United States Lime & Minerals (USLM) 10-K 27 Feb 25 2024 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2024	Feb. 25, 2025	Jun. 30, 2024
Cover Abstract
Entity Registrant Name	UNITED STATES LIME & MINERALS INC
Entity Central Index Key	0000082020
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2024
Document Transition Report	false
Securities Act File Number	000-04197
Entity Incorporation, State or Country Code	TX
Entity Tax Identification Number	75-0789226
Entity Address, Address Line One	5429 LBJ Freeway, Suite 230
Entity Address, City or Town	Dallas
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	75240
City Area Code	972
Local Phone Number	991-8400
Title of 12(b) Security	Common stock, $0.10 par value
Trading Symbol	USLM
Security Exchange Name	NASDAQ
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 773,374,833
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		28,620,799
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	FY
Auditor Name	GRANT THORNTON LLP
Auditor Firm ID	248
Auditor Location	February 27, 2025

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 278,031	$ 187,964
Trade receivables, net	43,982	38,052
Inventories	27,686	24,313
Prepaid expenses and other current assets	5,083	4,640
Total current assets	354,782	254,969
Property, plant and equipment:
Mineral reserves and land	60,952	59,307
Proved natural gas properties, successful-efforts method	15,934	15,934
Buildings and building and leasehold improvements	13,246	10,732
Machinery and equipment	393,312	374,000
Furniture and fixtures	1,409	1,312
Automotive equipment	8,393	8,313
Property, plant and equipment	493,246	469,598
Less accumulated depreciation and depletion	(310,355)	(289,803)
Property, plant and equipment, net	182,891	179,795
Operating lease right-of-use assets	4,855	5,273
Other assets, net	635	565
Total assets	543,163	440,602
Current liabilities:
Accounts payable	8,819	7,404
Current portion of operating lease liabilities	1,602	1,582
Accrued expenses	6,541	8,505
Total current liabilities	16,962	17,491
Deferred tax liabilities, net	23,659	24,659
Operating lease liabilities, excluding current portion	3,437	3,919
Other liabilities	1,364	1,429
Total liabilities	45,422	47,498
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $5.00 par value; authorized 500,000 shares; none issued or outstanding
Common stock, $0.10 par value; 45,000,000 and 30,000,000 shares authorized at December 31, 2024 and 2023, respectively; 29,671,768 and 29,549,431 shares issued at December 31, 2024 and 2023, respectively	2,968	2,955
Additional paid-in capital	40,549	35,539
Retained earnings	515,622	412,499
Less treasury stock; 1,051,931 and 1,026,651 shares at December 31, 2024 and 2023, respectively, at cost	(61,398)	(57,889)
Total stockholders' equity	497,741	393,104
Total liabilities and stockholders' equity	$ 543,163	$ 440,602

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2024	Dec. 31, 2023
Consolidated Balance Sheets
Preferred stock, par value (in dollars per share)	$ 5	$ 5
Preferred stock, authorized shares	500,000	500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.1	$ 0.1
Common stock, authorized shares	45,000,000	30,000,000
Common stock, shares issued	29,671,768	29,549,431
Treasury stock, shares	1,051,931	1,026,651

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Revenues
Revenues	$ 317,721	$ 281,330	$ 236,150
Cost of revenues
Labor and other operating expenses	149,885	154,930	143,887
Depreciation, depletion and amortization	23,855	23,533	21,921
Total cost of revenues	173,740	178,463	165,808
Gross profit	143,981	102,867	70,342
Selling, general and administrative expenses	19,058	17,445	15,559
Operating profit	124,923	85,422	54,783
Other (income) expense, net
Other (income) expense, net	(11,460)	(7,940)	(1,779)
Income before income tax expense	136,383	93,362	56,562
Income tax expense	27,544	18,813	11,133
Net income	$ 108,839	$ 74,549	$ 45,429
Net income per share of common stock
Basic (in dollars per share)	$ 3.81	$ 2.62	$ 1.6
Diluted (in dollars per share)	$ 3.79	$ 2.61	$ 1.6

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Total
Balances at Dec. 31, 2021	$ 2,930	$ 29,513	$ 301,611	$ (55,848)	$ 278,206
Balances (in shares) at Dec. 31, 2021	28,330,060
Increase (Decrease) in Stockholders' Equity
Stock options exercised	$ 1	119			120
Stock options exercised (in shares)	12,000
Stock-based compensation	$ 10	2,626			2,636
Stock-based compensation (in shares)	96,485
Treasury shares purchased				(767)	(767)
Treasury shares purchased (in shares)	(28,150)
Cash dividends paid			(4,536)		(4,536)
Net income			45,429		45,429
Balances at Dec. 31, 2022	$ 2,941	32,258	342,504	(56,615)	321,088
Balances (in shares) at Dec. 31, 2022	28,410,395
Increase (Decrease) in Stockholders' Equity
Stock options exercised	$ 5	108			113
Stock options exercised (in shares)	46,440
Stock-based compensation	$ 9	3,173			3,182
Stock-based compensation (in shares)	93,765
Treasury shares purchased				(1,274)	(1,274)
Treasury shares purchased (in shares)	(27,820)
Cash dividends paid			(4,554)		(4,554)
Net income			74,549		74,549
Balances at Dec. 31, 2023	$ 2,955	35,539	412,499	(57,889)	393,104
Balances (in shares) at Dec. 31, 2023	28,522,780
Increase (Decrease) in Stockholders' Equity
Stock options exercised	$ 5	125			130
Stock options exercised (in shares)	52,025
Stock-based compensation	$ 8	4,885			4,893
Stock-based compensation (in shares)	73,060
Treasury shares purchased				(3,509)	(3,509)
Treasury shares purchased (in shares)	(28,028)
Cash dividends paid			(5,716)		(5,716)
Net income			108,839		108,839
Balances at Dec. 31, 2024	$ 2,968	$ 40,549	$ 515,622	$ (61,398)	$ 497,741
Balances (in shares) at Dec. 31, 2024	28,619,837

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
OPERATING ACTIVITIES:
Net income	$ 108,839	$ 74,549	$ 45,429
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	24,169	23,827	22,199
Amortization of deferred financing costs	27	17	2
Deferred income taxes	(1,000)	(923)	2,527
Loss on disposition of property, plant and equipment	49	363	(312)
Stock-based compensation	4,893	3,182	2,636
Changes in operating assets and liabilities:
Trade receivables, net	(5,930)	(4,460)	(6,438)
Inventories	(3,373)	(4,734)	(4,294)
Prepaid expenses and other current assets	(443)	(1,140)	(191)
Other assets	(97)	(142)	8
Accounts payable and accrued expenses	(1,010)	1,666	2,701
Other liabilities	(104)	54	96
Net cash provided by operating activities	126,020	92,259	64,363
INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(27,414)	(34,250)	(26,815)
Acquisition of a business, net of cash acquired			(5,630)
Proceeds from sale of property, plant and equipment	556	2,286	1,294
Net cash used in investing activities	(26,858)	(31,964)	(31,151)
FINANCING ACTIVITIES:
Cash dividends paid	(5,716)	(4,554)	(4,536)
Proceeds from exercise of stock options	130	113	120
Purchase of treasury shares	(3,509)	(1,274)	(767)
Net cash used in financing activities	(9,095)	(5,715)	(5,183)
Net increase in cash and cash equivalents	90,067	54,580	28,029
Cash and cash equivalents at beginning of period	187,964	133,384	105,355
Cash and cash equivalents at end of period	$ 278,031	$ 187,964	$ 133,384

