Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Consolidation	The accompanying consolidated financial statements include our accounts and the accounts of our subsidiaries. Intercompany amounts and transactions with our consolidated subsidiaries have been eliminated. Transactions with our non-consolidated affiliates (referred to herein as affiliates) have not been eliminated.
Reclassifications	We reclassified certain prior period amounts to conform to the current period presentation, including the categorization of our revenues for 2016 and 2015. See Note 9—Products and Services Revenues for additional information. These changes had no impact on total operating revenues, total operating expenses or net income for any period presented.
Use of Estimates	Use of Estimates Our consolidated financial statements are prepared in accordance with U.S. generally accepted accounting principles. These accounting principles require us to make certain estimates, judgments and assumptions. We believe that the estimates, judgments and assumptions we make when accounting for specific items and matters, including, but not limited to, long-term contracts, customer retention patterns, allowance for doubtful accounts, depreciation, amortization, asset valuations, rates used for affiliate cost allocations, internal labor capitalization rates, recoverability of assets (including deferred tax assets), impairment assessments, taxes, certain liabilities and other provisions and contingencies, are reasonable, based on information available at the time they are made. Our accounting for CenturyLink's indirect acquisition of us required extensive use of estimates in determining the acquisition date fair values of our assets and liabilities. These estimates, judgments and assumptions can materially affect the reported amounts of assets, liabilities and components of stockholder's equity as of the dates of the consolidated balance sheets, as well as the reported amounts of revenues, expenses and components of cash flows during the periods presented in our other consolidated financial statements. We also make estimates in our assessments of potential losses in relation to threatened or pending tax and legal matters. See Note 11—Income Taxes and Note 15—Commitments and Contingencies for additional information. For matters not related to income taxes, if a loss is considered probable and the amount can be reasonably estimated, we recognize an expense for the estimated loss. If we have the potential to recover a portion of the estimated loss from a third party, we make a separate assessment of recoverability and reduce the estimated loss if recovery is also deemed probable. For matters related to income taxes, if we determine that the impact of an uncertain tax position is more likely than not to be sustained upon audit by the relevant taxing authority, then we recognize a benefit for the largest amount that is more likely than not to be sustained. No portion of an uncertain tax position will be recognized if the position has less than a 50% likelihood of being sustained. Interest is recognized on the amount of unrecognized benefit from uncertain tax positions. For all of these and other matters, actual results could differ materially from our estimates.
Revenue Recognition	Revenue Recognition We recognize revenue for services when the related services are provided. Recognition of certain payments received in advance of services being provided is deferred until the service is provided. These advance payments include activation and installation charges, which we recognize as revenue over the expected customer relationship period, which ranges from three to seven years depending on the service. We also defer costs for customer activations and installations. The deferral of customer activation and installation costs is limited to the amount of revenue deferred on advance payments. Costs in excess of advance payments are recorded as expense in the period such costs are incurred. Expected customer relationship periods are estimated using historical experience. In most cases, termination fees or other fees on existing contracts that are negotiated in conjunction with new contracts are deferred and recognized over the new contract term. We offer bundle discounts to our customers who receive certain groupings of services. These bundle discounts are recognized concurrently with the associated revenue and are allocated to the various services in the bundled offering based on the estimated selling price of services included in each bundled combination. Customer arrangements that include both equipment and services are evaluated to determine whether the elements are separable. If the elements are deemed separable and separate earnings processes exist, the revenue associated with the customer arrangement is allocated to each element based on the relative estimated selling price of the separate elements. We have estimated the selling prices of each element by reference to vendor-specific objective evidence of selling prices when the elements are sold separately. The revenue associated with each element is then recognized as earned. For example, if we receive an advance payment when we sell equipment and continuing service together, we immediately recognize as revenue the amount allocated to the equipment as long as all the conditions for revenue recognition have been satisfied. The portion of the advance payment allocated to the service based upon its relative selling price is recognized ratably over the longer of the contractual period or the expected customer relationship period. In connection with offering products and services provided by third-party vendors, we review the relationship between us, the vendor and the end customer to assess whether revenue should be reported on a gross or net basis. In assessing whether revenue should be reported on a gross or net basis, we consider whether we act as a principal in the transaction, take title to the products, have risk and rewards of ownership or act as an agent or broker.
