Solaris Energy Infrastructure (SEI) 10-Q 1 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Oct. 28, 2021
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-38090
Entity Registrant Name	SOLARIS OILFIELD INFRASTRUCTURE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-5223109
Entity Address, Address Line One	9811 Katy Freeway, Suite 700
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77024
City Area Code	281
Local Phone Number	501-3070
Title of 12(b) Security	Class A Common Stock
Trading Symbol	SOI
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Central Index Key	0001697500
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false
Class A Common Stock
Document and Entity Information
Entity Common Stock, Shares Outstanding		31,956,979
Class B Common Stock
Document and Entity Information
Entity Common Stock, Shares Outstanding		13,818,517

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 42,831	$ 60,366
Accounts receivable, net of allowances for credit losses of $936 and $1,099, respectively	37,461	18,243
Prepaid expenses and other current assets	6,337	2,169
Inventories	1,223	954
Total current assets	87,852	81,732
Property, plant and equipment, net	240,554	245,884
Non-current inventories	2,805	3,318
Operating lease right-of-use assets	4,317	4,708
Goodwill	13,004	13,004
Intangible assets, net	2,398	2,982
Deferred tax assets	63,499	59,805
Other assets	340	463
Total assets	414,769	411,896
Current liabilities:
Accounts payable	13,668	6,863
Accrued liabilities	18,125	11,986
Current portion of payables related to Tax Receivable Agreement	589	606
Current portion of operating lease liabilities	705	647
Current portion of finance lease liabilities	30	30
Other current liabilities	567	75
Total current liabilities	33,684	20,207
Operating lease liabilities, net of current	6,843	7,419
Finance lease liabilities, net of current	77	100
Payables related to Tax Receivable Agreement	72,925	68,097
Other long-term liabilities	564	594
Total liabilities	114,093	96,417
Commitments and contingencies (Note 8)
Stockholders' equity:
Preferred stock, $0.01 par value, 50,000 shares authorized, none issued and outstanding
Additional paid-in capital	195,862	180,415
Retained earnings	8,640	20,549
Total stockholders' equity attributable to Solaris	204,813	201,254
Non-controlling interest	95,863	114,225
Total stockholders' equity	300,676	315,479
Total liabilities and stockholders' equity	414,769	411,896
Class A Common Stock
Stockholders' equity:
Common Stock	311	290
Class B Common Stock
Stockholders' equity:
Common Stock

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Allowance for credit losses	$ 936	$ 1,099
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	50,000	50,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A Common Stock
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	600,000	600,000
Common stock, shares issued	31,094	28,943
Common stock, shares outstanding	31,094	28,943
Class B Common Stock
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, shares authorized	180,000	180,000
Common stock, shares issued	13,820	15,685
Common stock, shares outstanding	13,820	15,685

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Total revenue	$ 49,377	$ 20,531	$ 113,240	$ 77,700
Operating costs and expenses:
Depreciation and amortization	6,842	6,594	20,288	20,378
Selling, general and administrative (excluding $164 and $177 and $531 and $497 of depreciation and amortization for the three and nine months ended September 30, 2021 and 2020, respectively, shown separately)	4,760	3,840	14,326	12,212
Impairment losses				47,828
Other operating (income) expense	(2,690)	1,856	(2,074)	5,329
Total operating costs and expenses	47,372	26,937	115,356	134,181
Operating income (loss)	2,005	(6,406)	(2,116)	(56,481)
Interest income (expense), net	(66)	(40)	(170)	36
Total other expense (income)	(66)	(40)	(170)	36
Income (loss) before income tax expense	1,939	(6,446)	(2,286)	(56,445)
Income tax (expense) benefit	(507)	843	(77)	8,193
Net income (loss)	1,432	(5,603)	(2,363)	(48,252)
Less: net (income) loss related to non-controlling interests	(558)	2,320	857	20,347
Net income (loss) attributable to Solaris	874	(3,283)	(1,506)	(27,905)
System rental
Revenue:
Total revenue	16,091	9,197	44,063	40,720
Operating costs and expenses:
Cost of revenue	2,536	1,181	5,704	4,018
System services
Revenue:
Total revenue	32,990	10,855	68,317	35,231
Operating costs and expenses:
Cost of revenue	35,617	13,126	76,151	43,269
Transloading services
Revenue:
Total revenue	86	310	239	1,039
Operating costs and expenses:
Cost of revenue	220	243	672	783
Inventory software services
Revenue:
Total revenue	210	169	621	710
Operating costs and expenses:
Cost of revenue	$ 87	$ 97	$ 289	$ 364
Class A Common Stock
Operating costs and expenses:
Income (loss) per share of Class A common stock - basic (in dollars per share)	$ 0.03	$ (0.12)	$ (0.06)	$ (0.97)
Income (loss) per share of Class A common stock - diluted (in dollars per share)	$ 0.03	$ (0.12)	$ (0.06)	$ (0.97)
Basic weighted-average shares of Class A common stock outstanding (in shares)	31,058	28,787	30,671	28,912
Diluted weighted-average shares of Class A common stock outstanding (in shares)	31,058	28,787	30,671	28,912

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Depreciation and amortization, nonproduction	$ 163	$ 177	$ 530	$ 498
Stock-based compensation expense	1,355	1,077	3,907	3,732
Selling, general and administrative expenses
Stock-based compensation expense	1,254	1,011	3,521	3,356
System rental
Depreciation and amortization, production	6,250	6,052	18,578	18,087
Stock-based compensation expense	8	(14)	20	16
System services
Depreciation and amortization, production	234	172	596	803
Stock-based compensation expense	89	76	349	349
Transloading services
Depreciation and amortization, production	0	0	0	411
Stock-based compensation expense	4	4	17	11
Inventory software services
Depreciation and amortization, production	$ 195	$ 193	$ 584	$ 579

