Organization and Basis of Presentation (Policies)	9 Months Ended
Organization and Basis of Presentation (Policies)	Sep. 30, 2018
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations NOW Inc. (“NOW” or the “Company”) is a holding company headquartered in Houston, Texas that was incorporated in Delaware on November 22, 2013. NOW operates primarily under the DistributionNOW and Wilson Export brands. NOW is a global distributor of energy products as well as products for industrial applications through its locations in the U.S., Canada and internationally which are geographically positioned to serve the energy and industrial markets in over 80 countries. NOW’s energy product offerings are used in the oil and gas industry including upstream drilling and completion, exploration and production, midstream infrastructure development and downstream petroleum refining – as well as in other industries, such as chemical processing, power generation and industrial manufacturing operations. The industrial distribution portion of NOW’s business targets a diverse range of manufacturing and other facilities across numerous industries and end markets. NOW also provides supply chain management to drilling contractors, E&P operators, midstream operators, downstream energy and industrial manufacturing companies. NOW’s supplier network consists of thousands of vendors in approximately 40 countries.
Basis of Presentation	Basis of Presentation All significant intercompany transactions and accounts have been eliminated. The unaudited consolidated financial information included in this report has been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and Article 10 of SEC Regulation S-X. The principles for interim financial information do not require the inclusion of all the information and footnotes required by generally accepted accounting principles for complete financial statements. Therefore, these financial statements should be read in conjunction with the financial statements included in the Company’s most recent Annual Report on Form 10-K. In the opinion of the Company’s management, the consolidated financial statements include all adjustments, all of which are of a normal recurring nature, necessary for a fair presentation of the results for the interim periods. The results of operations for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for the full year.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect reported and contingent amounts of assets and liabilities as of the date of the financial statements and reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of cash and cash equivalents, receivables and payables approximated fair value because of the relatively short maturity of these instruments. Cash equivalents include only those investments having a maturity date of three months or less at the time of purchase. See Note 12 “Derivative Financial Instruments” for the fair value of derivative financial instruments.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842). ASU 2016-02 requires lessees to recognize a lease liability and a right-to-use asset for all leases, including operating leases, with a term greater than twelve months on its balance sheet. ASU 2016-02 is effective for annual and interim periods in fiscal years beginning after December 15, 2018, with early adoption permitted, and requires a modified retrospective transition method. In July 2018, the FASB issued ASU 2018-11, Targeted Improvements, which provided entities with an additional (and optional) transition method to adopt the new lease standard, allowing an entity to apply the new lease standard at the adoption date and to recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. The Company is currently assessing the impact of ASU 2016-02 on its consolidated financial statements, evaluating practical expedients and updating processes and controls to implement ASC 842. Based on the Company’s preliminary assessment, which is subject to change, the Company believes the recognition of lease liabilities and right-of-use assets will result in a material increase in total assets and total liabilities on the Company’s consolidated balance sheets for lessee arrangements. The Company plans to adopt Topic 842 in the first quarter of fiscal year 2019 using the transition method allowed under ASU 2018-11. The Company does not expect the adoption of this standard to have a material impact on its consolidated statements of operations and cash flows. In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments (Topic 326), which replaces the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to determine credit loss estimates. ASU 2016-13 requires entities to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions and reasonable and supportable forecasts. Entities will now use forward-looking information to better form their credit loss estimates. ASU 2016-13 is effective for annual and interim periods in fiscal years beginning after December 15, 2019, with early adoption permitted as of December 15, 2018, and requires the modified retrospective transition method. The Company is currently assessing the impact of ASU 2016-13 on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-13, Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement (Topic 820), which modified the disclosure requirements on fair value measurements. ASU 2018-13 is effective for annual and interim periods in fiscal years beginning after December 15, 2019, with early adoption permitted for removed or modified disclosures. The Company is currently assessing the impact of ASU 2018-13 on its consolidated financial statements. In August 2018, the FASB issued ASU 2018-14, Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans (Subtopic 715-20), which modified the disclosure requirements on defined benefit plans. ASU 2018-14 is effective for annual and interim periods in fiscal years beginning after December 15, 2020, with early adoption permitted, and required to be applied on a retrospective basis. The Company is currently assessing the impact of ASU 2018-14 on its consolidated financial statements.