned before adjustment based upon the attainment of certain performance conditions. Holders of PSUs do not have voting rights but are entitled to receive non-forfeitable dividends or other distributions equal to those declared on the Company’s common stock for PSUs that are earned, which are paid when the shares underlying the PSUs are issued. To estimate the fair value of the TSR PSUs on the grant date, the Company uses a Monte-Carlo simulation model, which simulates future stock prices of the Company as well as the Company’s peer group. This model uses historical stock prices to estimate expected volatility and the Company’s correlation to the peer group. The risk-free rate was determined using the same methodology as the option valuations as discussed above. The Company’s closing stock price on the grant date was used to estimate the fair value of the ROIC PSUs and EBITDA Growth PSUs. The Company will adjust the expense of the ROIC PSUs and EBITDA Growth PSUs based upon its estimate of the number of shares that will ultimately vest at each interim date during the vesting period. During the three months ended March 31, 2021, the Company reissued the following number of shares from treasury stock: 5,948 shares related to the exercise of stock options , 1,945 share s related to the release of RSUs which vested, and 12,730 shares related to stock payments. In 2020, the Company issue d 72,454 net shares from treasury stock. The Company withheld a total of 4,225 shares with a fair value of $0.2 million r elated to the vesting of RSUs and exercised options during the three months ended March 31, 2021. The fair value of the shares were valued at the closing price at the vesting date and represent the employee tax withholding for the employee’s compensation. The Company recognized a tax deficiency of $0.1 million from its equity compensation awards as an increase to income tax expense during the three months ended March 31, 2021. During the three months ended March 31, 2021 and 2020, the Company recorded $4.0 million and $2.9 million (includes $0.5 million paid in cash), respectively, of compensation expense pursuant to its stock-based compensation plans. No amounts have been capitalized. The following table summarizes stock-based compensation activity during the three months ended March 31, 2021: Stock Options RSUs PSUs (a) Number Weighted-average Number Weighted-average Number Weighted-average Outstanding at December 31, 2020 868,772 $ 63.06 207,982 $ 55.68 241,794 $ 65.57 Granted 120,602 63.14 89,998 63.14 96,002 63.14 Exercised (b) (5,948) 58.11 — — — — Released from restriction (b) — — (1,945) 42.63 — — Cancelled/expired (52,468) 86.87 (2,218) 65.70 (23,962) 60.43 Outstanding at March 31, 2021 930,958 $ 61.76 293,817 $ 57.98 313,834 $ 65.22 (a) Until the performance period is completed, PSUs are included in the table at the target level at their grant date and at that level represent one share of common stock per PSU. (b) Common stock issued for exercised options and for vested and earned RSUs and PSUs was issued from treasury stock. Accumulated Other Comprehensive Loss (“AOCL”) The Company’s comprehensive income (loss) is comprised of net (loss) earnings, net amortization of the unrealized loss of the pension obligation, the change in the unrealized gain (loss) on natural gas and foreign currency cash flow hedges and foreign currency translation adjustments. The components of and changes in AOCL as of and for the three months ended March 31, 2021 and 2020, are as follows (in millions): Three Months Ended March 31, 2021 (a) Gains and Defined Foreign Total Beginning balance $ 0.2 $ (9.4) $ (294.1) $ (303.3) Other comprehensive income (loss) before reclassifications (b) 1.9 — (20.5) (18.6) Amounts reclassified from accumulated other comprehensive loss (1.8) 0.2 — (1.6) Net current period other comprehensive income (loss) 0.1 0.2 (20.5) (20.2) Ending balance $ 0.3 $ (9.2) $ (314.6) $ (323.5) Three Months Ended March 31, 2020 (a) Gains and Defined Foreign Total Beginning balance $ (0.6) $ (6.9) $ (184.6) $ (192.1) Other comprehensive income (loss) before reclassifications (b) 2.7 — (173.5) (170.8) Amounts reclassified from accumulated other comprehensive loss (2.6) 0.2 — (2.4) Net current period other comprehensive income (loss) 0.1 0.2 (173.5) (173.2) Ending balance $ (0.5) $ (6.7) $ (358.1) $ (365.3) (a) With the exception of the cumulative foreign currency translation adjustment, for which no tax effect is recorded, the changes in the components of accumulated other comprehensive loss presented in the tables above are reflected net of applicable income taxes. (b) The Company recorded a foreign exchange loss of $(19.2) million an d $(75.5) million in the three months ended March 31, 2021 and 2020, respectively, in accumulated other comprehensive loss related to intercompany notes which were deemed to be of a long-term investment nature. The amounts reclassified from AOCL to expense (income) for the three months ended March 31, 2021 and 2020, are shown below (in millions): Amount Reclassified from AOCL Three Months Ended Three Months Ended March 31, 2020 Line Item Impacted in the Gains (losses) on cash flow hedges: Natural gas instruments $ (0.2) $ (0.3) Product cost Foreign currency contracts (2.5) (3.6) Interest expense Income tax expense 0.9 1.3 Reclassifications, net of income taxes (1.8) (2.6) Amortization of defined benefit pension: Amortization of loss 0.3 0.2 Product cost Income tax benefit (0.1) — Reclassifications, net of income taxes 0.2 0.2 Total reclassifications, net of income taxes $ (1.6) $ (2.4)