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common StockClass A Common Stock	Common StockClass B Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Non-controlling Interest	Total
Balance at beginning of period at Dec. 31, 2019	$ 308		$ 191,843	$ 74,222	$ (2,526)	$ 145,811	$ 409,658
Balance at beginning of period (in shares) at Dec. 31, 2019	30,765	15,940			163
Changes in Stockholders' Equity
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock	$ 1		460			(461)
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock (in shares)	50	(50)
Net effect of deferred tax asset and payables related to Tax Receivable Agreement from the exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock			(303)				(303)
Stock option exercises			66		$ (80)	(11)	(25)
Stock option exercises (in shares)	9				7
Share and unit repurchases and retirements	$ (24)		(14,804)	(10,177)		(1,711)	(26,716)
Share and unit repurchases and retirements (in shares)	(2,374)
Stock-based compensation			907			492	1,399
Vesting of restricted stock	$ 1		471		$ (373)	(473)	(374)
Vesting of restricted stock (in shares)	105				37
Solaris LLC distribution paid to Solaris LLC unitholders						(1,668)	(1,668)
Dividends paid (Class A common stock)				(3,087)			(3,087)
Treasury stock retirements			(1,247)	(1,732)	$ 2,979
Treasury stock retirements (in shares)					(207)
Net income (loss)				(19,081)		(14,071)	(33,152)
Balance at end of period at Mar. 31, 2020	$ 286		177,393	40,145		127,908	345,732
Balance at end of period (in shares) at Mar. 31, 2020	28,555	15,890
Balance at beginning of period at Dec. 31, 2019	$ 308		191,843	74,222	$ (2,526)	145,811	409,658
Balance at beginning of period (in shares) at Dec. 31, 2019	30,765	15,940			163
Changes in Stockholders' Equity
Net income (loss)							(48,252)
Balance at end of period at Sep. 30, 2020	$ 289		179,811	25,098		117,657	322,855
Balance at end of period (in shares) at Sep. 30, 2020	28,842	15,785
Balance at beginning of period at Mar. 31, 2020	$ 286		177,393	40,145		127,908	345,732
Balance at beginning of period (in shares) at Mar. 31, 2020	28,555	15,890
Changes in Stockholders' Equity
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock	$ 1		395			(395)	1
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock (in shares)	50	(50)
Net effect of deferred tax asset and payables related to Tax Receivable Agreement from the exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock			(310)				(310)
Stock option exercises			36			(16)	20
Stock option exercises (in shares)	7
Stock-based compensation			895			497	1,392
Vesting of restricted stock			171			(171)
Vesting of restricted stock (in shares)	80
Cancelled shares withheld for taxes from RSU vesting			(69)			(38)	(107)
Cancelled shares withheld for taxes from RSU vesting (in shares)	(19)
Solaris LLC distribution paid to Solaris LLC unitholders						(1,663)	(1,663)
Dividends paid (Class A common stock)				(3,089)			(3,089)
Net income (loss)				(5,542)		(3,955)	(9,497)
Balance at end of period at Jun. 30, 2020	$ 287		178,511	31,514		122,167	332,479
Balance at end of period (in shares) at Jun. 30, 2020	28,673	15,840
Changes in Stockholders' Equity
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock	$ 1		422			(423)
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock (in shares)	55	(55)
Net effect of deferred tax asset and payables related to Tax Receivable Agreement from the exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock			(40)				(40)
Stock-based compensation			726			415	1,141
Vesting of restricted stock	$ 1		308			(309)
Vesting of restricted stock (in shares)	140
Cancelled shares withheld for taxes from RSU vesting			(84)	(31)		(66)	(181)
Cancelled shares withheld for taxes from RSU vesting (in shares)	(26)
Solaris LLC distribution paid to Solaris LLC unitholders for income tax withholding			(32)			(150)	(182)
Solaris LLC distribution paid to Solaris LLC unitholders						(1,657)	(1,657)
Dividends paid (Class A common stock)				(3,102)			(3,102)
Net income (loss)				(3,283)		(2,320)	(5,603)
Balance at end of period at Sep. 30, 2020	$ 289		179,811	25,098		117,657	322,855
Balance at end of period (in shares) at Sep. 30, 2020	28,842	15,785
Balance at beginning of period at Dec. 31, 2020	$ 290		180,415	20,549		114,225	315,479
Balance at beginning of period (in shares) at Dec. 31, 2020	28,943	15,685
Changes in Stockholders' Equity
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock	$ 19		13,526			(13,545)
Exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock (in shares)	1,865	(1,865)
Net effect of deferred tax asset and payables related to Tax Receivable Agreement from the exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock			(1,184)				(1,184)
Stock option exercises			18			(6)	12
Stock option exercises (in shares)	4
Stock-based compensation			854			418	1,272
Vesting of restricted stock	$ 2		407			(409)
Vesting of restricted stock (in shares)	223
Cancelled shares withheld for taxes from RSU vesting	$ (1)		(146)	(319)		(207)	(673)
Cancelled shares withheld for taxes from RSU vesting (in shares)	(57)
Solaris LLC distribution paid to Solaris LLC unitholders						(1,451)	(1,451)
Dividends paid (Class A common stock)				(3,346)			(3,346)
Net income (loss)				(1,169)		(756)	(1,925)
Balance at end of period at Mar. 31, 2021	$ 310		193,890	15,715		98,269	308,184
Balance at end of period (in shares) at Mar. 31, 2021	30,978	13,820
Balance at beginning of period at Dec. 31, 2020	$ 290		180,415	20,549		114,225	315,479
Balance at beginning of period (in shares) at Dec. 31, 2020	28,943	15,685
Changes in Stockholders' Equity
Net income (loss)							(2,363)
Balance at end of period at Sep. 30, 2021	$ 311		195,862	8,640		95,863	300,676
Balance at end of period (in shares) at Sep. 30, 2021	31,094	13,820
Balance at beginning of period at Mar. 31, 2021	$ 310		193,890	15,715		98,269	308,184
Balance at beginning of period (in shares) at Mar. 31, 2021	30,978	13,820
Changes in Stockholders' Equity
Net effect of deferred tax asset and payables related to Tax Receivable Agreement from the exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock			(198)				(198)
Stock-based compensation			989			442	1,431
Vesting of restricted stock			15			(15)
Vesting of restricted stock (in shares)	8
Cancelled shares withheld for taxes from RSU vesting			(6)	(21)		(9)	(36)
Cancelled shares withheld for taxes from RSU vesting (in shares)	(2)
Solaris LLC distribution paid to Solaris LLC unitholders						(1,451)	(1,451)
Dividends paid (Class A common stock)				(3,346)			(3,346)
Net income (loss)				(1,211)		(659)	(1,870)
Balance at end of period at Jun. 30, 2021	$ 310		194,690	11,137		96,577	302,714
Balance at end of period (in shares) at Jun. 30, 2021	30,984	13,820
Changes in Stockholders' Equity
Net effect of deferred tax asset and payables related to Tax Receivable Agreement from the exchange of Solaris LLC Units and shares of Class B common stock for shares of Class A common stock			(9)				(9)
Stock-based compensation			991			441	1,432
Vesting of restricted stock	$ 1		235			(236)
Vesting of restricted stock (in shares)	121
Cancelled shares withheld for taxes from RSU vesting			(45)	(16)		(26)	(87)
Cancelled shares withheld for taxes from RSU vesting (in shares)	(11)
Solaris LLC distribution paid to Solaris LLC unitholders						(1,451)	(1,451)
Dividends paid (Class A common stock)				(3,355)			(3,355)
Net income (loss)				874		558	1,432
Balance at end of period at Sep. 30, 2021	$ 311		$ 195,862	$ 8,640		$ 95,863	$ 300,676
Balance at end of period (in shares) at Sep. 30, 2021	31,094	13,820

