Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Significant Accounting Policies)	9 Months Ended
Sep. 30, 2016
Accounting Policies [Abstract]
Principles of Consolidation	The accounting policies of Telephone and Data Systems, Inc. (“TDS”) conform to accounting principles generally accepted in the United States of America (“GAAP”) as set forth in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”). The consolidated financial statements include the accounts of TDS and subsidiaries in which it has a controlling financial interest, including TDS’ 83%-owned wireless telephone subsidiary, United States Cellular Corporation (“U.S. Cellular”) and TDS’ wholly-owned subsidiary, TDS Telecommunications Corporation (“TDS Telecom”). In addition, the consolidated financial statements include certain entities in which TDS has a variable interest that require consolidation under GAAP. All material intercompany accounts and transactions have been eliminated. TDS’ business segments reflected in this Quarterly Report on Form 10-Q for the period ended September 30, 2016 are U.S. Cellular, Wireline, Cable, and Hosted and Managed Services (“HMS”) operations. TDS’ non-reportable other business activities are presented as “Corporate, Eliminations and Other”, which includes the operations of TDS’ wholly-owned subsidiary Suttle-Straus, Inc. (“Suttle-Straus”). Suttle-Straus’ financial results were not significant to TDS’ operations. All of TDS’ segments operate only in the United States, except for HMS, which includes an insignificant foreign operation. See Note 11— Business Segment Information for summary financial information on each business segment.
Basis of Accounting	The unaudited consolidated financial statements included herein have been prepared by TDS pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, TDS believes that the disclosures included herein are adequate to make the information presented not misleading. Calculated amounts and percentages are based on the underlying actual numbers rather than the numbers rounded to millions as presented. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in TDS’ Annual Report on Form 10-K (“Form 10-K”) for the year ended December 31, 2015. The accompanying unaudited consolidated financial statements contain all adjustments (consisting of normal recurring items, unless otherwise disclosed) necessary for the fair statement of TDS’ financial position as of September 30, 2016 and December 31, 2015, its results of operations and comprehensive income for the three and nine months ended September 30, 2016 and 2015, and its cash flows and changes in equity for the nine months ended September 30, 2016and 2015. These results are not necessarily indicative of the results to be expected for the full year.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”) and has since amended the standard with Accounting Standards Update 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date, Accounting Standards Update 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net), Accounting Standards Update 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing, and Accounting Standards Update 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients. These standards replace existing revenue recognition rules with a single comprehensive model to use in accounting for revenue arising from contracts with customers. TDS is required to adopt ASU 2014-09, as amended, on January 1, 2018. Early adoption as of January 1, 2017 is permitted; however, TDS does not intend to adopt early. ASU 2014-09, as amended, impacts TDS’ revenue recognition related to the allocation of contract revenues between various services and equipment, and the timing of when those revenues are recognized. In addition, the new requirements require deferral of incremental contract acquisition and fulfillment costs and subsequent expense recognition over the contract period or expected customer life. TDS expects to transition to the new standard under the modified retrospective transition method whereby a cumulative effect adjustment is recognized upon adoption and the guidance is applied prospectively. TDS is currently evaluating the guidance, developing its implementation plan, and evaluating the effects ASU 2014-09, as amended, will have on its financial position and results of operations upon adoption. In August 2014, the FASB issued Accounting Standards Update 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 requires TDS to assess its ability to continue as a going concern each interim and annual reporting period and provide certain disclosures if there is substantial doubt about the entity’s ability to continue as a going concern, including management’s plan to alleviate the substantial doubt. TDS is required to adopt the provisions of ASU 2014-15 for the annual period ending December 31, 2016. The adoption of ASU 2014-15 will not impact TDS’ financial position or results of operations but may impact future disclosures. In July 2015, the FASB issued Accounting Standards Update 2015-11, Inventory: Simplifying the Measurement of Inventory (“ASU 2015-11”), which requires inventory to be measured at the lower of cost or net realizable value. TDS is required to adopt ASU 2015-11 on January 1, 2017. Early adoption is permitted. The adoption of ASU 2015-11 is not expected to have a significant impact on TDS’ financial position or results of operations. In January 2016, the FASB issued Accounting Standards Update 2016-01, Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). This ASU introduces changes to current accounting for equity investments and financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. TDS is required to adopt ASU 2016-01 on January 1, 2018. Certain provisions are eligible for early adoption. The adoption of ASU 2016-01 is not expected to have a significant impact on TDS’ financial position or results of operations. In February 2016, the FASB issued Accounting Standards Update 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 requires lessees to record a right-of-use asset and lease liability for almost all leases. This ASU does not substantially impact lessor accounting. TDS is required to adopt ASU 2016-02 on January 1, 2019. Early adoption is permitted. Upon adoption of ASU 2016-02, TDS expects a substantial increase to assets and liabilities on its balance sheet. TDS is evaluating the full effects that adoption of ASU 2016-02 will have on its financial position and results of operations. In March 2016, the FASB issued Accounting Standards Update 2016-04, Liabilities – Extinguishments of Liabilities: Recognition of Breakage from Certain Prepaid Stored-Value Products (“ASU 2016-04”). ASU 2016-04 requires companies that sell prepaid stored-value products redeemable for goods, services or cash at third-party merchants to recognize breakage (i.e., the value that is ultimately not redeemed by the consumer) in a way that is consistent with how it will be recognized under the new revenue recognition standard. TDS is required to adopt ASU 2016-04 on January 1, 2018. Early adoption is permitted. The adoption of ASU 2016-04 is not expected to have a significant impact on TDS’ financial position or results of operations. In March 2016, the FASB issued Accounting Standards Update 2016-09, Compensation – Stock Compensation: Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”). ASU 2016-09 intends to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. TDS will adopt ASU 2016-09 on January 1, 2017. The adoption of ASU 2016-09 is not expected to have a significant impact on TDS’ financial position, results of operations, or cash flows. In June 2016, the FASB issued Accounting Standards Update 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 requires entities to use a new forward-looking, expected loss model to estimate credit losses. It also requires additional disclosure relating to the credit quality of trade and other receivables, including information relating to management’s estimate of credit allowances. TDS is required to adopt ASU 2016-13 on January 1, 2020. Early adoption as of January 1, 2019 is permitted. TDS is evaluating the effects that adoption of ASU 2016-13 will have on its financial position, results of operations and disclosures. In August 2016, the FASB issued Accounting Standards Update 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 provides guidance on eight targeted cash flow classification issues. TDS is required to adopt ASU 2016-15 on January 1, 2018. TDS is evaluating the effects that adoption of ASU 2016-15 will have on its statement of cash flows. In October 2016, the FASB issued Accounting Standards Update 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory (“ASU 2016-16”). ASU 2016-16 impacts the accounting for the income tax consequences of intra-entity transfers of assets other than inventory when the transfer occurs between entities in different tax jurisdictions. TDS is required to adopt ASU 2016-16 on January 1, 2018. Early adoption is permitted. The adoption of ASU 2016-16 is not expected to have a significant impact on TDS’ financial position or results of operations. In October 2016, the FASB issued Accounting Standards Update 2016-17, Consolidation: Interests Held through Related Parties That Are under Common Control (“ASU 2016-17”). ASU 2016-17 provides guidance on how a reporting entity that is the single decision maker of a VIE should treat indirect interests in an entity held through related parties that are under common control. TDS is required to adopt ASU 2016-17 on January 1, 2017. Early adoption is permitted. TDS is evaluating the effects that adoption of ASU 2016-17 will have on its financial position, results of operations and disclosures.
Variable Interest Entities	TDS consolidates variable interest entities (“VIEs”) in which it has a controlling financial interest as defined by GAAP and is therefore deemed the primary beneficiary. A controlling financial interest will have both of the following characteristics: (a) the power to direct the VIE activities that most significantly impact economic performance and (b) the obligation to absorb the VIE losses and right to receive benefits that are significant to the VIE. TDS reviews these criteria initially at the time it enters into agreements and subsequently when events warranting reconsideration occur. These VIEs have risks similar to those described in the “Risk Factors” in TDS’ Form 10-K for the year ended December 31, 2015.