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments: The Company is subject to various types of market risks, including interest rate risk, foreign currency exchange rate transaction and translation risk and commodity pricing risk. Management may take actions to mitigate the exposure to these types of risks, including entering into forward purchase contracts and other financial instruments. Currently, the Company manages a portion of its commodity pricing risks by using derivative instruments. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangement. The Company has entered into natural gas derivative instruments with counterparties it views as creditworthy. However, the Company does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with some of these counterparties. The Company records derivative financial instruments as either assets or liabilities at fair value in the Consolidated Balance Sheets. The assets and liabilities recorded as of March 31, 2021 and December 31, 2020 were not material. Derivatives qualify for treatment as hedges when there is a high correlation between the change in fair value of the derivative instrument and the related change in value of the underlying hedged item. Depending on the exposure being hedged, the Company must designate the hedging instrument as a fair value hedge, a cash flow hedge or a net investment in foreign operations hedge. For the qualifying derivative instruments that have been designated as hedges, the change in fair value is recognized through earnings when the underlying transaction being hedged affects earnings, allowing a derivative’s gains and losses to offset related results from the hedged item in the statements of operations. Any ineffectiveness related to these hedges was not material for any of the periods presented. For derivative instruments that have not been designated as hedges, the entire change in fair value is recorded through earnings in the period of change. Natural Gas Derivative Instruments Natural gas is consumed at several of the Company’s production facilities, and changes in natural gas prices impact the Company’s operating margin. The Company’s objective is to reduce the earnings and cash flow impacts of changes in market prices of natural gas by fixing the purchase price of up to 90% of its forecasted natural gas usage. It is the Company’s policy to consider hedging portions of its natural gas usage up to 36 months in advance of the forecasted purchase. As of March 31, 2021, the Company had entered into natural gas derivative instruments to hedge a portion of its natural gas purchase requirements through December 2022. As of March 31, 2021 and December 31, 2020, the Company had agreements in place to hedge forecasted natural gas purchases of 2.9 million a nd 2.5 million MMBtus, respectively. All natural gas derivative instruments held by the Company as of March 31, 2021 and December 31, 2020 qualified and were designated as cash flow hedges. As of March 31, 2021, the Company expects to reclassify from AOCL to earnings during the next twelve months $0.6 million of net gains on derivative instruments related to its natur al gas hedges.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements: The Company’s financial instruments are measured and reported at their estimated fair values. Fair value is the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction. When available, the Company uses quoted prices in active markets to determine the fair values for its financial instruments (Level 1 inputs) or, absent quoted market prices, observable market-corroborated inputs over the term of the financial instruments (Level 2 inputs). The Company does not have any unobservable inputs that are not corroborated by market inputs (Level 3 inputs). The Company holds marketable securities associated with its defined contribution and pre-tax savings plans, which are valued based on readily available quoted market prices. The Company utilizes derivative instruments to manage its risk of changes in natural gas prices (see Note 12 ). The fair values of the natural gas derivative instruments are determined using market data of forward prices for all of the Company’s contracts. The estimated fair values for each type of instrument are presented below (in millions): March 31, Level One Level Two Level Three Asset Class: Mutual fund investments in a non-qualified savings plan (a) $ 2.1 $ 2.1 $ — $ — Derivatives – natural gas instruments, net 0.4 — 0.4 — Total Assets $ 2.5 $ 2.1 $ 0.4 $ — Liability Class: Liabilities related to non-qualified savings plan $ (2.1) $ (2.1) $ — $ — Total Liabilities $ (2.1) $ (2.1) $ — $ — (a) Includes mutual fund investments of approximately 30% in common stock of large-cap U.S. companies, 10% in common stock of small to mid-cap U.S. companies, 10% in international companies, 20% in bond funds, 5% in short-term investments and 25% in blended funds. December 31, Asset Class: Mutual fund investments in a non-qualified savings plan (a) $ 1.9 $ 1.9 $ — $ — Derivatives – natural gas instruments, net 0.2 — 0.2 — Total Assets $ 2.1 $ 1.9 $ 0.2 $ — Liability Class: Liabilities related to non-qualified savings plan $ (1.9) $ (1.9) $ — $ — Total Liabilities $ (1.9) $ (1.9) $ — $ — (a) Includes mutual fund investments of approximately 30% in the common stock of large-cap U.S. companies, 10% in the common stock of small to mid-cap U.S. companies, 5% in the common stock of international companies, 15% in bond funds, 15% in short-term investments and 25% in blended funds. Cash and cash equivalents, receivables (net of allowance for doubtful accounts) and accounts payable are carried at cost, which approximates fair value due to their liquid and short-term nature. The Company’s investments related to its nonqualified savings plan of $2.1 million and $1.9 million at March 31, 2021 and December 31, 2020, respectively, are stated at fair value based on quoted market prices. As of March 31, 2021 and December 31, 2020, the estimated fair value of the Company’s fixed-rate 4.875% Senior Notes due July 2024, based on available trading information (Level 2), totaled $255.6 million and $260.3 million, respectively, compared with the aggregate principal amount at maturity of $250.0 million. As of March 31, 2021 and December 31, 2020, the estimated fair value of the Company’s fixed-rate 6.75% Senior Notes due December 2027, based on available trading information (Level 2), totaled $533.8 million a nd $543.1 million, respectively, compared with the aggregate principal amount at maturity of $500.0 million. The fair value at March 31, 2021 and December 31, 2020 of amounts outstanding under the Company’s term loans and revolving credit facility, based upon available bid information received from the Co mpany’s lender (Level 2), totaled approximately $342.3 million and $513.8 million, respectively, compared with the aggregate principal amount at maturity of $345.8 million and $520.3 million , respectively. We performed an impairment analysis for our Plant Nutrition South America businesses during the first quarter 2021, which resulted in an impairment loss. The fair value measurements used in this analysis were a combination of Level 2 and Level 3 inputs. Refer to Note 2

Earnings (loss) per Share

Earnings (loss) per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings (loss) per Share	Earnings (loss) per Share: The Company calculates earnings per share using the two-class method. The two-class method requires allocating the Company’s net earnings (loss) to both common shares and participating securities. The following table sets forth the computation of basic and diluted earnings (loss) per common share (in millions, except for share and per-share data): Three Months Ended 2021 2020 Numerator: Net earnings from continuing operations $ 32.9 $ 33.9 Less: net earnings allocated to participating securities (a) (0.5) (0.6) Net earnings from continuing operations available to common stockholders 32.4 33.3 Net loss from discontinued operations (256.5) (6.3) Net (loss) earnings available to common stockholders $ (224.1) $ 27.0 Denominator (in thousands): Weighted-average common shares outstanding, shares for basic earnings per share 33,974 33,892 Weighted-average awards outstanding (b) 38 — Shares for diluted earnings per share 34,012 33,892 Basic net earnings from continuing operations per common share $ 0.96 $ 0.99 Basic net loss from discontinued operations per common share (7.55) (0.19) Basic net (loss) earnings per common share $ (6.59) $ 0.80 Diluted net earnings from continuing operations per common share $ 0.95 $ 0.99 Diluted net loss from discontinued operations per common share (7.55) (0.19) Diluted net (loss) earnings per common share $ (6.60) $ 0.80 (a) Weighted participating securities include RSUs and PSUs that receive non-forfeitable dividends and consis t of 445,000 and 412,000 weighted participating securities for the three months ended March 31, 2021 and 2020, respectively. (b) For the calculation of diluted net (loss) earnings per share, the Company uses the more dilutive of eithe r the treasury stock method or the two-class method to determine the weighted-average number of outstanding common shares. In addition, the Company had 1,278,000 and 1,266,000 weighted-average equity awards outstanding for the three months ended March 31, 2021 and 2020, respectively,

