U.S. Silica (SLCA) 10-Q 28 Jul 23 2023 Q2 Quarterly report Financial data

Cover

Cover - shares	6 Months Ended
	Jun. 30, 2023	Jul. 21, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2023
Document Transition Report	false
Entity File Number	001-35416
Entity Registrant Name	U.S. Silica Holdings, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-3718801
Entity Address, Address Line One	24275 Katy Freeway, Suite 600
Entity Address, City or Town	Katy
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77494
City Area Code	281
Local Phone Number	258-2170
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	SLCA
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		77,116,746
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001524741
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 186,961	$ 280,845
Accounts receivable, net	194,679	208,631
Inventories, net	161,820	147,626
Prepaid expenses and other current assets	13,678	20,182
Total current assets	557,138	657,284
Property, plant and mine development, net	1,148,681	1,178,834
Lease right-of-use assets	43,619	42,374
Goodwill	185,649	185,649
Intangible assets, net	136,097	140,809
Other assets	10,182	9,630
Total assets	2,081,366	2,214,580
Current Liabilities:
Accounts payable and accrued expenses	156,973	216,239
Current portion of operating lease liabilities	19,654	19,773
Current portion of long-term debt	10,152	19,535
Current portion of deferred revenue	8,244	16,275
Income tax payable	3,362	128
Total current liabilities	198,385	271,950
Long-term debt, net	871,913	1,037,458
Deferred revenue	13,355	14,477
Liability for pension and other post-retirement benefits	28,343	30,911
Deferred income taxes, net	85,444	64,636
Operating lease liabilities	61,937	64,478
Other long-term liabilities	27,649	25,976
Total liabilities	1,287,026	1,509,886
Commitments and Contingencies (Note N)
Stockholders’ Equity:
Preferred stock, $0.01 par value, 10,000,000 shares authorized; zero issued and outstanding at June 30, 2023 and December 31, 2022	0	0
Common stock, $0.01 par value, 500,000,000 shares authorized; 87,845,898 issued and 77,112,289 outstanding at June 30, 2023; 85,631,109 issued and 75,738,512 outstanding at December 31, 2022	877	854
Additional paid-in capital	1,241,828	1,234,834
Retained deficit	(260,177)	(351,084)
Treasury stock, at cost, 10,733,609 and 9,892,597 shares at June 30, 2023 and December 31, 2022, respectively	(196,162)	(186,196)
Accumulated other comprehensive income (loss)	857	(1,723)
Total U.S. Silica Holdings, Inc. stockholders’ equity	787,223	696,685
Non-controlling interest	7,117	8,009
Total stockholders' equity	794,340	704,694
Total liabilities and stockholders’ equity	$ 2,081,366	$ 2,214,580

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Jun. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock authorized (in shares)	10,000,000	10,000,000
Preferred stock issued (in shares)	0	0
Preferred stock outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock authorized (in shares)	500,000,000	500,000,000
Common stock issued (in shares)	87,845,898	85,631,109
Common stock outstanding (in shares)	77,112,289	75,738,512
Treasury stock, at cost (in shares)	10,733,609	9,892,597

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Sales:
Total sales	$ 406,784	$ 388,513	$ 849,024	$ 693,400
Cost of sales (excluding depreciation, depletion and amortization):
Total cost of sales (excluding depreciation, depletion and amortization)	259,773	268,896	552,906	495,765
Operating expenses:
Selling, general and administrative	28,694	34,817	57,857	74,927
Depreciation, depletion and amortization	33,546	34,715	68,932	72,464
Total operating expenses	62,240	69,532	126,789	147,391
Operating income	84,771	50,085	169,329	50,244
Other (expense) income:
Interest expense	(25,987)	(17,430)	(50,048)	(34,603)
Other income, net, including interest income	2,497	2,099	145	3,630
Total other expense	(23,490)	(15,331)	(49,903)	(30,973)
Income before income taxes	61,281	34,754	119,426	19,271
Income tax expense	(15,137)	(11,919)	(28,710)	(4,950)
Net income	46,144	22,835	90,716	14,321
Less: Net loss attributable to non-controlling interest	(115)	(73)	(191)	(194)
Net income attributable to U.S. Silica Holdings, Inc.	$ 46,259	$ 22,908	$ 90,907	$ 14,515
Earnings per share attributable to U.S. Silica Holdings, Inc.:
Basic (in dollars per share)	$ 0.60	$ 0.30	$ 1.18	$ 0.19
Diluted (in dollars per share)	$ 0.59	$ 0.29	$ 1.16	$ 0.19
Weighted average shares outstanding:
Basic (in shares)	77,089	75,508	76,804	75,373
Diluted (in shares)	78,338	77,966	78,309	77,494
Dividends declared per share (in dollars per share)	$ 0	$ 0	$ 0	$ 0
Product
Sales:
Total sales	$ 322,514	$ 290,325	$ 671,183	$ 523,559
Cost of sales (excluding depreciation, depletion and amortization):
Total cost of sales (excluding depreciation, depletion and amortization)	206,116	199,744	435,320	373,352
Service
Sales:
Total sales	84,270	98,188	177,841	169,841
Cost of sales (excluding depreciation, depletion and amortization):
Total cost of sales (excluding depreciation, depletion and amortization)	$ 53,657	$ 69,152	$ 117,586	$ 122,413

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 46,144	$ 22,835	$ 90,716	$ 14,321
Other comprehensive income (loss):
Unrealized gain on derivatives (net of tax of $613 and $0 for the three months ended June 30, 2023 and 2022, respectively, and $304 and $0 for the six months ended June 30, 2023 and 2022, respectively).	1,924	0	955	0
Foreign currency translation adjustment (net of tax of $16 and $(250) for the three months ended June 30, 2023 and 2022, respectively, and $87 and $(348) for the six months ended June 30, 2023 and 2022, respectively).	51	(783)	273	(1,092)
Pension and other post-retirement benefits liability adjustment (net of tax of $424 and $(937) for the three months ended June 30, 2023 and 2022, respectively, and $431and $147 for the six months ended June 30, 2023 and 2022, respectively).	1,330	(3,000)	1,352	462
Comprehensive income	49,449	19,052	93,296	13,691
Less: Comprehensive loss attributable to non-controlling interest	(115)	(73)	(191)	(194)
Comprehensive income attributable to U.S. Silica Holdings, Inc.	$ 49,564	$ 19,125	$ 93,487	$ 13,885

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Tax benefit on unrealized loss on derivatives	$ 613	$ 0	$ 304	$ 0
Tax expense (benefit) on foreign currency translation adjustment	16	(250)	87	(348)
Tax benefit on pension and other post-retirement benefits liability adjustment	$ 424	$ (937)	$ 431	$ 147

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Total U.S. Silica Holdings Inc., Stockholders’ Equity	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Deficit	Accumulated Other Comprehensive (Loss) Income	Non-controlling Interest
Beginning Balance at Dec. 31, 2021	$ 614,083	$ 604,215	$ 845	$ (186,294)	$ 1,218,575	$ (429,260)	$ 349	$ 9,868
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	14,321	14,515				14,515		(194)
Unrealized gain on derivatives	0
Foreign currency translation adjustment	(1,092)	(1,092)					(1,092)
Pension and post-retirement liability	462	462					462
Distributions to non-controlling interest	(724)							(724)
Common stock-based compensation plans activity:
Equity-based compensation	9,078	9,078			9,078
Proceeds from options exercised	533	533		1,695	(1,162)
Tax payments related to shares withheld for vested restricted stock and stock units	(2,227)	(2,227)	7	(2,227)	(7)
Ending Balance at Jun. 30, 2022	634,434	625,484	852	(186,826)	1,226,484	(414,745)	(281)	8,950
Beginning Balance at Mar. 31, 2022	610,794	601,400	851	(188,092)	1,222,780	(437,641)	3,502	9,394
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	22,835	22,908				22,908		(73)
Unrealized gain on derivatives	0
Foreign currency translation adjustment	(783)	(783)					(783)
Pension and post-retirement liability	(3,000)	(3,000)					(3,000)
Cash dividends	(12)	(12)				(12)
Distributions to non-controlling interest	(371)							(371)
Common stock-based compensation plans activity:
Equity-based compensation	4,696	4,696			4,696
Proceeds from options exercised	450	450		1,441	(991)
Tax payments related to shares withheld for vested restricted stock and stock units	(175)	(175)	1	(175)	(1)
Ending Balance at Jun. 30, 2022	634,434	625,484	852	(186,826)	1,226,484	(414,745)	(281)	8,950
Beginning Balance at Dec. 31, 2022	704,694	696,685	854	(186,196)	1,234,834	(351,084)	(1,723)	8,009
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	90,716	90,907				90,907		(191)
Unrealized gain on derivatives	955	955					955
Foreign currency translation adjustment	273	273					273
Pension and post-retirement liability	1,352	1,352					1,352
Distributions to non-controlling interest	(701)							(701)
Common stock-based compensation plans activity:
Equity-based compensation	7,017	7,017			7,017
Tax payments related to shares withheld for vested restricted stock and stock units	(9,966)	(9,966)	23	(9,966)	(23)
Ending Balance at Jun. 30, 2023	794,340	787,223	877	(196,162)	1,241,828	(260,177)	857	7,117
Beginning Balance at Mar. 31, 2023	741,557	733,974	876	(196,116)	1,238,098	(306,436)	(2,448)	7,583
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	46,144	46,259				46,259		(115)
Unrealized gain on derivatives	1,924	1,924					1,924
Foreign currency translation adjustment	51	51					51
Pension and post-retirement liability	1,330	1,330					1,330
Distributions to non-controlling interest	(351)							(351)
Common stock-based compensation plans activity:
Equity-based compensation	3,731	3,731			3,731
Tax payments related to shares withheld for vested restricted stock and stock units	(46)	(46)	1	(46)	(1)
Ending Balance at Jun. 30, 2023	$ 794,340	$ 787,223	$ 877	$ (196,162)	$ 1,241,828	$ (260,177)	$ 857	$ 7,117

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Operating activities:
Net income	$ 90,716	$ 14,321
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	68,932	72,464
Debt issuance amortization	1,836	2,501
Original issue discount amortization	1,295	510
Deferred income taxes	19,985	2,413
Deferred revenue	(9,153)	(3,961)
Gain on disposal of property, plant and equipment	(828)	(663)
Equity-based compensation	7,017	9,078
Allowance for credit losses, net of recoveries	68	258
Other	16,760	6,181
Changes in operating assets and liabilities:
Accounts receivable	13,884	(24,006)
Inventories	(14,132)	(17,280)
Prepaid expenses and other current assets	6,504	4,625
Income taxes	3,234	977
Accounts payable and accrued expenses	(56,006)	52,705
Operating lease liabilities	(12,774)	(12,497)
Liability for pension and other post-retirement benefits	(2,553)	(956)
Other noncurrent assets and liabilities	(1,768)	(3,489)
Net cash provided by operating activities	133,017	103,181
Investing activities:
Capital expenditures	(34,023)	(17,573)
Capitalized intellectual property costs	(173)	(132)
Proceeds from sale of property, plant and equipment	1,805	1,748
Net cash used in investing activities	(32,391)	(15,957)
Financing activities:
Dividends paid	(23)	(163)
Proceeds from options exercised	0	533
Tax payments related to shares withheld for vested restricted stock and stock units	(9,966)	(2,227)
Payments on short-term debt	(5,628)	(4,424)
Payments on long-term debt	(136,437)	(6,538)
Financing fees paid	(41,353)	0
Distributions to non-controlling interest	(701)	(724)
Principal payments on finance lease obligations	(402)	(727)
Net cash used in financing activities	(194,510)	(14,270)
Net (decrease) increase in cash and cash equivalents	(93,884)	72,954
Cash and cash equivalents, beginning of period	280,845	239,425
Cash and cash equivalents, end of period	186,961	312,379
Cash paid (received) during the period for:
Interest	47,548	31,606
Taxes, net of refunds	5,477	(19,543)
Non-cash items:
Accrued capital expenditures	$ 3,252	$ 1,478

Organization and Basis of Prese

Organization and Basis of Presentation	6 Months Ended
	Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND BASIS OF PRESENTATION	NOTE A—ORGANIZATION AND BASIS OF PRESENTATION Organization U.S. Silica Holdings, Inc. (“Holdings,” and together with its subsidiaries “we,” “us” or the “Company”) is a global performance materials company and a leading producer of commercial silica used in the oil and gas industry and in a wide range of industrial applications. In addition, through our subsidiary EP Minerals, LLC ("EPM"), we are an industry leader in the production of industrial minerals, including diatomaceous earth, clay (calcium bentonite and calcium montmorillonite) and perlite. During our 123-year history, we have developed core competencies in mining, processing, logistics and materials science that enable us to produce and cost-effectively deliver products to customers across our end markets. Our operations are organized into two reportable segments based on end markets served: (1) Oil & Gas Proppants and (2) Industrial & Specialty Products. See Note T - Segment Reporting for more information on our reportable segments. Basis of Presentation and Consolidation The accompanying unaudited Condensed Consolidated Financial Statements as of and for the three and six months ended June 30, 2023 included in this Quarterly Report on Form 10-Q have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X issued by the U.S. Securities and Exchange Commission (“SEC”). They do not contain certain information included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022; therefore, the unaudited Condensed Consolidated Financial Statements should be read in conjunction with that Annual Report on Form 10-K. Operating results for the six-month period ended June 30, 2023 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2023. In the opinion of management, all adjustments necessary for a fair presentation have been included. Such adjustments are of a normal, recurring nature. The unaudited Condensed Consolidated Financial Statements include the accounts of Holdings and its direct and indirect wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. Throughout this report we refer to (i) our unaudited Condensed Consolidated Balance Sheets as our “Balance Sheets,” (ii) our unaudited Condensed Consolidated Statements of Operations as our “Income Statements,” and (iii) our unaudited Condensed Consolidated Statements of Cash Flows as our “Cash Flows.”