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2024
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	(1) Summary of Significant Accounting Policies (a) Organization and Presentation United States Lime & Minerals, Inc. (the “Company”) is a manufacturer of lime and limestone products, supplying primarily the construction (including highway, road, and building contractors), industrial (including paper and glass manufacturers), environmental (including municipal sanitation and water treatment facilities and flue gas treatment processes), metals (including steel producers), roof shingle manufacturers, agriculture (including poultry producers), and oil and gas services industries. The Company is headquartered in Dallas, Texas and operates lime and limestone plants and distribution facilities in Arkansas, Colorado, Louisiana, Missouri, Oklahoma, and Texas through its wholly owned subsidiaries, Arkansas Lime Company, ART Quarry TRS LLC (DBA Carthage Crushed Limestone), Colorado Lime Company, Mill Creek Dolomite, LLC, Texas Lime Company, U.S. Lime Company, U.S. Lime Company-Shreveport, U.S. Lime Company-St. Clair, and U.S. Lime Company-Transportation. In addition, the Company, through its wholly owned subsidiary, U.S. Lime Company-O & G, LLC, has royalty and non-operated working interests in natural gas wells located in Johnson County, Texas, in the Barnett Shale Formation. On May 2, 2024, the shareholders of the Company approved an increase in the Company’s number of authorized shares of common stock from 30,000,000 to 45,000,000 . On July 12, 2024, the Company effected a additional shares of common stock for each share outstanding to shareholders of record at the close of business on June 21, 2024 (the “Stock Split”). All share and per share information, including stock-based compensation, throughout this Annual Report on Form 10-K has been retroactively adjusted to reflect the Stock Split. The shares of common stock retain a par value of The number and terms of stock-based compensation awards outstanding on the date of the Stock Split were adjusted, in order to prevent dilution or enlargement of the rights of participants under the Company’s 2001 Long-Term Incentive Plan, as Amended and Restated (the “Plan”). The fair value of all outstanding awards immediately after the Stock Split did not change when compared to the fair value of such awards immediately prior to the Stock Split. In addition, there was no change to the vesting conditions or classification of any of the awards. No incremental compensation expense was recognized as a result of such adjustments. (b) Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany balances and transactions have been eliminated. (c) Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“US GAAP”) requires management to make estimates and judgments that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates and judgments. (d) Statements of Cash Flows For purposes of reporting cash flows, the Company considers all bank deposits and highly liquid debt instruments, such as United States Treasury bills and notes, with maturities, at the time of purchase, of three months or less to be cash equivalents. Cash equivalents are carried at cost plus accrued interest, which approximates fair market value. Supplemental cash flow information is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2024 ​ 2023 ​ 2022 Cash paid during the year for: ​ ​ ​ ​ Interest ​ $ 169 ​ $ 196 ​ $ 113 ​ Income taxes ​ $ 30,405 ​ $ 17,994 ​ $ 7,827 ​ ​ (e) Revenue Recognition The Company recognizes revenue for its lime and limestone operations when (i) a contract with the customer exists and the performance obligations are identified; (ii) the price has been established; and (iii) the performance obligations have been satisfied, which is at a point in time, generally upon shipment. Revenues include external freight billed to customers with related costs accounted for as fulfillment costs and included in cost of revenues. The Company operates within a single geographic region. The Company’s returns and allowances are minimal. External freight billed to customers included in revenues was (f) Fair Values of Financial Instruments Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The carrying values of cash and cash equivalents, trade receivables, other current assets, accounts payable, and accrued expenses approximate fair value due to the short maturities of these instruments. (g) Concentration of Credit Risk and Trade Receivables Financial instruments that potentially subject the Company to a concentration of credit risk consist principally of cash and cash equivalents and trade receivables. The Company places its cash and cash equivalents with high-credit quality financial institutions and in highly rated commercial paper or United States Treasury bills and notes with maturities, at the time of purchase, of three months or less. The Company’s cash and cash equivalents at commercial banking institutions normally exceed federally insured limits. The majority of the Company’s trade receivables are unsecured. Payment terms for all trade receivables are based on the underlying purchase orders, contracts, or purchase agreements, and are generally fixed, short-term, and do not contain a significant financing component. The Company estimates credit losses relating to trade receivables based on an assessment of the current and forecasted probability of collection, historical trends, economic conditions, and other significant events that may impact the collectability of trade receivables. Due to the relatively homogenous nature of its trade receivables, the Company does not believe there is any meaningful asset-specific differences within its accounts receivable portfolio that would require the portfolio to be grouped below the consolidated level for review of credit losses. Credit losses relating to trade receivables have generally been within management expectations and historical trends. Uncollected trade receivables are charged-off when identified by management to be unrecoverable. Trade receivables are presented net of the related estimated credit losses, which totaled ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 Beginning balance ​ $ 575 ​ $ 550 ​ Additions ​ 110 ​ 49 ​ Adjustments for expected credit loss factors ​ ​ — ​ ​ — ​ Write-offs ​ (84) ​ (24) ​ Ending balance ​ $ 601 ​ $ 575 ​ ​ (h) Inventories Inventories are valued principally at the lower of cost, determined using the average cost method, or net realizable value. Costs for raw materials and finished goods include materials, labor, and production overhead. A summary of inventories is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ 2024 ​ 2023 Lime and limestone inventories: ​ ​ ​ Raw materials ​ $ 8,947 ​ $ 7,834 ​ Finished goods ​ 3,000 ​ 3,107 ​ ​ ​ ​ 11,947 ​ ​ 10,941 ​ Parts inventories ​ 15,739 ​ 13,372 ​ ​ ​ $ 27,686 ​ $ 24,313 ​ ​ (i) Property, Plant and Equipment For major constructed assets, the capitalized cost includes the price paid by the Company for labor and materials plus interest and internal and external project management costs that are directly related to the constructed assets. Machinery and equipment at December 31, 2024 and 2023 included $8,098 and $6,001, respectively, of construction in progress for various capital projects. No interest costs were capitalized for the years ended December 31, 2024 and 2023. At December 31, 2024 and 2023, accounts payable and accrued expenses included $1,657 and $1,196, respectively, of capitalized costs. Selling, general, and administrative expenses included depreciation expense of $318, $294, and $278 in 2024, 2023, and 2022, respectively. Depreciation of property, plant and equipment is being provided for by the straight-line method over estimated useful lives as follows: ​ ​ ​ ​ ​ ​ ​ ​ Buildings and building and leasehold improvements 3 - 25 years ​ Machinery and equipment 2 - 30 years ​ Furniture and fixtures 3 - 10 years ​ Automotive equipment 3 - 10 years ​ ​ Maintenance and repairs are charged to expense as incurred; renewals and betterments are capitalized. When units of property are retired or otherwise disposed of, their cost and related accumulated depreciation are removed from the accounts, and any resulting gain or loss is credited or charged to income. The Company expenses all exploration costs as incurred, as well as costs incurred at an operating quarry or mine, other than capital expenditures and inventory. Costs to acquire mineral reserves are capitalized upon acquisition. Costs incurred to develop new mineral reserves, to expand the capacity of a quarry or mine, or to develop quarry or mine areas substantially in advance of current production are capitalized once proven and probable reserves exist and can be economically produced. For each quarry or mine, capitalized costs to acquire and develop mineral reserves are depleted using the units-of-production method based on the proven and probable reserves for such quarry or mine. The Company reviews its long-lived assets for impairment and, when events or circumstances indicate the carrying amount of an asset may not be recoverable, the Company determines if impairment of value exists. If the estimated undiscounted future net cash flows are less than the carrying amount of the asset, an impairment exists, and an impairment loss must be calculated and recorded. If an impairment exists, the impairment loss is calculated based on the excess of the carrying amount of the asset over the asset’s fair value. Any impairment loss is treated as a permanent reduction in the carrying value of the asset. The Company had no impairments in the years presented in the financial statements. ​ (j) Asset Retirement Obligations The Company recognizes legal obligations for reclamation and remediation associated with the retirement of long- lived assets at their fair value at the time the obligations are incurred (“AROs”). Over time, the liability for AROs is recorded at its present value each period through accretion expense, and the capitalized cost is depreciated over the useful life of the related asset. Upon settlement of the liability, the Company either settles the AROs for the recorded amount or recognizes a gain or loss. The Company’s AROs of as of December 31, 2024 and 2023, respectively, are included in Other liabilities and Accrued expenses on the Company’s Consolidated Balance Sheets. As of December 31, 2024, assets, net of accumulated depreciation, associated with the Company’s AROs totaled . During 2024 and 2023, the Company spent The AROs were estimated based on studies and the Company’s process knowledge and estimates and are discounted using a credit adjusted risk-free interest rate. The AROs are adjusted when further information warrants an adjustment. The Company estimates annual expenditures of approximately $100 per year in years 2025 through 2029 relating to its AROs. (k) Accrued Expenses Accrued expenses consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2024 2023 Personnel related expenses ​ $ 3,371 ​ $ 4,073 ​ Income taxes ​ ​ 466 ​ ​ 2,010 ​ Other taxes ​ ​ 1,098 ​ ​ 1,112 ​ Utilities ​ ​ 893 ​ ​ 944 ​ Other ​ 713 ​ 366 ​ ​ ​ $ 6,541 ​ $ 8,505 ​ ​ (l) Environmental Expenditures Environmental expenditures that relate to current operations are expensed or capitalized as appropriate. Expenditures that relate to an existing condition caused by past operations, and which do not contribute to current or future revenue generation, are expensed. Liabilities are recorded at their present value when environmental assessments and/or remedial efforts are probable, and the costs can be reasonably estimated. Generally, the timing of these accruals will coincide with completion of a feasibility study or the Company’s commitment to a formal plan of action. The Company incurred capital expenditures related to environmental matters of $997 in 2024, $1,456 in 2023, and $779 in 2022. (m) Income and Dividends Per Share of Common Stock The following table sets forth the computation of basic and diluted income per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2024 2023 2022 Net income for basic and diluted income per common share ​ $ 108,839 ​ $ 74,549 ​ $ 45,429 ​ Weighted-average shares for basic income per common share ​ 28,579,354 ​ 28,461,955 ​ 28,359,800 ​ Effect of dilutive securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Employee and director stock options (1) ​ 109,017 ​ 71,425 ​ 42,245 ​ Adjusted weighted-average shares and assumed exercises for diluted income per common share ​ 28,688,371 ​ 28,533,380 ​ 28,402,045 ​ Basic net income per common share ​ $ 3.81 ​ $ 2.62 ​ $ 1.60 ​ Diluted net income per common share ​ $ 3.79 ​ $ 2.61 ​ $ 1.60 ​ (1) Excludes 9,375 and 80,625 stock options in 2023 and 2022, respectively, as antidilutive because the exercise price exceeded the average per share market price for the periods presented. No stock options were excluded in 2024 as antidilutive. The Company paid $0.20, $0.16, and $0.16 of cash dividends per share of common stock in 2024, 2023, and 2022, respectively. (n) Stock-Based Compensation The Company expenses all stock-based payments to employees and directors, including grants of stock options and restricted stock, in the Company’s Consolidated Statements of Income based on their fair values. Compensation cost is recognized on a straight-line basis over the vesting period. (o) Income Taxes The Company utilizes the asset and liability approach in its reporting for income taxes. Deferred income tax assets and liabilities are computed for differences between the financial statement and tax bases of assets and liabilities that will result in taxable or deductible amounts in the future based on enacted tax laws and rates applicable to the periods in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amount more likely than not to be realized. Income tax related interest and penalties are included in income tax expense. The Company also assesses individual tax positions to determine if they meet the criteria for some or all of the benefits of that position to be recognized in the Company’s financial statements. The Company only recognizes tax positions that meet the more-likely-than-not recognition threshold. (p) Segment Reporting – In November 2023, the Financial Accounting Standards Board (the “FASB”) issued guidance that expands segment disclosures for public entities, including requiring disclosure of significant segment expenses that are regularly provided to the chief operating decision maker (“CODM”), the title and position of the CODM and an explanation of how the CODM uses reported measures of segment profit or loss in assessing segment performance and allocating resources (“ASU 2023-07”). ASU 2023-07 also expands disclosures about a reportable segment’s profit or loss and assets in interim periods and clarifies that a public entity may report additional measures of segment profit if the CODM uses more than one measure of a segment’s profit or loss. ASU 2023-07 does not remove existing segment disclosure requirements or change how a public entity identifies its operating segments, aggregates those operating segments, or determines its reportable segments. The Company adopted ASU 2023-07 in the fourth quarter 2024. See Note (9) Business Segment. Improvements to Income Tax Disclosures – In December 2023, the FASB issued guidance that expands income tax disclosures for public entities, including requiring enhanced disclosures related to the rate reconciliation and income taxes paid information (“ASU 2023-09”). ASU 2023-09 is effective for annual disclosures for fiscal years beginning after December 15, 2024, with early adoption permitted. The guidance should be applied on a prospective basis, with retrospective application to all prior periods presented in the financial statements permitted. The Company is currently evaluating the impact ASU 2023-09 will have on its financial statements and related disclosures. Expense Disaggregation Disclosures - In November 2024, the FASB issued guidance that requires disclosure of specified information about certain costs and expenses in the notes to the consolidated financial statements (“ASU 2024-03”). ASU 2024-03 is effective for annual periods beginning after December 15, 2026, and interim periods within annual periods beginning after December 15, 2027, with early adoption permitted. ASU 2024-03 is to be applied on a prospective basis, with retrospective application permitted. The Company is evaluating the impact, if any, of ASU 2024-03 on its financial statements and related disclosures.