Accounting Policies and Basis_2

Accounting Policies and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Consolidation	CMI is a holding company with no significant operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMI and its wholly-owned domestic and foreign subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Basis of Presentation	The accompanying unaudited consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of the Company for the year ended December 31, 2020, as filed with the Securities and Exchange Commission (“SEC”) in its Annual Report on Form 10-K on February 26, 2021. In the opinion of management, all adjustments, consisting of normal recurring adjustments considered necessary for a fair presentation, have been included.
Significant and Recent Accounting Pronouncements	Significant Accounting Policies The Company’s significant accounting policies are detailed in “Note 2 – Summary of Significant Accounting Policies” within Part II, Item 8 of its Annual Report on Form 10-K for the year ended December 31, 2020. The Company reports its financial results from discontinued operations and continuing operations separately to recognize the financial impact of disposal transactions from ongoing operations. Discontinued operations reporting occurs when a component or a group of components of an entity has been disposed of or classified as held for sale and represents a strategic shift that has a major effect on the entity’s operations and financial results. In the Company’s Consolidated Statements of Cash Flows, the cash flows from discontinued operations are not separately classified. The Company has reclassified certain prior year amounts, including the results of discontinued operations, assets and liabilities held for sale and reportable segment information, to conform to the current year presentation. Unless otherwise indicated, amounts provided in these Notes pertain to continuing operations. See Note 2 for information on discontinued operations and Note 10 for information on the Company’s reportable segments. Recent Accounting Pronouncements The Company has evaluated all of the recently issued, but not yet effective, accounting standards that have been issued or proposed by the FASB or other standards-setting bodies through the filing date of these unaudited consolidated financial statements and does not believe the future adoption of any such pronouncements will have a material impact on its consolidated financial statements.
Strategic Evaluation and Plan to Sell Businesses	Strategic Evaluation and Plan to Sell Businesses During 2020, the Company initiated an evaluation of the strategic fit of certain of the Company’s businesses. On February 16, 2021, the Company announced its plan to restructure its former Plant Nutrition South America segment to enable targeted and separate sales processes for each portion of the former segment, including its chemicals and specialty plant nutrition businesses along with the Company’s equity method investment in Fermavi Eletroquímica Ltda. (“Fermavi”). Concurrently, to optimize its asset base in North America, the Company evaluated the strategic fit of its North America micronutrient product business. On March 16, 2021, the Board of the Directors of the Company approved a plan to sell the Company’s South America chemicals and specialty plant nutrition businesses, investment in Fermavi and North America micronutrient product business (collectively, the “Specialty Businesses”) with the goal of reducing the Company’s leverage and enabling increased focus on optimizing the Company’s core businesses. The South America chemicals and specialty plant nutrition businesses and investment in Fermavi were previously reported as the Company’s Plant Nutrition South America segment. The North America micronutrient product business was previously included as part of the Company’s Plant Nutrition North America segment, which has been renamed as the Plant Nutrition segment. The Company now has two reportable segments, Salt and Plant Nutrition, as discussed further in Note 10 . The Company concluded that the Specialty Businesses met the criteria for classification as held for sale upon receiving approval from its Board of Directors to sell the Specialty Businesses in the first quarter of 2021. In addition, the Company believes there is a single disposal plan representing a strategic shift that will have a material effect on its operations and financial results. Consequently, the Specialty Businesses qualify for presentation as assets and liabilities held for sale and discontinued operations in accordance with U.S. GAAP . Accordingly, current and noncurrent assets and liabilities of the Specialty Businesses are presented in the Consolidated Balance Sheets as assets and liabilities held for sale for both periods presented and their results of operations are presented as discontinued operations in the Consolidated Statements of Operations for each period presented. Interest expense attributed to discontinued operations represents interest expense for loans in Brazil by the Company’s South America chemicals and specialty plant nutrition businesses, which are expected to be fully repaid from proceeds received from the Company’s sale of its South America specialty plant nutrition business. As described further in Note 2 , on March 23, 2021, and April 7, 2021, the Company entered into definitive agreements to sell its South America specialty plant nutrition business and a component of its North America micronutrient business, respectively. The Company continues to actively pursue the sales of the remaining South America chemicals business and its investment in Fermavi, and the Company believes these sales are probable to occur within the next twelve months.
Derivative Financial Instruments	The Company is subject to various types of market risks, including interest rate risk, foreign currency exchange rate transaction and translation risk and commodity pricing risk. Management may take actions to mitigate the exposure to these types of risks, including entering into forward purchase contracts and other financial instruments. Currently, the Company manages a portion of its commodity pricing risks by using derivative instruments. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangement. The Company has entered into natural gas derivative instruments with counterparties it views as creditworthy. However, the Company does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with some of these counterparties. The Company records derivative financial instruments as either assets or liabilities at fair value in the Consolidated Balance Sheets. The assets and liabilities recorded as of March 31, 2021 and December 31, 2020 were not material. Derivatives qualify for treatment as hedges when there is a high correlation between the change in fair value of the derivative instrument and the related change in value of the underlying hedged item. Depending on the exposure being hedged, the Company must designate the hedging instrument as a fair value hedge, a cash flow hedge or a net investment in foreign operations hedge. For the qualifying derivative instruments that have been designated as hedges, the change in fair value is recognized through earnings when the underlying transaction being hedged affects earnings, allowing a derivative’s gains and losses to offset related results from the hedged item in the statements of operations. Any ineffectiveness related to these hedges was not material for any of the periods presented. For derivative instruments that have not been designated as hedges, the entire change in fair value is recorded through earnings in the period of change.
Earnings Per Share	The Company calculates earnings per share using the two-class method. The two-class method requires allocating the Company’s net earnings (loss) to both common shares and participating securities.

Discontinued Operations (Tables

Discontinued Operations (Tables)	3 Months Ended
	Mar. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations	The following table represents summarized balance sheet information of assets and liabilities held for sale (in millions): March 31, December 31, Cash and cash equivalents $ 20.8 $ 10.5 Receivables, less allowance for doubtful accounts of $6.7 in 2021 and $7.1 in 2020 111.4 111.5 Inventories 72.5 70.7 Property, plant and equipment, net 103.3 — Goodwill 207.6 — Loss recognized on held for sale classification (255.2) — Other 78.4 13.8 Current assets held for sale $ 338.8 $ 206.5 Property, plant and equipment, net $ — $ 113.2 Goodwill — 225.5 Other — 65.4 Noncurrent assets held for sale $ — $ 404.1 Current portion of long-term debt $ 94.3 $ 53.7 Accounts payable 48.9 34.3 Accrued expenses and other current liabilities 56.1 23.5 Current liabilities held for sale $ 199.3 $ 111.5 Long-term debt, net of current portion $ — $ 38.6 Other noncurrent liabilities — 37.5 Noncurrent liabilities held for sale $ — $ 76.1 The following table represents summarized statements of operations information of discontinued operations (in millions): Three Months Ended 2021 2020 Sales $ 85.4 $ 67.0 Shipping and handling cost 3.8 3.3 Product cost 62.8 51.6 Gross profit 18.8 12.1 Selling, general and administrative expenses 13.5 13.3 Operating earnings (loss) 5.3 (1.2) Interest expense 1.7 2.4 Loss on foreign exchange 4.3 3.7 Loss on impairment 255.2 — Other income, net (0.4) (0.1) Loss from discontinued operations before income taxes (255.5) (7.2) Income tax expense (benefit) 1.0 (0.9) Net loss from discontinued operations $ (256.5) $ (6.3) The significant components included in our Consolidated Statements of Cash Flows for the discontinued operations are as follows (in millions): Three Months Ended 2021 2020 Depreciation, depletion and amortization $ 4.7 $ 5.7 Loss on impairment of long-lived assets 253.1 — Capital expenditures 1.6 1.4 Proceeds from issuance of long-term debt 21.0 22.0 Principal payments on long-term debt (10.9) (16.2)

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories consist of the following (in millions): March 31, December 31, Finished goods $ 168.8 $ 252.1 Raw materials and supplies 51.1 47.8 Total inventories $ 219.9 $ 299.9

Property, Plant and Equipment_2

Property, Plant and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Summary of Property, Plant and Equipment, Net	Property, plant and equipment, net, consists of the following (in millions): March 31, December 31, Land, buildings and structures, and leasehold improvements $ 547.8 $ 544.5 Machinery and equipment 1,041.7 1,035.4 Office furniture and equipment 54.2 50.7 Mineral interests 168.9 172.4 Construction in progress 59.7 43.7 1,872.3 1,846.7 Less: accumulated depreciation and depletion (1,027.3) (995.0) Property, plant and equipment, net $ 845.0 $ 851.7