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	NOTE B—SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates and Assumptions The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the related disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The areas requiring the use of management estimates and assumptions relate to the purchase price allocation for businesses acquired; mineral reserves that are the basis for future cash flow estimates utilized in impairment calculations and units-of-production amortization calculations; environmental, reclamation and closure obligations; estimates of recoverable minerals; estimates of allowance for credit losses; estimates of fair value for certain reporting units and asset impairments (including impairments of goodwill, intangible assets and other long-lived assets); write-downs of inventory to net realizable value; equity-based compensation expense; post-employment, post-retirement and other employee benefit liabilities; valuation allowances for deferred tax assets; contingent considerations; reserves for contingencies and litigation and the fair value and accounting treatment of financial instruments. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Accordingly, actual results may differ significantly from these estimates under different assumptions or conditions. New Accounting Pronouncements Recently Adopted None. New Accounting Pronouncements Not Yet Adopted In March 2020, the FASB issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting followed by ASU 2021-01, Reference Rate Reform (Topic 848): Scope, issued in January 2021 to provide clarifying guidance regarding the scope of Topic 848. ASU 2020-04 was issued to provide optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. Generally, the guidance is to be applied as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. ASU 2020-04 and ASU 2021-01 are effective for all entities through December 31, 2022. In April 2022, the FASB proposed to extend the effective date through December 31, 2024 and affirmed this decision in December 2022. Upon execution of the Fourth Amended and Restated Credit Agreement, we have transitioned from LIBOR. See Note I - Debt for discussion of the Fourth Amendment of the Credit Agreement.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
EARNINGS PER SHARE	NOTE C—EARNINGS PER SHARE Basic earnings per common share is computed by dividing income available to common stockholders by the weighted average number of common shares outstanding for the period. Diluted earnings per common share is computed similarly to basic earnings per common share except that the weighted average number of common shares outstanding is increased to include the number of additional common shares that would have been outstanding if the potentially dilutive common shares had been issued. Diluted net earnings per share assumes the conversion of contingently convertible securities and stock options under the treasury stock method, if dilutive. Contingently convertible securities and stock options are excluded from the calculation of fully diluted earnings per share if they are anti-dilutive, including when we incur a loss from continuing operations. The following table shows the computation of basic and diluted earnings per share: In thousands, except per share amounts Three Months Ended Six Months Ended 2023 2022 2023 2022 Numerator: Net income attributable to U.S. Silica Holdings, Inc. $ 46,259 $ 22,908 $ 90,907 $ 14,515 Denominator: Weighted average shares outstanding 77,089 75,508 76,804 75,373 Diluted effect of stock awards 1,249 2,458 1,505 2,121 Weighted average shares outstanding assuming dilution 78,338 77,966 78,309 77,494 Earnings per share attributable to U.S. Silica Holdings, Inc.: Basic earnings per share $ 0.60 $ 0.30 $ 1.18 $ 0.19 Diluted earnings per share $ 0.59 $ 0.29 $ 1.16 $ 0.19 Potentially dilutive shares are excluded from the calculation of diluted weighted average shares outstanding and diluted earnings per share if we are in a net loss position. Certain stock options, restricted stock awards and performance share units were excluded from the computation of diluted earnings per share because their effect would have been anti-dilutive. Such potentially dilutive shares and stock awards excluded from the calculation of diluted earnings per common share were as follows: In thousands Three Months Ended Six Months Ended 2023 2022 2023 2022 Potentially dilutive shares excluded — — — — Stock options excluded 413 509 413 509 Restricted stock and performance share unit awards excluded 38 3 54 2

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	NOTE D—ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Accumulated other comprehensive income (loss) consists of fair value adjustments associated with cash flow hedges, accumulated adjustments for net experience losses and prior service costs related to employee benefit plans and foreign currency translation adjustments, net of tax. The following table presents the changes in accumulated other comprehensive income (loss) by component (in thousands): For the Six Months Ended June 30, 2023 Unrealized (loss) gain on natural gas swaps Foreign currency translation adjustments Pension and other post-retirement benefits liability Total Beginning Balance $ (2,342) $ (1,262) $ 1,881 $ (1,723) Other comprehensive income before reclassifications 955 273 2,311 3,539 Amounts reclassified from accumulated other comprehensive income — — (959) (959) Ending Balance $ (1,387) $ (989) $ 3,233 $ 857 Any amounts reclassified from accumulated other comprehensive income (loss) related to pension and other post-retirement benefits are included in the computation of net periodic benefit costs at their pre-tax amounts.

Accounts Receivable

Accounts Receivable	6 Months Ended
	Jun. 30, 2023
Receivables [Abstract]
ACCOUNTS RECEIVABLE	NOTE E—ACCOUNTS RECEIVABLE Accounts receivable are recorded when billed or accrued and represent claims against third parties that will be settled in cash. The carrying value of our accounts receivable, net of the allowance for credit losses, represents their estimated net realizable value. Accounts receivable (in thousands) consisted of the following: June 30, December 31, Trade receivables $ 198,005 $ 209,683 Less: Allowance for credit losses (5,699) (5,691) Net trade receivables 192,306 203,992 Other receivables 2,373 4,639 Total accounts receivable $ 194,679 $ 208,631 We classify our trade receivables into the following portfolio segments: Oil & Gas Proppants and Industrial & Specialty Products, which also aligns with our reporting segments. We estimate the allowance for credit losses based on historical collection trends, the age of outstanding receivables, risks attributable to specific customers, such as credit history, bankruptcy or other going concern issues, and current economic and industry conditions. If events or circumstances indicate that specific receivable balances may be impaired, further consideration is given to the collectability of those balances and the allowance is adjusted accordingly. Past due balances are written off when we have exhausted our internal and external collection efforts and have been unsuccessful in collecting the amount due. The following table reflects the change of the allowance for credit losses (in thousands): Oil & Gas Proppants Industrial & Specialty Products Total Beginning balance, December 31, 2022 $ 4,028 $ 1,663 $ 5,691 Allowance for credit losses — 68 68 Write-offs — (60) (60) Ending balance, June 30, 2023 $ 4,028 $ 1,671 $ 5,699

Inventories

Inventories	6 Months Ended
	Jun. 30, 2023
Inventory Disclosure [Abstract]
INVENTORIES	NOTE F—INVENTORIES Inventories (in thousands) consisted of the following: June 30, 2023 December 31, 2022 Supplies $ 63,804 $ 54,805 Raw materials and work in process 53,585 47,042 Finished goods 44,431 45,779 Total inventories $ 161,820 $ 147,626

Property, Plant and Mine Develo

Property, Plant and Mine Development	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND MINE DEVELOPMENT	NOTE G—PROPERTY, PLANT AND MINE DEVELOPMENT Property, plant and mine development (in thousands) consisted of the following: June 30, December 31, Mining property and mine development $ 791,229 $ 789,601 Asset retirement cost 10,056 8,869 Land 53,288 53,128 Land improvements 87,208 76,456 Buildings 75,914 73,151 Machinery and equipment 1,238,004 1,217,933 Furniture and fixtures 3,029 3,922 Construction-in-progress 47,042 55,696 2,305,770 2,278,756 Accumulated depreciation, depletion, amortization and impairment charges (1,157,089) (1,099,922) Total property, plant and mine development, net $ 1,148,681 $ 1,178,834 Depreciation, depletion, and amortization expense related to property, plant and mine development was $30.5 million and $31.7 million for the three months ended June 30, 2023 and 2022, respectively, and $62.8 million and $66.6 million for the six months ended June 30, 2023 and 2022, respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	NOTE H—GOODWILL AND INTANGIBLE ASSETS The changes in the carrying amount of goodwill (in thousands) by business segment consisted of the following: Oil & Gas Proppants Segment Industrial & Specialty Products Segment Total Balance at December 31, 2022 $ — $ 185,649 $ 185,649 Impairment loss — — — Balance at June 30, 2023 $ — $ 185,649 $ 185,649 Goodwill and trade names are evaluated for impairment annually as of October 31, or more frequently when indicators of impairment exist. We evaluated events and circumstances since the date of our last qualitative assessment, including macroeconomic conditions, industry and market conditions, and our overall financial performance. There were no triggering events during the first six months of 2023, therefore, no impairment charges were recorded related to goodwill or trade names for the six months ended June 30, 2023. The changes in the carrying amount of intangible assets (in thousands) consisted of the following: June 30, 2023 December 31, 2022 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Technology and intellectual property $ 71,788 $ (32,439) $ 39,349 $ 71,651 $ (29,990) $ 41,661 Customer relationships 66,999 (35,191) 31,808 66,999 (32,791) 34,208 Total definite-lived intangible assets: $ 138,787 $ (67,630) $ 71,157 $ 138,650 $ (62,781) $ 75,869 Trade names 64,240 — 64,240 64,240 — 64,240 Other 700 — 700 700 — 700 Total intangible assets: $ 203,727 $ (67,630) $ 136,097 $ 203,590 $ (62,781) $ 140,809 Estimated useful life of technology and intellectual property is 15 years. Estimated useful life of customer relationships is a range of 13 - 20 years. Amortization expense was $2.5 million and $4.9 million for the three and six months ended June 30, 2023, respectively, and $2.4 million and $4.8 million for the three and six months ended June 30, 2022, respectively. The estimated amortization expense related to definite-lived intangible assets (in thousands) for the five succeeding years is as follows: 2023 (remaining six months) $ 4,855 2024 $ 9,707 2025 $ 9,706 2026 $ 9,706 2027 $ 9,706

Debt

Debt	6 Months Ended
	Jun. 30, 2023
Debt Disclosure [Abstract]
DEBT	NOTE I—DEBT Debt (in thousands) consisted of the following: June 30, December 31, Senior secured credit facility: Revolver expiring March 23, 2028 (9.95% at June 30, 2023 and 8.44% at December 31, 2022) $ — $ — Term Loan—final maturity March 23, 2030 (9.95% at June 30, 2023 and 8.44% at December 31, 2022) 922,625 1,059,062 Less: Unamortized original issue discount (27,678) (2,035) Less: Unamortized debt issuance cost (15,076) (8,922) Insurance financing notes payable — 5,628 Finance leases (See Note P - Leases) 2,194 3,260 Total debt 882,065 1,056,993 Less: current portion (10,152) (19,535) Total long-term portion of debt $ 871,913 $ 1,037,458 Senior Secured Credit Facility On March 23, 2023, we entered into the Fourth Amended and Restated Credit Agreement (the "Credit Agreement"), by entering into a new $1.1 billion senior secured credit facility, consisting of a $950 million Term Loan (the "Term Loan") and a $150 million revolving credit facility (the "Revolver") (collectively the "Credit Facility") that may also be used for swingline loans or letters of credit, and we may elect to increase the term loan or the revolving credit facility in accordance with the terms of the Credit Agreement. Borrowings under the Credit Agreement will bear interest at variable rates as determined at our election, based on the Term Secured Overnight Financing Rate ("SOFR") or a base rate, in each case, plus an applicable margin. In addition, under the Credit Agreement, we are required to pay a per annum commitment fee to revolving lenders and fees for letters of credit. The Credit Agreement is secured by substantially all of our assets and our domestic subsidiaries' assets and a pledge of the equity interests in such entities. The Term Loan matures on March 23, 2030, and the Revolver expires March 23, 2028. We capitalized $45.6 million in debt issuance costs and original issue discount as a result of the Credit Agreement. Additionally, as a result of the exit of certain lending parties, a portion of debt issuance and original discount costs were written off which resulted in additional expense of approximately $4.3 million. This was recorded as a loss on the extinguishment of debt, which was recorded in Other (expense) income, net, including interest income in the Condensed Consolidated Statements of Operations. The Credit Facility contains covenants that, among other things, limit our ability, and certain of our subsidiaries' abilities, to create, incur or assume indebtedness and liens, to make acquisitions or investments, to sell assets and to pay dividends. The Credit Agreement also requires us to maintain a consolidated leverage ratio of no more than 4.00:1.00 as of the last day of any fiscal quarter whenever usage of the Revolver (other than certain undrawn letters of credit) exceeds 2.85:1.00, or 35%, of the Revolver commitment. These covenants are subject to a number of important exceptions and qualifications. The Credit Agreement includes events of default and other affirmative and negative covenants that are usual for facilities and transactions of this type. As of June 30, 2023 and December 31, 2022, we were in compliance with all covenants in accordance with our senior secured Credit Facility. Term Loan At June 30, 2023, contractual maturities of our Term Loan (in thousands) are as follows: 2023 (remaining six months) $ 4,625 2024 9,250 2025 9,250 2026 9,250 2027 9,250 Thereafter 881,000 Total $ 922,625 Prior to the execution of the Fourth Amendment to the Credit Agreement, we repurchased outstanding debt under the Term Loan in the amount of $109 million. A proportionate share of debt issuance and original discount costs were written off in conjunction with this repurchase which resulted in additional expense of approximately $1.0 million. As a result, we recorded a loss on extinguishment of debt in the amount of $1.0 million. The loss on extinguishment was recorded in Other (expense) income, net, including interest income in the Condensed Consolidated Statements of Operations. During the second quarter of 2023, we made a voluntary prepayment on the Term Loan of $25 million. A proportionate share of debt issuance and original discount costs were written off in conjunction with the prepayment of this debt which resulted in additional expense of $1.1 million. This expense was recorded in Other (expense) income, net, including interest income in the Condensed Consolidated Statements of Operations. Revolving Line-of-Credit We have a $150.0 million Revolver with zero drawn and $21.3 million allocated for letters of credit as of June 30, 2023, leaving $128.7 million available under the Revolver. Based on our consolidated leverage ratio of 1.94:1.00 as of June 30, 2023, we have access to the full availability of the Revolver.