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY
Distributions paid to unit holders (in dollars per unit)	$ 0.105	$ 0.105	$ 0.105	$ 0.105	$ 0.105	$ 0.105
Cash dividends paid (in dollars per share)	$ 0.105	$ 0.105	$ 0.105	$ 0.105	$ 0.105	$ 0.105

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (2,363)	$ (48,252)
Adjustment to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	20,288	20,378
Loss on disposal of assets	113	1,439
Allowance for credit losses	630	2,880
Stock-based compensation	3,907	3,732
Amortization of debt issuance costs	132	132
Deferred income tax benefit	(273)	(8,299)
Impairment losses		47,828
Other	(153)	(151)
Changes in operating assets and liabilities:
Accounts receivable	(19,847)	17,630
Prepaid expenses and other assets	(3,266)	1,876
Inventories	(714)	(359)
Accounts payable	7,076	5,245
Accrued liabilities	6,167	(6,069)
Net cash provided by operating activities	11,697	38,010
Cash flows from investing activities:
Investment in property, plant and equipment	(13,702)	(2,901)
Cash received from insurance proceeds	35	53
Proceeds from disposal of assets	42	724
Net cash used in investing activities	(13,625)	(2,124)
Cash flows from financing activities:
Share repurchases		(26,717)
Distribution and dividend paid to Solaris LLC unitholders (other than Solaris Inc.) and Class A common shareholders	(14,400)	(14,267)
Distribution to Solaris LLC unitholders for income tax withholding		(150)
Payments under finance leases	(23)	(24)
Payments under insurance premium financing	(410)
Proceeds from stock option exercises	12	64
Payments for shares withheld for taxes from RSU vesting and cancelled	(786)	(276)
Payments related to purchase of treasury stock		(454)
Net cash used in financing activities	(15,607)	(41,824)
Net decrease in cash	(17,535)	(5,938)
Cash at beginning of period	60,366	66,882
Cash at end of period	42,831	60,944
Non-cash activities
Employee retention credit	1,900
Capitalized depreciation in property, plant and equipment	2,260	359
Capitalized stock based compensation	228	198
Accrued capital expenditures	323	12
Property, plant and equipment additions transferred from inventory	958	359
Insurance premium financing	410
Cash paid for:
Interest	99	99
Income taxes	$ 325	$ 796

