Preparation of Interim Financial Statements and Other Items (Policies)	9 Months Ended
	Sep. 30, 2019
Preparation Of Interim Financial Statements And Other Items
Basis of Presentation	Basis of Presentation The unaudited condensed consolidated financial statements (“consolidated financial statements” or “consolidated balance sheets” or “consolidated statements of income”) have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) for interim financial information. These consolidated financial statements include the accounts of Cactus Inc. and its wholly owned subsidiaries. Accordingly, these consolidated financial statements do not include all information or notes required by generally accepted accounting principles for annual financial statements and should be read together with our Annual Report on Form 10‑K for the year ended December 31, 2018. All significant intercompany transactions and balances have been eliminated upon consolidation. The consolidated financial statements include all adjustments, which are of a normal recurring nature, unless otherwise disclosed, necessary for a fair statement of the consolidated financial statements for the interim periods. The results of operations for any interim period are not necessarily indicative of the results to be expected for the full year. As discussed in Note 1, as a result of our IPO and related equity transactions (the “Reorganization”), Cactus Inc. is the sole managing member of Cactus LLC and consolidates the financial results of Cactus LLC and its subsidiaries and reports a non-controlling interest related to the portion of CW Units not owned by Cactus Inc., which reduces net income attributable to holders of Class A common stock. The Reorganization was considered a transaction between entities under common control. As a result, the financial statements for periods prior to our IPO and the Reorganization have been adjusted to combine the previously separate entities for presentation purposes. Our operations are organized into a single reporting segment.
Limitation of Members’ Liability	Limitation of Members’ Liability Under the terms of the Cactus LLC Agreement, the members of Cactus LLC are not obligated for debt, liabilities, contracts or other obligations of Cactus LLC. Profits and losses are allocated to members as defined in the Cactus LLC Agreement.
Interim Period Tax Allocation	Interim Period Tax Allocation For interim income tax reporting we estimate our annual effective tax rate and apply it to our year-to-date ordinary income. The tax effects of unusual or infrequently occurring items, including changes in judgment about valuation allowances and effects of changes in tax laws or rates, are reported in the interim period in which they occur. Net income attributable to Cactus Inc. includes Cactus Inc.’s U.S. federal and state income tax expense. Net income attributable to non-controlling interest is not subject to U.S. federal and state income tax.
Significant Customers	Significant Customers For the nine months ended September 30, 2019 and 2018, one customer represented 10% and 11%, respectively, of consolidated revenues, and no other customers represented 10% or more of our consolidated revenues during the comparative periods.
Significant Vendors	Significant Vendors We purchase a significant portion of supplies, equipment and machined components from a single vendor. For the nine months ended September 30, 2019 and 2018, purchases from this vendor totaled $30.3 million and $36.4 million, respectively. These figures represent approximately 17% and 22% for the respective periods of our total third-party vendor purchases of raw materials, finished products, equipment, machining and other services. Amounts due to the vendor included in accounts payable in the consolidated balance sheets as of September 30, 2019 and December 31, 2018 totaled $5.4 million and $5.0 million, respectively.
Use of Estimates	Use of Estimates 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 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. Such estimates include but are not limited to estimated losses on accounts receivable, estimated realizable value of excess and obsolete inventory, assessments of long-lived assets for possible impairment and estimates of deferred tax assets related to the step-up in basis under the TRA and the associated liability under the TRA. Actual results could differ from those estimates.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Standards Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), which amends the FASB Accounting Standards Codification (“ASC”) and creates Topic 842, Leases. On January 1, 2019, we adopted ASC Topic 842, which is effective for interim and annual reporting periods beginning on or after December 15, 2018. This Topic requires balance sheet recognition of lease assets and lease liabilities for leases classified as operating leases under previous GAAP. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. To adopt Topic 842, we elected the modified retrospective approach and as of January 1, 2019, there was no cumulative-effect adjustment required to the opening balance of retained earnings. We completed a review of contracts representative of our business and assessed the terms under the new standard. Adoption of the standard resulted in the recognition of right-of-use (“ROU”) assets and lease liabilities for operating leases on our consolidated balance sheets but did not have a material impact on our consolidated statements of income and consolidated statements of comprehensive income or consolidated statements of cash flows. Our accounting for finance leases remained substantially unchanged. Adoption of this standard resulted in the recognition of operating lease ROU assets of $25.3 million, reversal of previously recorded deferred rent of $0.5 million, and corresponding operating short-term and long-term lease liabilities of $6.2 million and $19.6 million, respectively, on the consolidated balance sheet as of January 1, 2019. See Note 7 for further details regarding leases. In addition, we utilized the package of practical expedients permitted under the transition guidance within the standard. The expedient package allowed us to not reassess whether existing contracts contained a lease, to not reassess the lease classification of existing leases, and to not consider the initial direct cost for existing leases. In addition to the package of practical expedients, we also utilized expedients and elections allowing for the exclusion of leases with terms of less than twelve months across all asset classes, the portfolio approach to determine discount rates, the election to not separate non-lease components from lease components and to not apply the use of hindsight to the existing lease population. As a lessor, recognition of lease revenue associated with short-term equipment rentals remained consistent with previous guidance and the adoption of this standard did not have a significant impact on our consolidated statements of income. In February 2018, the FASB issued ASU 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220) Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this update allow a reclassification from accumulated other comprehensive income (loss) to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. However, because the amendments only relate to the reclassification of the income tax effects of the Tax Cuts and Jobs Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. The amendments in this update also require certain disclosures about stranded tax effects. The amendments in this update are effective for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. We adopted this ASU on January 1, 2019. The adoption of this pronouncement did not have an impact on our consolidated financial statements. Standards Not Yet Adopted In January 2017, the FASB issued ASU 2017-04, Intangibles – Goodwill and Other (Topic 350), which simplifies the accounting for goodwill impairment by eliminating Step 2 of the current goodwill impairment test. In computing the implied fair value of goodwill under Step 2, an entity had to perform procedures to determine the fair value at the impairment testing date of its assets and liabilities (including unrecognized assets and liabilities) following the procedure that would be required in determining the fair value of assets acquired and liabilities assumed in a business combination. Instead, under the new standard, an entity should perform its annual, or interim, goodwill impairment test by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. The new guidance should be adopted for annual or any interim goodwill impairment tests in fiscal years beginning after December 15, 2019. We do not expect the adoption of this pronouncement will have a material impact on our consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 changes the measurement of credit losses on financial assets measured at amortized cost, including but not limited to trade receivables. The new guidance replaces the current methodology for recognizing credit losses when it is probable that a loss has been incurred (incurred loss model) with an expected loss model that requires consideration of a broader range of information to estimate expected credit losses over the lifetime of an asset. Application of this new guidance may result in an earlier recognition of credit losses as the allowance for credit losses is measured and recorded upon the initial recognition of the financial asset. The allowance for credit losses under the new guidance represents the portion of the asset’s amortized cost basis that we do not expect to collect over the asset’s contractual life, considering past events, current conditions and reasonable and supportable forecasts of future economic conditions. The new standard is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years, with a modified-retrospective approach to be used for implementation. Our historical credit losses have been insignificant due to our proven ability to collect on our trade receivables. Therefore, we believe that our expected future credit losses will not be significant and do not believe that the adoption of ASU 2016-13 will have a material impact on our consolidated financial statements. We are in the process of finalizing our methodology for estimating expected credit losses, including the assumptions used in order to pool receivables with similar risk characteristics.