Affiliate Transactions	Affiliate Transactions We provide to our affiliates telecommunications services that we also provide to external customers. In addition, we provide to our affiliates computer system development and support services. Services provided by us to our affiliates are recognized as operating revenue-affiliates in our consolidated statements of operations. We also purchase services from our affiliates including telecommunications services, marketing and employee-related support services. Services provided to us from our affiliates are recognized as operating expenses-affiliates on our consolidated statements of operations. Because of the significance of the services we provide to our affiliates and our affiliates provide to us, the results of operations, financial position and cash flows presented herein are not necessarily indicative of the results of operations, financial position and cash flows we would have achieved had we operated as a stand-alone entity during the periods presented. We recognize intercompany charges at the amounts billed to us by our affiliates and we recognize intercompany revenue for services we bill to our affiliates. Regulatory rules require certain revenues and expenses to be recorded at market price or fully distributed cost. Our compliance with regulations is subject to review by regulators. Adjustments to intercompany charges that result from these reviews are recorded in the period they become known. CenturyLink has cash management arrangements between certain of its subsidiaries that include lines of credit, affiliate obligations, capital contributions and dividends. As part of these cash management arrangements, an affiliate provides lines of credit to certain other affiliates. Amounts outstanding under these lines of credit and intercompany obligations vary from time to time. Under these arrangements, the majority of our cash balance is transferred on a daily basis to CenturyLink and most affiliate transactions are deemed to be settled at the time the transactions are recorded in our accounting records, with the resulting net balance at the end of each period reflected as advances to affiliates on the accompanying consolidated balance sheets. From time to time we declare and pay dividends to our parent, QSC, which are settled through the advances to affiliates, which has the net effect of reducing the amount of these advances. Dividends declared are reflected on our consolidated statements of stockholder's equity and the consolidated statements of cash flows reflects the changes in advances to affiliates as investing activities and changes in advances from affiliates as financing activities. Interest is assessed on the advances to/from affiliates on either the three-month U.S T-bill rate (for advances to affiliates) or CenturyLink’s weighted average borrowing rate (for advances from affiliates). The affiliate obligations, net in current and noncurrent liabilities on our consolidated balance sheets primarily represents the cumulative allocation of expense, net of payments, associated with QCII’s pension plans and post-retirement benefits plans prior to the plan mergers. In 2015, we agreed to a plan to settle the outstanding affiliate obligations, net balance with QCII over a 30 year term. Under the plan, payments are scheduled to be made on a monthly basis. For the years ended December 31, 2017 and 2016, we made settlement payments of $87 million and $97 million, respectively, to QCII in accordance with plan. Changes in the affiliate obligations, net are reflected in operating activities on our consolidated statements of cash flows. In the normal course of business, we transfer assets to and from various affiliates through our parent, QSC, which are recorded through our equity. It is our policy to record asset transfers based on carrying values.
USF, Gross Receipts Taxes and Other Surcharges	USF Surcharges, Gross Receipts Taxes and Other Surcharges In determining whether to include in our revenues and expenses the taxes and surcharges collected from customers and remitted to government authorities, including USF surcharges, sales, use, value added and some excise taxes, we assess, among other things, whether we are the primary obligor or principal taxpayer for the taxes assessed in each jurisdiction where we do business. In jurisdictions where we determine that we are the principal taxpayer, we record the surcharges on a gross basis and include them in our revenues and costs of services and products. In jurisdictions where we determine that we are merely a collection agent for the government authority, we record the taxes on a net basis and do not include them in our revenues and costs of services and products.
Advertising Costs	Advertising Costs Costs related to advertising are expensed as incurred and included in selling, general and administrative expenses in our consolidated statements of operations. Our advertising expense was $139 million, $91 million and $84 million for the years ended December 31, 2017, 2016 and 2015, respectively.
Legal Costs	Legal Costs In the normal course of our business, we incur costs to hire and retain external legal counsel to advise us on regulatory, litigation and other matters. We expense these costs as the related services are received.
