Compass Minerals International (CMP) 10-Q 28 Oct 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 23, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	COMPASS MINERALS INTERNATIONAL INC
Entity Central Index Key	1,227,654
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		33,701,533
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 119.1	$ 266.8
Receivables, less allowance for doubtful accounts of $1.4 in 2015 and 2014	138.1	213
Inventories	268.7	199
Deferred income taxes, net	8.4	9.7
Other	19.9	14.2
Total current assets	554.2	702.7
Property, plant and equipment, net	762.9	700.9
Intangible assets, net	93.6	106.2
Goodwill	60	68.5
Other	58	58.9
Total assets	1,528.7	1,637.2
Current liabilities:
Current portion of long-term debt	3.9	3.9
Accounts payable	77.9	97.6
Accrued expenses	65.8	60.6
Accrued salaries and wages	19.9	24.4
Income taxes payable	5.5	44.4
Accrued interest	3	6.8
Total current liabilities	176	237.7
Long-term debt, net of current portion	619.6	622.5
Deferred income taxes, net	81.7	88.9
Other noncurrent liabilities	$ 31.4	$ 34.5
Commitments and contingencies
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	89.9	82.5
Treasury stock, at cost — 1,669,346 shares at September 30, 2015 and 1,757,997 shares at December 31, 2014	(3.2)	(3.3)
Retained earnings	623.1	589.5
Accumulated other comprehensive loss	(90.2)	(15.5)
Total stockholders' equity	620	653.6
Total liabilities and stockholders' equity	$ 1,528.7	$ 1,637.2

CONSOLIDATED BALANCE SHEETS (U3

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Allowance for doubtful accounts	$ 1.4	$ 1.4
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)	1,669,346	1,757,997

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Sales	$ 232.7	$ 240.5	$ 809.4	$ 849.1
Shipping and handling cost	53.2	57.5	195.9	233
Product cost	111.5	33.2	381.7	336.5
Gross profit	68	149.8	231.8	279.6
Selling, general and administrative expenses	27.2	26.8	82.3	76.2
Operating earnings	40.8	123	149.5	203.4
Other (income) expense:
Interest expense	5.4	5.5	16.1	14.4
Other, net	(4.3)	(3.1)	(9)	0.9
Earnings before income taxes	39.7	120.6	142.4	188.1
Income tax expense	12.7	32.7	41.6	50.7
Net earnings	$ 27	$ 87.9	$ 100.8	$ 137.4
Basic net earnings per common share (in dollars per share)	$ 0.80	$ 2.60	$ 2.98	$ 4.07
Diluted net earnings per common share (in dollars per share)	$ 0.80	$ 2.60	$ 2.97	$ 4.07
Weighted-average common shares outstanding (in thousands):
Basic (in shares)	33,696	33,575	33,668	33,542
Diluted (in shares)	33,708	33,601	33,687	33,566
Cash dividends per share (in dollars per share)	$ 0.66	$ 0.60	$ 1.98	$ 1.8

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net earnings	$ 27	$ 87.9	$ 100.8	$ 137.4
Other comprehensive income (loss):
Unrealized gain from change in pension obligations, net of tax of $(0.1) and $(0.2) in the three and nine months ended September 30, 2015, respectively, and $(0.1) and $(0.3) in the three and nine months ended September 30, 2014, respectively	0.2	0.3	0.8	0.9
Unrealized gain (loss) on cash flow hedges, net of tax of $0.1 and $(0.3) in the three and nine months ended September 30, 2015, respectively, and $0.3 and $0.2 in the three and nine months ended September 30, 2014, respectively	0	(0.5)	0.5	(0.4)
Cumulative translation adjustment	(37.4)	(28.4)	(76)	(25)
Comprehensive income (loss)	$ (10.2)	$ 59.3	$ 26.1	$ 112.9

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Unrealized gain from change in pension obligations, tax	$ (0.1)	$ (0.1)	$ (0.2)	$ (0.3)
Unrealized gain (loss) on cash flow hedges, tax	$ 0.1	$ 0.3	$ (0.3)	$ 0.2

CONSOLIDATED STATEMENT OF STOCK

CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - 9 months ended Sep. 30, 2015 - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2014	$ 653.6	$ 0.4	$ 82.5	$ (3.3)	$ 589.5	$ (15.5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common stock/equity awards	(67)		0.2		(67.2)
Stock options exercised	2.3		2.2	0.1
Income tax benefit from equity awards	0.1		0.1
Stock-based compensation	4.9		4.9
Comprehensive income (loss)	26.1				100.8	(74.7)
Balance at Sep. 30, 2015	$ 620	$ 0.4	$ 89.9	$ (3.2)	$ 623.1	$ (90.2)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net earnings	$ 100.8	$ 137.4
Adjustments to reconcile net earnings to net cash flows provided by operating activities:
Depreciation, depletion and amortization	57.8	57.2
Finance fee amortization	0.9	0.9
Early extinguishment of debt	0	6.9
Stock-based compensation	4.9	3.7
Deferred income taxes	1.2	13
Gain from insurance settlement	0	(83.3)
Other, net	2.6	(0.3)
Insurance receipts for operating purposes, Goderich tornado	0	11.9
Changes in operating assets and liabilities, net of acquisition:
Receivables	70.1	64
Inventories	(78.2)	(38.1)
Other assets	(11.7)	(11.3)
Accounts payable and accrued expenses	(54)	(32.1)
Other liabilities	0.7	(0.2)
Net cash provided by operating activities	95.1	129.7
Cash flows from investing activities:
Capital expenditures	(154.4)	(83.5)
Acquisition of business	0	(86.5)
Insurance receipts for investment purposes, Goderich tornado	0	19.4
Other, net	(0.9)	3.1
Net cash used in investing activities	(155.3)	(147.5)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	0	250
Principal payments on long-term debt	(2.9)	(101.4)
Premium and other payments to refinance debt	0	(5.5)
Deferred financing costs	0	(4.1)
Dividends paid	(67)	(60.6)
Proceeds received from stock option exercises	2.3	6.1
Excess tax benefit (deficiency) from equity compensation awards	0.1	(0.2)
Net cash provided by (used in) financing activities	(67.5)	84.3
Effect of exchange rate changes on cash and cash equivalents	(20)	(6.1)
Net change in cash and cash equivalents	(147.7)	60.4
Cash and cash equivalents, beginning of the year	266.8	159.6
Cash and cash equivalents, end of period	119.1	220
Supplemental cash flow information:
Interest paid, net of amounts capitalized	18.6	10.8
Income taxes paid, net of refunds	$ 83.5	33.2
Fair value of assets acquired		99.2
Cash paid during the nine months ended September 30, 2014		(86.5)
Liabilities assumed		$ 12.7

Accounting Policies and Basis o

Accounting Policies and Basis of Presentation	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Accounting Policies and Basis of Presentation	Accounting Policies and Basis of Presentation: Compass Minerals International, Inc., through its subsidiaries, is a producer and marketer of essential mineral products with manufacturing sites in North America and the United Kingdom (“U.K.”). References to the “Company,” “Compass,” “Compass Minerals,” “CMP,” “we,” “us” and “our” refer to Compass Minerals International, Inc. (“CMI”, the parent holding company) and its consolidated subsidiaries. The Company’s principal products are salt, consisting of sodium chloride and magnesium chloride, and sulfate of potash (“SOP”), a specialty fertilizer the Company markets under the trade name Protassium+™. Additionally, the Company sells various premium micronutrient products under its Wolf Trax® brand. The Company provides highway deicing products to customers in North America and the U.K., and plant nutrients to growers and fertilizer distributors worldwide. The Company also produces and markets consumer deicing and water conditioning products, ingredients used in consumer and commercial food preparation, and other mineral-based products for consumer, agricultural and industrial applications. Compass Minerals also provides records management services to businesses located in the U.K. CMP is a holding company with no operations other than those of its wholly-owned subsidiaries. The consolidated financial statements include the accounts of CMP and its wholly-owned 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 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. generally accepted accounting principles (“GAAP”) for complete financial statements. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements of CMP for the year ended December 31, 2014 as filed with the Securities and Exchange Commission in its Annual Report on Form 10-K. In the opinion of management, all adjustments, consisting of normal recurring accruals considered necessary for a fair presentation, have been included. The Company experiences a substantial amount of seasonality in salt segment sales, primarily with respect to its deicing products. As a result, sales and operating income 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 product is 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 upcoming winter season. Production of deicing salt can 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 year. Recent Accounting Pronouncements – In July 2015, the Financial Accounting Standards Board ("FASB") issued guidance that requires entities to measure inventory within the scope of the standard at the lower of cost or net realizable value. "Net realizable value" is defined as the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In April 2015, the FASB issued guidance about whether fees paid by customers in cloud computing arrangements include a software license. If a cloud computing arrangement includes a software license, a customer should account for the software license element in a manner consistent with previously issued guidance for software licenses. If the arrangement does not include a software license, a customer should account for the arrangement as a service contract. The guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. An entity can adopt the guidance prospectively or retrospectively and early adoption is permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In April 2015, the FASB issued guidance which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the related debt liability rather than an asset. The recognition and measurement guidance for debt issuance costs are not affected by this guidance. This new guidance is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In August 2014, the FASB issued guidance which requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide disclosure in the footnotes under certain circumstances. This guidance is effective for fiscal years ending after December 15, 2016 with early adoption permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In May 2014, the FASB issued guidance to provide a single, comprehensive revenue recognition model for all contracts with customers. The new revenue recognition model supersedes existing revenue recognition guidance and requires revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration an entity expects to receive in exchange for those goods or services. This guidance is effective for fiscal years and interim periods with those years beginning after December 15, 2017 and early adoption is not permitted. The guidance permits the use of either a full or modified retrospective or cumulative effect transition method. The Company is currently evaluating the impact that the implementation of this standard will have on its consolidated financial statements.