Banking Facilities and Debt

Banking Facilities and Debt	12 Months Ended
	Dec. 31, 2024
Banking Facilities and Debt
Banking Facilities and Debt	(2) Banking Facilities and Debt The Company’s credit agreement with Wells Fargo Bank, N.A. (the “Lender”), as amended as of August 3, 2023, provides for a $75,000 revolving credit facility (the “Revolving Facility”) and an incremental four-year accordion feature to borrow up to an additional $50,000 on the same terms, subject to approval by the Lender or another lender selected by the Company. The credit agreement also provides for a letter of credit sublimit under the Revolving Facility. The Revolving Facility and any incremental loans mature on August 3, 2028. Interest rates on the Revolving Facility are, at the Company’s option, SOFR, plus a SOFR adjustment rate of 0.10%, plus a margin of 1.000% to 2.000%, or the Lender’s Prime Rate, plus a margin of 0.000% to 1.000%, and a commitment fee range of 0.225% to 0.350% on the undrawn portion of the Revolving Facility. The Revolving Facility interest rate margins and commitment fee are determined quarterly in accordance with a pricing grid based upon the Company’s Cash Flow Leverage Ratio, defined as the ratio of the Company’s total funded senior indebtedness to earnings before interest, taxes, depreciation, depletion, amortization, and stock-based compensation expense (“EBITDA”) for the 12 months ended on the last day of the most recent calendar quarter, plus pro forma EBITDA from any businesses acquired during the period. Pursuant to a security agreement, dated August 25, 2004, the Revolving Facility is secured by the Company’s existing and hereafter acquired tangible assets, intangible assets, and real property. The maturity of the Revolving Facility and any incremental loans can be accelerated if any event of default, as defined under the credit agreement, occurs. The Company’s maximum Cash Flow Leverage Ratio is The Company may pay dividends so long as it remains in compliance with the provisions of the Company’s credit agreement, and may purchase, redeem, or otherwise acquire shares of its common stock so long as its pro forma Cash Flow Leverage Ratio is less than 3.00 to 1.00 and no default or event of default exists or would exist after giving effect to such stock repurchase. The Company had no debt outstanding at December 31, 2024 or 2023. The Company had

Leases

Leases	12 Months Ended
	Dec. 31, 2024
Leases
Leases	(3) Leases The Company has operating leases for the use of equipment, corporate office space, and some of its terminal and distribution facilities. The leases have remaining lease terms of 0 . Some operating leases include options to extend the leases for up to . The Company’s lease calculations include the impact of options to extend when it is reasonably certain the Company will exercise the option. The Company used a weighted-average discount rate of for leases entered into during 2024 and 2023, respectively. The components of net operating lease costs for 2024, 2023, and 2022 were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ Classification 2024 2023 ​ 2022 ​ Operating lease costs (1) ​ Cost of revenues $ 2,642 ​ $ 3,090 ​ $ 2,374 ​ Operating lease costs (1) ​ Selling, general and administrative expenses 307 ​ 216 ​ 275 ​ Rental revenues ​ Revenues ​ (332) ​ ​ (470) ​ ​ (419) ​ Rental revenues ​ Other (income) expense, net (95) ​ (91) ​ (70) ​ Net operating lease costs ​ ​ $ 2,522 ​ $ 2,745 ​ $ 2,160 ​ (1) Includes the costs of leases with a term of one year or less. ​ As of December 31, 2024, future minimum payments under operating leases that were either non-cancelable or subject to significant penalty upon cancellation, including future minimum payments under renewal options that the Company is reasonably certain to exercise, were as follows (in thousands): ​ ​ ​ ​ ​ 2025 ​ $ 1,691 2026 ​ ​ 1,508 2027 ​ ​ 1,141 2028 ​ ​ 454 2029 ​ ​ 159 Thereafter ​ ​ 565 Total future minimum lease payments ​ ​ 5,518 Less imputed interest ​ ​ (479) Present value of lease liabilities ​ $ 5,039 ​ Supplemental cash flow information pertaining to the Company’s leasing activity for the years ended December 31, 2024, 2023, and 2022 was as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2024 ​ 2023 ​ 2022 Cash payments for lease liabilities included in operating cash flows ​ $ 1,954 ​ $ 1,641 ​ $ 1,660 Right-of-use assets obtained in exchange for operating lease obligations ​ $ 998 ​ $ 1,286 ​ $ 3,456 ​

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2024
Income Taxes
Income Taxes	(4) Income Taxes Income tax expense (benefit) for the years ended December 31 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 Current income tax expense ​ $ 28,544 ​ $ 19,736 ​ $ 8,606 ​ Deferred income tax (benefit) expense ​ (1,000) ​ (923) ​ 2,527 ​ Income tax expense ​ $ 27,544 ​ $ 18,813 ​ $ 11,133 ​ ​ A reconciliation of income taxes computed at the federal statutory rate to income tax expense for the years ended December 31 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ ​ ​ ​ ​ Percent of ​ ​ ​ ​ Percent of ​ ​ ​ ​ Percent of ​ ​ ​ ​ ​ ​ Pretax ​ ​ ​ ​ Pretax ​ ​ ​ ​ Pretax ​ ​ Amount Income Amount Income Amount Income ​ Income taxes computed at the federal statutory rate $ 28,640 21.0 % $ 19,606 21.0 % $ 11,878 21.0 % ​ (Reduction) increase in taxes resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Statutory depletion in excess of basis ​ (2,701) (2.0) ​ (2,172) (2.3) ​ (1,869) (3.3) ​ ​ State income taxes, net of federal income tax benefit ​ 682 0.5 ​ 1,144 1.2 ​ 557 1.0 ​ ​ Disallowed executive compensation ​ ​ 2,040 ​ 1.5 ​ ​ 818 ​ 0.9 ​ ​ 493 ​ 0.9 ​ ​ Stock-based compensation ​ ​ (1,105) ​ (0.8) ​ ​ (218) ​ (0.2) ​ ​ 33 ​ — ​ ​ Other ​ (12) 0.0 ​ (365) (0.4) ​ 41 0.1 ​ ​ Income tax expense ​ $ 27,544 20.2 % $ 18,813 20.2 % $ 11,133 19.7 % ​ ​ Components of the Company’s deferred tax liabilities and assets are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 Deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ $ 24,187 ​ $ 25,207 ​ Operating lease right-of-use assets ​ ​ 1,095 ​ ​ 1,195 ​ ​ ​ 25,282 ​ 26,402 ​ Deferred tax assets ​ ​ ​ ​ ​ ​ ​ Operating lease liabilities ​ ​ 1,136 ​ ​ 1,247 ​ Other ​ 487 ​ 496 ​ ​ ​ 1,623 ​ 1,743 ​ Deferred tax liabilities, net ​ $ 23,659 ​ $ 24,659 ​ Current income taxes are classified on the Company’s Consolidated Balance Sheets as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2024 ​ 2023 Accrued expenses ​ $ 466 ​ $ 2,010 ​ The Company had no federal net operating loss carry forwards at December 31, 2024. The Company reduces deferred tax assets by a valuation allowance if, based on the weight of available evidence, it is “more likely than not” that some portion or all of the deferred tax assets will not be realized. Deferred tax assets are considered fully recognizable because of the Company’s recent income history and expectations of income in the future. The Company’s federal income tax returns for the year ended December 31, 2021 and subsequent years remain subject to examination. The Company’s income tax returns in certain state income tax jurisdictions remain subject to examination for various periods for the year ended December 31, 2020 and subsequent years.