Asset Retirement Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2023
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT OBLIGATIONS	NOTE J—ASSET RETIREMENT OBLIGATIONS Mine reclamation or future remediation costs for inactive mines are accrued based on management’s best estimate at the end of each period of the costs expected to be incurred at such site at the expected abandonment date. Such cost estimates include, where applicable, ongoing care, maintenance and monitoring costs. Changes in estimates at inactive mines are reflected in earnings in the period an estimate is revised. Liabilities related to our asset retirement obligations are reflected in other long-term liabilities on our balance sheets. Changes in the asset retirement obligations (in thousands) are as follows: Six Months Ended 2023 2022 Beginning balance $ 20,732 $ 32,049 Accretion 1,025 749 Additions and revisions of estimates 1,187 (3,126) Payments (14) (62) Ending balance $ 22,930 $ 29,610

Fair Value Accounting

Fair Value Accounting	6 Months Ended
	Jun. 30, 2023
Fair Value Disclosures [Abstract]
FAIR VALUE ACCOUNTING	NOTE K—FAIR VALUE ACCOUNTING Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability. Cash Equivalents Due to the short-term maturity, we believe our cash equivalent instruments approximated their reported carrying values, therefore we have classified our cash equivalents as Level 1 of the fair value hierarchy. Long-Term Debt, Including Current Maturities The fair values of our long-term debt, including current maturities, approximated their carrying values based on their effective interest rates compared to current market rates, therefore we have classified our long-term debt as Level 1 of the fair value hierarchy. Derivative Instruments The estimated fair value of our derivative instruments is recorded at each reporting period and is determined based on inputs that are readily available in public markets or can be derived from information available in publicly quoted markets. Therefore, we have classified these swap agreements as Level 2 of the fair value hierarchy.

Derivative Instruments

Derivative Instruments	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS	NOTE L—DERIVATIVE INSTRUMENTS Cash Flow Hedges of Natural Gas Price Risk Natural gas is the primary fuel source used for drying in the commercial silica production process. In the past, the price of natural gas has been volatile, and we believe this volatility may continue. In order to manage our exposure to natural gas price increases, we entered into natural gas swaps. The derivative instruments are recorded on the balance sheet within other current or long-term assets or liabilities based on maturity dates at their fair values. As of June 30, 2023, the fair value of our natural gas swaps was a liability of $1.8 million, of which $1.4 million was classified within accounts payable and accrued liabilities on our balance sheet and $0.4 million was classified within other long-term obligations on our balance sheet. At December 31, 2022, the fair value of our natural gas swaps was a liability of $3.1 million, of which $2.3 million was classified within accounts payable and accrued liabilities on our balance sheet and $0.8 million was classified within other long-term obligations on our balance sheet. We designated the natural gas swap agreements as qualified cash flow hedges. Accordingly, the effective portion of the gain or loss on the derivative instrument was reported as a component of other comprehensive income and recognized in earnings in the same period or periods during which the hedged transaction affects earnings. The following table summarizes the fair values of our derivative instruments (in thousands, except contract/notional amount). See Note K - Fair Value Accounting for more information regarding the estimated fair values of our derivative instruments. June 30, 2023 December 31, 2022 Maturity Contract/Notional Carrying Fair Maturity Date Contract/Notional Carrying Fair Natural Gas - W. Texas (WAHA) - Inside FERC 2023 1,200,000 $ (683) $ (683) 2023 1,200,000 $ (1,887) $ (1,887) Natural Gas - W. Texas (WAHA) - Inside FERC 2024 870,000 $ (742) $ (742) 2024 870,000 $ (656) $ (656) Natural Gas - W. Texas (WAHA) - Inside FERC 2024 750,000 $ 205 $ 205 N/A N/A $ — $ — Natural Gas - Henry Hub - NYMEX 2023 300,000 $ (361) $ (361) 2023 300,000 $ (425) $ (425) Natural Gas - Henry Hub - NYMEX 2024 120,000 $ (174) $ (174) 2024 120,000 $ (85) $ (85) Natural Gas - Henry Hub - NYMEX 2025 90,000 $ (73) $ (73) 2025 90,000 $ (35) $ (35) During the six months ended June 30, 2023, we had no ineffectiveness for the natural gas swap derivatives. The following table summarizes the effect of derivative instruments (in thousands) on our income statements and our consolidated statements of comprehensive income: Six Months Ended 2023 2022 Deferred losses from derivatives in OCI, beginning of period $ (2,342) $ — Gain recognized in OCI from derivative instruments 955 — Deferred losses from derivatives in OCI, end of period $ (1,387) $ —

Equity-Based Compensation

Equity-Based Compensation	6 Months Ended
	Jun. 30, 2023
Share-Based Payment Arrangement [Abstract]
EQUITY-BASED COMPENSATION	NOTE M—EQUITY-BASED COMPENSATION In July 2011, we adopted the U.S. Silica Holdings, Inc. 2011 Incentive Compensation Plan (the “2011 Plan”), which was amended and restated effective May 2015, amended and restated effective February 1, 2020, amended and restated effective May 13, 2021, amended and restated effective May 12, 2022 and amended and restated effective May 11, 2023. The 2011 Plan provides for grants of stock options, restricted stock, performance share units and other incentive-based awards. We believe our 2011 Plan aligns the interests of our employees and directors with those of our common stockholders. We use a combination of treasury stock and new shares, if necessary, to satisfy option exercises or vesting of restricted awards and performance share units. Stock Options The following table summarizes the status of, and changes in, our stock option awards during the six months ended June 30, 2023: Number of Weighted Weighted Outstanding at December 31, 2022 508,523 $ 36.22 2.0 years Granted — $ — Exercised — $ — Forfeited (58,160) $ 36.65 Expired (37,434) $ 24.80 Outstanding at June 30, 2023 412,929 $ 37.20 1.6 years Exercisable at June 30, 2023 412,929 $ 37.20 1.6 years There were no grants of stock options during the three and six months ended June 30, 2023 and 2022. The following table summarizes stock option exercise activity: Three months ended June 30, Six months ended June 30, 2023 2022 2023 2022 Options exercised (in actual shares) — 42,500 — 50,000 Intrinsic value of options exercised (in thousands) $ — $ 421 $ — $ 446 Cash received from options exercised (in thousands) $ — $ 449 $ — $ 533 Tax benefit realized from options exercised (in thousands) $ — $ 102 $ — $ 108 As of June 30, 2023 and 2022, there was no unrecognized compensation expense related to these options. We account for forfeitures as they occur. Restricted Stock and Restricted Stock Unit Awards The following table summarizes the status of, and changes in, our unvested restricted stock awards during the six months ended June 30, 2023: Number of Shares Grant Date Weighted Unvested, December 31, 2022 1,438,386 $ 9.37 Granted 635,605 $ 12.02 Vested (665,756) $ 8.95 Forfeited (118,426) $ 8.62 Unvested, June 30, 2023 1,289,809 $ 10.96 We granted 141,671 and 635,605 restricted stock and restricted stock unit awards during the three and six months ended June 30, 2023, respectively. We granted 42,220 and 630,712 restricted stock and restricted stock units during the three and six months ended June 30, 2022, respectively.The fair value of the awards was based on the market price of our stock at date of grant. We recognized $1.9 million and $3.5 million of equity-based compensation expense related to restricted stock and restricted stock units during the three and six months ended June 30, 2023, respectively. We recognized $1.8 million and $3.4 million of equity-based compensation expense related to restricted stock and restricted stock units during the three and six months ended June 30, 2022, respectively. As of June 30, 2023, there was $11.3 million of unrecognized compensation expense related to these restricted stock and restricted stock units, which is expected to be recognized over a weighted-average period of 1.9 years. We also granted cash awards during the three months ended March 31, 2020. These awards vested over a period of three years and were settled in cash. As such, these awards were classified as liability instruments. We recognized zero and $0.3 million of expense related to these awards for the three and six months ended June 30, 2023, respectively. We recognized $0.1 million and $0.4 million of expense related to these awards for the three and six months ended June 30, 2022, respectively. The liability for these awards was included in accounts payable and other accrued expenses on our balance sheets. These awards were remeasured at fair value each reporting period with resulting changes reflected in our income statements. As of June 30, 2023, there was no unrecognized expense related to these awards. Performance Share Unit Awards The following table summarizes the status of, and changes in, our performance share unit awards during the six months ended June 30, 2023: Number of Shares Grant Date Weighted Unvested, December 31, 2022 2,292,751 $ 9.51 Granted 1,295,904 $ 9.54 Vested (1,549,033) $ 6.60 Forfeited/Cancelled (109,259) $ 11.52 Unvested, June 30, 2023 1,930,363 $ 11.75 We granted 5,924 and 1,295,904 performance share unit awards during the three and six months ended June 30, 2023, respectively. We granted zero and 920,681 performance share unit awards during the three and six months ended June 30, 2022, respectively. A portion of these awards was measured against total shareholder return ("TSR"), and a portion was measured against adjusted free cash flow ("ACF") targets. The grant date weighted average fair value of these awards was estimated to be $9.54 and $11.79 for the six months ended June 30, 2023 and 2022, respectively. The number of TSR measured units that will vest will depend on the percentage ranking of our TSR compared to the TSR for each of the companies in the peer group over the three year period from January 1, 2023 through December 31, 2025 for the 2023 grant, January 1, 2022 through December 31, 2024 for the 2022 grant, and January 1, 2021 through December 31, 2023 for the 2021 grant. The number of ACF measured units that will vest will be based on ACF achievement versus target. The ACF targets are set annually and are approved by the Board of Directors. The related compensation expense is recognized on a straight-line basis over the vesting period. The grant date fair value for the TSR awards was estimated using a Monte Carlo simulation model. The Monte Carlo simulation model requires the use of highly subjective assumptions. Our key assumptions in the model included the price and the expected volatility of our common stock and our self-determined peer group companies’ stock, risk-free rate of interest, dividend yields and cross-correlations between our common stock and our self-determined peer group companies' stock. We recognized $1.8 million and $3.5 million of compensation expense related to performance share unit awards during the three and six months ended June 30, 2023, respectively. We recognized $2.9 million and $5.7 million of compensation expense related to performance share unit awards during the three and six months ended June 30, 2022, respectively. As of June 30, 2023, there was $12.0 million of unrecognized compensation expense related to these performance share unit awards, which is expected to be recognized over a weighted-average period of 2.0 years. We also granted cash awards during the three months ended March 31, 2020. These awards vested over a period of three years and were settled in cash. As such, these awards were classified as liability instruments. We recognized $0.1 million and $0.6 million of expense related to these awards for the six months ended June 30, 2023 and 2022, respectively. The liability for these awards was included in accounts payable and other accrued expenses on our balance sheets. These awards were remeasured at fair value each reporting period with resulting changes reflected in our income statements. As of June 30, 2023, there was no unrecognized expense related to these awards.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	NOTE N—COMMITMENTS AND CONTINGENCIES Future Minimum Annual Commitments at June 30, 2023 (in thousands): Minimum Purchase Commitments 2023 (remaining six months) $ 4,566 2024 7,640 2025 6,431 2026 3,844 2027 2,288 Thereafter 7,484 Total future purchase commitments $ 32,253 Minimum Purchase Commitments We enter into service agreements with our transload and transportation service providers. Some of these agreements require us to purchase a minimum amount of services over a specific period of time. Any inability to meet these minimum contract requirements requires us to pay a shortfall fee, which is based on the difference between the minimum amount contracted for and the actual amount purchased. Contingent Liability on Royalty Agreement On May 17, 2017, we purchased reserves in Crane County, Texas, for $94.4 million cash plus contingent consideration. The contingent consideration is a royalty that is based on the tonnage shipped to third-parties. Because the contingent consideration is dependent on future tonnage sold, the amounts of which are uncertain, it is not currently possible to estimate the fair value of these future payments. The contingent consideration will be capitalized at the time a payment is probable and reasonably estimable, and the related depletion expense will be adjusted prospectively. Other Commitments and Contingencies Our operating subsidiary, U.S. Silica Company (“U.S. Silica”), has been named as a defendant in various product liability claims alleging silica exposure causing silicosis. During the six months ended June 30, 2023, no new claims were brought against U.S. Silica. As of June 30, 2023, there were 42 active silica-related product liability claims pending in which U.S. Silica is a defendant. Although the outcomes of these claims cannot be predicted with certainty, in the opinion of management, it is not reasonably possible that the ultimate resolution of these matters will have a material adverse effect on our financial position or results of operations that exceeds the accrual amounts. We have recorded estimated liabilities for these claims in other long-term liabilities as well as estimated recoveries under the indemnity agreement and an estimate of future recoveries under insurance in other assets on our consolidated balance sheets. For both June 30, 2023 and December 31, 2022, other non-current assets included zero for insurance for third-party product liability claims. As of June 30, 2023 and December 31, 2022 other long-term liabilities included $0.7 million and $0.8 million, respectively, for third-party product liability claims. Obligations under Guarantees We have indemnified our insurers against any loss they may incur in the event that holders of surety bonds, issued on our behalf, execute the bonds. As of June 30, 2023, there was $42.6 million in bonds outstanding, of which $38.6 million related to reclamation requirements issued by various governmental authorities. Reclamation bonds remain outstanding until the mining area is reclaimed and the authority issues a formal release. The remaining bonds relate to licenses, permits, and tax collection.