Goderich Tornado

Goderich Tornado	9 Months Ended
	Sep. 30, 2015
Goderich Tornado [Abstract]
Goderich Tornado	Goderich Tornado: In August 2011, a tornado struck the Company’s salt mine and its salt mechanical evaporation plant, both located in Goderich, Ontario, Canada. There was no damage to the underground operations at the mine. However, some of the mine’s surface structures and the evaporation plant incurred significant damage which temporarily ceased production at both facilities. Both facilities resumed normal production and shipping activities in 2012. The Company recorded impairment of its property, plant and equipment and clean-up and restoration costs during 2011 through 2013 related to the impacted areas at both of the Goderich facilities. There were no material expenses or charges related to the tornado in 2014. In the third quarter of 2014, the Company resolved all contingencies and settled its insurance claim. The settlement included a substantial amount related to business interruption losses. Cumulatively, the Company received $114.9 million in cash, including approximately $28.6 million received in 2014 which was originally recorded as deferred revenue in the Company’s consolidated balance sheets. The insurance proceeds included approximately $26.9 million related to clean-up and restoration costs and asset impairment charges and approximately $83.3 million of proceeds for the replacement of property, plant and equipment and business interruption losses. In connection with the settlement, the Company released its deferred revenue balance of $83.3 million and recorded a gain of $82.3 million as a reduction to product cost and approximately $1.0 million as a reduction to selling, general and administrative expenses in its consolidated statements of operations for the third quarter of 2014. The difference between the cash received and the amounts recorded above relates to the foreign exchange impact from translating amounts from Canadian dollars to U.S. dollars.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories: Inventories consist of the following (in millions): September 30, December 31, Finished goods $ 218.1 $ 148.5 Raw materials and supplies 50.6 50.5 Total inventories $ 268.7 $ 199.0

Property, Plant and Equipment,

Property, Plant and Equipment, Net	9 Months Ended
	Sep. 30, 2015
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): September 30, December 31, Land, buildings and structures and leasehold improvements $ 347.3 $ 352.2 Machinery and equipment 696.7 669.1 Office furniture and equipment 19.6 17.5 Mineral interests 171.7 179.6 Construction in progress 164.2 108.9 1,399.5 1,327.3 Less accumulated depreciation and depletion (636.6 ) (626.4 ) Property, plant and equipment, net $ 762.9 $ 700.9

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, Net	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets, Net	Goodwill and Intangible Assets, Net: The estimated lives of the Company’s intangible assets are as follows: Intangible asset Estimated Lives Supply agreement 50 years SOP production rights 25 years Patents 10-20 years Developed technology 5 years Lease rights 25 years Customer and distributor relationships 10 years Trademarks 10 years Noncompete agreements 5 years Trade names Indefinite Water rights Indefinite None of the finite-lived intangible assets have a residual value. Aggregate amortization expense was $1.0 million and $1.3 million in the third quarters of 2015 and 2014 , respectively, and $3.3 million and $3.1 million in the first nine months of 2015 and 2014 , respectively. The Company has goodwill of $60.0 million and $68.5 million as of September 30, 2015 and December 31, 2014 in its consolidated balance sheets. Approximately $53.6 million and $62.0 million of the amounts recorded for goodwill as of September 30, 2015 and December 31, 2014 , respectively, were recorded in the Company’s plant nutrition segment and the remaining amounts in both periods were immaterial and recorded in its salt segment and corporate and other. The change in goodwill from December 31, 2014 was due to the impact from translating foreign-denominated amounts to U.S. dollars.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
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 tax rate differentials, foreign mining taxes, domestic manufacturing deductions, and interest expense recognition differences for book and tax purposes. The Company’s effective rate is impacted by permanent tax deductions which have a less favorable impact as pretax income increases. At both September 30, 2015 and December 31, 2014 , the Company had approximately $3.8 million of gross foreign federal net operating loss (“NOL”) carryforwards that have no expiration date. In addition, the Company had $8.0 million and $2.3 million as of September 30, 2015 and December 31, 2014 , respectively, of gross foreign federal NOL carryforwards which expire beginning in 2033 and $1.0 million and $0.3 million as of September 30, 2015 and December 31, 2014 , respectively, of tax-effected state NOL carryforwards which expire beginning in 2033 . In the future, if the Company determines, based on the existence of sufficient evidence, that it should realize more or less of its deferred tax assets, an adjustment to any existing valuation allowance will be made in the period such determination is made. 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 - 2009 . The reassessments are a result of ongoing audits and total approximately $80 million , including interest through September 30, 2015 . The Company disputes these reassessments and plans to continue to work with the 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 disputes. In connection with this dispute, local regulations require the Company to post security with the tax authority until the dispute is resolved. The Company and the tax authority have agreed that it will post collateral in the form of a $50 million performance bond. The Company has paid approximately $28 million (most of which is recorded in other assets in the consolidated balance sheets) with the remaining balance to be paid after 2015 . In addition, Canadian federal and provincial taxing authorities have reassessed the Company for years 2004 - 2006 which have been previously settled by agreement among the Company, the Canadian federal taxing authority and the U.S. federal taxing authority. The Company has fully complied with the agreement since entering into it and it believes this action is highly unusual. The Company is seeking to enforce the agreement which provided the basis upon which the returns were previously filed and settled. The total amount of the reassessments, including penalties and interest through September 30, 2015 , related to this matter is approximately $89 million . The Company has agreed to post collateral in the form of an approximately $18 million performance bond and $36 million in the form of a bank letter guarantee which is necessary to proceed with future appeals or litigation. The Company received Canadian income tax reassessments for years 2007 - 2008 . The total amount of the reassessments, including penalties and interest through September 30, 2015 , related to this matter is approximately $31 million . The Company does not agree with these adjustments and has filed for assistance from the tax jurisdictions for relief from the impact of double taxation as available in the tax treaty between the U.S. and Canada. The Company has filed protective Notices of Objection and has agreed to post collateral of an approximately $10 million performance bond and $10 million in the form of a bank letter guarantee which is necessary to proceed with future appeals or litigation. Although the outcome of examinations by taxing authorities is uncertain, the Company believes it has adequately reserved for this matter. The Company will be required by the same local regulations to provide security for additional interest on the above 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 dispute is 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 September 30, 2015 , the amount reserved related to these reassessments was immaterial to the Company’s consolidated financial statements. Additionally, the Company has other uncertain tax positions as well as assessments and disputed positions with taxing authorities in its various jurisdictions.

Long-term Debt

Long-term Debt	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Long-term Debt	Long-term Debt: Long-term debt consists of the following (in millions): September 30, December 31, Term Loan due May 2017 $ 373.5 $ 376.4 Revolving Credit Facility due August 2017 — — 4.875% Senior Notes due July 2024 250.0 250.0 623.5 626.4 Less current portion (3.9 ) (3.9 ) Long-term debt $ 619.6 $ 622.5 The term loan and revolving credit facility are secured by substantially all existing and future assets of the Company’s subsidiaries.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies: The Company is involved in legal and administrative proceedings and claims of various types from normal Company activities. The Company is aware of an aboriginal land claim filed in 2003 by The Chippewas of Nawash and The Chippewas of Saugeen (the “Chippewas”) in the Ontario Superior Court against The Attorney General of Canada and Her Majesty The Queen In Right of Ontario. The Chippewas claim that a large part of the land under Lake Huron was never surrendered by treaty and thus seek a declaration that the Chippewas hold aboriginal title to those submerged lands. The land to which aboriginal title is claimed includes land under which the Company’s Goderich mine operates and has mining rights granted to it by the government of Ontario. The actions also seek damages for the value and loss of use of lands. The Company is not a party to the court actions. The Company understands that the Canadian and Ontario governments are defending the actions for aboriginal title on the basis, among other things, that common law does not recognize aboriginal title to the Great Lakes and other navigable waterways. Similar claims are pending with respect to other parts of the Great Lakes by other aboriginal claimants. The Company has been informed by the Ministry of The Attorney General of Ontario that “Canada takes the position that the common law does not recognize aboriginal title to the Great Lakes and its connecting waterways.” The Company is involved in proceedings alleging unfair labor practices at its Cote Blanche, Louisiana, mine. This matter arises out of a labor dispute between the Company and the United Steelworkers Union over the terms of a new contract for certain employees at the mine. These employees initiated a strike that began on April 7, 2010, and ended on June 15, 2010. In September 2012, the U.S. National Labor Relations Board issued a decision finding that the Company had committed unfair labor practices in connection with the labor dispute. Under the ruling, the Company is responsible for back pay to affected employees as a result of changes made in union work rules and past practices beginning April 1, 2010. Any requirement for the Company to pay back wages will be offset by any wages earned at other places of employment during this period. In the fourth quarter of 2013, this ruling was upheld by an appeals court and the Company recorded a reserve of approximately $5 million in its consolidated financial statements related to expected payments required to resolve the dispute. In the first quarter of 2015, additional information became available and the Company recorded an additional $2 million reserve for this matter in its consolidated financial statements. Both parties are currently negotiating in an effort to reach a settlement. If the Company is unable to come to terms with the union, the parties may agree to arbitration and any decisions reached in arbitration would be binding. The Company may need to record additional losses in its financial statements as a result of future developments. The Wisconsin Department of Agriculture, Trade and Consumer Protection (“DATCP”) has information indicating that agricultural chemicals are present within the subsurface area of the Kenosha, Wisconsin plant. The agricultural chemicals were used by previous owners and operators of the site. None of the identified chemicals have been used in association with Compass Minerals’ operations since it acquired the property in 2002. DATCP directed the Company to conduct further investigations into the possible presence of agricultural chemicals in soil and ground water at the Kenosha plant. The Company has completed such investigations of the soils and ground water and has provided the findings to DATCP. The Company is presently proceeding with select remediation activities to mitigate agricultural chemical impact to soils and ground water at the site. All investigations and mitigation activities to date, and any potential future remediation work, are being conducted under the Wisconsin Agricultural Chemical Cleanup Program (“ACCP”), which would provide for reimbursement of some of the costs. The Company may seek participation by, or cost reimbursement from, the parties responsible for the presence of any agricultural chemicals found in soil and ground water at this site if the Company does not receive an acknowledgment of no further action and is required to conduct further investigation or remedial work that may not be eligible for reimbursement under the ACCP. The Company does not believe that these actions will have a material adverse financial effect on the Company. Furthermore, while any litigation contains an element of uncertainty, management presently believes that the outcome of each such proceeding or claim, which is pending or known to be threatened, or all of them combined, will not have a material adverse effect on the Company’s results of operations, cash flows or financial position.