Employee Retirement Plans

Employee Retirement Plans	12 Months Ended
	Dec. 31, 2024
Employee Retirement Plans
Employee Retirement Plans	(5) Employee Retirement Plans The Company has a contributory retirement (401(k)) savings plans for non-union employees and for union employees of Arkansas Lime Company, Carthage, and Texas Lime Company. Company contributions to these plans were $352, $329 and $311 in 2024, 2023, and 2022, respectively.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2024
Stock-Based Compensation
Stock-Based Compensation	(6) Stock-Based Compensation The Plan provides for stock options, restricted stock, and dollar-denominated cash awards, including performance-based awards. In addition to stock options, restricted stock, and cash awards, the Plan provides for the grant of stock appreciation rights, deferred stock, and other stock-based awards to directors, officers, employees, and consultants. The Plan was amended in 2024 to increase the number of shares of Company common stock reserved for stock-based awards under the Plan and to make other changes. At December 31, 2024, the number of shares of common stock remaining available for future grants of stock options, restricted stock, or other forms of stock-based awards under the Plan was 837,225. Stock options granted under the Plan expire ten years from the date of grant and generally become exercisable, or vest, immediately. Restricted stock generally vests over periods of one-half exercise of stock options, the Company issues common stock from its non- issued authorized or treasury shares that have been reserved for issuance pursuant to the Plan. Forfeitures are recognized in the period they occur. The Company recorded $4,893, $3,182, and $2,636 for stock-based compensation expense related to stock options and shares of restricted stock for 2024, 2023, and 2022, respectively. The amounts included in cost of revenues were $320, $248, and $211 and in selling, general and administrative expense were $4,573, $2,934, and $2,425, for 2024, 2023, and 2022, respectively. A summary of the Company’s stock option and restricted stock activity and related information for the year ended December 31, 2024 and certain other information for the years ended December 31, 2024, 2023, and 2022 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ Aggregate ​ ​ ​ Average ​ ​ Stock ​ Exercise ​ Intrinsic ​ Restricted ​ Grant-Date ​ Options ​ Price ​ Value ​ Stock ​ Fair Value Outstanding (stock options); non-vested (restricted stock) at December 31, 2023 232,500 ​ $ 25.43 ​ $ 4,799 ​ 91,235 ​ $ 40.32 ​ Granted 9,000 ​ 65.34 ​ 607 ​ 74,305 ​ 107.11 ​ Exercised (stock options); vested (restricted stock) (74,500) ​ 24.19 ​ 3,455 ​ (85,288) ​ 45.02 ​ Forfeited — ​ — ​ — ​ (1,245) ​ 38.25 ​ Outstanding (stock options); non-vested (restricted stock) at December 31, 2024 167,000 ​ $ 28.13 ​ $ 17,469 ​ 79,007 ​ $ 98.09 ​ Exercisable at December 31, 2024 154,500 ​ $ 26.68 ​ $ 16,386 ​ n/a ​ n/a ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 Weighted-average fair value of stock options granted during the year ​ $ 27.04 ​ $ 16.86 ​ $ 9.95 ​ Weighted-average remaining contractual life for stock options in years ​ 5.92 ​ 6.85 ​ 6.87 ​ Total fair value of stock options vested during the year ​ $ 744 ​ $ 434 ​ $ 287 ​ Total intrinsic value of stock options exercised during the year ​ $ 3,455 ​ $ 1,589 ​ $ 157 ​ Total fair value of restricted stock vested during the year ​ $ 3,839 ​ $ 2,663 ​ $ 2,235 ​ ​ There were 12,500 non-vested stock options at December 31, 2024, and the weighted-average remaining contractual life of the outstanding and exercisable stock options at such date was 5.92 years. The total compensation cost not yet recognized for restricted stock at December 31, 2024 was $7,190, which will be recognized over the weighted average of 1.04 years. The fair value for the stock options was estimated at the date of grant using a lattice-based option valuation model, with the following weighted-average assumptions for the 2024, 2023, and 2022 grants: risk-free interest rates of 4.57% in 2024, 3.41% to 3.84% (weighted average 3.74%) in 2023, and 2.92% to 3.94% (weighted average 3.74%) in 2022; a dividend yield of 0.31% in 2024, 0.35% to 0.48% (weighted average 0.39%) in 2023, and 0.57% to 0.73% (weighted average 0.62%) in 2022; and a volatility factor of .406 in 2024, .389 to .400 (weighted average .397) in 2023, and .374 to .385 (weighted average .382) in 2022, based on the daily per-share closing prices for five years preceding the date of issuance. In addition, the fair value of these options was estimated based on an expected life of five years. The fair value of restricted stock is based on the closing per-share price of the Company’s common stock on the date of grant.

Share Repurchases

Share Repurchases	12 Months Ended
	Dec. 31, 2024
Share Repurchases
Share Repurchases	​ (7) Share Repurchases

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2024
Commitments and Contingencies.
Commitments and Contingencies	(8) Commitments and Contingencies The Company is party to lawsuits and claims arising in the normal course of business, none of which, in the opinion of management, is expected to have a material adverse effect on the Company’s financial condition, results of operations, cash flows, or competitive position. The Company is not contractually committed to any planned capital expenditures until actual orders are placed for equipment or services. At December 31, 2024, the Company had $35,480 for open equipment and construction contracts.

Reportable Segment

Reportable Segment	12 Months Ended
	Dec. 31, 2024
Reportable Segment
Reportable Segment	(9) Reportable Segment In November 2023, the FASB amended guidance in ASC 280, Segment Reporting (“ASC 280”) by issuing ASU 2023-07, which updated the disclosure requirements for reportable segments, primarily through requiring enhanced disclosures about significant segment expenses. The Company adopted this guidance in the fourth quarter 2024, with retrospective application to the years ending December 31, 2023 and 2022. See Note 1(p). reportable segment, lime and limestone operations, based on the distinctness of the Company’s activities and products. All operations are in the United States. During 2024, the Company determined that the activities of its natural gas interests and the associated level of review of those activities by the CODM precluded the natural gas activities from meeting the definition of an operating segment, as provided in ASC 280. In addition, previously unallocated items, including cash, interest income and expense and other expense are now included as part of lime and limestone operations, and consolidated net income is now used as the measure of segment profit or loss. Segment disclosures for 2023 and 2022 have been recast to be consistent with the 2024 presentation. The Company’s CODM is the chief executive officer. The lime and limestone operations segment derives revenues from the sale of crushed limestone, pulverized limestone, aggregate, quicklime, hydrated lime, and lime slurry. The accounting policies of the lime and limestone operations segment are the same as those described in Note (1) Summary of Significant Accounting Policies. In evaluating the operating results of the Company, the CODM assesses performance for the lime and limestone operations segment and decides how to allocate resources (including, but not limited to, decisions on fuel blends, capital purchases, and staffing levels) based on net income that is also reported on the consolidated statements of income. The measure of segment assets is reported on the consolidated balance sheets as “Total assets” and the measure of segment capital expenditures is reported on the consolidated statements of cash flows as “Purchase of property, plant, and equipment.” ​ The following table presents revenue, significant expenses, and profit for the years ended December 31, 2024, 2023, and 2022 as reviewed and used by the CODM. There are no other significant segment items or reconciling items to consolidated net income. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ 2023 ​ ​ 2022 ​ Revenues ​ $ 317,721 ​ $ 281,330 ​ $ 236,150 ​ Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fuel, energy, and transportation ​ ​ 82,232 ​ ​ 88,521 ​ ​ 88,758 ​ Depreciation, depletion and amortization ​ ​ 23,855 ​ ​ 23,533 ​ ​ 21,922 ​ Outside services, maintenance, and supplies ​ ​ 28,536 ​ ​ 29,310 ​ ​ 22,086 ​ Personnel expenses ​ ​ 30,980 ​ ​ 29,209 ​ ​ 26,528 ​ Other cost of revenues ​ ​ 8,137 ​ ​ 7,890 ​ ​ 6,514 ​ Selling, general and administrative expenses ​ ​ 19,058 ​ ​ 17,445 ​ ​ 15,559 ​ Other (income) expense, net ​ ​ (11,460) ​ ​ (7,940) ​ ​ (1,779) ​ Income tax expense ​ ​ 27,544 ​ ​ 18,813 ​ ​ 11,133 ​ Net income ​ $ 108,839 ​ $ 74,549 ​ $ 45,429 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2024
Subsequent Events.
Subsequent Events	(10) Subsequent Events On February 3, 2025, the Company declared an increased regular quarterly cash dividend of $0.06 per share on the Company’s common stock. This dividend is payable on March 14, 2025 to shareholders of record at the close of business on February 21, 2025. ​

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 108,839	$ 74,549	$ 45,429

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Dec. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Insider Trading Policies and Pr

Insider Trading Policies and Procedures	12 Months Ended
	Dec. 31, 2024
Insider Trading Policies and Procedures [Line Items]
Insider Trading Policies and Procedures Adopted	true