Organization and Background of

Organization and Background of Business	9 Months Ended
	Sep. 30, 2021
Organization and Background of Business
Organization and Background of Business	1. Organization and Background of Business Description of Business We design and manufacture specialized equipment, which combined with field technician support, logistics services and our software solutions, enables us to provide a service offering that helps oil and natural gas operators and their suppliers drive efficiencies that reduce operational footprint and costs during the completion phase of well development. Our equipment and services are deployed in most of the active oil and natural gas basins in the United States.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Basis of Presentation and Consolidation Solaris Oilfield Infrastructure, Inc. (either individually or together with its subsidiaries, as the context requires “Solaris Inc.” or the “Company”) is the managing member of Solaris Oilfield Infrastructure, LLC (“Solaris LLC”) and is responsible for all operational, management and administrative decisions relating to Solaris LLC’s business. Solaris Inc. consolidates the financial results of Solaris LLC and its subsidiaries and reports non-controlling interest related to the portion of the units in Solaris LLC (the “Solaris LLC Units”) not owned by Solaris Inc., which will reduce net income attributable to the holders of Solaris Inc.’s Class A common stock. The accompanying interim unaudited condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). These financial statements reflect all normal recurring adjustments that are necessary for fair presentation. Operating results for the three and nine months ended September 30, 2021 and 2020 are not necessarily indicative of the results that may be expected for the full year or for any interim period. The unaudited interim condensed consolidated financial statements do not include all information or notes required by GAAP for annual financial statements and should be read together with Solaris Inc.’s Annual Report on Form 10-K for the year ended December 31, 2020 and notes thereto. All material intercompany transactions and balances have been eliminated upon consolidation. COVID-19 and Global Economic and Market Conditions The strain of coronavirus ("COVID-19") has caused, and continues to cause, severe disruptions to the U.S. and global economies, including the oil and gas industry and the demand for our products and services. The degree to which COVID-19 and related events outside of our control adversely impacts our results will depend on future developments, which are highly uncertain and cannot be predicted, including the timing, extent, trajectory and duration of the COVID-19 pandemic, the emergence of new strains or variants of COVID-19, the continued development, availability and administration of effective treatments and vaccines and the impact of the COVID-19 pandemic on the global economy and any subsequent recovery of normal economic and operating conditions. Use of Estimates The preparation of consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The most significant estimates relate to taxes, stock-based compensation, useful lives and salvage values of long-lived assets, future cash flows associated with goodwill and long-lived asset impairment, net realizable value of inventory, collectability of accounts receivable and estimates of allowance for credit losses and determination of the present value of lease payments and right-of-use assets. Recently Issued Accounting Standards In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) No. 2020-04, Reference Rate Reform, which provides temporary optional guidance to companies impacted by the transition away from the London Interbank Offered Rate (“LIBOR”). The guidance provides certain expedients and exceptions to applying GAAP in order to lessen the potential accounting burden when contracts, hedging relationships, and other transactions that reference LIBOR as a benchmark rate are modified. This guidance is effective upon issuance and expires on December 31, 2022. The Company is currently assessing the impact of the LIBOR transition and this ASU on the Company’s financial statements.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment
Property, Plant and Equipment	3. Property, Plant and Equipment Property, plant and equipment are stated at cost. We manufacture or construct most of our systems. During the manufacturing of these assets, they are reflected as systems in process until complete. Modifications to existing systems, including the expenditures for upgrades and enhancements that result in additional functionality, increased efficiency, or the extension of the estimated useful life, are capitalized. Property, plant and equipment consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ 2021 2020 Systems and related equipment ​ $ 304.2 ​ $ 299.4 Systems in process ​ ​ 17.7 ​ 12.6 Computer hardware and software ​ 1.1 ​ 1.0 Machinery and equipment ​ 5.4 ​ 5.3 Vehicles ​ 5.1 ​ 3.6 Buildings ​ 4.5 ​ 4.3 Land ​ 0.6 ​ 0.6 Furniture and fixtures ​ ​ 0.4 ​ 0.4 Property, plant and equipment, gross ​ $ 339.0 ​ $ 327.2 Less: accumulated depreciation ​ (98.4) ​ (81.3) Property, plant and equipment, net ​ $ 240.6 ​ $ 245.9 ​

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt
Debt	4. Debt On April 26, 2019, Solaris LLC entered into an Amended and Restated Credit Agreement (the “2019 Credit Agreement”) by and among Solaris LLC, as borrower, each of the lenders party thereto and Wells Fargo Bank, National Association, as administrative agent. The 2019 Credit Agreement consists of an initial $50.0 revolving loan commitment (the “Loan”) with a $25.0 uncommitted accordion option to increase the Loan availability to $75.0. The term of the 2019 Credit Agreement expires on April 26, 2022. The 2019 Credit Agreement requires that we prepay any outstanding borrowings under the Loan in the event our total leverage ratio is greater than 1.00 to 1.00 and our consolidated cash balance exceeds $20.0, taking into account certain adjustments. At September 30, 2021, we had no borrowings under the 2019 Credit Agreement outstanding and ability to draw $50.0. Although there were no borrowings outstanding under the 2019 Credit Agreement, the applicable margin ranges from 1.75% to 2.50% for Eurodollar loans and 0.75% to 1.50% for alternate base rate loans, in each case depending on our total leverage ratio. The 2019 Credit Agreement requires that we pay a quarterly commitment fee on undrawn amounts of the Loan, ranging from 0.25% to 0.375% depending upon the total leverage ratio. We were in compliance with all covenants in accordance with the 2019 Credit Agreement as of September 30, 2021.