Pension and Post-Retirement Ben

Pension and Post-Retirement Benefits	6 Months Ended
	Jun. 30, 2023
Retirement Benefits [Abstract]
PENSION AND POST-RETIREMENT BENEFITS	NOTE O—PENSION AND POST-RETIREMENT BENEFITS We maintain a single-employer noncontributory defined benefit pension plan covering certain employees. The plan is frozen to all new employees. The plan provides benefits based on each covered employee’s years of qualifying service. Our funding policy is to contribute amounts within the range of the minimum required and maximum deductible contributions for the plan consistent with a goal of appropriate minimization of the unfunded projected benefit obligations. The pension plan uses a benefit level per year of service for covered hourly employees and a final average pay method for covered salaried employees. The plan uses the projected unit credit cost method to determine the actuarial valuation. In addition, we provide defined benefit post-retirement health care and life insurance benefits to some employees. Covered employees become eligible for these benefits at retirement after meeting minimum age and service requirements. The projected future cost of providing post-retirement benefits, such as healthcare and life insurance, is recognized as an expense as employees render services. In general, retiree health benefits are paid as covered expenses are incurred. Expenses incurred other than service costs are reported in Other (expense) income in our Condensed Consolidated Statements of Operations. Net pension benefit cost (in thousands) consisted of the following: Three Months Ended Six Months Ended 2023 2022 2023 2022 Service cost $ 573 $ 692 $ 1,146 $ 1,381 Interest cost 1,249 692 2,497 1,381 Expected return on plan assets (1,518) (1,424) (3,037) (2,842) Net amortization and deferral (3) 502 (5) 1,001 Net pension benefit costs $ 301 $ 462 $ 601 $ 921 Net post-retirement benefit cost (in thousands) consisted of the following: Three Months Ended Six Months Ended 2023 2022 2023 2022 Service cost $ 4 $ 6 $ 8 $ 12 Interest cost 80 36 160 72 Unrecognized prior service cost (516) (515) (1,031) (1,031) Unrecognized net (gain)/loss (131) (35) (262) (69) Net post-retirement benefit income $ (563) $ (508) $ (1,125) $ (1,016) We made no contributions to the qualified pension plan for the three and six months ended June 30, 2023 and 2022. Our best estimates of expected contributions to the pension and post-retirement medical benefit plans for the 2023 fiscal year are zero and $1.0 million, respectively. We contribute to three multiemployer defined benefit pension plans under the terms of collective-bargaining agreements for union-represented employees. A multiemployer plan is subject to collective bargaining for employees of two or more unrelated companies. These plans allow multiple employers to pool their pension resources and realize efficiencies associated with the daily administration of the plan. Multiemployer plans are generally governed by a board of trustees composed of management and labor representatives and are funded through employer contributions. However, in most cases, management is not directly represented. Our contributions to individual multiemployer pension funds did not exceed 5% of the fund’s total contributions for the three and six months ended June 30, 2023 and 2022. Additionally, our contributions to multiemployer post-retirement benefit plans were immaterial for all periods presented in the accompanying condensed consolidated financial statements. We also sponsor a defined contribution plan covering certain employees. We contribute to the plan in two ways. For certain employees not covered by the defined benefit plan, we make a contribution equal to 4% of their salary. For all other eligible employees, we make a contribution up to 6% of eligible earnings. Contributions were $2.0 million and $4.1 million for the three and six months ended June 30, 2023, respectively, and $1.7 million and $3.5 million for the three and six months ended June 30, 2022, respectively.

Leases

Leases	6 Months Ended
	Jun. 30, 2023
Leases [Abstract]
LEASES	NOTE P— LEASES We lease railroad cars, office space, mining property, mining/processing equipment and transportation and other equipment. The majority of our leases have remaining lease terms of approximately one year to 20 years. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. We have lease agreements with lease and non-lease components, the latter of which are generally accounted for separately. Supplemental balance sheet information related to leases was as follows (in thousands, except lease term and discount rate): Leases Classification June 30, December 31, 2022 Assets Operating Lease right-of-use assets $ 41,382 $ 39,088 Finance Lease right-of-use assets 2,237 3,286 Total leased assets $ 43,619 $ 42,374 Liabilities Current Operating Current portion of operating lease liabilities $ 19,654 $ 19,773 Finance Current portion of long-term debt 902 1,107 Non-current Operating Operating lease liabilities 61,937 64,478 Finance Long-term debt, net 1,292 2,153 Total lease liabilities $ 83,785 $ 87,511 Lease Term and Discount Rate Weighted average remaining lease term: Operating 6.1 years 6.4 years Finance 4.4 years 4.4 years Weighted average discount rate: Operating 5.8% 5.7% Finance 5.6% 5.1% The components of lease expense (in thousands) were as follows: Lease Costs Classification Three Months Ended Three Months Ended Six Months Ended Six Months Ended Operating lease costs (1) Cost of sales $ 10,320 $ 9,291 $ 20,695 $ 16,919 Operating lease costs (2) Selling, general and administrative 748 447 1,343 801 Total (3) $ 11,068 $ 9,738 $ 22,038 $ 17,720 (1) Included short-term operating lease costs of $6.6 million and $13.4 million for the three and six months ended June 30, 2023, respectively, and $5.2 million and $9.9 million for the three and six months ended June 30, 2022, respectively. (2) Included short-term operating lease costs of $0.4 million and $0.7 million for the three and six months ended June 30, 2023, respectively, and $0.1 million and $0.2 million for the three and six months ended June 30, 2022, respectively. (3) Not included were expenses for finance leases of $0.2 million and $0.4 million for the three and six months ended June 30, 2023, respectively, and $0.4 million and $0.8 million for the three and six months ended June 30, 2022, respectively. Supplemental cash flow information (in thousands) related to leases was as follows: Six Months Ended Six Months Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 12,774 $ 12,497 Financing cash flows for finance leases $ 473 $ 727 Right-of-use assets obtained in exchange for new lease liabilities: Operating leases $ 3,376 $ 1,713 Finance leases $ 273 $ 8,865 Maturities of lease liabilities (in thousands) as of June 30, 2023: Operating leases Finance leases 2023 (remaining six months) $ 12,488 $ 425 2024 22,331 970 2025 16,667 688 2026 12,865 117 2027 9,091 46 Thereafter 26,012 190 Total lease payments $ 99,454 $ 2,436 Less: Interest 15,782 242 Less: Other operating expenses 2,081 — Total $ 81,591 $ 2,194
LEASES	NOTE P— LEASES We lease railroad cars, office space, mining property, mining/processing equipment and transportation and other equipment. The majority of our leases have remaining lease terms of approximately one year to 20 years. Our lease terms may include options to extend or terminate the lease when it is reasonably certain that we will exercise that option. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. We have lease agreements with lease and non-lease components, the latter of which are generally accounted for separately. Supplemental balance sheet information related to leases was as follows (in thousands, except lease term and discount rate): Leases Classification June 30, December 31, 2022 Assets Operating Lease right-of-use assets $ 41,382 $ 39,088 Finance Lease right-of-use assets 2,237 3,286 Total leased assets $ 43,619 $ 42,374 Liabilities Current Operating Current portion of operating lease liabilities $ 19,654 $ 19,773 Finance Current portion of long-term debt 902 1,107 Non-current Operating Operating lease liabilities 61,937 64,478 Finance Long-term debt, net 1,292 2,153 Total lease liabilities $ 83,785 $ 87,511 Lease Term and Discount Rate Weighted average remaining lease term: Operating 6.1 years 6.4 years Finance 4.4 years 4.4 years Weighted average discount rate: Operating 5.8% 5.7% Finance 5.6% 5.1% The components of lease expense (in thousands) were as follows: Lease Costs Classification Three Months Ended Three Months Ended Six Months Ended Six Months Ended Operating lease costs (1) Cost of sales $ 10,320 $ 9,291 $ 20,695 $ 16,919 Operating lease costs (2) Selling, general and administrative 748 447 1,343 801 Total (3) $ 11,068 $ 9,738 $ 22,038 $ 17,720 (1) Included short-term operating lease costs of $6.6 million and $13.4 million for the three and six months ended June 30, 2023, respectively, and $5.2 million and $9.9 million for the three and six months ended June 30, 2022, respectively. (2) Included short-term operating lease costs of $0.4 million and $0.7 million for the three and six months ended June 30, 2023, respectively, and $0.1 million and $0.2 million for the three and six months ended June 30, 2022, respectively. (3) Not included were expenses for finance leases of $0.2 million and $0.4 million for the three and six months ended June 30, 2023, respectively, and $0.4 million and $0.8 million for the three and six months ended June 30, 2022, respectively. Supplemental cash flow information (in thousands) related to leases was as follows: Six Months Ended Six Months Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 12,774 $ 12,497 Financing cash flows for finance leases $ 473 $ 727 Right-of-use assets obtained in exchange for new lease liabilities: Operating leases $ 3,376 $ 1,713 Finance leases $ 273 $ 8,865 Maturities of lease liabilities (in thousands) as of June 30, 2023: Operating leases Finance leases 2023 (remaining six months) $ 12,488 $ 425 2024 22,331 970 2025 16,667 688 2026 12,865 117 2027 9,091 46 Thereafter 26,012 190 Total lease payments $ 99,454 $ 2,436 Less: Interest 15,782 242 Less: Other operating expenses 2,081 — Total $ 81,591 $ 2,194

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2023
Income Tax Disclosure [Abstract]
INCOME TAXES	NOTE Q— INCOME TAXES For interim period reporting, we record income taxes using an estimated annual effective tax rate based upon projected annual income, forecasted permanent tax differences, discrete items and statutory rates in states in which we operate. At the end of each interim period, we update the estimated annual effective tax rate, and if the estimated tax rate changes based on new information, we make a cumulative adjustment in the period. We record the tax effect of an unusual or infrequently occurring item in the interim period in which it occurs as a discrete item of tax. For the three and six months ended June 30, 2023, we had tax expense of $15.1 million and $28.7 million, respectively. For the three and six months ended June 30, 2022, we had tax expense of $11.9 million and $5.0 million, respectively. The effective tax rates were 25% and 24% for the three and six months ended June 30, 2023, respectively, and 34% and 26% for the three and six months ended June 30, 2022, respectively. Without discrete items, which primarily consist of the tax impact of equity compensation and non-US income taxes, the effective tax rates for the three and six months ended June 30, 2023 would have been 24% and 25%, respectively, and 34% and 22% for the three and six months ended June 30, 2022, respectively. During the three and six months ended June 30, 2023, we recorded tax expense of $0.2 million and a tax benefit of $2.1 million, respectively, related to equity compensation. During the three and six months ended June 30, 2022, we recorded a tax benefit of $0.2 million and tax expense of $0.1 million, respectively, related to equity compensation. Historically, our actual effective tax rates have differed from the statutory effective rate primarily due to the benefit received from statutory percentage depletion allowances. The deduction for statutory percentage depletion does not necessarily change proportionately to changes in income before income taxes. For the three and six months ended June 30, 2023, the benefit received from statutory percentage depletion allowances was offset by nondeductible executive compensation and state income taxes.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
REVENUE	NOTE R— REVENUE We consider sales disaggregated at the product and service level by business segment to depict how the nature, amount, timing and uncertainty of revenues and cash flow are impacted by changes in economic factors. The following table disaggregates our sales by major source (in thousands): Three Months Ended Three Months Ended Category Oil & Gas Proppants Industrial & Specialty Products Total Sales Oil & Gas Proppants Industrial & Specialty Products Total Sales Product $ 178,015 $ 144,499 $ 322,514 $ 146,058 $ 144,267 $ 290,325 Service 84,270 — 84,270 98,188 — 98,188 Total Sales $ 262,285 $ 144,499 $ 406,784 $ 244,246 $ 144,267 $ 388,513 Six Months Ended Six Months Ended Category Oil & Gas Proppants Industrial & Specialty Products Total Sales Oil & Gas Proppants Industrial & Specialty Products Total Sales Product $ 384,457 $ 286,726 $ 671,183 $ 250,649 $ 272,910 $ 523,559 Service 177,841 — 177,841 169,841 — 169,841 Total Sales $ 562,298 $ 286,726 $ 849,024 $ 420,490 $ 272,910 $ 693,400 The following tables reflect the changes in our contract assets, which we classify as unbilled receivables and our contract liabilities, which we classify as deferred revenues, for the six months ended June 30, 2023 and 2022 (in thousands): Unbilled Receivables June 30, 2023 June 30, 2022 Beginning Balance $ — $ 1,957 Reclassifications to billed receivables — (4,457) Revenues recognized in excess of period billings — 2,930 Ending Balance $ — $ 430 Deferred Revenue June 30, 2023 June 30, 2022 Beginning Balance $ 30,752 $ 20,741 Revenues recognized from balances held at the beginning of the period (9,153) (2,591) Revenues deferred from period collections on unfulfilled performance obligations — 20,948 Revenues recognized from period collections — (2,816) Ending Balance $ 21,599 $ 36,282 We have elected to use the practical expedients allowed under ASC 606-10-50-14, pursuant to which we have excluded disclosures of transaction prices allocated to remaining performance obligations and when we expect to recognize such revenue. The majority of our remaining performance obligations are primarily comprised of unfulfilled product, transportation service, and labor service orders, all of which hold a remaining duration of less than one year. The long-term portion of deferred revenue primarily represents a combination of refundable and nonrefundable customer prepayments for which related current performance obligations do not yet exist, but are expected to arise, before the expiration of the contract. Our residual unfulfilled performance obligations are comprised primarily of long-term equipment rental arrangements in which we recognize revenues equal to what we have a right to invoice. Generally, no variable consideration exists related to our remaining performance obligations and no consideration is excluded from the associated transaction prices. Foreign Operations The following table includes information related to our foreign operations (in thousands): Three Months Ended Three Months Ended Six Months Ended Six Months Ended Total Sales $ 25,817 $ 29,658 $ 55,749 $ 54,912 Pre-tax income $ 4,299 $ 9,715 $ 11,201 $ 14,528 Net income $ 3,396 $ 7,675 $ 8,848 $ 11,477 Foreign operations constituted approximately $33.7 million and $38.2 million of consolidated assets as of June 30, 2023 and 2022, respectively.