Operating Segments

Operating Segments	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Operating Segments	Operating Segments: The Company broadened its portfolio of specialty plant nutrient products with the acquisition of Wolf Trax Inc. (renamed Compass Minerals Manitoba, Inc. or “Compass Manitoba”) in the second quarter of 2014. This acquisition expands the Company’s portfolio of specialty crop nutrient products and further differentiates it from commodity fertilizers. The results of operations and financial position for Compass Manitoba have been included in the Company’s plant nutrition segment from the date of the acquisition. Segment information is as follows (in millions): Three Months Ended September 30, 2015 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 179.9 $ 50.2 $ 2.6 $ 232.7 Intersegment sales — 1.6 (1.6 ) — Shipping and handling cost 48.5 4.7 — 53.2 Operating earnings (loss) 45.0 8.8 (13.0 ) 40.8 Depreciation, depletion and amortization 11.1 7.6 0.9 19.6 Total assets (as of end of period) 898.2 568.9 61.6 1,528.7 Three Months Ended September 30, 2014 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 175.4 $ 62.7 $ 2.4 $ 240.5 Intersegment sales 0.3 1.5 (1.8 ) — Shipping and handling cost 51.6 5.9 — 57.5 Operating earnings (loss) (b) 116.7 19.0 (12.7 ) 123.0 Depreciation, depletion and amortization 11.4 7.1 1.5 20.0 Total assets (as of end of period) 970.1 517.7 58.7 1,546.5 Nine Months Ended September 30, 2015 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 612.9 $ 187.9 $ 8.6 $ 809.4 Intersegment sales 0.1 5.1 (5.2 ) — Shipping and handling cost 178.1 17.8 — 195.9 Operating earnings (loss) 143.1 46.4 (40.0 ) 149.5 Depreciation, depletion and amortization 32.9 21.7 3.2 57.8 Nine Months Ended September 30, 2014 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 647.3 $ 194.4 $ 7.4 $ 849.1 Intersegment sales 0.7 4.7 (5.4 ) — Shipping and handling cost 211.7 21.3 — 233.0 Operating earnings (loss) (b) 187.0 53.2 (36.8 ) 203.4 Depreciation, depletion and amortization 33.5 20.0 3.7 57.2 (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 and finance functions. (b) Includes a gain of $82.3 million in the salt segment and $1.0 million in corporate and other resulting from an insurance settlement related to a tornado at its salt facilities in Goderich, Ontario in August 2011.

Stockholders' Equity and Equity

Stockholders' Equity and Equity Instruments	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Stockholders' Equity and Equity Instruments	Stockholders' Equity and Equity Instruments: In the first nine months of 2015, the Company granted 120,956 stock options, 19,492 restricted stock units (“RSUs”) and 35,584 performance stock units (“PSUs”) to certain employees under its 2005 Incentive Award Plan. The Company’s closing stock price on the grant date was used to set the exercise price for the options and the fair value of the RSUs. The options vest ratably on each anniversary date over a four -year service period. Unexercised options expire after seven years . The RSUs vest on the third anniversary following the grant date. None of the awards granted have voting rights. The RSUs granted entitle the holders to receive non-forfeitable dividends or other distributions equal to those declared on the Company’s common stock for RSUs earned. In May 2015, the Company’s shareholders approved the 2015 Incentive Award Plan, which authorizes the issuance of 3,000,000 shares. Since the date the 2015 Incentive Award Plan was approved, the Company ceased issuing equity awards under the 2005 Incentive Award Plan. The PSUs granted in the first nine months of 2015 have a three -year performance period beginning in 2015 and ending in 2017 and earn units of between 0% and 150% based upon the attainment of certain performance conditions. The Company granted two types of PSUs in the first nine months of 2015. The total shareholder return PSU (“TSR PSU”) is earned by determining the Company’s total shareholder return, compared to the total shareholder return for each company comprising the Russell 3000 Index over the three -year performance period. The return on invested capital PSU (“ROIC PSU”) is earned by averaging the Company’s annual return on invested capital over the three -year performance period. The performance units will vest three years after the grant date. The PSUs granted entitle the holders to receive non-forfeitable dividends or other distributions equal to those declared on the Company’s common stock from the grant date through the vest date for PSUs earned. 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 range of estimates and calculated fair values for options granted during the first nine months of 2015 is included in the table below. The weighted-average grant date fair value of these options was $14.78 . Range Fair value of options granted $ 14.22 - $15.09 Exercise price $ 91.75 - $93.26 Expected term (years) 4.5-5 Expected volatility 24.7% - 25.0% Dividend yield 3.1% Risk-free rate of return 1.3% - 1.6 % 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 companies comprising the Russell 3000 Index. This model uses historical stock prices to estimate expected volatility and the Company’s correlation to the Russell 3000 Index. The risk-free rate was determined using the same methodology as the option valuations as discussed above. The estimated fair value of the TSR PSUs granted in 2015 is $111.07 per unit. The Company’s closing stock price on the grant date was used to set the fair value of the ROIC PSUs. The Company will adjust the expense of the ROIC PSUs based upon its estimate of the number of shares that will ultimately vest at each interim date during the three -year vesting period. During the nine months ended September 30, 2015 , the Company reissued 31,104 shares of treasury stock related to the exercise of stock options, 15,952 shares related to the release of RSUs which vested, 10,454 shares related to the release of PSUs which vested and 31,141 shares related to stock payments. The Company recognized a tax benefit of $0.1 million from its equity compensation awards as an increase to additional paid-in capital during the first nine months of 2015 . During the first nine months of 2015 and 2014 , the Company recorded $4.9 million and $3.7 million , 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 nine months ended September 30, 2015 . Stock Options RSUs PSUs (a) Number Weighted-average exercise price Number Weighted-average fair value Number Weighted-average fair value Outstanding at December 31, 2014 278,429 $ 79.23 88,532 $ 76.58 59,627 $ 88.69 Granted 120,956 91.76 19,492 91.76 35,584 100.49 Exercised (b) (31,104 ) 72.20 — — — — Released from restriction (b) — — (15,952 ) 71.69 (10,454 ) 74.49 Cancelled/Expired (9,060 ) 84.81 (2,188 ) 81.56 (6,689 ) 81.47 Outstanding at September 30, 2015 359,221 $ 83.88 89,884 $ 80.62 78,068 $ 96.59 (a) Until they vest, PSUs are included in the table at the 100% attainment level at their grant date and at that level represent one share per unit. The final performance period for the 2012 PSU grant was completed in 2014. The Company issued 10,454 shares and cancelled 4,443 PSUs due to performance in the first quarter of 2015 related to the 2012 PSU grant. (b) Common stock issued for exercised options and RSUs and PSUs released from restriction was issued from treasury stock. Other Comprehensive Income (Loss) The Company’s comprehensive income (loss) is comprised of net earnings, net amortization of the unrealized loss of the pension obligation, the change in the unrealized gain (loss) on natural gas cash flow hedges and foreign currency translation adjustments. The components of and changes in accumulated other comprehensive income (loss) (“AOCI”) as of and for the three and nine months ended September 30, 2015 and 2014 are as follows (in millions): Three Months Ended September 30, 2015 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ (1.5 ) $ (8.4 ) $ (43.1 ) $ (53.0 ) Other comprehensive income (loss) before reclassifications (b) (0.3 ) — (37.4 ) (37.7 ) Amounts reclassified from accumulated other comprehensive income (loss) 0.3 0.2 — 0.5 Net current period other comprehensive income (loss) — 0.2 (37.4 ) (37.2 ) Ending balance $ (1.5 ) $ (8.2 ) $ (80.5 ) $ (90.2 ) Three Months Ended September 30, 2014 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ 0.4 $ (8.7 ) $ 46.9 $ 38.6 Other comprehensive income (loss) before reclassifications (b) (0.5 ) — (28.4 ) (28.9 ) Amounts reclassified from accumulated other comprehensive income (loss) — 0.3 — 0.3 Net current period other comprehensive income (loss) (0.5 ) 0.3 (28.4 ) (28.6 ) Ending balance $ (0.1 ) $ (8.4 ) $ 18.5 $ 10.0 Nine Months Ended September 30, 2015 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ (2.0 ) $ (9.0 ) $ (4.5 ) $ (15.5 ) Other comprehensive income (loss) before reclassifications (b) (0.9 ) — (76.0 ) (76.9 ) Amounts reclassified from accumulated other comprehensive income (loss) 1.4 0.8 — 2.2 Net current period other comprehensive income (loss) 0.5 0.8 (76.0 ) (74.7 ) Ending balance $ (1.5 ) $ (8.2 ) $ (80.5 ) $ (90.2 ) Nine Months Ended September 30, 2014 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ 0.3 $ (9.3 ) $ 43.5 $ 34.5 Other comprehensive income (loss) before reclassifications (b) 0.2 — (25.0 ) (24.8 ) Amounts reclassified from accumulated other comprehensive income (loss) (0.6 ) 0.9 — 0.3 Net current period other comprehensive income (loss) (0.4 ) 0.9 (25.0 ) (24.5 ) Ending balance $ (0.1 ) $ (8.4 ) $ 18.5 $ 10.0 (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 gain (loss) presented in the table above are reflected net of applicable income taxes. (b) The Company recorded foreign exchange (gains) losses of approximately $13.0 million and $27.6 million in the three months and nine months ended September 30, 2015 , respectively, and $10.4 million and $10.8 million in the three and nine months ended September 30, 2014 , respectively, in accumulated other comprehensive income (loss) related to intercompany notes which were deemed to be of long-term investment nature. The amounts reclassified from AOCI to (income) expense for the three and nine months ended September 30, 2015 and 2014 are shown below (in millions): Amount Reclassified from AOCI Three Months Ended Nine Months Ended Line Item Impacted in the Consolidated Statement of Operations Gains and (losses) on cash flow hedges: Natural gas instruments $ 0.5 $ 2.2 Product cost (0.2 ) (0.8 ) Income tax expense (benefit) Reclassifications, net of income taxes 0.3 1.4 Amortization of defined benefit pension: Amortization of loss $ 0.3 $ 1.0 Product cost (0.1 ) (0.2 ) Income tax expense (benefit) Reclassifications, net of income taxes 0.2 0.8 Total reclassifications, net of income taxes $ 0.5 $ 2.2 Amount Reclassified from AOCI Three Months Ended Nine Months Ended Line Item Impacted in the Consolidated Statement of Operations Gains and (losses) on cash flow hedges: Natural gas instruments $ (0.1 ) $ (1.0 ) Product cost 0.1 0.4 Income tax expense (benefit) Reclassifications, net of income taxes — (0.6 ) Amortization of defined benefit pension: Amortization of loss $ 0.4 $ 1.2 Product cost (0.1 ) (0.3 ) Income tax expense (benefit) Reclassifications, net of income taxes 0.3 0.9 Total reclassifications, net of income taxes $ 0.3 $ 0.3