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, Net (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	Amounts related to the Company’s amortization of intangible assets are as follows (in millions): Three Months Ended 2021 2020 Aggregate amortization expense $ 0.4 $ 0.4
Summary of Goodwill	Amounts related to the Company’s goodwill are as follows (in millions): March 31, December 31, Plant Nutrition Segment $ 50.3 $ 49.6 Other 6.1 6.1 Total $ 56.4 $ 55.7

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Summary of Long-Term Debt	Long-term debt consists of the following (in millions): March 31, December 31, 4.875% Senior Notes due July 2024 $ 250.0 $ 250.0 Term Loan due January 2025 345.8 390.0 Revolving Credit Facility due January 2025 — 130.3 6.75% Senior Notes due December 2027 500.0 500.0 AR Securitization Facility expires June 2023 100.0 51.2 1,195.8 1,321.5 Less unamortized debt issuance costs (11.8) (12.4) Total debt 1,184.0 1,309.1 Less: current portion — (10.0) Long-term debt $ 1,184.0 $ 1,299.1

Operating Segments (Tables)

Operating Segments (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Summary of Segment Information	Segment information is as follows (in millions): Three Months Ended March 31, 2021 Salt Plant Corporate & Other (a) Total Sales to external customers $ 369.0 $ 54.2 $ 2.8 $ 426.0 Intersegment sales — 0.5 (0.5) — Shipping and handling cost 115.5 7.7 — 123.2 Operating earnings (loss) 80.1 4.4 (20.9) 63.6 Depreciation, depletion and amortization 18.0 8.8 3.1 29.9 Total assets (as of end of period) 892.9 481.9 191.4 1,566.2 Three Months Ended March 31, 2020 Salt Plant Corporate & Other (a) Total Sales to external customers $ 287.8 $ 56.4 $ 2.7 $ 346.9 Intersegment sales — 0.3 (0.3) — Shipping and handling cost 89.9 8.6 — 98.5 Operating earnings (loss) 56.9 6.6 (18.1) 45.4 Depreciation, depletion and amortization 14.6 9.8 3.0 27.4 Total assets (as of end of period) 956.5 528.4 32.2 1,517.1
Summary of Disaggregated Revenue by Product Type	Disaggregated revenue by product type is as follows (in millions): Three Months Ended March 31, 2021 Salt Plant Corporate & Other (a) Total Highway Deicing Salt $ 291.3 $ — $ — $ 291.3 Consumer & Industrial Salt 77.7 — — 77.7 SOP — 54.7 — 54.7 Eliminations & Other — (0.5) 2.8 2.3 Sales to external customers $ 369.0 $ 54.2 $ 2.8 $ 426.0 Three Months Ended March 31, 2020 Salt Plant Corporate & Other (a) Total Highway Deicing Salt $ 215.1 $ — $ — $ 215.1 Consumer & Industrial Salt 72.7 — — 72.7 SOP — 56.7 — 56.7 Eliminations & Other — (0.3) 2.7 2.4 Sales to external customers $ 287.8 $ 56.4 $ 2.7 $ 346.9 (a) Corporate and other includes corporate entities, records management operations and other incidental operations and eliminations. Operating earnings (loss) for corporate and other includes indirect corporate overhead, including costs for general corporate governance and oversight, as well as costs for the human resources, information technology, legal and finance functions. Corporate assets in 2021 include assets under the Company’s A/R Facility.
Summary of Revenue by Geographic Area	The Company’s revenue by geographic area is as follows (in millions): Three Months Ended Revenue 2021 2020 United States (a) $ 316.0 $ 257.7 Canada 70.8 77.4 United Kingdom 34.9 11.8 Other 4.3 — Total revenue $ 426.0 $ 346.9 (a) United States sales exclude product sold to foreign customers at U.S. ports.

Stockholders' Equity and Equi_2

Stockholders' Equity and Equity Instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Schedule of Fair Value and Inputs Used to Calculate Fair Value for Options Granted	The fair value and inputs used to calculate fair value for options granted for the three months ended March 31, 2021, are included in the table below: Fair value of options granted $13.46 Exercise price $63.14 Expected term (years) 4.75 Expected volatility 36.1% Dividend yield 3.7% Risk-free rate of return 0.4%
Summary of Stock-Based Compensation Activity	The following table summarizes stock-based compensation activity during the three months ended March 31, 2021: Stock Options RSUs PSUs (a) Number Weighted-average Number Weighted-average Number Weighted-average Outstanding at December 31, 2020 868,772 $ 63.06 207,982 $ 55.68 241,794 $ 65.57 Granted 120,602 63.14 89,998 63.14 96,002 63.14 Exercised (b) (5,948) 58.11 — — — — Released from restriction (b) — — (1,945) 42.63 — — Cancelled/expired (52,468) 86.87 (2,218) 65.70 (23,962) 60.43 Outstanding at March 31, 2021 930,958 $ 61.76 293,817 $ 57.98 313,834 $ 65.22 (a) Until the performance period is completed, PSUs are included in the table at the target level at their grant date and at that level represent one share of common stock per PSU. (b) Common stock issued for exercised options and for vested and earned RSUs and PSUs was issued from treasury stock.
Summary of Components and Changes in Accumulated Other Comprehensive Income (Loss)	The components of and changes in AOCL as of and for the three months ended March 31, 2021 and 2020, are as follows (in millions): Three Months Ended March 31, 2021 (a) Gains and Defined Foreign Total Beginning balance $ 0.2 $ (9.4) $ (294.1) $ (303.3) Other comprehensive income (loss) before reclassifications (b) 1.9 — (20.5) (18.6) Amounts reclassified from accumulated other comprehensive loss (1.8) 0.2 — (1.6) Net current period other comprehensive income (loss) 0.1 0.2 (20.5) (20.2) Ending balance $ 0.3 $ (9.2) $ (314.6) $ (323.5) Three Months Ended March 31, 2020 (a) Gains and Defined Foreign Total Beginning balance $ (0.6) $ (6.9) $ (184.6) $ (192.1) Other comprehensive income (loss) before reclassifications (b) 2.7 — (173.5) (170.8) Amounts reclassified from accumulated other comprehensive loss (2.6) 0.2 — (2.4) Net current period other comprehensive income (loss) 0.1 0.2 (173.5) (173.2) Ending balance $ (0.5) $ (6.7) $ (358.1) $ (365.3) (a) With the exception of the cumulative foreign currency translation adjustment, for which no tax effect is recorded, the changes in the components of accumulated other comprehensive loss presented in the tables above are reflected net of applicable income taxes. (b) The Company recorded a foreign exchange loss of $(19.2) million an d $(75.5) million in the three months ended March 31, 2021 and 2020, respectively, in accumulated other comprehensive loss related to intercompany notes which were deemed to be of a long-term investment nature.
Summary of Reclassifications out of Accumulated Other Comprehensive Income	The amounts reclassified from AOCL to expense (income) for the three months ended March 31, 2021 and 2020, are shown below (in millions): Amount Reclassified from AOCL Three Months Ended Three Months Ended March 31, 2020 Line Item Impacted in the Gains (losses) on cash flow hedges: Natural gas instruments $ (0.2) $ (0.3) Product cost Foreign currency contracts (2.5) (3.6) Interest expense Income tax expense 0.9 1.3 Reclassifications, net of income taxes (1.8) (2.6) Amortization of defined benefit pension: Amortization of loss 0.3 0.2 Product cost Income tax benefit (0.1) — Reclassifications, net of income taxes 0.2 0.2 Total reclassifications, net of income taxes $ (1.6) $ (2.4)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The estimated fair values for each type of instrument are presented below (in millions): March 31, Level One Level Two Level Three Asset Class: Mutual fund investments in a non-qualified savings plan (a) $ 2.1 $ 2.1 $ — $ — Derivatives – natural gas instruments, net 0.4 — 0.4 — Total Assets $ 2.5 $ 2.1 $ 0.4 $ — Liability Class: Liabilities related to non-qualified savings plan $ (2.1) $ (2.1) $ — $ — Total Liabilities $ (2.1) $ (2.1) $ — $ — (a) Includes mutual fund investments of approximately 30% in common stock of large-cap U.S. companies, 10% in common stock of small to mid-cap U.S. companies, 10% in international companies, 20% in bond funds, 5% in short-term investments and 25% in blended funds. December 31, Asset Class: Mutual fund investments in a non-qualified savings plan (a) $ 1.9 $ 1.9 $ — $ — Derivatives – natural gas instruments, net 0.2 — 0.2 — Total Assets $ 2.1 $ 1.9 $ 0.2 $ — Liability Class: Liabilities related to non-qualified savings plan $ (1.9) $ (1.9) $ — $ — Total Liabilities $ (1.9) $ (1.9) $ — $ — (a) Includes mutual fund investments of approximately 30% in the common stock of large-cap U.S. companies, 10% in the common stock of small to mid-cap U.S. companies, 5% in the common stock of international companies, 15% in bond funds, 15% in short-term investments and 25% in blended funds.