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2023
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	NOTE S— RELATED PARTY TRANSACTIONS There were no related party transactions during the three and six months ended June 30, 2023 or 2022.

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
SEGMENT REPORTING	NOTE T— SEGMENT REPORTING Our business is organized into two reportable segments, Oil & Gas Proppants and Industrial & Specialty Products, based on end markets. The reportable segments are consistent with how management views the markets that we serve and the financial information reviewed by the chief operating decision maker. We manage our Oil & Gas Proppants and Industrial & Specialty Products businesses as components of an enterprise for which separate information is available and is evaluated regularly by the chief operating decision maker in deciding how to allocate resources and assess performance. In the Oil & Gas Proppants segment, we serve the oil and gas recovery market primarily by providing and delivering fracturing sand, or “frac sand,” which is pumped down oil and natural gas wells to prop open rock fissures and increase the flow rate of oil and natural gas from the wells. The Industrial & Specialty Products segment consists of over 600 product types and materials used in a variety of industries, including container glass, fiberglass, specialty glass, flat glass, building products, fillers and extenders, foundry products, chemicals, recreation products and filtration products. An operating segment’s performance is primarily evaluated based on segment contribution margin, which excludes selling, general, and administrative costs, depreciation, depletion and amortization, corporate costs, plant capacity expansion expenses, and facility closure costs. We believe that segment contribution margin, as defined above, is an appropriate measure for evaluating the operating performance of our segments. However, segment contribution margin is a non-GAAP measure and should be considered in addition to, not a substitute for, or superior to, net income (loss) or other measures of financial performance prepared in accordance with GAAP. The other accounting policies of each of the two reportable segments are the same as those in Note B - Summary of Significant Accounting Policies to the Consolidated Financial Statements in Item 8 of our 2022 Annual Report on Form 10-K. The following table presents sales and segment contribution margin (in thousands) for the reportable segments and other operating results not allocated to the reportable segments: Three Months Ended Six Months Ended 2023 2022 2023 2022 Sales: Oil & Gas Proppants $ 262,285 $ 244,246 $ 562,298 $ 420,490 Industrial & Specialty Products 144,499 144,267 286,726 272,910 Total sales 406,784 388,513 849,024 693,400 Segment contribution margin: Oil & Gas Proppants 99,069 77,353 208,966 122,106 Industrial & Specialty Products 51,595 45,915 94,524 83,749 Total segment contribution margin 150,664 123,268 303,490 205,855 Operating activities excluded from segment cost of sales (3,653) (3,651) (7,372) (8,220) Selling, general and administrative (28,694) (34,817) (57,857) (74,927) Depreciation, depletion and amortization (33,546) (34,715) (68,932) (72,464) Interest expense (25,987) (17,430) (50,048) (34,603) Other income, net, including interest income 2,497 2,099 145 3,630 Income tax expense (15,137) (11,919) (28,710) (4,950) Net income $ 46,144 $ 22,835 $ 90,716 $ 14,321 Less: Net loss attributable to non-controlling interest (115) (73) (191) (194) Net income attributable to U.S. Silica Holdings, Inc. $ 46,259 $ 22,908 $ 90,907 $ 14,515

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2023
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	NOTE U— SUBSEQUENT EVENTS We evaluated subsequent events through the date the consolidated financial statements were available for issuance and did not identify any events requiring disclosure.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pay vs Performance Disclosure
Net Income (Loss)	$ 46,259	$ 22,908	$ 90,907	$ 14,515

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Jun. 30, 2023
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

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	The accompanying unaudited Condensed Consolidated Financial Statements as of and for the three and six months ended June 30, 2023 included in this Quarterly Report on Form 10-Q have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X issued by the U.S. Securities and Exchange Commission (“SEC”). They do not contain certain information included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2022; therefore, the unaudited Condensed Consolidated Financial Statements should be read in conjunction with that Annual Report on Form 10-K. Operating results for the six-month period ended June 30, 2023 are not necessarily indicative of the results that may be expected for the full year ending December 31, 2023. In the opinion of management, all adjustments necessary for a fair presentation have been included. Such adjustments are of a normal, recurring nature.
Consolidation	The unaudited Condensed Consolidated Financial Statements include the accounts of Holdings and its direct and indirect wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates and Assumptions	Use of Estimates and Assumptions The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the related disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. The areas requiring the use of management estimates and assumptions relate to the purchase price allocation for businesses acquired; mineral reserves that are the basis for future cash flow estimates utilized in impairment calculations and units-of-production amortization calculations; environmental, reclamation and closure obligations; estimates of recoverable minerals; estimates of allowance for credit losses; estimates of fair value for certain reporting units and asset impairments (including impairments of goodwill, intangible assets and other long-lived assets); write-downs of inventory to net realizable value; equity-based compensation expense; post-employment, post-retirement and other employee benefit liabilities; valuation allowances for deferred tax assets; contingent considerations; reserves for contingencies and litigation and the fair value and accounting treatment of financial instruments. We base our estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Accordingly, actual results may differ significantly from these estimates under different assumptions or conditions.
New Accounting Pronouncements Recently Adopted and New Accounting Pronouncements Not Yet Adopted	New Accounting Pronouncements Recently Adopted None. New Accounting Pronouncements Not Yet Adopted In March 2020, the FASB issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting followed by ASU 2021-01, Reference Rate Reform (Topic 848): Scope, issued in January 2021 to provide clarifying guidance regarding the scope of Topic 848. ASU 2020-04 was issued to provide optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. Generally, the guidance is to be applied as of any date from the beginning of an interim period that includes or is subsequent to March 12, 2020, or prospectively from a date within an interim period that includes or is subsequent to March 12, 2020, up to the date that the financial statements are available to be issued. ASU 2020-04 and ASU 2021-01 are effective for all entities through December 31, 2022. In April 2022, the FASB proposed to extend the effective date through December 31, 2024 and affirmed this decision in December 2022. Upon execution of the Fourth Amended and Restated Credit Agreement, we have transitioned from LIBOR. See Note I - Debt for discussion of the Fourth Amendment of the Credit Agreement.
Fair Value Accounting	Fair value is defined as the price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability. Cash Equivalents Due to the short-term maturity, we believe our cash equivalent instruments approximated their reported carrying values, therefore we have classified our cash equivalents as Level 1 of the fair value hierarchy. Long-Term Debt, Including Current Maturities The fair values of our long-term debt, including current maturities, approximated their carrying values based on their effective interest rates compared to current market rates, therefore we have classified our long-term debt as Level 1 of the fair value hierarchy. Derivative Instruments The estimated fair value of our derivative instruments is recorded at each reporting period and is determined based on inputs that are readily available in public markets or can be derived from information available in publicly quoted markets. Therefore, we have classified these swap agreements as Level 2 of the fair value hierarchy.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2023
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Earnings Per Share	The following table shows the computation of basic and diluted earnings per share: In thousands, except per share amounts Three Months Ended Six Months Ended 2023 2022 2023 2022 Numerator: Net income attributable to U.S. Silica Holdings, Inc. $ 46,259 $ 22,908 $ 90,907 $ 14,515 Denominator: Weighted average shares outstanding 77,089 75,508 76,804 75,373 Diluted effect of stock awards 1,249 2,458 1,505 2,121 Weighted average shares outstanding assuming dilution 78,338 77,966 78,309 77,494 Earnings per share attributable to U.S. Silica Holdings, Inc.: Basic earnings per share $ 0.60 $ 0.30 $ 1.18 $ 0.19 Diluted earnings per share $ 0.59 $ 0.29 $ 1.16 $ 0.19
Schedule of Potentially Dilutive Shares Excluded from Computation of Diluted Earnings Per Share	Such potentially dilutive shares and stock awards excluded from the calculation of diluted earnings per common share were as follows: In thousands Three Months Ended Six Months Ended 2023 2022 2023 2022 Potentially dilutive shares excluded — — — — Stock options excluded 413 509 413 509 Restricted stock and performance share unit awards excluded 38 3 54 2

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
	Jun. 30, 2023
Equity [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Income (Loss)	The following table presents the changes in accumulated other comprehensive income (loss) by component (in thousands): For the Six Months Ended June 30, 2023 Unrealized (loss) gain on natural gas swaps Foreign currency translation adjustments Pension and other post-retirement benefits liability Total Beginning Balance $ (2,342) $ (1,262) $ 1,881 $ (1,723) Other comprehensive income before reclassifications 955 273 2,311 3,539 Amounts reclassified from accumulated other comprehensive income — — (959) (959) Ending Balance $ (1,387) $ (989) $ 3,233 $ 857

Accounts Receivable (Tables)

Accounts Receivable (Tables)	6 Months Ended
	Jun. 30, 2023
Receivables [Abstract]
Schedule of Accounts Receivable and Allowance for Credit Losses	Accounts receivable (in thousands) consisted of the following: June 30, December 31, Trade receivables $ 198,005 $ 209,683 Less: Allowance for credit losses (5,699) (5,691) Net trade receivables 192,306 203,992 Other receivables 2,373 4,639 Total accounts receivable $ 194,679 $ 208,631 The following table reflects the change of the allowance for credit losses (in thousands): Oil & Gas Proppants Industrial & Specialty Products Total Beginning balance, December 31, 2022 $ 4,028 $ 1,663 $ 5,691 Allowance for credit losses — 68 68 Write-offs — (60) (60) Ending balance, June 30, 2023 $ 4,028 $ 1,671 $ 5,699

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 30, 2023
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories (in thousands) consisted of the following: June 30, 2023 December 31, 2022 Supplies $ 63,804 $ 54,805 Raw materials and work in process 53,585 47,042 Finished goods 44,431 45,779 Total inventories $ 161,820 $ 147,626

Property, Plant and Mine Deve_2

Property, Plant and Mine Development (Tables)	6 Months Ended
	Jun. 30, 2023
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Mine Development	Property, plant and mine development (in thousands) consisted of the following: June 30, December 31, Mining property and mine development $ 791,229 $ 789,601 Asset retirement cost 10,056 8,869 Land 53,288 53,128 Land improvements 87,208 76,456 Buildings 75,914 73,151 Machinery and equipment 1,238,004 1,217,933 Furniture and fixtures 3,029 3,922 Construction-in-progress 47,042 55,696 2,305,770 2,278,756 Accumulated depreciation, depletion, amortization and impairment charges (1,157,089) (1,099,922) Total property, plant and mine development, net $ 1,148,681 $ 1,178,834

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Carrying Amount of Goodwill by Business Segment	The changes in the carrying amount of goodwill (in thousands) by business segment consisted of the following: Oil & Gas Proppants Segment Industrial & Specialty Products Segment Total Balance at December 31, 2022 $ — $ 185,649 $ 185,649 Impairment loss — — — Balance at June 30, 2023 $ — $ 185,649 $ 185,649
Schedule of Changes in the Carrying Amount of Definite-Lived Intangible Assets	The changes in the carrying amount of intangible assets (in thousands) consisted of the following: June 30, 2023 December 31, 2022 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Technology and intellectual property $ 71,788 $ (32,439) $ 39,349 $ 71,651 $ (29,990) $ 41,661 Customer relationships 66,999 (35,191) 31,808 66,999 (32,791) 34,208 Total definite-lived intangible assets: $ 138,787 $ (67,630) $ 71,157 $ 138,650 $ (62,781) $ 75,869 Trade names 64,240 — 64,240 64,240 — 64,240 Other 700 — 700 700 — 700 Total intangible assets: $ 203,727 $ (67,630) $ 136,097 $ 203,590 $ (62,781) $ 140,809
Schedule of Changes in the Carrying Amount of Indefinite-Lived Intangible Assets	The changes in the carrying amount of intangible assets (in thousands) consisted of the following: June 30, 2023 December 31, 2022 Gross Carrying Amount Accumulated Amortization Net Gross Carrying Amount Accumulated Amortization Net Technology and intellectual property $ 71,788 $ (32,439) $ 39,349 $ 71,651 $ (29,990) $ 41,661 Customer relationships 66,999 (35,191) 31,808 66,999 (32,791) 34,208 Total definite-lived intangible assets: $ 138,787 $ (67,630) $ 71,157 $ 138,650 $ (62,781) $ 75,869 Trade names 64,240 — 64,240 64,240 — 64,240 Other 700 — 700 700 — 700 Total intangible assets: $ 203,727 $ (67,630) $ 136,097 $ 203,590 $ (62,781) $ 140,809
Schedule of Estimated Amortization Expense Related to Definite-Lived Intangible Assets	The estimated amortization expense related to definite-lived intangible assets (in thousands) for the five succeeding years is as follows: 2023 (remaining six months) $ 4,855 2024 $ 9,707 2025 $ 9,706 2026 $ 9,706 2027 $ 9,706