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2015
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 risk by using derivative instruments. The Company does not seek to engage in trading activities or take speculative positions with any financial instrument arrangements. The Company has entered into natural gas derivative instruments with counterparties it views as creditworthy. However, management does attempt to mitigate its counterparty credit risk exposures by, among other things, entering into master netting agreements with these counterparties. Cash Flow Hedges As of September 30, 2015 , the Company has entered into natural gas derivative instruments. The Company records derivative financial instruments as either assets or liabilities at fair value in the consolidated statements of financial position. 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. All derivative instruments held by the Company as of September 30, 2015 and December 31, 2014 qualified as cash flow hedges. For these qualifying hedges, the effective portion of 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 (see Note 10). For derivative instruments that are not accounted for as hedges, or for the ineffective portions of qualifying hedges, the change in fair value is recorded through earnings in the period of change. The Company formally documents, designates, and assesses the effectiveness of transactions that receive hedge accounting treatment initially and on an ongoing basis. Any ineffectiveness related to these hedges was not material for any of the periods presented. Natural gas is consumed at several of the Company’s production facilities, and a change in natural gas prices impacts the Company’s operating margin. As of September 30, 2015 , the Company had entered into natural gas derivative instruments to hedge a portion of its natural gas purchase requirements through December 2016 . 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 September 30, 2015 and December 31, 2014 , the Company had agreements in place to hedge forecasted natural gas purchases of 1.9 million and 3.4 million MMBtus, respectively. As of September 30, 2015 , the Company expects to reclassify from accumulated other comprehensive loss to earnings during the next twelve months approximately $2.1 million of net losses on derivative instruments related to its natural gas hedges. The following tables present the fair value of the Company’s hedged items as of September 30, 2015 and December 31, 2014 , (in millions): Asset Derivatives Liability Derivatives Derivatives designated as hedging instruments (a) (b) Balance Sheet Location September 30, Balance Sheet Location September 30, Commodity contracts Other current assets $ 0.1 Accrued expenses $ 2.2 Commodity contracts Other assets — Other noncurrent liabilities 0.5 Total derivatives designated as hedging instruments $ 0.1 $ 2.7 (a) As of September 30, 2015 , the Company has commodity hedge agreements with four counterparties. Three of the counterparties are in payable positions. (b) The Company has master netting agreements with its counterparties and accordingly has netted in its consolidated balance sheets immaterial amounts that are in receivable and payable positions with larger amounts that are in payable and receivable positions, respectively. Asset Derivatives Liability Derivatives Derivatives designated as hedging instruments (a) (b) Balance Sheet Location December 31, Balance Sheet Location December 31, Commodity contracts Other current assets $ 0.1 Accrued expenses $ 2.5 Commodity contracts Other assets — Other noncurrent liabilities 1.0 Total derivatives designated as hedging instruments $ 0.1 $ 3.5 (a) The Company has commodity hedge agreements with four counterparties. Amounts recorded as liabilities for the Company’s commodity contracts are payable to all counterparties. The amount recorded as an asset is due from two counterparties. (b) The Company has master netting agreements with its counterparties and accordingly has netted in its consolidated balance sheets approximately $0.1 million of its commodity contracts that are in a receivable position against its contracts in payable positions.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company’s financial instruments are measured and reported at their estimated fair value. Fair value is the price that would be received to sell 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 one inputs), or absent quoted market prices, observable market-corroborated inputs over the term of the financial instruments (level two inputs). The Company does not have any unobservable inputs that are not corroborated by market inputs (level three inputs). The Company holds marketable securities associated with its non-qualified retirement plan, 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. The fair value 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). September 30, Level One Level Two Level Three Asset Class: Mutual fund investments in a non-qualified retirement plan (a) $ 1.6 $ 1.6 $ — $ — Total Assets $ 1.6 $ 1.6 $ — $ — Liability Class: Liabilities related to non-qualified retirement plan $ (1.6 ) $ (1.6 ) $ — $ — Derivatives – natural gas instruments (2.6 ) — (2.6 ) — Total Liabilities $ (4.2 ) $ (1.6 ) $ (2.6 ) $ — (a) Includes mutual fund investments of approximately 20% in the common stock of large-cap U.S. companies, approximately 5% in the common stock of small-cap U.S. companies, approximately 5% in international companies, approximately 5% in bond funds, approximately 35% in short-term investments and approximately 30% in blended funds. December 31, Level One Level Two Level Three Asset Class: Mutual fund investments in a non-qualified retirement plan (a) $ 1.9 $ 1.9 $ — $ — Total Assets $ 1.9 $ 1.9 $ — $ — Liability Class: Liabilities related to non-qualified retirement plan $ (1.9 ) $ (1.9 ) $ — $ — Derivatives – natural gas instruments (3.4 ) — (3.4 ) — Total Liabilities $ (5.3 ) $ (1.9 ) $ (3.4 ) $ — (a) Includes mutual fund investments of approximately 15% in the common stock of large-cap U.S. companies, approximately 5% in the common stock of international companies, approximately 5% in bond funds, approximately 35% in short-term investments and approximately 40% in blended funds. Cash and cash equivalents, accounts receivable (net of allowance for bad debts) and payables are carried at cost, which approximates fair value due to their liquid and short-term nature. The Company’s investments related to its nonqualified retirement plan of $1.6 million and $1.9 million as of September 30, 2015 and December 31, 2014 , respectively, are stated at fair value based on quoted market prices. As of September 30, 2015 , the estimated amount a third-party would pay for the fixed-rate 4.875% senior notes due July 2024, based on available trading information, totaled $231.3 million (level two) compared with the aggregate principal amount at maturity of $250.0 million . The estimated amount a third-party would pay at September 30, 2015 for the amounts outstanding under the credit agreement, based upon available bid information received from the Company’s lender, totaled $369.8 million (level two) compared with the aggregate principal balance of $373.5 million .