Cybersecurity Risk Management a

Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
	Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	Risk Management and Strategy. to assess, identify, manage, detect, and respond to material cybersecurity risks and threats to our IT systems, including the prevention, detection, mitigation, and remediation of cybersecurity incidents in order to protect the confidentiality, integrity, and availability of our IT systems and the information residing on those systems. These processes are part of our overall risk management process and are embedded in our operating policies, procedures, and controls. To protect our IT systems and information from cybersecurity risks, we use various security tools that help prevent, identify, escalate, investigate, resolve, and recover from identified cybersecurity vulnerabilities and incidents in a timely manner. These include, but are not limited to, internal reporting, monitoring, and detection tools. We also utilize a third-party security operations center connected to a networks operation center to identify, investigate, and resolve any cybersecurity threats and incidents. ​ We regularly assess technological risks to our IT systems and information and monitor our IT systems for potential vulnerabilities and risks. We frequently conduct mandatory cybersecurity and IT systems awareness training for all employees with access to our systems. We also conduct regular reviews and tests of our IT cybersecurity processes, including reviews, assessments, and exercises. ​ We aim to incorporate responsible practices throughout our cybersecurity risk management processes. Our cybersecurity strategy focuses on implementing effective and efficient controls, technologies, and other processes to assess, identify, and manage material cybersecurity risks to our IT systems and information. As a part of this process, ​ While we have not, as of the date of this Report on Form 10-K, experienced a cybersecurity threat or incident that has materially impacted our business or operations, there can be no guarantee that we will not experience such a threat or incident in the future. A material cybersecurity threat or incident could adversely impact our mining and manufacturing operations, our sales or financial and administrative functions, or result in the compromise of personal or other confidential information of our employees, customers, or suppliers. For this reason, we maintain cybersecurity liability insurance to provide additional support, expertise, and resources to help ensure the integrity of our cybersecurity processes through regular reviews and assessments, to provide incident response assistance and expertise, and to provide a level of financial protection in the event of cybersecurity incident related costs and losses.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	We have designed and implemented processes to assess, identify, manage, detect, and respond to material cybersecurity risks and threats to our IT systems, including the prevention, detection, mitigation, and remediation of cybersecurity incidents in order to protect the confidentiality, integrity, and availability of our IT systems and the information residing on those systems. These processes are part of our overall risk management process and are embedded in our operating policies, procedures, and controls.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Governance. . . Team members also include third-party service providers who have relevant education and experience in cybersecurity. Our CFO is informed about and coordinates prevention, detection, mitigation, and remediation efforts through regular communication and reporting from the professionals on our cybersecurity team. In addition, we have an escalation process in place to ​ Our Audit Committee has oversight of our cybersecurity risk processes, as part of its overall oversight of our risk management program. Our MIT regularly reports to and reviews our cybersecurity processes with the Audit Committee, with formal cybersecurity reviews with the Committee generally occurring at least annually, and sometimes more frequently, as appropriate.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Audit Committee
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our Audit Committee has oversight of our cybersecurity risk processes, as part of its overall oversight of our risk management program. Our MIT regularly reports to and reviews our cybersecurity processes with the Audit Committee, with formal cybersecurity reviews with the Committee generally occurring at least annually, and sometimes more frequently, as appropriate.
Cybersecurity Risk Role of Management [Text Block]	Our Manager of Information Technology (“MIT”) is responsible for our IT cybersecurity policies, procedures, and controls and reports to our Chief Financial Officer (“CFO”) . . Team members also include third-party service providers who have relevant education and experience in cybersecurity.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Manager of Information Technology (“MIT”)
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Our MIT has a Bachelor of Business Administration degree in management information systems and has over 20 years of relevant experience in the IT field
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	Our CFO is informed about and coordinates prevention, detection, mitigation, and remediation efforts through regular communication and reporting from the professionals on our cybersecurity team. In addition, we have an escalation process in place to
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2024
Summary of Significant Accounting Policies
Principles of Consolidation	(b) Principles of Consolidation The consolidated financial statements include the accounts of the Company and its subsidiaries. All intercompany balances and transactions have been eliminated.
Use of Estimates	(c) Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“US GAAP”) requires management to make estimates and judgments that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates and judgments.
Statements of Cash Flows	(d) Statements of Cash Flows For purposes of reporting cash flows, the Company considers all bank deposits and highly liquid debt instruments, such as United States Treasury bills and notes, with maturities, at the time of purchase, of three months or less to be cash equivalents. Cash equivalents are carried at cost plus accrued interest, which approximates fair market value. Supplemental cash flow information is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2024 ​ 2023 ​ 2022 Cash paid during the year for: ​ ​ ​ ​ Interest ​ $ 169 ​ $ 196 ​ $ 113 ​ Income taxes ​ $ 30,405 ​ $ 17,994 ​ $ 7,827 ​
Revenue Recognition	(e) Revenue Recognition The Company recognizes revenue for its lime and limestone operations when (i) a contract with the customer exists and the performance obligations are identified; (ii) the price has been established; and (iii) the performance obligations have been satisfied, which is at a point in time, generally upon shipment. Revenues include external freight billed to customers with related costs accounted for as fulfillment costs and included in cost of revenues. The Company operates within a single geographic region. The Company’s returns and allowances are minimal. External freight billed to customers included in revenues was
Fair Values of Financial Instruments	(f) Fair Values of Financial Instruments Fair value is defined as “the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.” The carrying values of cash and cash equivalents, trade receivables, other current assets, accounts payable, and accrued expenses approximate fair value due to the short maturities of these instruments.
Concentration of Credit Risk and Trade Receivables	(g) Concentration of Credit Risk and Trade Receivables Financial instruments that potentially subject the Company to a concentration of credit risk consist principally of cash and cash equivalents and trade receivables. The Company places its cash and cash equivalents with high-credit quality financial institutions and in highly rated commercial paper or United States Treasury bills and notes with maturities, at the time of purchase, of three months or less. The Company’s cash and cash equivalents at commercial banking institutions normally exceed federally insured limits. The majority of the Company’s trade receivables are unsecured. Payment terms for all trade receivables are based on the underlying purchase orders, contracts, or purchase agreements, and are generally fixed, short-term, and do not contain a significant financing component. The Company estimates credit losses relating to trade receivables based on an assessment of the current and forecasted probability of collection, historical trends, economic conditions, and other significant events that may impact the collectability of trade receivables. Due to the relatively homogenous nature of its trade receivables, the Company does not believe there is any meaningful asset-specific differences within its accounts receivable portfolio that would require the portfolio to be grouped below the consolidated level for review of credit losses. Credit losses relating to trade receivables have generally been within management expectations and historical trends. Uncollected trade receivables are charged-off when identified by management to be unrecoverable. Trade receivables are presented net of the related estimated credit losses, which totaled ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 Beginning balance ​ $ 575 ​ $ 550 ​ Additions ​ 110 ​ 49 ​ Adjustments for expected credit loss factors ​ ​ — ​ ​ — ​ Write-offs ​ (84) ​ (24) ​ Ending balance ​ $ 601 ​ $ 575 ​
Inventories	(h) Inventories Inventories are valued principally at the lower of cost, determined using the average cost method, or net realizable value. Costs for raw materials and finished goods include materials, labor, and production overhead. A summary of inventories is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ 2024 ​ 2023 Lime and limestone inventories: ​ ​ ​ Raw materials ​ $ 8,947 ​ $ 7,834 ​ Finished goods ​ 3,000 ​ 3,107 ​ ​ ​ ​ 11,947 ​ ​ 10,941 ​ Parts inventories ​ 15,739 ​ 13,372 ​ ​ ​ $ 27,686 ​ $ 24,313 ​
Property, Plant and Equipment	(i) Property, Plant and Equipment For major constructed assets, the capitalized cost includes the price paid by the Company for labor and materials plus interest and internal and external project management costs that are directly related to the constructed assets. Machinery and equipment at December 31, 2024 and 2023 included $8,098 and $6,001, respectively, of construction in progress for various capital projects. No interest costs were capitalized for the years ended December 31, 2024 and 2023. At December 31, 2024 and 2023, accounts payable and accrued expenses included $1,657 and $1,196, respectively, of capitalized costs. Selling, general, and administrative expenses included depreciation expense of $318, $294, and $278 in 2024, 2023, and 2022, respectively. Depreciation of property, plant and equipment is being provided for by the straight-line method over estimated useful lives as follows: ​ ​ ​ ​ ​ ​ ​ ​ Buildings and building and leasehold improvements 3 - 25 years ​ Machinery and equipment 2 - 30 years ​ Furniture and fixtures 3 - 10 years ​ Automotive equipment 3 - 10 years ​ ​ Maintenance and repairs are charged to expense as incurred; renewals and betterments are capitalized. When units of property are retired or otherwise disposed of, their cost and related accumulated depreciation are removed from the accounts, and any resulting gain or loss is credited or charged to income. The Company expenses all exploration costs as incurred, as well as costs incurred at an operating quarry or mine, other than capital expenditures and inventory. Costs to acquire mineral reserves are capitalized upon acquisition. Costs incurred to develop new mineral reserves, to expand the capacity of a quarry or mine, or to develop quarry or mine areas substantially in advance of current production are capitalized once proven and probable reserves exist and can be economically produced. For each quarry or mine, capitalized costs to acquire and develop mineral reserves are depleted using the units-of-production method based on the proven and probable reserves for such quarry or mine. The Company reviews its long-lived assets for impairment and, when events or circumstances indicate the carrying amount of an asset may not be recoverable, the Company determines if impairment of value exists. If the estimated undiscounted future net cash flows are less than the carrying amount of the asset, an impairment exists, and an impairment loss must be calculated and recorded. If an impairment exists, the impairment loss is calculated based on the excess of the carrying amount of the asset over the asset’s fair value. Any impairment loss is treated as a permanent reduction in the carrying value of the asset. The Company had no impairments in the years presented in the financial statements.
Asset Retirement Obligations	(j) Asset Retirement Obligations The Company recognizes legal obligations for reclamation and remediation associated with the retirement of long- lived assets at their fair value at the time the obligations are incurred (“AROs”). Over time, the liability for AROs is recorded at its present value each period through accretion expense, and the capitalized cost is depreciated over the useful life of the related asset. Upon settlement of the liability, the Company either settles the AROs for the recorded amount or recognizes a gain or loss. The Company’s AROs of as of December 31, 2024 and 2023, respectively, are included in Other liabilities and Accrued expenses on the Company’s Consolidated Balance Sheets. As of December 31, 2024, assets, net of accumulated depreciation, associated with the Company’s AROs totaled . During 2024 and 2023, the Company spent The AROs were estimated based on studies and the Company’s process knowledge and estimates and are discounted using a credit adjusted risk-free interest rate. The AROs are adjusted when further information warrants an adjustment. The Company estimates annual expenditures of approximately $100 per year in years 2025 through 2029 relating to its AROs.
Accrued Expenses	(k) Accrued Expenses Accrued expenses consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2024 2023 Personnel related expenses ​ $ 3,371 ​ $ 4,073 ​ Income taxes ​ ​ 466 ​ ​ 2,010 ​ Other taxes ​ ​ 1,098 ​ ​ 1,112 ​ Utilities ​ ​ 893 ​ ​ 944 ​ Other ​ 713 ​ 366 ​ ​ ​ $ 6,541 ​ $ 8,505 ​
Environmental Expenditures	(l) Environmental Expenditures Environmental expenditures that relate to current operations are expensed or capitalized as appropriate. Expenditures that relate to an existing condition caused by past operations, and which do not contribute to current or future revenue generation, are expensed. Liabilities are recorded at their present value when environmental assessments and/or remedial efforts are probable, and the costs can be reasonably estimated. Generally, the timing of these accruals will coincide with completion of a feasibility study or the Company’s commitment to a formal plan of action. The Company incurred capital expenditures related to environmental matters of $997 in 2024, $1,456 in 2023, and $779 in 2022.
Income and Dividends Per Share of Common Stock	(m) Income and Dividends Per Share of Common Stock The following table sets forth the computation of basic and diluted income per common share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2024 2023 2022 Net income for basic and diluted income per common share ​ $ 108,839 ​ $ 74,549 ​ $ 45,429 ​ Weighted-average shares for basic income per common share ​ 28,579,354 ​ 28,461,955 ​ 28,359,800 ​ Effect of dilutive securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Employee and director stock options (1) ​ 109,017 ​ 71,425 ​ 42,245 ​ Adjusted weighted-average shares and assumed exercises for diluted income per common share ​ 28,688,371 ​ 28,533,380 ​ 28,402,045 ​ Basic net income per common share ​ $ 3.81 ​ $ 2.62 ​ $ 1.60 ​ Diluted net income per common share ​ $ 3.79 ​ $ 2.61 ​ $ 1.60 ​ (1) Excludes 9,375 and 80,625 stock options in 2023 and 2022, respectively, as antidilutive because the exercise price exceeded the average per share market price for the periods presented. No stock options were excluded in 2024 as antidilutive. The Company paid $0.20, $0.16, and $0.16 of cash dividends per share of common stock in 2024, 2023, and 2022, respectively.
Stock-Based Compensation	(n) Stock-Based Compensation The Company expenses all stock-based payments to employees and directors, including grants of stock options and restricted stock, in the Company’s Consolidated Statements of Income based on their fair values. Compensation cost is recognized on a straight-line basis over the vesting period.
Income Taxes	(o) Income Taxes The Company utilizes the asset and liability approach in its reporting for income taxes. Deferred income tax assets and liabilities are computed for differences between the financial statement and tax bases of assets and liabilities that will result in taxable or deductible amounts in the future based on enacted tax laws and rates applicable to the periods in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amount more likely than not to be realized. Income tax related interest and penalties are included in income tax expense. The Company also assesses individual tax positions to determine if they meet the criteria for some or all of the benefits of that position to be recognized in the Company’s financial statements. The Company only recognizes tax positions that meet the more-likely-than-not recognition threshold.
New Accounting Pronouncements	Segment Reporting – In November 2023, the Financial Accounting Standards Board (the “FASB”) issued guidance that expands segment disclosures for public entities, including requiring disclosure of significant segment expenses that are regularly provided to the chief operating decision maker (“CODM”), the title and position of the CODM and an explanation of how the CODM uses reported measures of segment profit or loss in assessing segment performance and allocating resources (“ASU 2023-07”). ASU 2023-07 also expands disclosures about a reportable segment’s profit or loss and assets in interim periods and clarifies that a public entity may report additional measures of segment profit if the CODM uses more than one measure of a segment’s profit or loss. ASU 2023-07 does not remove existing segment disclosure requirements or change how a public entity identifies its operating segments, aggregates those operating segments, or determines its reportable segments. The Company adopted ASU 2023-07 in the fourth quarter 2024. See Note (9) Business Segment. Improvements to Income Tax Disclosures – In December 2023, the FASB issued guidance that expands income tax disclosures for public entities, including requiring enhanced disclosures related to the rate reconciliation and income taxes paid information (“ASU 2023-09”). ASU 2023-09 is effective for annual disclosures for fiscal years beginning after December 15, 2024, with early adoption permitted. The guidance should be applied on a prospective basis, with retrospective application to all prior periods presented in the financial statements permitted. The Company is currently evaluating the impact ASU 2023-09 will have on its financial statements and related disclosures. Expense Disaggregation Disclosures - In November 2024, the FASB issued guidance that requires disclosure of specified information about certain costs and expenses in the notes to the consolidated financial statements (“ASU 2024-03”). ASU 2024-03 is effective for annual periods beginning after December 15, 2026, and interim periods within annual periods beginning after December 15, 2027, with early adoption permitted. ASU 2024-03 is to be applied on a prospective basis, with retrospective application permitted. The Company is evaluating the impact, if any, of ASU 2024-03 on its financial statements and related disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2024
Summary of Significant Accounting Policies
Schedule of supplemental cash flow information (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2024 ​ 2023 ​ 2022 Cash paid during the year for: ​ ​ ​ ​ Interest ​ $ 169 ​ $ 196 ​ $ 113 ​ Income taxes ​ $ 30,405 ​ $ 17,994 ​ $ 7,827 ​
Schedule of additions and write-offs to the Company's allowance for doubtful accounts (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 Beginning balance ​ $ 575 ​ $ 550 ​ Additions ​ 110 ​ 49 ​ Adjustments for expected credit loss factors ​ ​ — ​ ​ — ​ Write-offs ​ (84) ​ (24) ​ Ending balance ​ $ 601 ​ $ 575 ​
Schedule of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ 2024 ​ 2023 Lime and limestone inventories: ​ ​ ​ Raw materials ​ $ 8,947 ​ $ 7,834 ​ Finished goods ​ 3,000 ​ 3,107 ​ ​ ​ ​ 11,947 ​ ​ 10,941 ​ Parts inventories ​ 15,739 ​ 13,372 ​ ​ ​ $ 27,686 ​ $ 24,313 ​
Schedule of estimated useful lives of property, plant and equipment (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ Buildings and building and leasehold improvements 3 - 25 years ​ Machinery and equipment 2 - 30 years ​ Furniture and fixtures 3 - 10 years ​ Automotive equipment 3 - 10 years ​
Schedule of accrued expenses (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2024 2023 Personnel related expenses ​ $ 3,371 ​ $ 4,073 ​ Income taxes ​ ​ 466 ​ ​ 2,010 ​ Other taxes ​ ​ 1,098 ​ ​ 1,112 ​ Utilities ​ ​ 893 ​ ​ 944 ​ Other ​ 713 ​ 366 ​ ​ ​ $ 6,541 ​ $ 8,505 ​
Schedule of computation of basic and diluted income per common share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2024 2023 2022 Net income for basic and diluted income per common share ​ $ 108,839 ​ $ 74,549 ​ $ 45,429 ​ Weighted-average shares for basic income per common share ​ 28,579,354 ​ 28,461,955 ​ 28,359,800 ​ Effect of dilutive securities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Employee and director stock options (1) ​ 109,017 ​ 71,425 ​ 42,245 ​ Adjusted weighted-average shares and assumed exercises for diluted income per common share ​ 28,688,371 ​ 28,533,380 ​ 28,402,045 ​ Basic net income per common share ​ $ 3.81 ​ $ 2.62 ​ $ 1.60 ​ Diluted net income per common share ​ $ 3.79 ​ $ 2.61 ​ $ 1.60 ​ (1) Excludes 9,375 and 80,625 stock options in 2023 and 2022, respectively, as antidilutive because the exercise price exceeded the average per share market price for the periods presented. No stock options were excluded in 2024 as antidilutive.