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2023
Debt Disclosure [Abstract]
Schedule of Debt	Debt (in thousands) consisted of the following: June 30, December 31, Senior secured credit facility: Revolver expiring March 23, 2028 (9.95% at June 30, 2023 and 8.44% at December 31, 2022) $ — $ — Term Loan—final maturity March 23, 2030 (9.95% at June 30, 2023 and 8.44% at December 31, 2022) 922,625 1,059,062 Less: Unamortized original issue discount (27,678) (2,035) Less: Unamortized debt issuance cost (15,076) (8,922) Insurance financing notes payable — 5,628 Finance leases (See Note P - Leases) 2,194 3,260 Total debt 882,065 1,056,993 Less: current portion (10,152) (19,535) Total long-term portion of debt $ 871,913 $ 1,037,458
Schedule of Contractual Maturities of Term Loan	At June 30, 2023, contractual maturities of our Term Loan (in thousands) are as follows: 2023 (remaining six months) $ 4,625 2024 9,250 2025 9,250 2026 9,250 2027 9,250 Thereafter 881,000 Total $ 922,625

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2023
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Changes in Asset Retirement Obligations	Changes in the asset retirement obligations (in thousands) are as follows: Six Months Ended 2023 2022 Beginning balance $ 20,732 $ 32,049 Accretion 1,025 749 Additions and revisions of estimates 1,187 (3,126) Payments (14) (62) Ending balance $ 22,930 $ 29,610

Derivative Instruments (Tables)

Derivative Instruments (Tables)	6 Months Ended
	Jun. 30, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The following table summarizes the fair values of our derivative instruments (in thousands, except contract/notional amount). See Note K - Fair Value Accounting for more information regarding the estimated fair values of our derivative instruments. June 30, 2023 December 31, 2022 Maturity Contract/Notional Carrying Fair Maturity Date Contract/Notional Carrying Fair Natural Gas - W. Texas (WAHA) - Inside FERC 2023 1,200,000 $ (683) $ (683) 2023 1,200,000 $ (1,887) $ (1,887) Natural Gas - W. Texas (WAHA) - Inside FERC 2024 870,000 $ (742) $ (742) 2024 870,000 $ (656) $ (656) Natural Gas - W. Texas (WAHA) - Inside FERC 2024 750,000 $ 205 $ 205 N/A N/A $ — $ — Natural Gas - Henry Hub - NYMEX 2023 300,000 $ (361) $ (361) 2023 300,000 $ (425) $ (425) Natural Gas - Henry Hub - NYMEX 2024 120,000 $ (174) $ (174) 2024 120,000 $ (85) $ (85) Natural Gas - Henry Hub - NYMEX 2025 90,000 $ (73) $ (73) 2025 90,000 $ (35) $ (35)
Schedule of Effect of Derivatives Instruments on Combined Statements of Operations and Comprehensive Income	The following table summarizes the effect of derivative instruments (in thousands) on our income statements and our consolidated statements of comprehensive income: Six Months Ended 2023 2022 Deferred losses from derivatives in OCI, beginning of period $ (2,342) $ — Gain recognized in OCI from derivative instruments 955 — Deferred losses from derivatives in OCI, end of period $ (1,387) $ —

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Options Activity	The following table summarizes the status of, and changes in, our stock option awards during the six months ended June 30, 2023: Number of Weighted Weighted Outstanding at December 31, 2022 508,523 $ 36.22 2.0 years Granted — $ — Exercised — $ — Forfeited (58,160) $ 36.65 Expired (37,434) $ 24.80 Outstanding at June 30, 2023 412,929 $ 37.20 1.6 years Exercisable at June 30, 2023 412,929 $ 37.20 1.6 years The following table summarizes stock option exercise activity: Three months ended June 30, Six months ended June 30, 2023 2022 2023 2022 Options exercised (in actual shares) — 42,500 — 50,000 Intrinsic value of options exercised (in thousands) $ — $ 421 $ — $ 446 Cash received from options exercised (in thousands) $ — $ 449 $ — $ 533 Tax benefit realized from options exercised (in thousands) $ — $ 102 $ — $ 108
Schedule of Restricted Stock, Restricted Stock Unit and Performance Share Unit Awards Activity	The following table summarizes the status of, and changes in, our unvested restricted stock awards during the six months ended June 30, 2023: Number of Shares Grant Date Weighted Unvested, December 31, 2022 1,438,386 $ 9.37 Granted 635,605 $ 12.02 Vested (665,756) $ 8.95 Forfeited (118,426) $ 8.62 Unvested, June 30, 2023 1,289,809 $ 10.96 The following table summarizes the status of, and changes in, our performance share unit awards during the six months ended June 30, 2023: Number of Shares Grant Date Weighted Unvested, December 31, 2022 2,292,751 $ 9.51 Granted 1,295,904 $ 9.54 Vested (1,549,033) $ 6.60 Forfeited/Cancelled (109,259) $ 11.52 Unvested, June 30, 2023 1,930,363 $ 11.75

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Annual Commitments	Future Minimum Annual Commitments at June 30, 2023 (in thousands): Minimum Purchase Commitments 2023 (remaining six months) $ 4,566 2024 7,640 2025 6,431 2026 3,844 2027 2,288 Thereafter 7,484 Total future purchase commitments $ 32,253

Pension and Post-Retirement B_2

Pension and Post-Retirement Benefits (Tables)	6 Months Ended
	Jun. 30, 2023
Retirement Benefits [Abstract]
Schedule of Net Pension and Post-Retirement Benefit Plans	Net pension benefit cost (in thousands) consisted of the following: Three Months Ended Six Months Ended 2023 2022 2023 2022 Service cost $ 573 $ 692 $ 1,146 $ 1,381 Interest cost 1,249 692 2,497 1,381 Expected return on plan assets (1,518) (1,424) (3,037) (2,842) Net amortization and deferral (3) 502 (5) 1,001 Net pension benefit costs $ 301 $ 462 $ 601 $ 921 Net post-retirement benefit cost (in thousands) consisted of the following: Three Months Ended Six Months Ended 2023 2022 2023 2022 Service cost $ 4 $ 6 $ 8 $ 12 Interest cost 80 36 160 72 Unrecognized prior service cost (516) (515) (1,031) (1,031) Unrecognized net (gain)/loss (131) (35) (262) (69) Net post-retirement benefit income $ (563) $ (508) $ (1,125) $ (1,016)

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2023
Leases [Abstract]
Schedule of Supplemental Balance Sheet Information	Supplemental balance sheet information related to leases was as follows (in thousands, except lease term and discount rate): Leases Classification June 30, December 31, 2022 Assets Operating Lease right-of-use assets $ 41,382 $ 39,088 Finance Lease right-of-use assets 2,237 3,286 Total leased assets $ 43,619 $ 42,374 Liabilities Current Operating Current portion of operating lease liabilities $ 19,654 $ 19,773 Finance Current portion of long-term debt 902 1,107 Non-current Operating Operating lease liabilities 61,937 64,478 Finance Long-term debt, net 1,292 2,153 Total lease liabilities $ 83,785 $ 87,511 Lease Term and Discount Rate Weighted average remaining lease term: Operating 6.1 years 6.4 years Finance 4.4 years 4.4 years Weighted average discount rate: Operating 5.8% 5.7% Finance 5.6% 5.1%
Schedule of Components of Lease Expense and Supplemental Cash Flow Information	The components of lease expense (in thousands) were as follows: Lease Costs Classification Three Months Ended Three Months Ended Six Months Ended Six Months Ended Operating lease costs (1) Cost of sales $ 10,320 $ 9,291 $ 20,695 $ 16,919 Operating lease costs (2) Selling, general and administrative 748 447 1,343 801 Total (3) $ 11,068 $ 9,738 $ 22,038 $ 17,720 (1) Included short-term operating lease costs of $6.6 million and $13.4 million for the three and six months ended June 30, 2023, respectively, and $5.2 million and $9.9 million for the three and six months ended June 30, 2022, respectively. (2) Included short-term operating lease costs of $0.4 million and $0.7 million for the three and six months ended June 30, 2023, respectively, and $0.1 million and $0.2 million for the three and six months ended June 30, 2022, respectively. (3) Not included were expenses for finance leases of $0.2 million and $0.4 million for the three and six months ended June 30, 2023, respectively, and $0.4 million and $0.8 million for the three and six months ended June 30, 2022, respectively. Supplemental cash flow information (in thousands) related to leases was as follows: Six Months Ended Six Months Ended Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 12,774 $ 12,497 Financing cash flows for finance leases $ 473 $ 727 Right-of-use assets obtained in exchange for new lease liabilities: Operating leases $ 3,376 $ 1,713 Finance leases $ 273 $ 8,865
Schedule of Maturity of Operating Lease Liabilities	Maturities of lease liabilities (in thousands) as of June 30, 2023: Operating leases Finance leases 2023 (remaining six months) $ 12,488 $ 425 2024 22,331 970 2025 16,667 688 2026 12,865 117 2027 9,091 46 Thereafter 26,012 190 Total lease payments $ 99,454 $ 2,436 Less: Interest 15,782 242 Less: Other operating expenses 2,081 — Total $ 81,591 $ 2,194
Schedule of Maturity of Finance Lease Liabilities	Maturities of lease liabilities (in thousands) as of June 30, 2023: Operating leases Finance leases 2023 (remaining six months) $ 12,488 $ 425 2024 22,331 970 2025 16,667 688 2026 12,865 117 2027 9,091 46 Thereafter 26,012 190 Total lease payments $ 99,454 $ 2,436 Less: Interest 15,782 242 Less: Other operating expenses 2,081 — Total $ 81,591 $ 2,194

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Sales by Major Source	The following table disaggregates our sales by major source (in thousands): Three Months Ended Three Months Ended Category Oil & Gas Proppants Industrial & Specialty Products Total Sales Oil & Gas Proppants Industrial & Specialty Products Total Sales Product $ 178,015 $ 144,499 $ 322,514 $ 146,058 $ 144,267 $ 290,325 Service 84,270 — 84,270 98,188 — 98,188 Total Sales $ 262,285 $ 144,499 $ 406,784 $ 244,246 $ 144,267 $ 388,513 Six Months Ended Six Months Ended Category Oil & Gas Proppants Industrial & Specialty Products Total Sales Oil & Gas Proppants Industrial & Specialty Products Total Sales Product $ 384,457 $ 286,726 $ 671,183 $ 250,649 $ 272,910 $ 523,559 Service 177,841 — 177,841 169,841 — 169,841 Total Sales $ 562,298 $ 286,726 $ 849,024 $ 420,490 $ 272,910 $ 693,400
Schedule of Changes in Contract Assets and Liabilities	The following tables reflect the changes in our contract assets, which we classify as unbilled receivables and our contract liabilities, which we classify as deferred revenues, for the six months ended June 30, 2023 and 2022 (in thousands): Unbilled Receivables June 30, 2023 June 30, 2022 Beginning Balance $ — $ 1,957 Reclassifications to billed receivables — (4,457) Revenues recognized in excess of period billings — 2,930 Ending Balance $ — $ 430 Deferred Revenue June 30, 2023 June 30, 2022 Beginning Balance $ 30,752 $ 20,741 Revenues recognized from balances held at the beginning of the period (9,153) (2,591) Revenues deferred from period collections on unfulfilled performance obligations — 20,948 Revenues recognized from period collections — (2,816) Ending Balance $ 21,599 $ 36,282
Schedule of Total Sales, Pre-tax Income and Net Income Related to Foreign Operations	The following table includes information related to our foreign operations (in thousands): Three Months Ended Three Months Ended Six Months Ended Six Months Ended Total Sales $ 25,817 $ 29,658 $ 55,749 $ 54,912 Pre-tax income $ 4,299 $ 9,715 $ 11,201 $ 14,528 Net income $ 3,396 $ 7,675 $ 8,848 $ 11,477

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2023
Segment Reporting [Abstract]
Schedule of Sales and Segment Contribution Margin for Reporting Segments and Operating Results	The following table presents sales and segment contribution margin (in thousands) for the reportable segments and other operating results not allocated to the reportable segments: Three Months Ended Six Months Ended 2023 2022 2023 2022 Sales: Oil & Gas Proppants $ 262,285 $ 244,246 $ 562,298 $ 420,490 Industrial & Specialty Products 144,499 144,267 286,726 272,910 Total sales 406,784 388,513 849,024 693,400 Segment contribution margin: Oil & Gas Proppants 99,069 77,353 208,966 122,106 Industrial & Specialty Products 51,595 45,915 94,524 83,749 Total segment contribution margin 150,664 123,268 303,490 205,855 Operating activities excluded from segment cost of sales (3,653) (3,651) (7,372) (8,220) Selling, general and administrative (28,694) (34,817) (57,857) (74,927) Depreciation, depletion and amortization (33,546) (34,715) (68,932) (72,464) Interest expense (25,987) (17,430) (50,048) (34,603) Other income, net, including interest income 2,497 2,099 145 3,630 Income tax expense (15,137) (11,919) (28,710) (4,950) Net income $ 46,144 $ 22,835 $ 90,716 $ 14,321 Less: Net loss attributable to non-controlling interest (115) (73) (191) (194) Net income attributable to U.S. Silica Holdings, Inc. $ 46,259 $ 22,908 $ 90,907 $ 14,515

Organization and Basis of Pre_2

Organization and Basis of Presentation (Details)	6 Months Ended
	Jun. 30, 2023 yr segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of years in business | yr	123
Number of reportable segments (segments) | segment	2

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Net income attributable to U.S. Silica Holdings, Inc. - Basic	$ 46,259	$ 22,908	$ 90,907	$ 14,515
Net income attributable to U.S. Silica Holdings, Inc. - Diluted	$ 46,259	$ 22,908	$ 90,907	$ 14,515
Denominator:
Weighted average shares outstanding (in shares)	77,089	75,508	76,804	75,373
Diluted effect of stock awards (in shares)	1,249	2,458	1,505	2,121
Weighted average shares outstanding assuming dilution (shares)	78,338	77,966	78,309	77,494
Earnings per share attributable to U.S. Silica Holdings, Inc.:
Basic earnings per share (in dollars per share)	$ 0.60	$ 0.30	$ 1.18	$ 0.19
Diluted earnings per share (in dollars per share)	$ 0.59	$ 0.29	$ 1.16	$ 0.19