Income Taxes	Income Taxes Our results are included in the CenturyLink consolidated federal income tax return and certain combined state income tax returns. CenturyLink allocates income tax expense to us based upon a separate return allocation method which results in income tax expense that approximates the expense that would result if we were a stand-alone entity. Our reported deferred tax assets and liabilities, as discussed below and in Note 11—Income Taxes, are primarily determined as a result of the application of the separate return allocation method and therefore the settlement of these amounts is dependent upon our parent, CenturyLink, rather than tax authorities. Our current expectation is that the vast majority of deferred tax assets and liabilities will be settled through our general intercompany obligation based upon the current CenturyLink policy. CenturyLink has the right to change their policy regarding settlement of these assets and liabilities at any time. The provision for income taxes consists of an amount for taxes currently payable, an amount for tax consequences deferred to future periods and adjustments to our liabilities for uncertain tax positions. We record deferred income tax assets and liabilities reflecting future tax consequences attributable to differences between the financial statement carrying value of assets and liabilities and the tax bases of those assets and liabilities. Deferred taxes are computed using enacted tax rates expected to apply in the year in which the differences are expected to affect taxable income. The effect on deferred income tax assets and liabilities of a change in tax rate is recognized in earnings in the period that includes the enactment date. We establish valuation allowances when necessary to reduce deferred income tax assets to the amounts that we believe are more likely than not to be recovered. Each quarter we evaluate the need to retain all or a portion of the valuation allowance on our deferred tax assets. See Note 11—Income Taxes for additional information.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include highly liquid investments that are readily convertible into cash and are not subject to significant risk from fluctuations in interest rates. As a result, the value at which cash and cash equivalents are reported in our consolidated financial statements approximates their fair value. Our cash collections are transferred to CenturyLink on a daily basis and our ultimate parent funds our cash disbursement needs. The net cash transferred to CenturyLink has been reflected as advances to affiliates in our consolidated balance sheets.
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Accounts receivable are recognized based upon the amount due from customers for the services provided or at cost for purchased and other receivables less an allowance for doubtful accounts. The allowance for doubtful accounts receivable reflects our best estimate of probable losses inherent in our receivable portfolio determined on the basis of historical experience, specific allowances for known troubled accounts and other currently available evidence. We generally consider our accounts past due if they are outstanding over 30 days. Our collection process varies by the customer segment, amount of the receivable, and our evaluation of the customer's credit risk. Our past due accounts are written off against our allowance for doubtful accounts when collection is considered to be not probable. Any recoveries of accounts previously written off are generally recognized as a reduction in bad debt expense in the period received. The carrying value of accounts receivable, net of the allowance for doubtful accounts, approximates fair value.
Property, Plant and Equipment	Property, Plant and Equipment As a result of our indirect acquisition by CenturyLink, property, plant and equipment acquired at the time of acquisition was recorded based on its estimated fair value as of the acquisition date. Subsequently purchased and constructed property, plant and equipment are recorded at cost. Property, plant and equipment is depreciated primarily using the straight-line group method. Under the straight-line group method, assets dedicated to providing telecommunications services (which comprise the majority of our property, plant and equipment) that have similar physical characteristics, use and expected useful lives are pooled for purposes of depreciation and tracking. The equal life group procedure is used to establish each pool's average remaining useful life. Generally, under the straight-line group method, when an asset is sold or retired in the course of normal business activities, the cost is deducted from property, plant and equipment and charged to accumulated depreciation without recognition of a gain or loss. A gain or loss is recognized in our consolidated statements of operations only if a disposal is unusual. Leasehold improvements are amortized over the shorter of the useful lives of the assets or the expected lease term. Expenditures for maintenance and repairs are expensed as incurred. Interest is capitalized during the construction phase of network and other internal-use capital projects. Employee-related costs for construction of network and other internal use assets are also capitalized during the construction phase. Property, plant and equipment supplies used internally are carried at average cost, except for significant individual items for which cost is based on specific identification. We perform annual internal reviews to evaluate the reasonableness of the depreciable lives for our property, plant and equipment. Our reviews utilize models that take into account actual usage, physical wear and tear, replacement history, assumptions about technology evolution and, in certain instances, actuarially determined probabilities to estimate the remaining useful life of our asset base. Our remaining useful life assessments anticipate the loss in service value of assets that may precede the physical retirement. Assets shared among many customers may lose service value as those customers leave the network. However, the asset is not retired until all customers no longer utilize the asset and we determine there is no alternative use for the asset. We review long-lived tangible assets for impairment whenever facts and circumstances indicate that the carrying amounts of the assets may not be recoverable. For assessment purposes, long-lived assets are grouped with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities, absent a material change in operations. An impairment loss is recognized only if the carrying amount of the asset group is not recoverable and exceeds its fair value. Recoverability of the asset group to be held and used is assessed by comparing the carrying amount of the asset group to the estimated undiscounted future net cash flows expected to be generated by the asset group. If the asset group's carrying value is not recoverable, an impairment charge is recognized for the amount by which the carrying amount of the asset group exceeds its fair value. We determine fair values by using a combination of comparable market values and discounted cash flows, as appropriate.