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2024
Leases
Schedule of lease costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ Classification 2024 2023 ​ 2022 ​ Operating lease costs (1) ​ Cost of revenues $ 2,642 ​ $ 3,090 ​ $ 2,374 ​ Operating lease costs (1) ​ Selling, general and administrative expenses 307 ​ 216 ​ 275 ​ Rental revenues ​ Revenues ​ (332) ​ ​ (470) ​ ​ (419) ​ Rental revenues ​ Other (income) expense, net (95) ​ (91) ​ (70) ​ Net operating lease costs ​ ​ $ 2,522 ​ $ 2,745 ​ $ 2,160 ​ (1) Includes the costs of leases with a term of one year or less.
Schedule of maturity of lease liability	​ ​ ​ ​ ​ 2025 ​ $ 1,691 2026 ​ ​ 1,508 2027 ​ ​ 1,141 2028 ​ ​ 454 2029 ​ ​ 159 Thereafter ​ ​ 565 Total future minimum lease payments ​ ​ 5,518 Less imputed interest ​ ​ (479) Present value of lease liabilities ​ $ 5,039
Schedule of supplemental cash flow information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2024 ​ 2023 ​ 2022 Cash payments for lease liabilities included in operating cash flows ​ $ 1,954 ​ $ 1,641 ​ $ 1,660 Right-of-use assets obtained in exchange for operating lease obligations ​ $ 998 ​ $ 1,286 ​ $ 3,456 ​