Earnings Per Share - Potentiall

Earnings Per Share - Potentially Dilutive Shares Excluded From Calculation of Diluted Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Potentially dilutive shares excluded
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares excluded from calculation of weighted average shares outstanding and diluted earnings per share (in shares)	0	0		0
Stock options excluded
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares excluded from calculation of weighted average shares outstanding and diluted earnings per share (in shares)	413	509	413	509
Restricted stock and performance share unit awards excluded
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares excluded from calculation of weighted average shares outstanding and diluted earnings per share (in shares)	38	3	54	2

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ 704,694	$ 614,083
Other comprehensive income before reclassifications	3,539
Amounts reclassified from accumulated other comprehensive income	(959)
Ending Balance	794,340	634,434
Total
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(1,723)	349
Ending Balance	857	(281)
Unrealized (loss) gain on natural gas swaps
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(2,342)	0
Other comprehensive income before reclassifications	955	0
Amounts reclassified from accumulated other comprehensive income	0
Ending Balance	(1,387)	$ 0
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(1,262)
Other comprehensive income before reclassifications	273
Amounts reclassified from accumulated other comprehensive income	0
Ending Balance	(989)
Pension and other post-retirement benefits liability
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	1,881
Other comprehensive income before reclassifications	2,311
Amounts reclassified from accumulated other comprehensive income	(959)
Ending Balance	$ 3,233

Accounts Receivable - Summary o

Accounts Receivable - Summary of Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Receivables [Abstract]
Trade receivables	$ 198,005	$ 209,683
Less: Allowance for credit losses	(5,699)	(5,691)
Net trade receivables	192,306	203,992
Other receivables	2,373	4,639
Total accounts receivable	$ 194,679	$ 208,631

Accounts Receivable - Changes i

Accounts Receivable - Changes in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Allowance for Doubtful Accounts Receivable Roll Forward
Beginning balance, December 31, 2022	$ 5,691
Allowance for credit losses	68	$ 258
Write-offs	(60)
Ending balance, June 30, 2023	5,699
Oil & Gas Proppants
Allowance for Doubtful Accounts Receivable Roll Forward
Beginning balance, December 31, 2022	4,028
Allowance for credit losses	0
Write-offs	0
Ending balance, June 30, 2023	4,028
Industrial & Specialty Products
Allowance for Doubtful Accounts Receivable Roll Forward
Beginning balance, December 31, 2022	1,663
Allowance for credit losses	68
Write-offs	(60)
Ending balance, June 30, 2023	$ 1,671

Accounts Receivable - Narrative

Accounts Receivable - Narrative (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Customer Concentration Risk | Sales | Ten Largest Customers
Concentration Risk [Line Items]
Concentration risk percentage (as a percent)	44%	38%	45%	39%

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Supplies	$ 63,804	$ 54,805
Raw materials and work in process	53,585	47,042
Finished goods	44,431	45,779
Total inventories	$ 161,820	$ 147,626

Property, Plant and Mine Deve_3

Property, Plant and Mine Development - Schedule (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment
Property, plant and mine development, gross	$ 2,305,770	$ 2,278,756
Accumulated depreciation, depletion, amortization and impairment charges	(1,157,089)	(1,099,922)
Total property, plant and mine development, net	1,148,681	1,178,834
Mining property and mine development
Property, Plant and Equipment
Property, plant and mine development, gross	791,229	789,601
Asset retirement cost
Property, Plant and Equipment
Property, plant and mine development, gross	10,056	8,869
Land
Property, Plant and Equipment
Property, plant and mine development, gross	53,288	53,128
Land improvements
Property, Plant and Equipment
Property, plant and mine development, gross	87,208	76,456
Buildings
Property, Plant and Equipment
Property, plant and mine development, gross	75,914	73,151
Machinery and equipment
Property, Plant and Equipment
Property, plant and mine development, gross	1,238,004	1,217,933
Furniture and fixtures
Property, Plant and Equipment
Property, plant and mine development, gross	3,029	3,922
Construction-in-progress
Property, Plant and Equipment
Property, plant and mine development, gross	$ 47,042	$ 55,696

Property, Plant and Mine Deve_4

Property, Plant and Mine Development - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Property, Plant and Equipment
Depreciation, depletion and amortization	$ 33,546	$ 34,715	$ 68,932	$ 72,464
Property, Plant and Equipment
Property, Plant and Equipment
Depreciation, depletion and amortization	$ 30,500	$ 31,700	$ 62,800	$ 66,600

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Carrying Amount of Goodwill by Business Segment (Details)	6 Months Ended
	Jun. 30, 2023 USD ($)
Goodwill [Roll Forward]
Balance at December 31, 2022	$ 185,649,000
Impairment loss	0
Balance at June 30, 2023	185,649,000
Oil & Gas Proppants Segment
Goodwill [Roll Forward]
Balance at December 31, 2022	0
Impairment loss	0
Balance at June 30, 2023	0
Industrial & Specialty Products Segment
Goodwill [Roll Forward]
Balance at December 31, 2022	185,649,000
Impairment loss	0
Balance at June 30, 2023	$ 185,649,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Goodwill impairment			$ 0
Amortization expense of intangibles	$ 2,500,000	$ 2,400,000	$ 4,900,000	$ 4,800,000
Technology and intellectual property
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	15 years		15 years
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	13 years		13 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives of intangibles	20 years		20 years

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Carrying Amount of Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 138,787	$ 138,650
Accumulated Amortization	(67,630)	(62,781)
Net	71,157	75,869
Total Intangible Assets
Gross Carrying Amount	203,727	203,590
Accumulated Amortization	(67,630)	(62,781)
Net	136,097	140,809
Trade names
Indefinite-lived Intangible Assets
Gross Carrying Amount	64,240	64,240
Other
Indefinite-lived Intangible Assets
Gross Carrying Amount	700	700
Technology and intellectual property
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	71,788	71,651
Accumulated Amortization	(32,439)	(29,990)
Net	39,349	41,661
Total Intangible Assets
Accumulated Amortization	(32,439)	(29,990)
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	66,999	66,999
Accumulated Amortization	(35,191)	(32,791)
Net	31,808	34,208
Total Intangible Assets
Accumulated Amortization	$ (35,191)	$ (32,791)

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Estimated Amortization Expense Related to Definite-Lived Intangible Assets (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2023 (remaining six months)	$ 4,855
2024	9,707
2025	9,706
2026	9,706
2027	$ 9,706

Debt - Schedule (Details)

Debt - Schedule (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Line of Credit Facility
Less: Unamortized original issue discount	$ (27,678)	$ (2,035)
Less: Unamortized debt issuance cost	(15,076)	(8,922)
Finance leases (See Note P - Leases)	2,194	3,260
Total debt	882,065	1,056,993
Less: current portion	(10,152)	(19,535)
Total long-term portion of debt	871,913	1,037,458
Notes Payable | Insurance financing notes payable
Line of Credit Facility
Insurance financing notes payable	$ 0	$ 5,628
Revolving Line-of-Credit | Revolver expiring March 23, 2028 (9.95% at June 30, 2023 and 8.44% at December 31, 2022)
Line of Credit Facility
Interest rate	9.95%	8.44%
Long-term debt	$ 0	$ 0
Senior Secured Credit Facility | Term Loan—final maturity March 23, 2030 (9.95% at June 30, 2023 and 8.44% at December 31, 2022)
Line of Credit Facility
Interest rate	9.95%	8.44%
Long-term debt	$ 922,625	$ 1,059,062

Debt - Narrative (Details)

Debt - Narrative (Details)			3 Months Ended	6 Months Ended
	Mar. 23, 2023 USD ($)	Mar. 22, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)
Debt Instrument [Line Items]
Prepayments of long-term loan				$ 136,437,000	$ 6,538,000
Revolving Line-of-Credit | Revolver
Debt Instrument [Line Items]
Available borrowing base			$ 150,000,000	150,000,000
Amount drawn from borrowing base			0	0
Amount available under the line of credit			$ 128,700,000	$ 128,700,000
Actual consolidated leverage ratio			1.94	1.94
Letter of Credit | Revolver
Debt Instrument [Line Items]
Amount allocated for letters of credit			$ 21,300,000	$ 21,300,000
Senior Secured Credit Facility
Debt Instrument [Line Items]
Debt issued	$ 1,100,000,000
Capitalized debt issuance costs and original issue discount	45,600,000
Loss on extinguishment of debt	4,300,000
Senior Secured Credit Facility | Term Loan
Debt Instrument [Line Items]
Debt issued	950,000,000
Debt, repurchase amount		$ 109,000,000
Debt issuance costs		1,000,000	1,100,000
Loss on extinguishment of debt		$ 1,000,000
Prepayments of long-term loan			$ 25,000,000
Senior Secured Credit Facility | Revolving Line-of-Credit | Revolver
Debt Instrument [Line Items]
Debt issued	$ 150,000,000
Credit facility consolidated total net leverage ratio, maximum	4
Credit facility consolidated total net leverage ratio, threshold borrowings outstanding, ratio	2.85
Credit facility consolidated total net leverage ratio, threshold borrowings outstanding, percent	35%

Debt - Contractual Maturities o

Debt - Contractual Maturities of Term Loan (Details) - Senior Secured Credit Facility - Term Loan - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
2023 (remaining six months)	$ 4,625
2024	9,250
2025	9,250
2026	9,250
2027	9,250
Thereafter	881,000
Total	$ 922,625	$ 1,059,062

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	$ 20,732	$ 32,049
Accretion	1,025	749
Additions and revisions of estimates	1,187	(3,126)
Payments	(14)	(62)
Ending balance	$ 22,930	$ 29,610

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Details) - USD ($)	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Interest Rate Cap | Cash Flow Hedges
Derivative [Line Items]
Fair Value	$ 1,800,000	$ 3,100,000
Interest Rate Cap | Cash Flow Hedges | Accounts payables and accrued liabilities
Derivative [Line Items]
Fair Value	1,400,000	2,300,000
Interest Rate Cap | Cash Flow Hedges | Other long-term obligations
Derivative [Line Items]
Fair Value	400,000	$ 800,000
Interest rate swap
Derivative [Line Items]
Ineffectiveness for interest rate swap derivatives	$ 0

Derivative Instruments - Estima

Derivative Instruments - Estimated Fair Values of Derivative Instruments (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023 USD ($) MMBTU	Dec. 31, 2022 USD ($) MMBTU
Natural Gas - W. Texas (WAHA) - Inside FERC
Derivative Instruments, Gain (Loss)
Contract/Notional Amount (MMBtu) | MMBTU	1,200,000	1,200,000
Carrying Amount	$ (683)	$ (1,887)
Fair Value	$ (683)	$ (1,887)
Natural Gas - W. Texas (WAHA) - Inside FERC
Derivative Instruments, Gain (Loss)
Contract/Notional Amount (MMBtu) | MMBTU	870,000	870,000
Carrying Amount	$ (742)	$ (656)
Fair Value	$ (742)	$ (656)
Natural Gas - W. Texas (WAHA) - Inside FERC
Derivative Instruments, Gain (Loss)
Contract/Notional Amount (MMBtu) | MMBTU	750,000
Carrying Amount	$ 205
Fair Value	$ 205
Natural Gas - Henry Hub - NYMEX
Derivative Instruments, Gain (Loss)
Contract/Notional Amount (MMBtu) | MMBTU	300,000	300,000
Carrying Amount	$ (361)	$ (425)
Fair Value	$ (361)	$ (425)
Natural Gas - Henry Hub - NYMEX
Derivative Instruments, Gain (Loss)
Contract/Notional Amount (MMBtu) | MMBTU	120,000	120,000
Carrying Amount	$ (174)	$ (85)
Fair Value	$ (174)	$ (85)
Natural Gas - Henry Hub - NYMEX
Derivative Instruments, Gain (Loss)
Contract/Notional Amount (MMBtu) | MMBTU	90,000	90,000
Carrying Amount	$ (73)	$ (35)
Fair Value	$ (73)	$ (35)

Derivative Instruments - Effect

Derivative Instruments - Effect of Derivative Instruments in Combined Statements of Operations and Comprehensive Income (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	$ 704,694	$ 614,083
Gain recognized in OCI from derivative instruments	3,539
Ending Balance	794,340	634,434
Unrealized (loss) gain on natural gas swaps
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	(2,342)	0
Gain recognized in OCI from derivative instruments	955	0
Ending Balance	$ (1,387)	$ 0

Equity-Based Compensation - Sto

Equity-Based Compensation - Stock Options (Details) - $ / shares	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Number of Shares
Outstanding at the beginning (in shares)			508,523
Granted (in shares)			0	0
Exercised (in shares)	0	(42,500)	0	(50,000)
Forfeited (in shares)			(58,160)
Expired (in shares)			(37,434)
Outstanding at the end (in shares)	412,929		412,929		508,523
Exercisable at the end (in shares)	412,929		412,929
Weighted Average Exercise Price
Outstanding at the beginning (in dollars per share)			$ 36.22
Granted (in dollars per share)			0
Exercised (in dollars per share)			0
Forfeited (in dollars per share)			36.65
Expired (in dollars per share)			24.80
Outstanding at the end (in dollars per share)	$ 37.20		37.20		$ 36.22
Exercisable at the end (in dollars per share)	$ 37.20		$ 37.20
Weighted Average Remaining Contractual Term in Years
Outstanding at the beginning			1 year 7 months 6 days		2 years
Outstanding at the end			1 year 7 months 6 days		2 years
Exercisable at the end			1 year 7 months 6 days