Earnings per Share

Earnings per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Earnings per Share	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 to both common shares and participating securities. The following table sets forth the computation of basic and diluted earnings per common share (in millions, except for share and per-share data): Three months ended Nine months ended 2015 2014 2015 2014 Numerator: Net earnings $ 27.0 $ 87.9 $ 100.8 $ 137.4 Less: net earnings allocated to participating securities (a) (0.1 ) (0.5 ) (0.6 ) (0.8 ) Net earnings Available to common shareholders $ 26.9 $ 87.4 $ 100.2 $ 136.6 Denominator (in thousands): Weighted-average common shares outstanding, shares for basic earnings per share 33,696 33,575 33,668 33,542 Weighted-average awards outstanding (b) 12 26 19 24 Shares for diluted earnings per share 33,708 33,601 33,687 33,566 Net earnings per common share, basic $ 0.80 $ 2.60 $ 2.98 $ 4.07 Net earnings per common share, diluted $ 0.80 $ 2.60 $ 2.97 $ 4.07 (a) Participating securities include options, PSUs and RSUs that receive non-forfeitable dividends. Weighted participating securities included 182,000 and 197,000 for the three and nine months ended September 30, 2015 , respectively, and 209,000 and 214,000 for the three and nine months ended September 30, 2014 , respectively. (b) For the calculation of diluted earnings per share, the Company uses the more dilutive of either the treasury stock method or the two-class method to determine the weighted average number of outstanding common shares. In addition, the Company had 450,000 and 429,000 weighted-awards outstanding for the three and nine months ended September 30, 2015 , respectively, and 389,000 and 397,000 for the three and nine months ended September 30, 2014 , respectively, which were anti-dilutive and therefore not included in the diluted earnings per-share calculation.

Accounting Policies and Basis22

Accounting Policies and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements – In July 2015, the Financial Accounting Standards Board ("FASB") issued guidance that requires entities to measure inventory within the scope of the standard at the lower of cost or net realizable value. "Net realizable value" is defined as the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. Early adoption is permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In April 2015, the FASB issued guidance about whether fees paid by customers in cloud computing arrangements include a software license. If a cloud computing arrangement includes a software license, a customer should account for the software license element in a manner consistent with previously issued guidance for software licenses. If the arrangement does not include a software license, a customer should account for the arrangement as a service contract. The guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2015. An entity can adopt the guidance prospectively or retrospectively and early adoption is permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In April 2015, the FASB issued guidance which requires debt issuance costs to be presented in the balance sheet as a direct deduction from the related debt liability rather than an asset. The recognition and measurement guidance for debt issuance costs are not affected by this guidance. This new guidance is effective retrospectively for fiscal years, and interim periods within those years, beginning after December 15, 2015. Early adoption is permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In August 2014, the FASB issued guidance which requires management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide disclosure in the footnotes under certain circumstances. This guidance is effective for fiscal years ending after December 15, 2016 with early adoption permitted. The Company does not expect that this guidance will have a material impact on its consolidated financial statements. In May 2014, the FASB issued guidance to provide a single, comprehensive revenue recognition model for all contracts with customers. The new revenue recognition model supersedes existing revenue recognition guidance and requires revenue recognition to depict the transfer of promised goods or services to customers in an amount that reflects the consideration an entity expects to receive in exchange for those goods or services. This guidance is effective for fiscal years and interim periods with those years beginning after December 15, 2017 and early adoption is not permitted. The guidance permits the use of either a full or modified retrospective or cumulative effect transition method. The Company is currently evaluating the impact that the implementation of this standard will have on its consolidated financial statements.

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2015
Inventory Disclosure [Abstract]
Inventories	Inventories consist of the following (in millions): September 30, December 31, Finished goods $ 218.1 $ 148.5 Raw materials and supplies 50.6 50.5 Total inventories $ 268.7 $ 199.0

Property, Plant and Equipment24

Property, Plant and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2015
Property, Plant and Equipment [Abstract]
Property, plant and equipment	Property, plant and equipment, net consists of the following (in millions): September 30, December 31, Land, buildings and structures and leasehold improvements $ 347.3 $ 352.2 Machinery and equipment 696.7 669.1 Office furniture and equipment 19.6 17.5 Mineral interests 171.7 179.6 Construction in progress 164.2 108.9 1,399.5 1,327.3 Less accumulated depreciation and depletion (636.6 ) (626.4 ) Property, plant and equipment, net $ 762.9 $ 700.9

Goodwill and Intangible Asset25

Goodwill and Intangible Assets, Net (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Estimated lives of intangible assets	The estimated lives of the Company’s intangible assets are as follows: Intangible asset Estimated Lives Supply agreement 50 years SOP production rights 25 years Patents 10-20 years Developed technology 5 years Lease rights 25 years Customer and distributor relationships 10 years Trademarks 10 years Noncompete agreements 5 years Trade names Indefinite Water rights Indefinite

Long-term Debt (Tables)

Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Long-term debt	Long-term debt consists of the following (in millions): September 30, December 31, Term Loan due May 2017 $ 373.5 $ 376.4 Revolving Credit Facility due August 2017 — — 4.875% Senior Notes due July 2024 250.0 250.0 623.5 626.4 Less current portion (3.9 ) (3.9 ) Long-term debt $ 619.6 $ 622.5

Operating Segments (Tables)

Operating Segments (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment information	Segment information is as follows (in millions): Three Months Ended September 30, 2015 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 179.9 $ 50.2 $ 2.6 $ 232.7 Intersegment sales — 1.6 (1.6 ) — Shipping and handling cost 48.5 4.7 — 53.2 Operating earnings (loss) 45.0 8.8 (13.0 ) 40.8 Depreciation, depletion and amortization 11.1 7.6 0.9 19.6 Total assets (as of end of period) 898.2 568.9 61.6 1,528.7 Three Months Ended September 30, 2014 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 175.4 $ 62.7 $ 2.4 $ 240.5 Intersegment sales 0.3 1.5 (1.8 ) — Shipping and handling cost 51.6 5.9 — 57.5 Operating earnings (loss) (b) 116.7 19.0 (12.7 ) 123.0 Depreciation, depletion and amortization 11.4 7.1 1.5 20.0 Total assets (as of end of period) 970.1 517.7 58.7 1,546.5 Nine Months Ended September 30, 2015 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 612.9 $ 187.9 $ 8.6 $ 809.4 Intersegment sales 0.1 5.1 (5.2 ) — Shipping and handling cost 178.1 17.8 — 195.9 Operating earnings (loss) 143.1 46.4 (40.0 ) 149.5 Depreciation, depletion and amortization 32.9 21.7 3.2 57.8 Nine Months Ended September 30, 2014 Salt Plant Nutrition Corporate and Other (a) Total Sales to external customers $ 647.3 $ 194.4 $ 7.4 $ 849.1 Intersegment sales 0.7 4.7 (5.4 ) — Shipping and handling cost 211.7 21.3 — 233.0 Operating earnings (loss) (b) 187.0 53.2 (36.8 ) 203.4 Depreciation, depletion and amortization 33.5 20.0 3.7 57.2 (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 and finance functions. (b) Includes a gain of $82.3 million in the salt segment and $1.0 million in corporate and other resulting from an insurance settlement related to a tornado at its salt facilities in Goderich, Ontario in August 2011.