Equity

Equity	9 Months Ended
	Sep. 30, 2021
Equity
Equity	5. Equity Dividends Solaris LLC paid distributions totaling $4.8 and $4.8 to all Solaris LLC unitholders in the three months ended September 30, 2021 and 2020, respectively, of which $3.4 and $3.1 was paid to Solaris Inc. Solaris LLC paid distributions totaling $14.4 and $14.3 to all Solaris LLC unitholders in the nine months ended September 30, 2021 and 2020, respectively, of which $10.0 and $9.3 was paid to Solaris Inc. Solaris Inc. used the proceeds from the distributions to pay quarterly cash dividends to all holders of shares of Class A common stock. Stock-based compensation The Company’s long-term incentive plan for employees, directors and consultants (the “LTIP”) provides for the grant of all or any of the following types of equity-based awards: (1) incentive stock options qualified as such under United States federal income tax laws; (2) stock options that do not qualify as incentive stock options; (3) stock appreciation rights; (4) restricted stock awards; (5) restricted stock units; (6) bonus stock; (7) performance awards; (8) dividend equivalents; (9) other stock-based awards; (10) cash awards; and (11) substitute awards. Subject to adjustment in accordance with the terms of the LTIP, 5,118,080 shares of Solaris Inc.’s Class A common stock have been reserved for issuance pursuant to awards under the LTIP. As of September 30, 2021, 2,452,821 stock awards were available for grant. The following table summarizes activity related to restricted stock for the three and nine months ended September 30, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ Restricted Stock Awards ​ ​ 2021 ​ 2020 Unvested at January 1, 703,115 ​ 627,251 Awarded 414,185 ​ 386,146 Vested (223,275) ​ (141,700) Forfeited (5,388) ​ (32,845) Unvested at March 31, ​ 888,637 ​ 838,852 Awarded ​ 3,376 ​ 10,194 Vested ​ (8,797) ​ (80,203) Forfeited ​ (2,306) ​ (37,164) Unvested at June 30, ​ 880,910 ​ 731,679 Awarded ​ 105,233 ​ 139,961 Vested ​ (121,235) ​ (137,490) Forfeited ​ (3,426) ​ (29,537) Unvested at September 30, ​ 861,482 ​ 704,613 ​ Of the unvested 861,482 shares of restricted stock, it is expected that 420,543 shares, 271,931 shares, and 169,008 shares will vest in 2022, 2023 and 2024, respectively, in each case, subject to the applicable vesting terms governing such shares of restricted stock. There was approximately $7.2 of unrecognized compensation expense related to unvested restricted stock as of September 30, 2021. The unrecognized compensation expense will be recognized over the weighted average remaining vesting period of 1.2 years. Income (Loss) Per Share Basic income (loss) per share of Class A common stock is computed by dividing net income (loss) attributable to Solaris Inc. by the weighted-average number of shares of Class A common stock outstanding during the same period. Diluted income (loss) per share is computed giving effect to all potentially dilutive shares. The following table sets forth the calculation of income (loss) per share for the three and nine months ended September 30, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, Basic net income (loss) per share: ​ 2021 ​ 2020 ​ 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to Solaris ​ $ 0.9 ​ $ (3.3) ​ $ (1.5) ​ $ (27.9) Income (loss) attributable to participating securities (1) ​ ​ (0.1) ​ ​ (0.1) ​ ​ (0.3) ​ ​ (0.2) Net income (loss) attributable to common stockholders ​ $ 0.8 ​ $ (3.4) ​ $ (1.8) ​ $ (28.1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of unrestricted outstanding common shares used to calculate basic net income (loss) per share ​ ​ 31,058 ​ ​ 28,787 ​ ​ 30,671 ​ ​ 28,912 Diluted weighted-average shares of Class A common stock outstanding used to calculate diluted net income (loss) per share ​ ​ 31,058 ​ ​ 28,787 ​ ​ 30,671 ​ ​ 28,912 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income (loss) per share of Class A common stock - basic ​ $ 0.03 ​ $ (0.12) ​ $ (0.06) ​ $ (0.97) Income (loss) per share of Class A common stock - diluted ​ $ 0.03 ​ $ (0.12) ​ $ (0.06) ​ $ (0.97) ​ (1) The Company’s restricted shares of common stock are participating securities. ​ The following number of weighted-average potentially dilutive shares were excluded from the calculation of diluted loss per share because the effect of including such potentially dilutive shares would have been antidilutive upon conversion: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2021 ​ 2020 ​ 2021 2020 Class B common stock ​ ​ 13,819 ​ ​ 15,803 ​ ​ 14,119 ​ ​ 15,860 Restricted stock awards ​ ​ 868 ​ ​ 703 ​ ​ 839 ​ ​ 718 Stock Options ​ ​ 7 ​ ​ 13 ​ ​ 10 ​ ​ 16 Total ​ ​ 14,694 ​ ​ 16,519 ​ ​ 14,968 ​ ​ 16,594 ​

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Taxes
Income Taxes	6. Income Taxes Income Taxes Based on our cumulative earnings history and forecasted future sources of taxable income, we believe that we will be able to realize our deferred tax assets in the future. As the Company reassesses this position in the future, changes in cumulative earnings history, excluding non-recurring charges, or changes to forecasted taxable income may alter this expectation and may result in an increase in the valuation allowance and an increase in the effective tax rate. ​ Section 382 of the Internal Revenue Code of 1986, contains rules that limit the ability of a company that undergoes an “ownership change” to utilize its net operating loss and tax credit carryovers and certain built-in losses recognized in years after the “ownership change.” An “ownership change” is generally defined as any change in ownership of more than 50% of a corporation’s stock over a rolling three-year period by stockholders that own (directly or indirectly) 5% or more of the stock of a corporation, or arising from a new issuance of stock by a corporation. If an ownership change occurs, Section 382 generally imposes an annual limitation on the use of pre-ownership change net operating loss carryovers to offset taxable income earned after the ownership change. We do not believe the Section 382 annual limitation related to historical ownership changes impacts our ability to utilize our net operating losses; however, if we were to experience a future ownership change our ability to use net operating losses may be impacted. The Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was enacted on March 27, 2020 in the United States to provide emergency assistance to individuals and businesses affected by the COVID-19 pandemic. The CARES Act includes temporary changes to both income and non-income based tax laws. For the three and nine months ended September 30, 2021 and 2020 the impact of the CARES Act was immaterial to the Company’s tax provision. However, under the CARES Act, the Company is deferring the employer portion of payroll tax payments through December 31, 2022. Future regulatory guidance under the CARES Act or additional legislation enacted by Congress in connection with the COVID-19 pandemic could impact our tax provision in future periods. is included in prepaid expenses and other current assets on the consolidated balance sheet. The calculation of the credit is based on employees continued employment and represents a portion of the wages paid to them. For income tax purposes, the credit will result in decreased expense related to the wages it offsets in the period received. The Company accounted for the employee retention credit as a government grant in accordance with ASU Topic 958, Not-for-Profit Entities – Revenue Recognition. ​ Payables Related to the Tax Receivable Agreement these cash savings. As of September 30, 2021 and December 31, 2020, Solaris Inc. recorded a payable related to the Tax Receivable Agreement of $73.5 and $68.7, respectively, $0.6 and $0.6 of which has been recorded as a current liability, respectively. The increase in payables related to the Tax Receivable Agreement is a result of Solaris Inc.’s acquisition (or deemed acquisition for United States federal income tax purposes) of Solaris LLC Units from TRA Holders during the nine months ended September 30, 2021.