Equity-Based Compensation - Nar

Equity-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Mar. 31, 2020	Jun. 30, 2023	Jun. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants of stock options (in shares)				0	0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 0	$ 0		$ 0	$ 0
Restricted Stock and Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	141,671	42,220		635,605	630,712
Recognized equity-based compensation	$ 1,900,000	$ 1,800,000		$ 3,500,000	$ 3,400,000
Unrecognized compensation expense related to awards	11,300,000			$ 11,300,000
Recognized weighted-average period				1 year 10 months 24 days
Granted (in dollars per share)				$ 12.02
Restricted Stock and Restricted Stock Units Cash Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity-based compensation	0	$ 100,000		$ 300,000	$ 400,000
Unrecognized compensation expense related to awards	$ 0			$ 0
Award vesting period			3 years
Performance Share Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	5,924	0		1,295,904	920,681
Recognized equity-based compensation	$ 1,800,000	$ 2,900,000		$ 3,500,000	$ 5,700,000
Unrecognized compensation expense related to awards	$ 12,000,000			$ 12,000,000
Recognized weighted-average period				2 years
Granted (in dollars per share)				$ 9.54	$ 11.79
Performance Share Units Cash Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized equity-based compensation				$ 100,000	$ 600,000
Award vesting period			3 years

Equity-Based Compensation - S_2

Equity-Based Compensation - Stock Option Exercise Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
Options exercised (in shares)	0	42,500	0	50,000
Intrinsic value of options exercised (in thousands)	$ 0	$ 421	$ 0	$ 446
Cash received from options exercised (in thousands)	0	449	0	533
Tax benefit realized from options exercised (in thousands)	$ 0	$ 102	$ 0	$ 108

Equity-Based Compensation - Res

Equity-Based Compensation - Restricted Stock and Restricted Stock Units Awards (Details) - Restricted Stock and Restricted Stock Units - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Number of Shares
Unvested, beginning balance (in shares)			1,438,386
Granted (in shares)	141,671	42,220	635,605	630,712
Vested (in shares)			(665,756)
Forfeited (in shares)			(118,426)
Unvested, ending balance (in shares)	1,289,809		1,289,809
Grant Date Weighted Average Fair Value
Unvested, beginning balance (in dollars per share)			$ 9.37
Granted (in dollars per share)			12.02
Vested (in dollars per share)			8.95
Forfeited (in dollars per share)			8.62
Unvested, ending balance (in dollars per share)	$ 10.96		$ 10.96

Equity-Based Compensation - Per

Equity-Based Compensation - Performance Share Awards (Details) - Performance Share Units - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Number of Shares
Unvested, beginning balance (in shares)			2,292,751
Granted (in shares)	5,924	0	1,295,904	920,681
Vested (in shares)			(1,549,033)
Forfeited/Cancelled (in shares)			(109,259)
Unvested, ending balance (in shares)	1,930,363		1,930,363
Grant Date Weighted Average Fair Value
Unvested, beginning balance (in dollars per share)			$ 9.51
Granted (in dollars per share)			9.54	$ 11.79
Vested (in dollars per share)			6.60
Forfeited/Cancelled (in dollars per share)			11.52
Unvested, ending balance (in dollars per share)	$ 11.75		$ 11.75

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Annual Commitments (Details) $ in Thousands	Jun. 30, 2023 USD ($)
Minimum Purchase Commitments
2023 (remaining six months)	$ 4,566
2024	7,640
2025	6,431
2026	3,844
2027	2,288
Thereafter	7,484
Total future purchase commitments	$ 32,253

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details)		6 Months Ended
	May 17, 2017 USD ($)	Jun. 30, 2023 USD ($) claim	Dec. 31, 2022 USD ($)
Loss Contingencies
Purchased reserves	$ 94,400,000
Number of new claims | claim		0
Surety Bonds
Loss Contingencies
Surety bonds outstanding		$ 42,600,000
Reclamation Bonds
Loss Contingencies
Surety bonds outstanding		38,600,000
Other non-current assets
Loss Contingencies
Third party products claims liability under insurance in other long-term obligations		0	$ 0
Other long-term obligations
Loss Contingencies
Third party products claims liability under insurance in other long-term obligations		$ 700,000	$ 800,000
Pending Litigation
Loss Contingencies
Number of pending claims | claim		42

Pension and Post-Retirement B_3

Pension and Post-Retirement Benefits - Net Pension and Post-Retirement Benefit Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Pension Benefits
Pension Plans, Postretirement and Other Employee Benefits
Service cost	$ 573	$ 692	$ 1,146	$ 1,381
Interest cost	1,249	692	2,497	1,381
Expected return on plan assets	(1,518)	(1,424)	(3,037)	(2,842)
Net amortization and deferral	(3)	502	(5)	1,001
Net pension and post-retirement benefit costs (income)	301	462	601	921
Post-retirement Benefits
Pension Plans, Postretirement and Other Employee Benefits
Service cost	4	6	8	12
Interest cost	80	36	160	72
Unrecognized prior service cost	(516)	(515)	(1,031)	(1,031)
Unrecognized net (gain)/loss	(131)	(35)	(262)	(69)
Net pension and post-retirement benefit costs (income)	$ (563)	$ (508)	$ (1,125)	$ (1,016)

Pension and Post-Retirement B_4

Pension and Post-Retirement Benefits - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($) plan	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) plan	Jun. 30, 2022 USD ($)
Pension Plans, Postretirement and Other Employee Benefits
Number of multiemployer defined benefit plans | plan	3		3
Percentage of contributions to individual multiemployer plan (less than)	5%	5%	5%	5%
Company contributions to qualified pension plans	$ 2	$ 1.7	$ 4.1	$ 3.5
Certain Employees
Pension Plans, Postretirement and Other Employee Benefits
Percentage of contribution over defined benefit plan			4%
All Other Eligible Employees
Pension Plans, Postretirement and Other Employee Benefits
Percentage of contribution over defined benefit plan based on eligible earnings (up to)			6%
Pension Plans
Pension Plans, Postretirement and Other Employee Benefits
Company's contributions to qualified plans	0	$ 0	$ 0	$ 0
Expected contributions to the plans for the 2023 fiscal year	0		0
Post-retirement Medical Plan
Pension Plans, Postretirement and Other Employee Benefits
Expected contributions to the plans for the 2023 fiscal year	$ 1		$ 1

Leases - Narrative (Details)

Leases - Narrative (Details)	6 Months Ended
	Jun. 30, 2023
Minimum
Lessee, Lease, Description [Line Items]
Remaining term of lease contracts	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining term of lease contracts	20 years

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Assets
Operating	$ 41,382	$ 39,088
Finance	2,237	3,286
Total leased assets	$ 43,619	$ 42,374
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Total leased assets	Total leased assets
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Total leased assets	Total leased assets
Current
Operating	$ 19,654	$ 19,773
Finance	$ 902	$ 1,107
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current portion of long-term debt	Current portion of long-term debt
Non-current
Operating	$ 61,937	$ 64,478
Finance	1,292	2,153
Total lease liabilities	$ 83,785	$ 87,511
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt, net	Long-term debt, net
Weighted average remaining lease term:
Operating	6 years 1 month 6 days	6 years 4 months 24 days
Finance	4 years 4 months 24 days	4 years 4 months 24 days
Weighted average discount rate:
Operating	5.80%	5.70%
Finance	5.60%	5.10%

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Lessee, Lease, Description [Line Items]
Total lease costs	$ 11,068	$ 9,738	$ 22,038	$ 17,720
Finance lease expense	200	400	400	800
Cost of sales
Lessee, Lease, Description [Line Items]
Operating lease costs	10,320	9,291	20,695	16,919
Short-term operating lease costs	6,600	5,200	13,400	9,900
Selling, general and administrative
Lessee, Lease, Description [Line Items]
Operating lease costs	748	447	1,343	801
Short-term operating lease costs	$ 400	$ 100	$ 700	$ 200

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$ 12,774	$ 12,497
Financing cash flows for finance leases	473	727
Right-of-use assets obtained in exchange for new lease liabilities:
Operating leases	3,376	1,713
Finance leases	$ 273	$ 8,865

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Operating leases
2023 (remaining six months)	$ 12,488
2024	22,331
2025	16,667
2026	12,865
2027	9,091
Thereafter	26,012
Total lease payments	99,454
Less: Interest	15,782
Less: Other operating expenses	2,081
Total	81,591
Finance leases
2023 (remaining six months)	425
2024	970
2025	688
2026	117
2027	46
Thereafter	190
Total lease payments	2,436
Less: Interest	242
Less: Other operating expenses	0
Total	$ 2,194	$ 3,260

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 15,137	$ 11,919	$ 28,710	$ 4,950
Effective tax rate (as a percent)	25%	34%	24%	26%
Effective tax rate without the effects of discrete tax items	24%	34%	25%	22%
Tax expense (benefit) related equity compensation	$ 200	$ (200)	$ (2,100)	$ 100

Revenue - Sales by Major Source

Revenue - Sales by Major Source (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total sales	$ 406,784	$ 388,513	$ 849,024	$ 693,400
Oil & Gas Proppants
Disaggregation of Revenue [Line Items]
Total sales	262,285	244,246	562,298	420,490
Industrial & Specialty Products
Disaggregation of Revenue [Line Items]
Total sales	144,499	144,267	286,726	272,910
Product
Disaggregation of Revenue [Line Items]
Total sales	322,514	290,325	671,183	523,559
Product | Oil & Gas Proppants
Disaggregation of Revenue [Line Items]
Total sales	178,015	146,058	384,457	250,649
Product | Industrial & Specialty Products
Disaggregation of Revenue [Line Items]
Total sales	144,499	144,267	286,726	272,910
Service
Disaggregation of Revenue [Line Items]
Total sales	84,270	98,188	177,841	169,841
Service | Oil & Gas Proppants
Disaggregation of Revenue [Line Items]
Total sales	84,270	98,188	177,841	169,841
Service | Industrial & Specialty Products
Disaggregation of Revenue [Line Items]
Total sales	$ 0	$ 0	$ 0	$ 0

Revenue - Changes in Contract A

Revenue - Changes in Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Unbilled Receivables
Beginning Balance	$ 0	$ 1,957
Reclassifications to billed receivables	0	(4,457)
Revenues recognized in excess of period billings	0	2,930
Ending Balance	0	430
Deferred Revenue
Beginning Balance	30,752	20,741
Revenues recognized from balances held at the beginning of the period	(9,153)	(2,591)
Revenues deferred from period collections on unfulfilled performance obligations	0	20,948
Revenues recognized from period collections	0	(2,816)
Ending Balance	$ 21,599	$ 36,282

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total assets of VIE	$ 2,081,366	$ 2,214,580
Foreign Operations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total assets of VIE	$ 33,700		$ 38,200
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining duration period of expected satisfaction of performance obligations (less than)	1 year

Revenue - Foreign Operations (D

Revenue - Foreign Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total sales	$ 406,784	$ 388,513	$ 849,024	$ 693,400
Pre-tax income	61,281	34,754	119,426	19,271
Net income	46,259	22,908	90,907	14,515
Foreign Operations
Disaggregation of Revenue [Line Items]
Total sales	25,817	29,658	55,749	54,912
Pre-tax income	4,299	9,715	11,201	14,528
Net income	$ 3,396	$ 7,675	$ 8,848	$ 11,477

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Related Party Transactions [Abstract]
Related party transaction, amounts of transaction	$ 0	$ 0	$ 0	$ 0

Segment Reporting - Narrative (

Segment Reporting - Narrative (Details)	6 Months Ended
	Jun. 30, 2023 USD ($) product segment	Dec. 31, 2022 USD ($)
Segment Reporting Information
Number of reportable segments (segments) | segment	2
Number of product types (over) | product	600
Goodwill	$ 185,649,000	$ 185,649,000
Oil & Gas Proppants
Segment Reporting Information
Goodwill	0	0
Industrial & Specialty Products
Segment Reporting Information
Goodwill	$ 185,600,000	$ 185,600,000

Segment Reporting - Sales and S

Segment Reporting - Sales and Segment Contribution Margin for Reporting Segments and Other Operating Results (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Segment Reporting Information
Total sales	$ 406,784	$ 388,513	$ 849,024	$ 693,400
Total segment contribution margin	150,664	123,268	303,490	205,855
Operating activities excluded from segment cost of sales	(3,653)	(3,651)	(7,372)	(8,220)
Selling, general and administrative	(28,694)	(34,817)	(57,857)	(74,927)
Depreciation, depletion and amortization	(33,546)	(34,715)	(68,932)	(72,464)
Interest expense	(25,987)	(17,430)	(50,048)	(34,603)
Other income, net, including interest income	2,497	2,099	145	3,630
Income tax expense	(15,137)	(11,919)	(28,710)	(4,950)
Net income	46,144	22,835	90,716	14,321
Less: Net loss attributable to non-controlling interest	(115)	(73)	(191)	(194)
Net income attributable to U.S. Silica Holdings, Inc.	46,259	22,908	90,907	14,515
Oil & Gas Proppants
Segment Reporting Information
Total sales	262,285	244,246	562,298	420,490
Total segment contribution margin	99,069	77,353	208,966	122,106
Industrial & Specialty Products
Segment Reporting Information
Total sales	144,499	144,267	286,726	272,910
Total segment contribution margin	$ 51,595	$ 45,915	$ 94,524	$ 83,749