Goodwill, Customer Relationships and Other Intangible Assets	Goodwill, Customer Relationships and Other Intangible Assets Intangible assets arising from business combinations, such as goodwill, customer relationships and capitalized software are initially recorded at estimated fair value. We amortize customer relationships primarily over an estimated life of ten years, using either the sum-of-the-years-digits or the straight-line methods, depending on the type of customer. We amortize capitalized software using the straight-line method over estimated lives ranging up to seven years. Other intangible assets not arising from business combinations are initially recorded at cost. Internally used software, whether purchased or developed by us, is capitalized and amortized using the straight-line method over its estimated useful life. We have capitalized certain costs associated with software such as costs of employees devoting time to the projects and external direct costs for materials and services. Costs associated with software to be used for internal purposes are expensed until the point at which the project has reached the development stage. Subsequent additions, modifications or upgrades to internal-use software are capitalized only to the extent that they allow the software to perform a task it previously did not perform. Software maintenance, data conversion and training costs are expensed in the period in which they are incurred. We review the remaining economic lives of our capitalized software annually. Capitalized software is included in other intangible assets, net, in our consolidated balance sheets. We are required to assess goodwill for impairment at least annually, or more frequently, if an event occurs or circumstances change that would indicate an impairment may have occurred. We are required to write-down the value of goodwill in periods in which the recorded amount of goodwill exceeds the implied fair value of goodwill. The impairment assessment is performed annually at the reporting unit level. We have determined that our operations consist of one reporting unit, consistent with our determination that our business consists of one operating segment. See Note 2—Goodwill, Customer Relationships and Other Intangible Assets for additional information.
Pension and Post-Retirement Benefits	Pension and Post-Retirement Benefits A substantial portion of our active and retired employees participate in the CenturyLink Combined Pension Plan. On December 31, 2014, the QCII pension plan and a pension plan of an affiliate were merged into the CenturyLink Retirement Plan. The CenturyLink Retirement Plan was renamed the CenturyLink Combined Pension Plan. Prior to the pension plan merger, the above-noted employees participated in the QCII pension plan. In addition, certain of our employees participate in CenturyLink's post-retirement health care and life insurance benefit plans. CenturyLink allocates service costs relating to pension and post-retirement health care and life insurance benefits to us and its other affiliates. The amounts contributed by us through CenturyLink are not segregated or restricted to pay amounts due to our employees and may be used to provide benefits to other employees of CenturyLink. The allocation of the service costs to us is based upon our employees who are currently earning benefits under the plans. For further information on qualified pension, post-retirement and other post-employment benefit plans, see CenturyLink's annual report on Form 10-K for the year ended December 31, 2017.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Goodwill Impairment On January 26, 2017, The Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") ASU 2017-04, “Simplifying the Test for Goodwill Impairment” (“ASU 2017-04”). ASU 2017-04 simplifies the impairment testing for goodwill by changing the measurement for goodwill impairment. Under current rules, we are required to compute the implied fair value of goodwill to measure the impairment amount if the carrying value of a reporting unit exceeds its fair value. Under ASU 2017-04, the goodwill impairment charge will equal the excess of the reporting unit carrying value above fair value, limited to the amount of goodwill assigned to the reporting unit. We are required to adopt the provisions of ASU 2017-04 for any goodwill impairment tests, including our required annual test, occurring after January 1, 2020, but have the option to early adopt for any impairment test that we are required to perform. We have not determined if we will elect to early adopt the provisions of ASU 2017-04. The provisions of ASU 2017-04 would not have affected our last goodwill impairment assessment, but no assurance can be provided that the simplified testing methodology will not affect our goodwill impairment assessment in the future. Income Taxes On October 24, 2016, the FASB issued ASU 2016-16, “Intra-Entity Transfers of Assets Other Than Inventory” ("ASU 2016-16"). ASU 2016-16 eliminates the current prohibition on the recognition of the income tax effects on the transfer of assets among our subsidiaries. After adoption of this ASU, the income tax effects associated with these asset transfers, except for the transfer of inventory, will be recognized in the period the asset is transferred versus the current deferral and recognition upon either the sale of the asset to a third party or over the remaining