Concentrations

Concentrations	9 Months Ended
	Sep. 30, 2021
Concentrations
Concentrations	7. Concentrations For the three months ended September 30, 2021, one customer accounted for 26% of the Company’s revenues. For the three months ended September 30, 2020, one customer accounted for 28% of the Company’s revenues. For the nine months ended September 30, 2021, one customer accounted for 24% of the Company’s revenues. For the nine months ended September 30, 2020, one customer accounted for 11 % of the Company’s revenues. As of September 30, 2021, three customers accounted for 49% of the Company’s accounts receivable. As of December 31, 2020, four customers accounted for 42% of the Company’s accounts receivable. For the three months ended September 30, 2021, no supplier accounted for more than 10% of the Company’s total purchases. For the three months ended September 30, 2020, three suppliers accounted for 16%, 12%, and 10% of the Company’s total purchases. For the nine months ended September 30, 2021, no supplier accounted for more than 10% of the Company’s total purchases. For the nine months ended September 30, 2020, one supplier accounted for 32% of the Company’s total purchases. As of September 30, 2021, no supplier accounted for 10% of the Company’s accounts payable. As of December 31, 2020, two suppliers accounted for 23% of the Company’s accounts payable.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies
Commitments and Contingencies	8. Commitments and Contingencies In the normal course of business, the Company is subjected to various claims, legal actions, contract negotiations and disputes. The Company provides for losses, if any, in the year in which they can be reasonably estimated. In management’s opinion, there are currently no such matters outstanding that would have a material effect on the accompanying condensed consolidated financial statements. See Note 9 “Related Party Transactions” for contingent payments related to contracts with customers.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions
Related Party Transactions	9. Related Party Transactions The Company recognizes certain costs incurred in relation to transactions incurred in connection with the amended and restated administrative services agreement, dated May 17, 2017, between Solaris LLC and Solaris Energy Management, LLC, a company partially owned by William A. Zartler, the Chief Executive Officer and Chairman of the Board. These services include rent paid for office space, travel services, personnel, consulting and administrative costs. For the three months ended September 30, 2021 and 2020, Solaris LLC paid $0.3 and $0.2, respectively, for these services. For the nine months ended September 30, 2021 and 2020, Solaris LLC paid $0.6 and $0.6, respectively, for these services. As of September 30, 2021, and December 31, 2020, the Company included $0.1 and $0.1, respectively, in prepaid expenses and other current assets on the condensed consolidated balance sheets. Additionally, as of September 30, 2021 and December 31, 2020, the Company included $0.1 and $0.1, respectively, of accruals to related parties in accrued liabilities on the consolidated balance sheet The Company has executed a guarantee of lease agreement with Solaris Energy Management, LLC, a related party of the Company, related to the rental of office space for the Company’s corporate headquarters. The total future guaranty under the guarantee of lease agreement with Solaris Energy Management, LLC is $4.5 as of September 30, 2021. On March 26, 2021, THRC Holdings, LP (“THRC”), purchased shares representing an 8.7% ownership of the Company’s Class A common stock and 6.0% total shares outstanding as of September 30, 2021. THRC is affiliated with certain of the Company’s customers, including ProFrac Services, LLC (“ProFrac”) and FTS International and certain of the Company’s suppliers including Automatize Logistics, LLC, IOT-EQ, LLC and Cisco Logistics, LLC (“Cisco”) (together the “THRC Affiliates”). For the three and nine months ended September 30, 2021, the Company recognized revenues related to our service offering provided to the THRC Affiliates of $3.0 and $9.1, respectively. Accounts receivable related to THRC Affiliates as of September 30, 2021, were $1.9. For the three and nine months ended September 30, 2021, the Company recognized cost of services provided by THRC Affiliates of $1.8 and $2.8, respectively. There were no accounts payable related to THRC Affiliates as of September 30, 2021. ​ In August 2021, the Company executed a three-year agreement with ProFrac and Cisco (the “ProFrac-Cisco Agreement”). The primary terms of the ProFrac-Cisco Agreement include provisions whereby (i) Solaris shall be ProFrac’s dedicated wellsite sand storage provider (“Services”), (ii) Solaris shall provide volume-based pricing to ProFrac for the Services and (iii) Solaris shall acquire certain equipment from Cisco (“Equipment”). During the third quarter of 2021, Solaris paid an initial $1.5 for the Equipment which was recognized in Property, plant and equipment. Solaris may be required to pay up to $4.5 in additional payments throughout the three-year term of the agreement contingent upon ProFrac meeting certain minimum Services revenue thresholds. ​ On October 1, 2021, the Company made payments totaling $0.6 for payables related to the Tax Receivable Agreement.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Summary of Significant Accounting Policies
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation Solaris Oilfield Infrastructure, Inc. (either individually or together with its subsidiaries, as the context requires “Solaris Inc.” or the “Company”) is the managing member of Solaris Oilfield Infrastructure, LLC (“Solaris LLC”) and is responsible for all operational, management and administrative decisions relating to Solaris LLC’s business. Solaris Inc. consolidates the financial results of Solaris LLC and its subsidiaries and reports non-controlling interest related to the portion of the units in Solaris LLC (the “Solaris LLC Units”) not owned by Solaris Inc., which will reduce net income attributable to the holders of Solaris Inc.’s Class A common stock. The accompanying interim unaudited condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”). These financial statements reflect all normal recurring adjustments that are necessary for fair presentation. Operating results for the three and nine months ended September 30, 2021 and 2020 are not necessarily indicative of the results that may be expected for the full year or for any interim period. The unaudited interim condensed consolidated financial statements do not include all information or notes required by GAAP for annual financial statements and should be read together with Solaris Inc.’s Annual Report on Form 10-K for the year ended December 31, 2020 and notes thereto. All material intercompany transactions and balances have been eliminated upon consolidation.
COVID-19 and Global Economic and Market Conditions	COVID-19 and Global Economic and Market Conditions The strain of coronavirus ("COVID-19") has caused, and continues to cause, severe disruptions to the U.S. and global economies, including the oil and gas industry and the demand for our products and services. The degree to which COVID-19 and related events outside of our control adversely impacts our results will depend on future developments, which are highly uncertain and cannot be predicted, including the timing, extent, trajectory and duration of the COVID-19 pandemic, the emergence of new strains or variants of COVID-19, the continued development, availability and administration of effective treatments and vaccines and the impact of the COVID-19 pandemic on the global economy and any subsequent recovery of normal economic and operating conditions.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The most significant estimates relate to taxes, stock-based compensation, useful lives and salvage values of long-lived assets, future cash flows associated with goodwill and long-lived asset impairment, net realizable value of inventory, collectability of accounts receivable and estimates of allowance for credit losses and determination of the present value of lease payments and right-of-use assets.
Recently Issued Accounting Standards	In March 2020, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) No. 2020-04, Reference Rate Reform, which provides temporary optional guidance to companies impacted by the transition away from the London Interbank Offered Rate (“LIBOR”). The guidance provides certain expedients and exceptions to applying GAAP in order to lessen the potential accounting burden when contracts, hedging relationships, and other transactions that reference LIBOR as a benchmark rate are modified. This guidance is effective upon issuance and expires on December 31, 2022. The Company is currently assessing the impact of the LIBOR transition and this ASU on the Company’s financial statements.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment
Schedule of property plant and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ 2021 2020 Systems and related equipment ​ $ 304.2 ​ $ 299.4 Systems in process ​ ​ 17.7 ​ 12.6 Computer hardware and software ​ 1.1 ​ 1.0 Machinery and equipment ​ 5.4 ​ 5.3 Vehicles ​ 5.1 ​ 3.6 Buildings ​ 4.5 ​ 4.3 Land ​ 0.6 ​ 0.6 Furniture and fixtures ​ ​ 0.4 ​ 0.4 Property, plant and equipment, gross ​ $ 339.0 ​ $ 327.2 Less: accumulated depreciation ​ (98.4) ​ (81.3) Property, plant and equipment, net ​ $ 240.6 ​ $ 245.9