Earnings (loss) per Share (Tabl

Earnings (loss) per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Summary of Basic and Diluted Earnings Per Common Share	The following table sets forth the computation of basic and diluted earnings (loss) per common share (in millions, except for share and per-share data): Three Months Ended 2021 2020 Numerator: Net earnings from continuing operations $ 32.9 $ 33.9 Less: net earnings allocated to participating securities (a) (0.5) (0.6) Net earnings from continuing operations available to common stockholders 32.4 33.3 Net loss from discontinued operations (256.5) (6.3) Net (loss) earnings available to common stockholders $ (224.1) $ 27.0 Denominator (in thousands): Weighted-average common shares outstanding, shares for basic earnings per share 33,974 33,892 Weighted-average awards outstanding (b) 38 — Shares for diluted earnings per share 34,012 33,892 Basic net earnings from continuing operations per common share $ 0.96 $ 0.99 Basic net loss from discontinued operations per common share (7.55) (0.19) Basic net (loss) earnings per common share $ (6.59) $ 0.80 Diluted net earnings from continuing operations per common share $ 0.95 $ 0.99 Diluted net loss from discontinued operations per common share (7.55) (0.19) Diluted net (loss) earnings per common share $ (6.60) $ 0.80 (a) Weighted participating securities include RSUs and PSUs that receive non-forfeitable dividends and consis t of 445,000 and 412,000 weighted participating securities for the three months ended March 31, 2021 and 2020, respectively. (b) For the calculation of diluted net (loss) earnings per share, the Company uses the more dilutive of eithe r the treasury stock method or the two-class method to determine the weighted-average number of outstanding common shares. In addition, the Company had 1,278,000 and 1,266,000 weighted-average equity awards outstanding for the three months ended March 31, 2021 and 2020, respectively,

Accounting Policies and Basis_3

Accounting Policies and Basis of Presentation (Details)	3 Months Ended
	Mar. 31, 2021segment
Accounting Policies [Abstract]
Number of reportable segments	2

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) $ in Thousands, R$ in Millions	Mar. 23, 2021BRL (R$)	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Apr. 07, 2021USD ($)	Mar. 23, 2021USD ($)	Dec. 31, 2020USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Term of agreement (in months)	18 months
Impairment loss on equity method investment		$ 8,000
Goodwill		56,400				$ 55,700
North America Micronutrient Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment		0
Chemicals Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment		92,700
Specialty Plant Nutrition Bussines
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment		154,500
Discontinued Operations, Held-for-sale or Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on impairment		255,200	$ 0
Discontinued Operations, Held-for-sale or Disposed of by Sale | Plant Nutrition South America
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Potential cash proceeds	R$ 1110.0				$ 198,300
Additional earn out payment | R$	R$ 88.0
Discontinued Operations, Held-for-sale or Disposed of by Sale | North America Micronutrient Assets
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill		$ 6,900				$ 6,800
Discontinued Operations, Held-for-sale or Disposed of by Sale | North America Micronutrient Assets | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Potential cash proceeds				$ 60,250

Discontinued Operations - Sched

Discontinued Operations - Schedule of Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Property, plant and equipment, net			$ 0
Goodwill			0
Current assets held for sale	$ 338.8		206.5
Disposal Group, Including Discontinued Operation, Assets, Noncurrent [Abstract]
Noncurrent assets held for sale	0		404.1
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Current liabilities held for sale	199.3		111.5
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent [Abstract]
Noncurrent liabilities held for sale	0		76.1
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Net loss from discontinued operations	(256.5)	$ (6.3)
Discontinued Operations, Held-for-sale or Disposed of by Sale
Disposal Group, Including Discontinued Operation, Assets, Current [Abstract]
Cash and cash equivalents	20.8		10.5
Receivables, less allowance for doubtful accounts of $6.7 in 2021 and $7.1 in 2020	111.4		111.5
Allowance for doubtful accounts	(6.7)		(7.1)
Inventories	72.5		70.7
Property, plant and equipment, net	103.3
Goodwill	207.6
Loss recognized on held for sale classification	(255.2)		0
Other	78.4		13.8
Current assets held for sale	338.8		206.5
Disposal Group, Including Discontinued Operation, Assets, Noncurrent [Abstract]
Property, plant and equipment, net	0		113.2
Goodwill	0		225.5
Other	0		65.4
Noncurrent assets held for sale	0		404.1
Disposal Group, Including Discontinued Operation, Liabilities, Current [Abstract]
Current portion of long-term debt	94.3		53.7
Accounts payable	48.9		34.3
Accrued expenses and other current liabilities	56.1		23.5
Current liabilities held for sale	199.3		111.5
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent [Abstract]
Long-term debt, net of current portion	0		38.6
Other noncurrent liabilities	0		37.5
Noncurrent liabilities held for sale	0		$ 76.1
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Sales	85.4	67
Gross profit	18.8	12.1
Selling, general and administrative expenses	13.5	13.3
Operating earnings (loss)	5.3	(1.2)
Interest expense	1.7	2.4
Loss on foreign exchange	4.3	3.7
Loss on impairment	255.2	0
Other income, net	(0.4)	(0.1)
Loss from discontinued operations before income taxes	(255.5)	(7.2)
Income tax expense (benefit)	1	(0.9)
Net loss from discontinued operations	(256.5)	(6.3)
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Depreciation, depletion and amortization	4.7	5.7
Loss on impairment of long-lived assets	253.1	0
Capital expenditures	1.6	1.4
Proceeds from issuance of long-term debt	21	22
Principal payments on long-term debt	(10.9)	(16.2)
Discontinued Operations, Held-for-sale or Disposed of by Sale | Shipping and handling cost
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Cost of goods and services sold	3.8	3.3
Discontinued Operations, Held-for-sale or Disposed of by Sale | Product cost
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract]
Cost of goods and services sold	$ 62.8	$ 51.6