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2024
Income Taxes
Schedule of income tax (benefit) expense (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 Current income tax expense ​ $ 28,544 ​ $ 19,736 ​ $ 8,606 ​ Deferred income tax (benefit) expense ​ (1,000) ​ (923) ​ 2,527 ​ Income tax expense ​ $ 27,544 ​ $ 18,813 ​ $ 11,133 ​
Schedule of reconciliation of income taxes computed at the federal statutory rate to income tax expense (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ 2023 ​ 2022 ​ ​ ​ ​ ​ ​ Percent of ​ ​ ​ ​ Percent of ​ ​ ​ ​ Percent of ​ ​ ​ ​ ​ ​ Pretax ​ ​ ​ ​ Pretax ​ ​ ​ ​ Pretax ​ ​ Amount Income Amount Income Amount Income ​ Income taxes computed at the federal statutory rate $ 28,640 21.0 % $ 19,606 21.0 % $ 11,878 21.0 % ​ (Reduction) increase in taxes resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Statutory depletion in excess of basis ​ (2,701) (2.0) ​ (2,172) (2.3) ​ (1,869) (3.3) ​ ​ State income taxes, net of federal income tax benefit ​ 682 0.5 ​ 1,144 1.2 ​ 557 1.0 ​ ​ Disallowed executive compensation ​ ​ 2,040 ​ 1.5 ​ ​ 818 ​ 0.9 ​ ​ 493 ​ 0.9 ​ ​ Stock-based compensation ​ ​ (1,105) ​ (0.8) ​ ​ (218) ​ (0.2) ​ ​ 33 ​ — ​ ​ Other ​ (12) 0.0 ​ (365) (0.4) ​ 41 0.1 ​ ​ Income tax expense ​ $ 27,544 20.2 % $ 18,813 20.2 % $ 11,133 19.7 % ​
Summary of the Company's deferred tax liabilities and assets (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2024 ​ 2023 Deferred tax liabilities ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ $ 24,187 ​ $ 25,207 ​ Operating lease right-of-use assets ​ ​ 1,095 ​ ​ 1,195 ​ ​ ​ 25,282 ​ 26,402 ​ Deferred tax assets ​ ​ ​ ​ ​ ​ ​ Operating lease liabilities ​ ​ 1,136 ​ ​ 1,247 ​ Other ​ 487 ​ 496 ​ ​ ​ 1,623 ​ 1,743 ​ Deferred tax liabilities, net ​ $ 23,659 ​ $ 24,659 ​ Current income taxes are classified on the Company’s Consolidated Balance Sheets as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2024 ​ 2023 Accrued expenses ​ $ 466 ​ $ 2,010

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2024
Stock-Based Compensation
Summary of the Company's stock option and restricted stock activity (in thousands)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ Aggregate ​ ​ ​ Average ​ ​ Stock ​ Exercise ​ Intrinsic ​ Restricted ​ Grant-Date ​ Options ​ Price ​ Value ​ Stock ​ Fair Value Outstanding (stock options); non-vested (restricted stock) at December 31, 2023 232,500 ​ $ 25.43 ​ $ 4,799 ​ 91,235 ​ $ 40.32 ​ Granted 9,000 ​ 65.34 ​ 607 ​ 74,305 ​ 107.11 ​ Exercised (stock options); vested (restricted stock) (74,500) ​ 24.19 ​ 3,455 ​ (85,288) ​ 45.02 ​ Forfeited — ​ — ​ — ​ (1,245) ​ 38.25 ​ Outstanding (stock options); non-vested (restricted stock) at December 31, 2024 167,000 ​ $ 28.13 ​ $ 17,469 ​ 79,007 ​ $ 98.09 ​ Exercisable at December 31, 2024 154,500 ​ $ 26.68 ​ $ 16,386 ​ n/a ​ n/a ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 2023 2022 Weighted-average fair value of stock options granted during the year ​ $ 27.04 ​ $ 16.86 ​ $ 9.95 ​ Weighted-average remaining contractual life for stock options in years ​ 5.92 ​ 6.85 ​ 6.87 ​ Total fair value of stock options vested during the year ​ $ 744 ​ $ 434 ​ $ 287 ​ Total intrinsic value of stock options exercised during the year ​ $ 3,455 ​ $ 1,589 ​ $ 157 ​ Total fair value of restricted stock vested during the year ​ $ 3,839 ​ $ 2,663 ​ $ 2,235 ​

Reportable Segment (Tables)

Reportable Segment (Tables)	12 Months Ended
	Dec. 31, 2024
Reportable Segment
Schedule of revenue, significant expenses, and profit used by the CODM	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2024 ​ ​ 2023 ​ ​ 2022 ​ Revenues ​ $ 317,721 ​ $ 281,330 ​ $ 236,150 ​ Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fuel, energy, and transportation ​ ​ 82,232 ​ ​ 88,521 ​ ​ 88,758 ​ Depreciation, depletion and amortization ​ ​ 23,855 ​ ​ 23,533 ​ ​ 21,922 ​ Outside services, maintenance, and supplies ​ ​ 28,536 ​ ​ 29,310 ​ ​ 22,086 ​ Personnel expenses ​ ​ 30,980 ​ ​ 29,209 ​ ​ 26,528 ​ Other cost of revenues ​ ​ 8,137 ​ ​ 7,890 ​ ​ 6,514 ​ Selling, general and administrative expenses ​ ​ 19,058 ​ ​ 17,445 ​ ​ 15,559 ​ Other (income) expense, net ​ ​ (11,460) ​ ​ (7,940) ​ ​ (1,779) ​ Income tax expense ​ ​ 27,544 ​ ​ 18,813 ​ ​ 11,133 ​ Net income ​ $ 108,839 ​ $ 74,549 ​ $ 45,429 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Disclosures (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Jul. 12, 2024 $ / shares shares	Dec. 31, 2024 USD ($) $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($)	May 02, 2024 shares
Summary of Significant Accounting Policies
Common stock, authorized shares | shares		45,000,000	30,000,000		45,000,000
Stock split ratio	5
Number of additional share issued in stock split conversion | shares	4
Common stock, par value (in dollars per share) | $ / shares	$ 0.1	$ 0.1	$ 0.1
Additions and write-offs to the company's allowance for doubtful accounts
Beginning balance		$ 575	$ 550
Additions		110	49
Write-offs		(84)	(24)
Ending balance		601	575	$ 550
Lime and limestone inventories:
Raw materials		8,947	7,834
Finished goods		3,000	3,107
Total		11,947	10,941
Parts inventories		15,739	13,372
Total inventories		27,686	24,313
Supplemental cash flow information
Interest		169	196	113
Income taxes		30,405	17,994	7,827
Revenue Recognition
External freight billed to customers included in revenue		$ 45,514	$ 46,270	$ 44,233

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - PP&E, ARO and Other (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment
Construction in progress	$ 8,098,000	$ 6,001,000
Interest costs capitalized	0	0
Capitalized cost in accounts payable and accrued expenses	1,657,000	1,196,000
Impairment of long-lived assets	0	0
Asset Retirement Obligations
ARO included in other liabilities and accrued expenses	1,484,000	1,548,000
Amount of assets associated with AROs not fully depreciated	580,000
Amount spent on AROs	94,000	36,000
Accretion expense recognized on AROs	102,000	99,000	$ 97,000
Estimated annual expenditures in years 2025 through 2029 relating to AROs	100,000
Accrued Expenses
Personnel related expenses	3,371,000	4,073,000
Income taxes	466,000	2,010,000
Other taxes	1,098,000	1,112,000
Utilities	893,000	944,000
Other	713,000	366,000
Total accrued expenses	6,541,000	8,505,000
Environmental Expenditures
Capital expenditures related to environmental matters	997,000	1,456,000	779,000
Selling, general and administrative expense.
Property, Plant and Equipment
Depreciation	$ 318,000	$ 294,000	$ 278,000
Buildings and building improvements and leasehold improvements | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	3 years
Buildings and building improvements and leasehold improvements | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	25 years
Machinery and equipment | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	2 years
Machinery and equipment | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	30 years
Furniture and fixtures | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	10 years
Automotive equipment | Minimum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	3 years
Automotive equipment | Maximum
Property, Plant and Equipment
Estimated useful lives of property, plant and equipment	10 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Anti-dilutive securities
Net Income (Loss)	$ 108,839	$ 74,549	$ 45,429
Weighted-average shares for basic income per common share (in shares)	28,579,354	28,461,955	28,359,800
Effect of dilutive securities:
Employee and director stock options (in shares)	109,017	71,425	42,245
Adjusted weighted-average shares and assumed exercises for diluted income per common share (in shares)	28,688,371	28,533,380	28,402,045
Basic net income per common share (in dollars per share)	$ 3.81	$ 2.62	$ 1.6
Diluted net income per common share (in dollars per share)	3.79	2.61	1.6
Cash dividends per share of common stock (in dollars per share)	$ 0.2	$ 0.16	$ 0.16
Options
Effect of dilutive securities:
Anti-dilutive shares of common stock excluded from the calculation of dilutive securities	0	9,375	80,625

Banking Facilities and Debt (De

Banking Facilities and Debt (Details) $ in Thousands			12 Months Ended
	Aug. 03, 2023 USD ($)	May 07, 2015	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Summary of outstanding debt
Total Debt			$ 0	$ 0
Maximum
Banking facilities and other debt
Pro forma Cash Flow Leverage Ratio to be maintained to purchase, redeem or otherwise acquire shares of common stock			3
Cash flow leverage ratio		3.5
Revolving Facilities
Banking facilities and other debt
Maximum borrowing capacity	$ 75,000
Accordion feature period	4 years
Maximum borrowing capacity accordion feature	$ 50,000
Revolving Facilities | SOFR
Banking facilities and other debt
Interest rate margin (as a percent)	0.10%
Revolving Facilities | Minimum
Banking facilities and other debt
Commitment fee (as a percent)	0.225%
Revolving Facilities | Minimum | Lender's prime rate
Banking facilities and other debt
Interest rate margin (as a percent)	0%
Revolving Facilities | Minimum | SOFR
Banking facilities and other debt
Interest rate margin (as a percent)	1%
Revolving Facilities | Maximum
Banking facilities and other debt
Commitment fee (as a percent)	0.35%
Revolving Facilities | Maximum | Lender's prime rate
Banking facilities and other debt
Interest rate margin (as a percent)	1%
Revolving Facilities | Maximum | SOFR
Banking facilities and other debt
Interest rate margin (as a percent)	2%
Letter of Credit
Banking facilities and other debt
Maximum borrowing capacity	$ 10,000
Revolving Facility
Banking facilities and other debt
Letters of credit outstanding			$ 6,632