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). ASU 2014-09 affects any entity using GAAP that enters into contracts with customers to transfer goods or services or contracts for the transfer of nonfinancial assets unless those contracts are within the scope of other standards (e.g., insurance contracts or lease contracts). This ASU supersedes the revenue recognition requirements in Revenue Recognition (Topic 605), and most industry-specific guidance. The Company adopted this standard as of January 1, 2018, using the modified retrospective transition method resulting in an immaterial increase to the opening accumulated deficit due to the cumulative impact of adopting Topic 606. The adoption of the new standard had no material impact on the measurement or recognition of revenue, however additional disclosures have been added in accordance with Topic 606. See Note 2 “Revenue” for additional details on the Company’s revenue policies. In March 2017, the FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost (Topic 715). ASU 2017-07 requires the disaggregation of the service cost component from the other components of net periodic benefit cost and allows only the service cost component of net benefit cost to be eligible for capitalization. ASU 2017-07 is effective for annual and interim periods in fiscal years beginning after December 15, 2017. The Company sponsors two defined benefit plans in the UK under which accrual of pension benefits has ceased and there will not be a service cost component to the net periodic pension cost. Plan member benefits that have previously been accrued are indexed in line with inflation during the period up to retirement in order to protect their purchasing power. The Company adopted this standard as of January 1, 2018, with no material impact on its consolidated financial statements. In March 2018, the FASB issued ASU 2018-05, Income Taxes: Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 (Topic 740), which updates the income tax accounting in U.S. GAAP to reflect the Securities and Exchange Commission interpretive guidance released on December 22, 2017, when the Tax Cuts and Jobs Act of 2017 (“Tax Cuts and Jobs Act”) was enacted into law. The Company evaluated the potential impacts of SEC Staff Accounting Bulletin No. 118 (“SAB 118”) along with this ASU and has applied them to its consolidated financial statements and related disclosures. See Note 8 “Income Taxes” for additional information.
Revenue Recognition	Revenue Recognition The Company’s primary source of revenue is the sale of energy products and an extensive selection of products for industrial applications based upon purchase orders or contracts with customers. The majority of revenue is recognized at a point in time once the Company has determined that the customer has obtained control over the product. Control is typically deemed to have been transferred to the customer when the product is shipped, delivered, or picked up by the customer. The Company does not grant extended payment terms. Revenue is recognized net of any taxes collected from customers, which are subsequently remitted to government authorities. Shipping and handling costs for product shipments occur prior to the customer obtaining control of the goods, and are recorded in cost of products. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for products sold. Revenue is recorded at the transaction price net of estimates of variable consideration, which may include product returns, trade discounts and allowances. The Company accrues for variable consideration using the expected value method. Estimates of variable consideration are included in revenue to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur. See Note 7 “Business Segments” for disaggregation of revenue by reporting segments. The Company believes this disaggregation best depicts how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors.
Remaining Performance Obligations	Remaining Performance Obligations Remaining performance obligations represent the transaction price of firm orders for which work has not been performed on contracts with an original expected duration of one year or more. The Company’s contracts are predominantly short-term in nature with a contract term of one year or less. For those contracts, the Company has utilized the practical expedient in ASC Topic 606 exempting the Company from disclosure of the transaction price allocated to remaining performance obligations if the performance obligation is part of a contract that has an original expected duration of one year or less.
Receivables	Receivables Receivables are recorded when the Company has an unconditional right to consideration.
Contract Assets and Liabilities	Contract Assets and Liabilities Contract assets primarily consist of retainage amounts held as a form of security by customers until the Company satisfies its remaining performance obligations. These assets were de minimis for the nine months ended September 30, 2018 and were included in receivables, net in the consolidated balance sheets. The Company applied the practical expedient to recognize the incremental costs of obtaining a contract as an expense when incurred if the amortization period of the asset that the entity otherwise would have recognized is one year or less. These expenses were not material for the three and nine months ended September 30, 2018. Contract liabilities primarily consist of deferred revenues recorded when customer payments are received or due in advance of satisfying performance obligations, including amounts which are refundable, and other accrued customer liabilities. Revenue recognition is deferred to a future period until the Company completes its obligations contractually agreed with customers. Approximately $12 million of revenue that was deferred at the beginning of the period was recognized as revenue during the nine months ended September 30, 2018.