Revenues (Details)

Revenues (Details)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Payment terms for delivery	30 days

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Finished goods	$ 168.8	$ 252.1
Raw materials and supplies	51.1	47.8
Total inventories	$ 219.9	$ 299.9

Property, Plant and Equipment_3

Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property plant and equipment	$ 1,872.3	$ 1,846.7
Less: accumulated depreciation and depletion	(1,027.3)	(995)
Property, plant and equipment, net	845	851.7
Land, buildings and structures, and leasehold improvements
Property, Plant and Equipment [Line Items]
Total property plant and equipment	547.8	544.5
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property plant and equipment	1,041.7	1,035.4
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Total property plant and equipment	54.2	50.7
Mineral interests
Property, Plant and Equipment [Line Items]
Total property plant and equipment	168.9	172.4
Construction in progress
Property, Plant and Equipment [Line Items]
Total property plant and equipment	$ 59.7	$ 43.7

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Goodwill [Line Items]
Amortization of Intangible Assets	$ 0.4	$ 0.4
Goodwill	56.4		$ 55.7
Other
Goodwill [Line Items]
Goodwill	6.1		6.1
Plant Nutrition | Operating Segments
Goodwill [Line Items]
Goodwill	$ 50.3		$ 49.6

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Income Tax Disclosure [Line Items]
Increase to tax payment from settlement			$ 5.3
Scenario, Forecast
Income Tax Disclosure [Line Items]
Increase to tax payment from settlement		$ 1.4
Tax Year 2007 Through 2012
Income Tax Disclosure [Line Items]
Intercompany cash payments for tax settlements				$ 85.7
Tax Year 2013 Through 2021
Income Tax Disclosure [Line Items]
Intercompany cash payments for tax settlements			106.1
Foreign Tax Authority
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	$ 3.4				$ 3.4
Foreign Tax Authority | NOL carryforwards expire beginning in 2033
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	0				0.1
Foreign Tax Authority | Tax Year 2007 Through 2012
Income Tax Disclosure [Line Items]
Payments for income tax settlements				$ 17.5
Foreign Tax Authority | Tax Year 2013 Through 2021
Income Tax Disclosure [Line Items]
Payments for income tax settlements			$ 29.9
Expected tax payment to be (received) paid					1.4
Foreign Tax Authority | Canadian Tax Authority
Income Tax Disclosure [Line Items]
Total reassessments including interest	157
Amount of security posted in the form of a performance bond	121.7
Amount of security posted in the form of cash	39.5				39.5
State and Local | NOL carryforwards expire beginning in 2027
Income Tax Disclosure [Line Items]
Net operating loss carryforwards	0.2				$ 0.2
U.S. Federal | Tax Year 2007 Through 2012
Income Tax Disclosure [Line Items]
Tax refund received	22.3
U.S. Federal | Tax Year 2007 Through 2012 | Scenario, Forecast
Income Tax Disclosure [Line Items]
Expected tax payment to be (received) paid		(0.7)
U.S. Federal | Tax Year 2013 Through 2021
Income Tax Disclosure [Line Items]
Tax refund received	$ 60
U.S. Federal | Tax Year 2013 Through 2021 | Scenario, Forecast
Income Tax Disclosure [Line Items]
Expected tax payment to be (received) paid		$ 1.7

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt, gross	$ 1,195.8	$ 1,321.5
Less unamortized debt issuance costs	(11.8)	(12.4)
Total debt	1,184	1,309.1
Less: current portion	0	(10)
Long-term debt	1,184	1,299.1
Term Loan due January 2025
Debt Instrument [Line Items]
Long-term debt, gross	345.8	390
6.75% Senior Notes due December 2027
Debt Instrument [Line Items]
Long-term debt, gross	$ 500	$ 500
Interest rate stated percentage	6.75%	6.75%
AR Securitization Facility expires June 2023
Debt Instrument [Line Items]
Long-term debt, gross	$ 100	$ 51.2
Revolving Credit Facility due January 2025 | Revolving Credit Facility due January 2025
Debt Instrument [Line Items]
Long-term debt, gross	0	130.3
Senior Notes | 4.875% Senior Notes due July 2024
Debt Instrument [Line Items]
Long-term debt, gross	$ 250	$ 250
Interest rate stated percentage	4.875%	4.875%
Senior Notes | 6.75% Senior Notes due December 2027
Debt Instrument [Line Items]
Interest rate stated percentage	6.75%

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details) - USD ($)	Jun. 30, 2020	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Required prepayment of term loan		$ 55,100,000	$ 18,700,000
Weighted average interest rate of debt (as a percent)		2.10%
Unallocated Financing Receivables | Account Receivable Financing Receivable
Debt Instrument [Line Items]
Financing receivable, term	3 years
Revolving accounts receivable financing facility	$ 100,000,000
Term Loan due January 2025
Debt Instrument [Line Items]
Required prepayment of term loan		$ 41,700,000

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Maximum exposure for other labor matters	$ 13	$ 16
Compass Minerals South America
Loss Contingencies [Line Items]
Contingent liabilities assumed	2.8	3.5
Brazilian Tax Litigation and Assessments
Loss Contingencies [Line Items]
Amount of potential payments	$ 7.5	$ 7.9

Operating Segments (Details)

Operating Segments (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)segment	Mar. 31, 2020USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	2
Segment Reporting Information [Abstract]
Sales	$ 426	$ 346.9
Operating earnings (loss)	63.6	45.4
Depreciation, depletion and amortization	29.9	27.4
Total assets (as of end of period)	1,566.2	1,517.1
United States
Segment Reporting Information [Abstract]
Sales	316	257.7
Canada
Segment Reporting Information [Abstract]
Sales	70.8	77.4
United Kingdom
Segment Reporting Information [Abstract]
Sales	34.9	11.8
Other
Segment Reporting Information [Abstract]
Sales	4.3	0
Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	123.2	98.5
Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	291.3	215.1
Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	77.7	72.7
SOP
Segment Reporting Information [Abstract]
Sales	54.7	56.7
Operating Segments | Salt
Segment Reporting Information [Abstract]
Sales	369	287.8
Operating earnings (loss)	80.1	56.9
Depreciation, depletion and amortization	18	14.6
Total assets (as of end of period)	892.9	956.5
Operating Segments | Salt | Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	115.5	89.9
Operating Segments | Salt | Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	291.3	215.1
Operating Segments | Salt | Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	77.7	72.7
Operating Segments | Salt | SOP
Segment Reporting Information [Abstract]
Sales	0	0
Operating Segments | Salt | Eliminations & Other
Segment Reporting Information [Abstract]
Sales	0	0
Operating Segments | Plant Nutrition
Segment Reporting Information [Abstract]
Sales	54.2	56.4
Operating earnings (loss)	4.4	6.6
Depreciation, depletion and amortization	8.8	9.8
Total assets (as of end of period)	481.9	528.4
Operating Segments | Plant Nutrition | Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	7.7	8.6
Operating Segments | Plant Nutrition | Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	0	0
Operating Segments | Plant Nutrition | Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	0	0
Operating Segments | Plant Nutrition | SOP
Segment Reporting Information [Abstract]
Sales	54.7	56.7
Operating Segments | Plant Nutrition | Eliminations & Other
Segment Reporting Information [Abstract]
Sales	(0.5)	(0.3)
Corporate & Other
Segment Reporting Information [Abstract]
Sales	2.8	2.7
Operating earnings (loss)	(20.9)	(18.1)
Depreciation, depletion and amortization	3.1	3
Total assets (as of end of period)	191.4	32.2
Corporate & Other | Shipping and handling cost
Segment Reporting Information [Abstract]
Shipping and handling cost	0	0
Corporate & Other | Highway Deicing Salt
Segment Reporting Information [Abstract]
Sales	0	0
Corporate & Other | Consumer & Industrial Salt
Segment Reporting Information [Abstract]
Sales	0	0
Corporate & Other | SOP
Segment Reporting Information [Abstract]
Sales	0	0
Corporate & Other | Eliminations & Other
Segment Reporting Information [Abstract]
Sales	2.8	2.7
Intersegment Eliminations
Segment Reporting Information [Abstract]
Sales	(0.5)	(0.3)
Intersegment Eliminations | Eliminations & Other
Segment Reporting Information [Abstract]
Sales	2.3	2.4
Intersegment Eliminations | Salt
Segment Reporting Information [Abstract]
Sales	0	0
Intersegment Eliminations | Plant Nutrition
Segment Reporting Information [Abstract]
Sales	$ 0.5	$ 0.3