Leases - Costs Disclosure (Deta

Leases - Costs Disclosure (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Leases
Weighted average remaining lease term	4 years
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Average discount rate (as a percent)	6.40%	6.20%
Lease cost
Net operating lease costs	$ 2,522	$ 2,745	$ 2,160
Minimum
Leases
Remaining lease term	0 years
Maximum
Leases
Remaining lease term	7 years
Lease extension term	5 years
Cost of revenues
Lease cost
Operating lease cost	$ 2,642	3,090	2,374
Selling, general and administrative expense.
Lease cost
Operating lease cost	307	216	275
Revenues
Lease cost
Rental revenues	(332)	(470)	(419)
Interest and other income (expense), net
Lease cost
Rental revenues	$ (95)	$ (91)	$ (70)

Leases - Maturity (Details)

Leases - Maturity (Details) $ in Thousands	Dec. 31, 2024 USD ($)
Maturity
2025	$ 1,691
2026	1,508
2027	1,141
2028	454
2029	159
Thereafter	565
Total future minimum lease payments	5,518
Less imputed interest	(479)
Present value of lease liabilities	$ 5,039

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Leases
Cash payments for lease liabilities included in operating cash flows	$ 1,954	$ 1,641	$ 1,660
Right-of-use assets obtained in exchange for operating lease obligations	$ 998	$ 1,286	$ 3,456

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Amount
Income taxes computed at the federal statutory rate	$ 28,640	$ 19,606	$ 11,878
(Reduction) increase in taxes resulting from:
Statutory depletion in excess of basis	(2,701)	(2,172)	(1,869)
State income taxes, net of federal income tax benefit	682	1,144	557
Disallowed executive compensation	2,040	818	493
Stock-based compensation	(1,105)	(218)	33
Other	(12)	(365)	41
Income tax expense	$ 27,544	$ 18,813	$ 11,133
Percent of Pretax Income
Income taxes computed at the federal statutory rate (as a percent)	21%	21%	21%
(Reduction) increase in taxes resulting from (as a percent):
Statutory depletion in excess of basis (as a percent)	(2.00%)	(2.30%)	(3.30%)
State income taxes, net of federal income tax benefit (as a percent)	0.50%	1.20%	1%
Disallowed executive compensation (as a percent)	1.50%	0.90%	0.90%
Stock-based compensation (as a percent)	(0.80%)	(0.20%)
Other (as a percent)	0%	(0.40%)	0.10%
Income tax expense (as a percent)	20.20%	20.20%	19.70%
Deferred tax liabilities
Property, plant and equipment	$ 24,187	$ 25,207
Operating lease right-of-use assets	1,095	1,195
Total	25,282	26,402
Deferred tax assets
Operating lease liabilities	1,136	1,247
Other	487	496
Total	1,623	1,743
Deferred tax liabilities, net, Total	23,659	24,659
Current income taxes:
Accrued expenses	466	2,010
Current income tax expense	28,544	19,736	$ 8,606
Deferred income tax (benefit) expense	(1,000)	(923)	2,527
Income tax expense	27,544	$ 18,813	$ 11,133
Federal
Operating loss carry forwards
Net operating loss carryforwards	$ 0

Employee Retirement Plans (Deta

Employee Retirement Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Contributory retirement (401(k)) savings plans
Company contributions	$ 352	$ 329	$ 311

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stock-based compensation
Number of shares of common stock remaining available for future grants of stock options, restricted stock or other forms of stock-based compensation under the 2001 Plan	837,225
Stock-based compensation expense	$ 4,893	$ 3,182	$ 2,636
Cost of revenues
Stock-based compensation
Stock-based compensation expense	320	248	211
Selling, general and administrative expense.
Stock-based compensation
Stock-based compensation expense	$ 4,573	$ 2,934	$ 2,425
Options
Stock-based compensation
Expiration period	10 years
Stock Options
Outstanding at the beginning of the period (in shares)	232,500
Granted (in shares)	9,000
Exercised (in shares)	(74,500)
Outstanding at the end of the period (in shares)	167,000	232,500
Exercisable at the end of the period (in shares)	154,500
Weighted-Average Exercise Price
Outstanding at the beginning of the period (in dollars per share)	$ 25.43
Granted (in dollars per share)	65.34
Exercised (in dollars per share)	24.19
Outstanding at the end of the period (in dollars per share)	28.13	$ 25.43
Exercisable at the end of the period (in dollars per share)	$ 26.68
Aggregate Intrinsic Value
Outstanding at the beginning of the period	$ 4,799
Granted	607
Exercised	3,455
Outstanding at the end of the period	17,469	$ 4,799
Exercisable at the end of the period	$ 16,386
Additional disclosures
Weighted-average fair value of stock options granted during the year (in dollars per share)	$ 27.04	$ 16.86	$ 9.95
Weighted-average remaining contractual life for stock options	5 years 11 months 1 day	6 years 10 months 6 days	6 years 10 months 13 days
Total fair value of stock options vested during the year	$ 744	$ 434	$ 287
Total intrinsic value of stock options exercised during the year	$ 3,455	$ 1,589	$ 157
Weighted-average remaining contractual life of the outstanding and exercisable stock options	5 years 11 months 1 day
Non-vested stock options	12,500
Weighted-average assumptions used to estimate the fair value for the stock options
Risk-free interest rates (as a percent)	4.57%
Dividend yield (as a percent)	0.31%
Volatility factor (as a percent)	0.406%
Time period used to calculate weighted averages for fair value assumptions	5 years
Options | Minimum
Weighted-average assumptions used to estimate the fair value for the stock options
Risk-free interest rates (as a percent)		3.41%	2.92%
Dividend yield (as a percent)		0.35%	0.57%
Volatility factor (as a percent)		0.389%	0.374%
Options | Maximum
Weighted-average assumptions used to estimate the fair value for the stock options
Risk-free interest rates (as a percent)		3.84%	3.94%
Dividend yield (as a percent)		0.48%	0.73%
Volatility factor (as a percent)		0.40%	0.385%
Expected life	5 years
Options | Weighted-average
Weighted-average assumptions used to estimate the fair value for the stock options
Risk-free interest rates (as a percent)		3.74%	3.74%
Dividend yield (as a percent)		0.39%	0.62%
Volatility factor (as a percent)		0.397%	0.382%
Restricted stock
Restricted Stock
Non-vested at the beginning of the period (in shares)	91,235
Granted (in shares)	74,305
Vested (in shares)	(85,288)
Forfeited (in shares)	(1,245)
Non-vested at the end of the period (in shares)	79,007	91,235
Weighted-Average Grant-Date Fair Value
Non-vested at the beginning of the period (in dollars per share)	$ 40.32
Granted (in dollars per share)	107.11
Vested (in dollars per share)	45.02
Forfeited (in dollars per share)	38.25
Non-vested at the end of the period (in dollars per share)	$ 98.09	$ 40.32
Additional disclosures
Total fair value of restricted stock vested during the year	$ 3,839	$ 2,663	$ 2,235
Total compensation cost not yet recognized	$ 7,190
Weighted-average period for recognition of total compensation cost not yet recognized	1 year 14 days
Restricted stock | Minimum
Stock-based compensation
Vesting period	6 months
Restricted stock | Maximum
Stock-based compensation
Vesting period	3 years

Share Repurchases (Details)

Share Repurchases (Details)	12 Months Ended
	Dec. 31, 2024 $ / shares shares
Share Repurchases
Shares paid for tax withholding for share-based compensation | shares	28,028
Weighted average per share prices for shares used to pay tax withholding liability (in dollars per share) | $ / shares	$ 125.09

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)
Equipment and Construction Contracts
Commitment and Contingencies
Purchase commitment	$ 35,480

Reportable Segment (Details)

Reportable Segment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) segment	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Business segments
Number of reportable segment | segment	1
Revenues	$ 317,721	$ 281,330	$ 236,150
Depreciation, depletion and amortization	23,855	23,533	21,921
Selling, general and administrative expenses	19,058	17,445	15,559
Other (income) expense, net	(11,460)	(7,940)	(1,779)
Income tax expense	27,544	18,813	11,133
Net income	108,839	74,549	45,429
Lime and limestone operations
Business segments
Revenues	317,721	281,330	236,150
Fuel, energy, and transportation	82,232	88,521	88,758
Depreciation, depletion and amortization	23,855	23,533	21,922
Outside services, maintenance, and supplies	28,536	29,310	22,086
Personnel expenses	30,980	29,209	26,528
Other cost of revenues	8,137	7,890	6,514
Selling, general and administrative expenses	19,058	17,445	15,559
Other (income) expense, net	(11,460)	(7,940)	(1,779)
Income tax expense	27,544	18,813	11,133
Net income	$ 108,839	$ 74,549	$ 45,429

Subsequent Event (Details)

Subsequent Event (Details) - 2025 Q1 Dividends - Subsequent event	1 Months Ended
	Feb. 03, 2025 $ / shares
Subsequent event
Dividends payable date declared	Feb. 03, 2025
Quarterly cash dividend declared (in dollars per share)	$ 0.06
Dividends payable date to be paid	Mar. 14, 2025
Dividends payable date of record	Feb. 21, 2025