useful life of the asset. We plan to adopt the provisions of ASU 2016-16 on January 1, 2018. The adoption of ASU 2016-16 is not expected to have a material impact to our consolidated financial statements. Financial Instruments On June 16, 2016, the FASB issued ASU 2016-13, “Measurement of Credit Losses on Financial Instruments” (“ASU 2016-13”). The primary impact of ASU 2016-13 for us is a change in the model for the recognition of credit losses related to our financial instruments from an incurred loss model, which recognized credit losses only if it was probable that a loss had been incurred, to an expected loss model, which requires our management team to estimate the total credit losses expected on the portfolio of financial instruments. We are currently reviewing the requirements of the standard and evaluating the impact on our consolidated financial statements. We are required to adopt the provisions of ASU 2016-13 effective January 1, 2020, but could elect to early adopt the provisions as of January 1, 2019. We expect to recognize the impacts of adopting ASU 2016-13 through a cumulative adjustment to retained earnings as of the date of adoption. As of the date of this report, we have not yet determined the date we will adopt ASU 2016-13. Leases On February 25, 2016, the FASB issued ASU 2016-02, “Leases” (“ASU 2016-02”). The core principle of ASU 2016-02 will require lessees to present right-of-use assets and lease liabilities on their balance sheets for operating leases, which are currently not reflected on their balance sheets. ASU 2016-02 is effective for annual and interim periods beginning January 1, 2019. Early adoption of ASU 2016-02 is permitted. Upon adoption of ASU 2016-02, we are required to recognize and measure leases at the beginning of the earliest period presented in our consolidated financial statements using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that we may elect to apply. We have completed our initial assessment of our business and system requirements and we are currently developing and implementing a new lease accounting and administrative system to comply with the requirements of ASU 2016-02. We plan to adopt the standard when it becomes effective for us beginning January 1, 2019 and the adoption of the standard will result in the recognition of right of use assets and lease liabilities that have not previously been recorded. Although we believe it is premature as of the date of this report to provide any estimate of the impact of adopting ASU 2016-02, we do expect that it will have a material impact on our consolidated financial statements. Revenue Recognition On May 28, 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers” (“ASU 2014-09”). ASU 2014-09 replaces virtually all existing generally accepted accounting principles (“GAAP”) on revenue recognition and replaces them with a principles-based approach for determining revenue recognition using a new five step model. The core principle of ASU 2014-09 is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 also includes new accounting principles related to the deferral and amortization of contract acquisition and fulfillment costs. On July 9, 2015, the FASB approved the deferral of the effective date of ASU 2014-09 by one year until January 1, 2018, which is the date we plan to adopt this standard. ASU 2014-09 may be adopted by applying the provisions of this standard on a retrospective basis to the periods included in the financial statements or on a modified retrospective basis which would result in the recognition of a cumulative effect of adopting ASU 2014-09 in the first quarter of 2018. We plan to adopt the new revenue recognition standard under the modified retrospective transition method. The most significant judgments and impacts upon adoption of the standard include the following items: Upon adoption, we will defer (i.e. capitalize) incremental contract acquisition costs and recognize (i.e. amortize) them over the term of the initial contract and anticipated renewal contracts to which the costs relate. Our deferred contract costs for our business and consumer customers have average amortization periods of approximately 49 months and 30 months, respectively, and are subject to being monitored every period to reflect any significant change in assumptions. In addition, we will assess our deferred contract cost asset for impairment on a periodic basis. Promotional bill credits, discounts and prepaid cards offered to customers as part of renewing services or entering into a new services arrangement that are paid over time and are contingent on the customer maintaining a service contract results in an extended service contract term with multiple performance obligations, which impacts the allocation and timing of revenue recognition between service revenue and revenue assigned to the customer credits. A contract asset will be recorded when services are delivered to the customer, and subsequently recognized as a reduction to service revenue over the extended contract term. We are in the process of implementing a new revenue accounting system, as well as, new processes and internal controls over revenue recognition to assist us in the application of the new standard. The cumulative effect of initially applying the new revenue standard on January 1, 2018 is estimated to be an increase to retained earnings of approximately $150 million to $300 million.