Stockholders' Equity and Equi_3

Stockholders' Equity and Equity Instruments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	May 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Treasury stock reissued (in shares)			72,454
Tax deficiency from equity compensation awards recorded as an increase to income tax expense	$ 0.1
Compensation expense recorded during period pursuant to stock-based compensation plans	$ 4	$ 2.9
Compensation expense to be paid in cash		$ 0.5
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Options expiration period	7 years
Number of shares available from conversion (in shares)	1
Reissued shares of treasury stock (in shares)	5,948
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available from conversion (in shares)	1
Reissued shares of treasury stock (in shares)	1,945
TSR PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of PSUs	3 years
TSR PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned	0.00%
TSR PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned	200.00%
ROIC PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of PSUs	3 years
ROIC PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned	0.00%
ROIC PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned	200.00%
EBITDA Growth PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned	0.00%
EBITDA Growth PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares earned	300.00%
Stock Payments
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reissued shares of treasury stock (in shares)	12,730
Equity Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares withheld related to vesting of RSUs and PSUs (in shares)	4,225
Fair value of stock withheld related to vesting of RSUs and PSUs	$ 0.2
2020 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)				2,977,933
2020 Incentive Award Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	3 years
2015 Incentive Award Plan | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period	1 year

Stockholders' Equity and Equi_4

Stockholders' Equity and Equity Instruments - Schedule of Fair Value and Inputs Used to Calculate Fair Value for Options Granted (Details)	3 Months Ended
	Mar. 31, 2021$ / shares
Equity [Abstract]
Fair value of options granted (in dollars per share)	$ 13.46
Exercise price (in dollars per share)	$ 63.14
Expected term (years)	4 years 9 months
Expected volatility (as a percent)	36.10%
Dividend yield (as a percent)	3.70%
Risk-free rate of return (as a percent)	0.40%

Stockholders' Equity and Equi_5

Stockholders' Equity and Equity Instruments - Stock-Based Compensation Activity (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Weighted-average exercise price
Weighted-average exercise price, exercised (in dollars per share) | $ / shares	$ 63.14
Stock Options
Number
Outstanding at beginning of period (in shares) | shares	868,772
Granted (in shares) | shares	120,602
Exercised (in shares) | shares	(5,948)
Released from restriction (in shares) | shares	0
Cancelled/expired (in shares) | shares	(52,468)
Outstanding at end of period (in shares) | shares	930,958
Weighted-average exercise price
Weighted-average exercise price at beginning of period (in dollars per share) | $ / shares	$ 63.06
Weighted-average exercise price, granted (in dollars per share) | $ / shares	63.14
Weighted-average exercise price, exercised (in dollars per share) | $ / shares	58.11
Weighted-average exercise price, released from restriction (in dollars per share) | $ / shares	0
Weighted-average exercise price, cancelled/expired (in dollars per share) | $ / shares	86.87
Weighted-average exercise price at end of period (in dollars per share) | $ / shares	$ 61.76
RSUs
Number
Outstanding at beginning of period (in shares) | shares	207,982
Granted (in shares) | shares	89,998
Exercised (in shares) | shares	0
Released from restriction (in shares) | shares	(1,945)
Cancelled/expired (in shares) | shares	(2,218)
Outstanding at end of period (in shares) | shares	293,817
Weighted-average fair value
Weighted-average fair value at beginning of period (in dollars per share) | $ / shares	$ 55.68
Weighted-average fair value, granted (in dollars per share) | $ / shares	63.14
Weighted-average fair value, exercised (in dollars per share) | $ / shares	0
Weighted-average fair value, released from restriction (in dollars per share) | $ / shares	42.63
Weighted-average fair value, cancelled/expired (in dollars per share) | $ / shares	65.70
Weighted-average fair value at end of period (in dollars per share) | $ / shares	$ 57.98
PSUs
Number
Outstanding at beginning of period (in shares) | shares	241,794
Granted (in shares) | shares	96,002
Exercised (in shares) | shares	0
Released from restriction (in shares) | shares	0
Cancelled/expired (in shares) | shares	(23,962)
Outstanding at end of period (in shares) | shares	313,834
Weighted-average fair value
Weighted-average fair value at beginning of period (in dollars per share) | $ / shares	$ 65.57
Weighted-average fair value, granted (in dollars per share) | $ / shares	63.14
Weighted-average fair value, exercised (in dollars per share) | $ / shares	0
Weighted-average fair value, released from restriction (in dollars per share) | $ / shares	0
Weighted-average fair value, cancelled/expired (in dollars per share) | $ / shares	60.43
Weighted-average fair value at end of period (in dollars per share) | $ / shares	$ 65.22
PSU at grant date (in shares per unit) | shares	1

Stockholders' Equity and Equi_6

Stockholders' Equity and Equity Instruments - Components and Changes In AOCL (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 387	$ 529.6
Other comprehensive (loss) income before reclassifications	(18.6)	(170.8)
Amounts reclassified from accumulated other comprehensive loss	(1.6)	(2.4)
Net current period other comprehensive income (loss)	(20.2)	(173.2)
Ending balance	123.3	361.5
Gains (loss) on foreign exchange of intercompany notes of long-term nature	(19.2)	(75.5)
Gains and (Losses) on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	0.2	(0.6)
Other comprehensive (loss) income before reclassifications	1.9	2.7
Amounts reclassified from accumulated other comprehensive loss	(1.8)	(2.6)
Net current period other comprehensive income (loss)	0.1	0.1
Ending balance	0.3	(0.5)
Defined Benefit Pension
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(9.4)	(6.9)
Other comprehensive (loss) income before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive loss	0.2	0.2
Net current period other comprehensive income (loss)	0.2	0.2
Ending balance	(9.2)	(6.7)
Foreign Currency
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(294.1)	(184.6)
Other comprehensive (loss) income before reclassifications	(20.5)	(173.5)
Amounts reclassified from accumulated other comprehensive loss	0	0
Net current period other comprehensive income (loss)	(20.5)	(173.5)
Ending balance	(314.6)	(358.1)
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(303.3)	(192.1)
Ending balance	$ (323.5)	$ (365.3)