Stockholders' Equity and Equi28

Stockholders' Equity and Equity Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Range of estimates and calculated fair values of options granted in period	The range of estimates and calculated fair values for options granted during the first nine months of 2015 is included in the table below. The weighted-average grant date fair value of these options was $14.78 . Range Fair value of options granted $ 14.22 - $15.09 Exercise price $ 91.75 - $93.26 Expected term (years) 4.5-5 Expected volatility 24.7% - 25.0% Dividend yield 3.1% Risk-free rate of return 1.3% - 1.6 %
Stock-based compensation activity	The following table summarizes stock-based compensation activity during the nine months ended September 30, 2015 . Stock Options RSUs PSUs (a) Number Weighted-average exercise price Number Weighted-average fair value Number Weighted-average fair value Outstanding at December 31, 2014 278,429 $ 79.23 88,532 $ 76.58 59,627 $ 88.69 Granted 120,956 91.76 19,492 91.76 35,584 100.49 Exercised (b) (31,104 ) 72.20 — — — — Released from restriction (b) — — (15,952 ) 71.69 (10,454 ) 74.49 Cancelled/Expired (9,060 ) 84.81 (2,188 ) 81.56 (6,689 ) 81.47 Outstanding at September 30, 2015 359,221 $ 83.88 89,884 $ 80.62 78,068 $ 96.59 (a) Until they vest, PSUs are included in the table at the 100% attainment level at their grant date and at that level represent one share per unit. The final performance period for the 2012 PSU grant was completed in 2014. The Company issued 10,454 shares and cancelled 4,443 PSUs due to performance in the first quarter of 2015 related to the 2012 PSU grant. (b) Common stock issued for exercised options and RSUs and PSUs released from restriction was issued from treasury stock.
Components of and changes in accumulated other comprehensive income	The components of and changes in accumulated other comprehensive income (loss) (“AOCI”) as of and for the three and nine months ended September 30, 2015 and 2014 are as follows (in millions): Three Months Ended September 30, 2015 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ (1.5 ) $ (8.4 ) $ (43.1 ) $ (53.0 ) Other comprehensive income (loss) before reclassifications (b) (0.3 ) — (37.4 ) (37.7 ) Amounts reclassified from accumulated other comprehensive income (loss) 0.3 0.2 — 0.5 Net current period other comprehensive income (loss) — 0.2 (37.4 ) (37.2 ) Ending balance $ (1.5 ) $ (8.2 ) $ (80.5 ) $ (90.2 ) Three Months Ended September 30, 2014 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ 0.4 $ (8.7 ) $ 46.9 $ 38.6 Other comprehensive income (loss) before reclassifications (b) (0.5 ) — (28.4 ) (28.9 ) Amounts reclassified from accumulated other comprehensive income (loss) — 0.3 — 0.3 Net current period other comprehensive income (loss) (0.5 ) 0.3 (28.4 ) (28.6 ) Ending balance $ (0.1 ) $ (8.4 ) $ 18.5 $ 10.0 Nine Months Ended September 30, 2015 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ (2.0 ) $ (9.0 ) $ (4.5 ) $ (15.5 ) Other comprehensive income (loss) before reclassifications (b) (0.9 ) — (76.0 ) (76.9 ) Amounts reclassified from accumulated other comprehensive income (loss) 1.4 0.8 — 2.2 Net current period other comprehensive income (loss) 0.5 0.8 (76.0 ) (74.7 ) Ending balance $ (1.5 ) $ (8.2 ) $ (80.5 ) $ (90.2 ) Nine Months Ended September 30, 2014 (a) Gains and (Losses) on Cash Flow Hedges Defined Benefit Pension Foreign Currency Total Beginning balance $ 0.3 $ (9.3 ) $ 43.5 $ 34.5 Other comprehensive income (loss) before reclassifications (b) 0.2 — (25.0 ) (24.8 ) Amounts reclassified from accumulated other comprehensive income (loss) (0.6 ) 0.9 — 0.3 Net current period other comprehensive income (loss) (0.4 ) 0.9 (25.0 ) (24.5 ) Ending balance $ (0.1 ) $ (8.4 ) $ 18.5 $ 10.0 (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 gain (loss) presented in the table above are reflected net of applicable income taxes. (b) The Company recorded foreign exchange (gains) losses of approximately $13.0 million and $27.6 million in the three months and nine months ended September 30, 2015 , respectively, and $10.4 million and $10.8 million in the three and nine months ended September 30, 2014 , respectively, in accumulated other comprehensive income (loss) related to intercompany notes which were deemed to be of long-term investment nature.
Reclassifications out of Accumulated Other Comprehensive Income	The amounts reclassified from AOCI to (income) expense for the three and nine months ended September 30, 2015 and 2014 are shown below (in millions): Amount Reclassified from AOCI Three Months Ended Nine Months Ended Line Item Impacted in the Consolidated Statement of Operations Gains and (losses) on cash flow hedges: Natural gas instruments $ 0.5 $ 2.2 Product cost (0.2 ) (0.8 ) Income tax expense (benefit) Reclassifications, net of income taxes 0.3 1.4 Amortization of defined benefit pension: Amortization of loss $ 0.3 $ 1.0 Product cost (0.1 ) (0.2 ) Income tax expense (benefit) Reclassifications, net of income taxes 0.2 0.8 Total reclassifications, net of income taxes $ 0.5 $ 2.2 Amount Reclassified from AOCI Three Months Ended Nine Months Ended Line Item Impacted in the Consolidated Statement of Operations Gains and (losses) on cash flow hedges: Natural gas instruments $ (0.1 ) $ (1.0 ) Product cost 0.1 0.4 Income tax expense (benefit) Reclassifications, net of income taxes — (0.6 ) Amortization of defined benefit pension: Amortization of loss $ 0.4 $ 1.2 Product cost (0.1 ) (0.3 ) Income tax expense (benefit) Reclassifications, net of income taxes 0.3 0.9 Total reclassifications, net of income taxes $ 0.3 $ 0.3

Derivative Financial Instrume29

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of hedged items	The following tables present the fair value of the Company’s hedged items as of September 30, 2015 and December 31, 2014 , (in millions): Asset Derivatives Liability Derivatives Derivatives designated as hedging instruments (a) (b) Balance Sheet Location September 30, Balance Sheet Location September 30, Commodity contracts Other current assets $ 0.1 Accrued expenses $ 2.2 Commodity contracts Other assets — Other noncurrent liabilities 0.5 Total derivatives designated as hedging instruments $ 0.1 $ 2.7 (a) As of September 30, 2015 , the Company has commodity hedge agreements with four counterparties. Three of the counterparties are in payable positions. (b) The Company has master netting agreements with its counterparties and accordingly has netted in its consolidated balance sheets immaterial amounts that are in receivable and payable positions with larger amounts that are in payable and receivable positions, respectively. Asset Derivatives Liability Derivatives Derivatives designated as hedging instruments (a) (b) Balance Sheet Location December 31, Balance Sheet Location December 31, Commodity contracts Other current assets $ 0.1 Accrued expenses $ 2.5 Commodity contracts Other assets — Other noncurrent liabilities 1.0 Total derivatives designated as hedging instruments $ 0.1 $ 3.5 (a) The Company has commodity hedge agreements with four counterparties. Amounts recorded as liabilities for the Company’s commodity contracts are payable to all counterparties. The amount recorded as an asset is due from two counterparties. (b) The Company has master netting agreements with its counterparties and accordingly has netted in its consolidated balance sheets approximately $0.1 million of its commodity contracts that are in a receivable position against its contracts in payable positions.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair value measurements	The estimated fair values for each type of instrument are presented below (in millions). September 30, Level One Level Two Level Three Asset Class: Mutual fund investments in a non-qualified retirement plan (a) $ 1.6 $ 1.6 $ — $ — Total Assets $ 1.6 $ 1.6 $ — $ — Liability Class: Liabilities related to non-qualified retirement plan $ (1.6 ) $ (1.6 ) $ — $ — Derivatives – natural gas instruments (2.6 ) — (2.6 ) — Total Liabilities $ (4.2 ) $ (1.6 ) $ (2.6 ) $ — (a) Includes mutual fund investments of approximately 20% in the common stock of large-cap U.S. companies, approximately 5% in the common stock of small-cap U.S. companies, approximately 5% in international companies, approximately 5% in bond funds, approximately 35% in short-term investments and approximately 30% in blended funds. December 31, Level One Level Two Level Three Asset Class: Mutual fund investments in a non-qualified retirement plan (a) $ 1.9 $ 1.9 $ — $ — Total Assets $ 1.9 $ 1.9 $ — $ — Liability Class: Liabilities related to non-qualified retirement plan $ (1.9 ) $ (1.9 ) $ — $ — Derivatives – natural gas instruments (3.4 ) — (3.4 ) — Total Liabilities $ (5.3 ) $ (1.9 ) $ (3.4 ) $ — (a) Includes mutual fund investments of approximately 15% in the common stock of large-cap U.S. companies, approximately 5% in the common stock of international companies, approximately 5% in bond funds, approximately 35% in short-term investments and approximately 40% in blended funds.

Earnings per Share (Tables)

Earnings per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per common share	The following table sets forth the computation of basic and diluted earnings per common share (in millions, except for share and per-share data): Three months ended Nine months ended 2015 2014 2015 2014 Numerator: Net earnings $ 27.0 $ 87.9 $ 100.8 $ 137.4 Less: net earnings allocated to participating securities (a) (0.1 ) (0.5 ) (0.6 ) (0.8 ) Net earnings Available to common shareholders $ 26.9 $ 87.4 $ 100.2 $ 136.6 Denominator (in thousands): Weighted-average common shares outstanding, shares for basic earnings per share 33,696 33,575 33,668 33,542 Weighted-average awards outstanding (b) 12 26 19 24 Shares for diluted earnings per share 33,708 33,601 33,687 33,566 Net earnings per common share, basic $ 0.80 $ 2.60 $ 2.98 $ 4.07 Net earnings per common share, diluted $ 0.80 $ 2.60 $ 2.97 $ 4.07 (a) Participating securities include options, PSUs and RSUs that receive non-forfeitable dividends. Weighted participating securities included 182,000 and 197,000 for the three and nine months ended September 30, 2015 , respectively, and 209,000 and 214,000 for the three and nine months ended September 30, 2014 , respectively. (b) For the calculation of diluted earnings per share, the Company uses the more dilutive of either the treasury stock method or the two-class method to determine the weighted average number of outstanding common shares. In addition, the Company had 450,000 and 429,000 weighted-awards outstanding for the three and nine months ended September 30, 2015 , respectively, and 389,000 and 397,000 for the three and nine months ended September 30, 2014 , respectively, which were anti-dilutive and therefore not included in the diluted earnings per-share calculation.