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2021
Equity
Summary of activity related to restricted stock	​ ​ ​ ​ ​ ​ ​ ​ Restricted Stock Awards ​ ​ 2021 ​ 2020 Unvested at January 1, 703,115 ​ 627,251 Awarded 414,185 ​ 386,146 Vested (223,275) ​ (141,700) Forfeited (5,388) ​ (32,845) Unvested at March 31, ​ 888,637 ​ 838,852 Awarded ​ 3,376 ​ 10,194 Vested ​ (8,797) ​ (80,203) Forfeited ​ (2,306) ​ (37,164) Unvested at June 30, ​ 880,910 ​ 731,679 Awarded ​ 105,233 ​ 139,961 Vested ​ (121,235) ​ (137,490) Forfeited ​ (3,426) ​ (29,537) Unvested at September 30, ​ 861,482 ​ 704,613
Schedule of earnings per share calculation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, Basic net income (loss) per share: ​ 2021 ​ 2020 ​ 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Numerator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to Solaris ​ $ 0.9 ​ $ (3.3) ​ $ (1.5) ​ $ (27.9) Income (loss) attributable to participating securities (1) ​ ​ (0.1) ​ ​ (0.1) ​ ​ (0.3) ​ ​ (0.2) Net income (loss) attributable to common stockholders ​ $ 0.8 ​ $ (3.4) ​ $ (1.8) ​ $ (28.1) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average number of unrestricted outstanding common shares used to calculate basic net income (loss) per share ​ ​ 31,058 ​ ​ 28,787 ​ ​ 30,671 ​ ​ 28,912 Diluted weighted-average shares of Class A common stock outstanding used to calculate diluted net income (loss) per share ​ ​ 31,058 ​ ​ 28,787 ​ ​ 30,671 ​ ​ 28,912 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Income (loss) per share of Class A common stock - basic ​ $ 0.03 ​ $ (0.12) ​ $ (0.06) ​ $ (0.97) Income (loss) per share of Class A common stock - diluted ​ $ 0.03 ​ $ (0.12) ​ $ (0.06) ​ $ (0.97) ​ (1) The Company’s restricted shares of common stock are participating securities.
Schedule of antidilutive shares	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2021 ​ 2020 ​ 2021 2020 Class B common stock ​ ​ 13,819 ​ ​ 15,803 ​ ​ 14,119 ​ ​ 15,860 Restricted stock awards ​ ​ 868 ​ ​ 703 ​ ​ 839 ​ ​ 718 Stock Options ​ ​ 7 ​ ​ 13 ​ ​ 10 ​ ​ 16 Total ​ ​ 14,694 ​ ​ 16,519 ​ ​ 14,968 ​ ​ 16,594

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment
Property, plant and equipment, gross	$ 339,000	$ 327,200
Less: accumulated depreciation	(98,400)	(81,300)
Property, plant and equipment, net	240,554	245,884
Systems and related equipment
Property, Plant and Equipment
Property, plant and equipment, gross	304,200	299,400
Systems in process
Property, Plant and Equipment
Property, plant and equipment, gross	17,700	12,600
Computer hardware and software
Property, Plant and Equipment
Property, plant and equipment, gross	1,100	1,000
Machinery and equipment
Property, Plant and Equipment
Property, plant and equipment, gross	5,400	5,300
Vehicles
Property, Plant and Equipment
Property, plant and equipment, gross	5,100	3,600
Buildings
Property, Plant and Equipment
Property, plant and equipment, gross	4,500	4,300
Land
Property, Plant and Equipment
Property, plant and equipment, gross	600	600
Furniture and fixtures
Property, Plant and Equipment
Property, plant and equipment, gross	$ 400	$ 400

Debt (Details)

Debt (Details) - 2019 Credit Agreement $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)	Apr. 26, 2019USD ($)
Debt
Maximum borrowing		$ 50
Potential additional borrowing available		25
Maximum borrowing capacity with accordion option		$ 75
Leverage ratio for threshold		1
Cash threshold triggering repayment		$ 20
Outstanding credit facility	$ 0
Remaining borrowing capacity	$ 50
Minimum
Debt
Commitment fee (as a percent)	0.25%
Maximum
Debt
Commitment fee (as a percent)	0.375%
Eurodollar | Minimum
Debt
Applicable margin rate	1.75%
Eurodollar | Maximum
Debt
Applicable margin rate	2.50%
Alternate base rate | Minimum
Debt
Applicable margin rate	0.75%
Alternate base rate | Maximum
Debt
Applicable margin rate	1.50%

Equity - Dividends (Details)