Stockholders' Equity and Equi_7

Stockholders' Equity and Equity Instruments - Reclassifications From AOCL (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (15.7)	$ (16.6)
Income tax benefit (expense)	12.6	12.6
Net (loss) earnings	(223.6)	27.6
Product cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	(206.8)	(173.2)
Amount Reclassified from AOCL
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net (loss) earnings	(1.6)	(2.4)
Amount Reclassified from AOCL | Gains (losses) on cash flow hedges:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit (expense)	0.9	1.3
Net (loss) earnings	(1.8)	(2.6)
Amount Reclassified from AOCL | Amortization of defined benefit pension:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax benefit (expense)	(0.1)	0
Net (loss) earnings	0.2	0.2
Amount Reclassified from AOCL | Amortization of defined benefit pension: | Product cost
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	0.3	0.2
Natural gas instruments | Amount Reclassified from AOCL | Gains (losses) on cash flow hedges:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	(0.2)	(0.3)
Foreign currency contracts | Amount Reclassified from AOCL | Gains (losses) on cash flow hedges:
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (2.5)	$ (3.6)

Derivative Financial Instrume_2

Derivative Financial Instruments - Narrative (Details) - Natural gas instruments MMBTU in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)MMBTU	Dec. 31, 2020MMBTU
Derivatives, Fair Value [Line Items]
Notional amount (in MMBtus) | MMBTU	2.9	2.5
Net gains to be reclassified from accumulated other comprehensive loss to earnings during the next 12 months | $	$ 0.6
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Percent of forecasted usage to be hedged	90.00%
Maximum period which the Company hedges in advance of forecasted purchase	36 months

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Estimated Fair Values (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Mutual Fund Investments, Concentration Risk | Common Stock, Large Cap US Companies
Liability Class:
Concentration risk percentage	30.00%	30.00%
Mutual Fund Investments, Concentration Risk | Common Stock of Small to Mid Cap US Companies
Liability Class:
Concentration risk percentage	10.00%	10.00%
Mutual Fund Investments, Concentration Risk | Common Stock, International Companies
Liability Class:
Concentration risk percentage	10.00%	5.00%
Mutual Fund Investments, Concentration Risk | Bond Funds
Liability Class:
Concentration risk percentage	20.00%	15.00%
Mutual Fund Investments, Concentration Risk | Short-Term Investments
Liability Class:
Concentration risk percentage	5.00%	15.00%
Mutual Fund Investments, Concentration Risk | Blended Funds
Liability Class:
Concentration risk percentage	25.00%	25.00%
Fair Value, Measurements, Recurring
Asset Class:
Mutual fund investments in a non-qualified savings plan	$ 2.1	$ 1.9
Total Assets	2.5	2.1
Liability Class:
Liabilities related to non-qualified savings plan	(2.1)	(1.9)
Total Liabilities	(2.1)	(1.9)
Fair Value, Measurements, Recurring | Natural gas instruments, net
Asset Class:
Derivatives – natural gas instruments, net	0.4	0.2
Fair Value, Measurements, Recurring | Level One
Asset Class:
Mutual fund investments in a non-qualified savings plan	2.1	1.9
Total Assets	2.1	1.9
Liability Class:
Liabilities related to non-qualified savings plan	(2.1)	(1.9)
Total Liabilities	(2.1)	(1.9)
Fair Value, Measurements, Recurring | Level One | Natural gas instruments, net
Asset Class:
Derivatives – natural gas instruments, net	0	0
Fair Value, Measurements, Recurring | Level Two
Asset Class:
Mutual fund investments in a non-qualified savings plan	0	0
Total Assets	0.4	0.2
Liability Class:
Liabilities related to non-qualified savings plan	0	0
Total Liabilities	0	0
Fair Value, Measurements, Recurring | Level Two | Natural gas instruments, net
Asset Class:
Derivatives – natural gas instruments, net	0.4	0.2
Fair Value, Measurements, Recurring | Level Three
Asset Class:
Mutual fund investments in a non-qualified savings plan	0	0
Total Assets	0	0
Liability Class:
Liabilities related to non-qualified savings plan	0	0
Total Liabilities	0	0
Fair Value, Measurements, Recurring | Level Three | Natural gas instruments, net
Asset Class:
Derivatives – natural gas instruments, net	$ 0	$ 0

Fair Value Measurement - Narrat

Fair Value Measurement - Narrative (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
6.75% Senior Notes due December 2027
Debt Instrument [Line Items]
Interest rate stated percentage	6.75%	6.75%
Senior Notes | 4.875% Senior Notes due July 2024
Debt Instrument [Line Items]
Interest rate stated percentage	4.875%	4.875%
Fair value of senior notes	$ 255,600,000	$ 260,300,000
Aggregate principal amount due at maturity	$ 250,000,000	250,000,000
Senior Notes | 6.75% Senior Notes due December 2027
Debt Instrument [Line Items]
Interest rate stated percentage	6.75%
Fair value of senior notes	$ 533,800,000	543,100,000
Senior Notes due 2027
Debt Instrument [Line Items]
Debt fair value amount	500,000,000	500,000,000
Term Loan
Debt Instrument [Line Items]
Aggregate principal amount due at maturity	345,800,000	520,300,000
Fair value of credit agreement debt	342,300,000	513,800,000
Fair Value, Measurements, Recurring
Debt Instrument [Line Items]
Mutual fund investments in a non-qualified savings plan	2,100,000	1,900,000
Fair Value, Measurements, Recurring | Level One
Debt Instrument [Line Items]
Mutual fund investments in a non-qualified savings plan	$ 2,100,000	$ 1,900,000

Earnings (loss) per Share (Deta

Earnings (loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net earnings from continuing operations	$ 32.9	$ 33.9
Less: net earnings allocated to participating securities	(0.5)	(0.6)
Net earnings from continuing operations available to common stockholders	32.4	33.3
Net loss from discontinued operations	(256.5)	(6.3)
Net (loss) earnings available to common stockholders	$ (224.1)	$ 27
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share (in shares)	33,974	33,892
Weighted-average awards outstanding (in shares)	38	0
Shares for diluted earnings per share (in shares)	34,012	33,892
Basic net earnings from continuing operations per common share (in dollars per share)	$ 0.96	$ 0.99
Basic net loss from discontinued operations per common share (in dollars per share)	(7.55)	(0.19)
Basic net (loss) earnings per common share (in dollars per share)	(6.59)	0.80
Diluted net earnings from continuing operations per common share (in dollars per share)	0.95	0.99
Diluted net loss from discontinued operations per common share (in dollars per share)	(7.55)	(0.19)
Diluted net (loss) earnings per common share (in dollars per share)	$ (6.60)	$ 0.80
Participating securities (in shares)	445	412
Weighted anti-dilutive awards outstanding (in shares)	1,278	1,266