Goderich Tornado (Details)

Goderich Tornado (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended	38 Months Ended
	Sep. 30, 2014	Dec. 31, 2014	Sep. 30, 2014
Goderich Tornado [Abstract]
Total insurance advances			$ 114.9
Deferred revenue		$ 28.6
Total insurance advances received and recorded as reduction to salt product costs			26.9
Insurance proceeds for replacement of property, plant and equipment and business interruption			83.3
Deferred released in connection with settlement	$ 83.3		$ 83.3
Gain recorded as reduction to production cost	82.3
Gain recorded as reduction to selling, general and administrative expenses	$ 1

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Finished goods	$ 218.1	$ 148.5
Raw materials and supplies	50.6	50.5
Total inventories	$ 268.7	$ 199

Property, Plant and Equipment34

Property, Plant and Equipment, Net (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,399.5	$ 1,327.3
Less accumulated depreciation and depletion	(636.6)	(626.4)
Property, plant and equipment, net	762.9	700.9
Land, Buildings and Structures and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	347.3	352.2
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	696.7	669.1
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	19.6	17.5
Mineral Interests [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	171.7	179.6
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 164.2	$ 108.9

Goodwill and Intangible Asset35

Goodwill and Intangible Assets, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 1	$ 1.3	$ 3.3	$ 3.1
Acquired Indefinite-lived Intangible Assets [Line Items]
Goodwill	60		60		$ 68.5
Plant Nutrition [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Goodwill	$ 53.6		$ 53.6		$ 62
Supply Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			50 years
SOP Production Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			25 years
Patents [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			10 years
Patents [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			20 years
Developed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			5 years
Lease Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			25 years
Customer and Distributor Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			10 years
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			10 years
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Estimated Lives			5 years

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Foreign Federal [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 3.8	$ 3.8
Foreign Federal 2033 [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 8	2.3
Expiration date	Dec. 31, 2033
State [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 1	$ 0.3
Expiration date	Dec. 31, 2033
Canadian Provincial [Member]
Income Tax Examination [Line Items]
Total reassessments including interest	$ 80
Amount of security posted in the form of a performance bond	50
Amount of security posted in the form of cash	$ 28
Canadian Provincial [Member] | Minimum [Member]
Income Tax Examination [Line Items]
Years under examination	2,002
Canadian Provincial [Member] | Maximum [Member]
Income Tax Examination [Line Items]
Years under examination	2,009
Canadian Federal and Provincial [Member] | Tax Year 2004 Through 2006 [Member]
Income Tax Examination [Line Items]
Amount of security posted in the form of a performance bond	$ 18
Total reassessment amount including penalty and interest	89
Amount of security in the form of a bank letter guarantee	36
Canadian Federal and Provincial [Member] | Tax Year 2007 Through 2008 [Member]
Income Tax Examination [Line Items]
Amount of security posted in the form of a performance bond	10
Total reassessment amount including penalty and interest	31
Amount of security in the form of a bank letter guarantee	$ 10
Canadian Federal and Provincial [Member] | Minimum [Member] | Tax Year 2004 Through 2006 [Member]
Income Tax Examination [Line Items]
Years under examination	2,004
Canadian Federal and Provincial [Member] | Minimum [Member] | Tax Year 2007 Through 2008 [Member]
Income Tax Examination [Line Items]
Years under examination	2,007
Canadian Federal and Provincial [Member] | Maximum [Member] | Tax Year 2004 Through 2006 [Member]
Income Tax Examination [Line Items]
Years under examination	2,006
Canadian Federal and Provincial [Member] | Maximum [Member] | Tax Year 2007 Through 2008 [Member]
Income Tax Examination [Line Items]
Years under examination	2,008

Long-term Debt (Details)

Long-term Debt (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term debt, total	$ 623.5	$ 626.4
Less current portion	(3.9)	(3.9)
Long-term debt	619.6	622.5
Revolving Credit Facility [Member] | Revolving Credit Facility due August 2017 [Member]
Debt Instrument [Line Items]
Long-term debt, total	$ 0	$ 0
Long term debt maturity date	Aug. 31, 2017	Aug. 31, 2017
Secured Debt [Member] | Term Loan due May 2017 [Member]
Debt Instrument [Line Items]
Long-term debt, total	$ 373.5	$ 376.4
Long term debt maturity date	May 31, 2017	May 31, 2017
Senior Notes [Member] | 4.875% Senior Notes due July 2024 [Member]
Debt Instrument [Line Items]
Long-term debt, total	$ 250	$ 250
Long term debt maturity date	Jul. 31, 2024	Jul. 31, 2024
Senior notes, interest rate	4.875%	4.875%

Commitments and Contingencies (

Commitments and Contingencies (Details) - Cote Blanche [Member] - USD ($) $ in Millions	Mar. 31, 2015	Dec. 31, 2013
Loss Contingencies [Line Items]
Reserve for expected payments required to resolve the dispute		$ 5
Additional amount of reserve for expected payments required to resolve the dispute	$ 2

Operating Segments (Details)

Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Gain from insurance settlement			$ 0	$ 83.3
Segment Reporting Information [Abstract]
Sales	$ 232.7	$ 240.5	809.4	849.1
Shipping and handling cost	53.2	57.5	195.9	233
Operating earnings (loss)	40.8	123	149.5	203.4
Depreciation, depletion and amortization	19.6	20	57.8	57.2
Total assets (as of end of period)	1,528.7	1,546.5	1,528.7	1,546.5	$ 1,637.2
Operating Segments [Member] | Salt [Member]
Segment Reporting Information [Line Items]
Gain from insurance settlement		82.3		82.3
Segment Reporting Information [Abstract]
Sales	179.9	175.4	612.9	647.3
Shipping and handling cost	48.5	51.6	178.1	211.7
Operating earnings (loss)	45	116.7	143.1	187
Depreciation, depletion and amortization	11.1	11.4	32.9	33.5
Total assets (as of end of period)	898.2	970.1	898.2	970.1
Operating Segments [Member] | Plant Nutrition [Member]
Segment Reporting Information [Abstract]
Sales	50.2	62.7	187.9	194.4
Shipping and handling cost	4.7	5.9	17.8	21.3
Operating earnings (loss)	8.8	19	46.4	53.2
Depreciation, depletion and amortization	7.6	7.1	21.7	20
Total assets (as of end of period)	568.9	517.7	568.9	517.7
Intersegment Sales [Member]
Segment Reporting Information [Abstract]
Sales	(1.6)	(1.8)	(5.2)	(5.4)
Intersegment Sales [Member] | Salt [Member]
Segment Reporting Information [Abstract]
Sales	0	0.3	0.1	0.7
Intersegment Sales [Member] | Plant Nutrition [Member]
Segment Reporting Information [Abstract]
Sales	1.6	1.5	5.1	4.7
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Gain from insurance settlement		1		1
Segment Reporting Information [Abstract]
Sales	2.6	2.4	8.6	7.4
Shipping and handling cost	0	0	0	0
Operating earnings (loss)	(13)	(12.7)	(40)	(36.8)
Depreciation, depletion and amortization	0.9	1.5	3.2	3.7
Total assets (as of end of period)	$ 61.6	$ 58.7	$ 61.6	$ 58.7

Stockholders' Equity and Equi40

Stockholders' Equity and Equity Instruments - Plan Information (Details) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2015shares	Sep. 30, 2015USD ($)award_type$ / sharesshares	Sep. 30, 2014USD ($)	May. 31, 2015shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reissued shares of treasury stock (in shares)		31,141
Tax benefit from equity compensation awards recorded as additional paid-in capital | $		$ 0.1
Compensation expense recorded during period pursuant to stock-based compensation plans | $		$ 4.9	$ 3.7
2015 Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for issuance (in shares)				3,000,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)		120,956
Vesting period		4 years
Options expiration period		7 years
Fair value measurement method		Black-Scholes option valuation model
Weighted-average grant date fair value of options (in dollars per share) | $ / shares		$ 14.78
Reissued shares of treasury stock (in shares)		31,104
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		19,492
Vesting period		3 years
Reissued shares of treasury stock (in shares)		15,952
PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		35,584
Vesting period		3 years
Performance period of PSUs		3 years
Minimum percentage of earnings (in hundredths)		0.00%
Maximum percentage of earnings (in hundredths)		150.00%
Number of award types | award_type		2
PSUs [Member] | 2012 Grant [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reissued shares of treasury stock (in shares)	10,454	10,454
TSR PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of PSUs		3 years
Fair value measurement method		Monte-Carlo simulation model
ROIC PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance period of PSUs		3 years

Stockholders' Equity and Equi41

Stockholders' Equity and Equity Instruments - Fair Value, Exercise Price Range, and Accumulated Other Comprehensive Income (Details) - Stock Options [Member]	9 Months Ended
	Sep. 30, 2015$ / shares
Fair value assumptions and methodology [Abstract]
Lower limit of fair value of options granted (in dollars per share)	$ 14.22
Upper limit of fair value of options granted (in dollars per share)	$ 15.09
Lower limit of expected volatility (in hundredths)	24.70%
Upper limit of expected volatility (in hundredths)	25.00%
Dividend yield (in hundredths)	3.10%
Risk-free rate of return lower limit (in hundredths)	1.30%
Risk-free rate of return upper limit (in hundredths)	1.60%
Minimum [Member]
Fair value assumptions and methodology [Abstract]
Exercise price (in dollars per share)	$ 91.75
Expected term	4 years 6 months
Maximum [Member]
Fair value assumptions and methodology [Abstract]
Exercise price (in dollars per share)	$ 93.26
Expected term	5 years