Equity - Dividends (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Equity
Distributions paid to unit holders			$ 14,400	$ 14,267
Distribution received	$ 3,400	$ 3,100	10,000	9,300
Solaris LLC
Equity
Distributions paid to unit holders	$ 4,800	$ 4,800	$ 14,400	$ 14,300

Equity - SBC (Details)

Equity - SBC (Details)	Sep. 30, 2021shares
Stock-based compensation
Available for grant (in shares)	2,452,821
Class A Common Stock
Stock-based compensation
Reserved for issuance (in shares)	5,118,080

Equity - Restricted stock (Deta

Equity - Restricted stock (Details) - Restricted stock awards - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021
Number of Shares
Unvested, beginning (in shares)	880,910	888,637	703,115	731,679	838,852	627,251	703,115
Awarded (in shares)	105,233	3,376	414,185	139,961	10,194	386,146
Vested (in shares)	(121,235)	(8,797)	(223,275)	(137,490)	(80,203)	(141,700)
Forfeited (in shares)	(3,426)	(2,306)	(5,388)	(29,537)	(37,164)	(32,845)
Unvested, end (in shares)	861,482	880,910	888,637	704,613	731,679	838,852	861,482
Other non-option information
Unrecognized compensation costs	$ 7.2						$ 7.2
Expected period for recognizing compensation expense							1 year 2 months 12 days
First vesting period
Number of Shares
Unvested, end (in shares)	420,543						420,543
Second vesting period
Number of Shares
Unvested, end (in shares)	271,931						271,931
Third vesting period
Number of Shares
Unvested, end (in shares)	169,008						169,008

Equity - EPS (Details)

Equity - EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator
Net income (loss) attributable to Solaris	$ 874	$ (3,283)	$ (1,506)	$ (27,905)
Income (loss) attributable to participating securities	(100)	(100)	(300)	(200)
Net income (loss) attributable to common stockholders	$ 800	$ (3,400)	$ (1,800)	$ (28,100)
Class A Common Stock
Denominator
Weighted average number of unrestricted outstanding common shares used to calculate basic net income (loss) per share	31,058	28,787	30,671	28,912
Diluted weighted-average shares of Class A common stock outstanding (in shares)	31,058	28,787	30,671	28,912
Income (loss) per share of Class A common stock - basic (in dollars per share)	$ 0.03	$ (0.12)	$ (0.06)	$ (0.97)
Income (loss) per share of Class A common stock - diluted (in dollars per share)	$ 0.03	$ (0.12)	$ (0.06)	$ (0.97)

Equity - Antidilutive (Details)

Equity - Antidilutive (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Potentially dilutive shares
Excluded from EPS calculation (in shares)	14,694	16,519	14,968	16,594
Class B Common Stock
Potentially dilutive shares
Excluded from EPS calculation (in shares)	13,819	15,803	14,119	15,860
Restricted stock awards
Potentially dilutive shares
Excluded from EPS calculation (in shares)	868	703	839	718
Stock options
Potentially dilutive shares
Excluded from EPS calculation (in shares)	7	13	10	16

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	May 17, 2017	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Income tax (expense) benefit		$ (507)	$ 843	$ (77)	$ 8,193
Effective tax rate		26.20%	13.10%	3.40%	14.50%
Current portion of payables related to Tax Receivable Agreement		$ 589		$ 589		$ 606
Employee retention credit
Other operating income		3,100		3,100
Proceeds from credit				1,200
Tax credit receivable		1,900		1,900
Tax Receivable Agreement
Payments of net cash saving (as a percent)	85.00%
Benefit of remaining cash savings (as a percent)	15.00%
Payables related to Tax Receivable Agreement		73,500		73,500		68,700
Current portion of payables related to Tax Receivable Agreement		$ 600		$ 600		$ 600

Concentrations (Details)

Concentrations (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2021customer	Sep. 30, 2020customeritem	Sep. 30, 2021customer	Sep. 30, 2020itemcustomer	Dec. 31, 2020itemcustomer
Revenue | Customer | One Customer
Concentrations
Number of customers | customer	1	1	1	1
Concentration risk (as a percent)	26.00%	28.00%	24.00%	11.00%
Accounts receivable | Customer | Three Customers
Concentrations
Number of customers | customer			3
Concentration risk (as a percent)			49.00%
Accounts receivable | Customer | Four Customers
Concentrations
Number of customers | customer					4
Concentration risk (as a percent)					42.00%
Purchases | Supplier
Concentrations
Number of suppliers | item		3
Purchases | Supplier | One Supplier
Concentrations
Number of suppliers | item				1
Concentration risk (as a percent)		16.00%		32.00%
Purchases | Supplier | Two Suppliers
Concentrations
Concentration risk (as a percent)		12.00%
Purchases | Supplier | Supplier Three
Concentrations
Concentration risk (as a percent)		10.00%
Accounts payables | Supplier | Two Suppliers
Concentrations
Number of suppliers | item					2
Concentration risk (as a percent)					23.00%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	Oct. 01, 2021	Aug. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Mar. 26, 2021	Dec. 31, 2020
ProFrac-Cisco Agreement
Related Party Transactions
Payment made to related party		$ 1.5
Other commitments		$ 4.5
Term of agreement		3 years
Tax Receivable Agreement
Related Party Transactions
Payment made to related party	$ 0.6
Payables related to Tax Receivable Agreement			$ 73.5		$ 73.5			$ 68.7
William A. Zartler
Related Party Transactions
Payment made to related party			0.3	$ 0.2	0.6	$ 0.6
Due from related party			0.1		0.1			0.1
Due to related party			0.1		0.1			$ 0.1
Solaris Energy Management, LLC
Related Party Transactions
Other commitments			4.5		4.5
THRC Affiliates
Related Party Transactions
Due from related party			1.9		1.9
Due to related party			0		0
Revenue from related party			3		9.1
Related party costs			$ 1.8		$ 2.8
THRC
Related Party Transactions
Voting power (as a percent)							6.00%
THRC | Solaris Oilfield Infrastructure
Related Party Transactions
Noncontrolling interest (as a percent)							8.70%