Stockholders' Equity and Equi42

Stockholders' Equity and Equity Instruments - Activity (Details) - $ / shares	3 Months Ended	9 Months Ended
	Mar. 31, 2015	Sep. 30, 2015
Weighted-average fair value
Reissued shares of treasury stock (in shares)		31,141
TSR PSUs [Member]
Weighted-average fair value
Weighted-average fair value, Granted (in dollars per share)		$ 111.07
Stock Options [Member]
Number
Outstanding at beginning of period (in shares)	278,429	278,429
Granted (in shares)		120,956
Exercised (in shares)		(31,104)
Cancelled/Expired (in shares)		(9,060)
Outstanding at end of period (in shares)		359,221
Weighted-average exercise price
Weighted-average exercise price at beginning of period (in dollars per share)	$ 79.23	$ 79.23
Weighted-average exercise price, Granted (in dollars per share)		91.76
Weighted-average exercise price, Exercised (in dollars per share)		72.20
Weighted-average exercise price, Cancelled/Expired (in dollars per share)		84.81
Weighted-average exercise price at end of period (in dollars per share)		$ 83.88
Weighted-average fair value
Reissued shares of treasury stock (in shares)		31,104
RSUs [Member]
Number
Outstanding at beginning of period (in shares)	88,532	88,532
Granted (in shares)		19,492
Released from restriction (in shares)		(15,952)
Cancelled/Expired (in shares)		(2,188)
Outstanding at end of period (in shares)		89,884
Weighted-average fair value
Weighted-average fair value at beginning of period (in dollars per share)	$ 76.58	$ 76.58
Weighted-average fair value, Granted (in dollars per share)		91.76
Weighted-average fair value, Released from restriction (in dollars per share)		71.69
Weighted-average fair value, Cancelled/Expired (in dollars per share)		81.56
Weighted-average fair value at end of period (in dollars per share)		$ 80.62
Reissued shares of treasury stock (in shares)		15,952
PSUs [Member]
Number
Outstanding at beginning of period (in shares)	59,627	59,627
Granted (in shares)		35,584
Released from restriction (in shares)		(10,454)
Cancelled/Expired (in shares)		(6,689)
Outstanding at end of period (in shares)		78,068
Weighted-average fair value
Weighted-average fair value at beginning of period (in dollars per share)	$ 88.69	$ 88.69
Weighted-average fair value, Granted (in dollars per share)		100.49
Weighted-average fair value, Released from restriction (in dollars per share)		74.49
Weighted-average fair value, Cancelled/Expired (in dollars per share)		81.47
Weighted-average fair value at end of period (in dollars per share)		$ 96.59
Attainment level of PSU at grant date		100.00%
PSU at grant date (in shares per unit)		1
PSUs [Member] | Grant Date 2012 [Member]
Number
Cancelled/Expired (in shares)	(4,443)
Weighted-average fair value
Reissued shares of treasury stock (in shares)	10,454	10,454

Stockholders' Equity and Equi43

Stockholders' Equity and Equity Instruments - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (53)	$ 38.6	$ (15.5)	$ 34.5
Other comprehensive income (loss) before reclassifications	(37.7)	(28.9)	(76.9)	(24.8)
Amounts reclassified from accumulated other comprehensive income (loss)	0.5	0.3	2.2	0.3
Net current period other comprehensive income (loss)	(37.2)	(28.6)	(74.7)	(24.5)
Ending balance	(90.2)	10	(90.2)	10
Losses (gains) on foreign exchange of intercompany notes of long-term nature	13	10.4	27.6	10.8
Gains and (Losses) on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(1.5)	0.4	(2)	0.3
Other comprehensive income (loss) before reclassifications	(0.3)	(0.5)	(0.9)	0.2
Amounts reclassified from accumulated other comprehensive income (loss)	0.3	0	1.4	(0.6)
Net current period other comprehensive income (loss)	0	(0.5)	0.5	(0.4)
Ending balance	(1.5)	(0.1)	(1.5)	(0.1)
Defined Benefit Pension [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(8.4)	(8.7)	(9)	(9.3)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	0.2	0.3	0.8	0.9
Net current period other comprehensive income (loss)	0.2	0.3	0.8	0.9
Ending balance	(8.2)	(8.4)	(8.2)	(8.4)
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(43.1)	46.9	(4.5)	43.5
Other comprehensive income (loss) before reclassifications	(37.4)	(28.4)	(76)	(25)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0	0
Net current period other comprehensive income (loss)	(37.4)	(28.4)	(76)	(25)
Ending balance	$ (80.5)	$ 18.5	$ (80.5)	$ 18.5

Stockholders' Equity and Equi44

Stockholders' Equity and Equity Instruments - Amount Reclassified from AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	$ 111.5	$ 33.2	$ 381.7	$ 336.5
Income tax expense (benefit)	12.7	32.7	41.6	50.7
Total reclassifications, net of income taxes	27	87.9	100.8	137.4
Reclassifications, net of income taxes [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Total reclassifications, net of income taxes	0.5	0.3	2.2	0.3
Reclassifications, net of income taxes [Member] | Gains and (losses) from cash flow hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	0.5	(0.1)	2.2	(1)
Income tax expense (benefit)	(0.2)	0.1	(0.8)	0.4
Total reclassifications, net of income taxes	0.3	0	1.4	(0.6)
Reclassifications, net of income taxes [Member] | Amortization of defined benefit pension [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Product cost	0.3	0.4	1	1.2
Income tax expense (benefit)	(0.1)	(0.1)	(0.2)	(0.3)
Total reclassifications, net of income taxes	$ 0.2	$ 0.3	$ 0.8	$ 0.9

Derivative Financial Instrume45

Derivative Financial Instruments (Details) MMBTU in Millions, $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2015USD ($)MMBTUcounterparty	Dec. 31, 2014USD ($)MMBTUcounterparty
Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 0.1	$ 0.1
Liability Derivatives	$ 2.7	$ 3.5
Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Underlying risk	change in natural gas prices
Period through which natural gas is hedged	Dec. 31, 2016
Percent of forecasted usage to be hedged (up to 90%)	90.00%
Maximum period which the Company hedges in advance of forecasted purchase	36 months
Notional amount (in MMBtus) | MMBTU	1.9	3.4
Net losses to be reclassified from accumulated other comprehensive loss to earnings during the next 12 months	$ 2.1
Number of counterparties | counterparty	4	4
Number of counterparties for amounts recorded as liabilities | counterparty	3
Number of counterparties for amounts recorded as assets | counterparty		2
Netting of contracts in a receivable position against contracts in payable position		$ 0.1
Commodity Contracts [Member] | Designated as Hedging Instruments [Member] | Other Current Asset [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 0.1	0.1
Commodity Contracts [Member] | Designated as Hedging Instruments [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	0	0
Commodity Contracts [Member] | Designated as Hedging Instruments [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	2.2	2.5
Commodity Contracts [Member] | Designated as Hedging Instruments [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 0.5	$ 1

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Liability Class:
Mutual fund investments percentage of fund invested in common stock of large-cap U.S. (in hundredths)	20.00%	15.00%
Mutual fund investments percentage of fund invested in common stock small-cap U.S. (in hundredths)	5.00%
Mutual fund investments percentage of fund invested in common stock of international companies (in hundredths)	5.00%	5.00%
Mutual fund investments percentage of fund invested in bond funds (in hundredths)	5.00%	5.00%
Mutual fund investments percentage of fund invested in short-term investments (in hundredths)	35.00%	35.00%
Mutual fund investments percentage of fund invested in blended funds (in hundredths)	30.00%	40.00%
Fair Value, Measurements, Recurring [Member]
Asset Class:
Mutual fund investments in a non-qualified retirement plan	$ 1.6	$ 1.9
Total Assets	1.6	1.9
Liability Class:
Liabilities related to non-qualified retirement plan	(1.6)	(1.9)
Derivatives – natural gas instruments	(2.6)	(3.4)
Total Liabilities	(4.2)	(5.3)
Fair Value, Measurements, Recurring [Member] | Level One [Member]
Asset Class:
Mutual fund investments in a non-qualified retirement plan	1.6	1.9
Total Assets	1.6	1.9
Liability Class:
Liabilities related to non-qualified retirement plan	(1.6)	(1.9)
Derivatives – natural gas instruments	0	0
Total Liabilities	(1.6)	(1.9)
Fair Value, Measurements, Recurring [Member] | Level Two [Member]
Asset Class:
Mutual fund investments in a non-qualified retirement plan	0	0
Total Assets	0	0
Liability Class:
Liabilities related to non-qualified retirement plan	0	0
Derivatives – natural gas instruments	(2.6)	(3.4)
Total Liabilities	(2.6)	(3.4)
Fair Value, Measurements, Recurring [Member] | Level Three [Member]
Asset Class:
Mutual fund investments in a non-qualified retirement plan	0	0
Total Assets	0	0
Liability Class:
Liabilities related to non-qualified retirement plan	0	0
Derivatives – natural gas instruments	0	0
Total Liabilities	$ 0	$ 0
4.875% Senior Notes [Member]
Fair Value of Outstanding Debt [Line Items]
Senior notes, interest rate	4.875%
Fair value of senior notes	$ 231.3
Aggregate principal amount due at maturity	250
Term loan [Member]
Fair Value of Outstanding Debt [Line Items]
Aggregate principal amount due at maturity	373.5
Fair value of credit agreement debt	$ 369.8

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Numerator:
Net earnings	$ 27	$ 87.9	$ 100.8	$ 137.4
Less: net earnings allocated to participating securities	(0.1)	(0.5)	(0.6)	(0.8)
Net earnings Available to common shareholders	$ 26.9	$ 87.4	$ 100.2	$ 136.6
Denominator (in thousands):
Weighted-average common shares outstanding, shares for basic earnings per share (in shares)	33,696	33,575	33,668	33,542
Weighted-average awards outstanding (in shares)	12	26	19	24
Shares for diluted earnings per share (in shares)	33,708	33,601	33,687	33,566
Net earnings per common share, basic (in dollars per share)	$ 0.80	$ 2.60	$ 2.98	$ 4.07
Net earnings per common share, diluted (in dollars per share)	$ 0.80	$ 2.60	$ 2.97	$ 4.07
Participating securities (in shares)	182	209	197	214
Weighted anti-dilutive awards outstanding (in shares)	450	389	429	397