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Significant Accounting Policies)

9 Months Ended

Sep. 30, 2016

The accounting policies of Telephone and Data Systems, Inc. (“TDS”) conform to accounting principles generally accepted in the United States of America (“GAAP”) as set forth in the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”). The consolidated financial statements include the accounts of TDS and subsidiaries in which it has a controlling financial interest, including TDS’ 83%-owned wireless telephone subsidiary, United States Cellular Corporation (“U.S. Cellular”) and TDS’ wholly-owned subsidiary, TDS Telecommunications Corporation (“TDS Telecom”). In addition, the consolidated financial statements include certain entities in which TDS has a variable interest that require consolidation under GAAP. All material intercompany accounts and transactions have been eliminated.

TDS’ business segments reflected in this Quarterly Report on Form 10-Q for the period ended September 30, 2016 are U.S. Cellular, Wireline, Cable, and Hosted and Managed Services (“HMS”) operations. TDS’ non-reportable other business activities are presented as “Corporate, Eliminations and Other”, which includes the operations of TDS’ wholly-owned subsidiary Suttle-Straus, Inc. (“Suttle-Straus”). Suttle-Straus’ financial results were not significant to TDS’ operations. All of TDS’ segments operate only in the United States, except for HMS, which includes an insignificant foreign operation. See Note 11— Business Segment Information for summary financial information on each business segment.

Basis of Accounting

The unaudited consolidated financial statements included herein have been prepared by TDS pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, TDS believes that the disclosures included herein are adequate to make the information presented not misleading. Calculated amounts and percentages are based on the underlying actual numbers rather than the numbers rounded to millions as presented. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in TDS’ Annual Report on Form 10-K (“Form 10-K”) for the year ended December 31, 2015.

The accompanying unaudited consolidated financial statements contain all adjustments (consisting of normal recurring items, unless otherwise disclosed) necessary for the fair statement of TDS’ financial position as of September 30, 2016 and December 31, 2015, its results of operations and comprehensive income for the three and nine months ended September 30, 2016 and 2015, and its cash flows and changes in equity for the nine months ended September 30, 2016and 2015. These results are not necessarily indicative of the results to be expected for the full year.

Recently Issued Accounting Pronouncements

In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers (“ASU 2014-09”) and has since amended the standard with Accounting Standards Update 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date, Accounting Standards Update 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net), Accounting Standards Update 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing, and Accounting Standards Update 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients. These standards replace existing revenue recognition rules with a single comprehensive model to use in accounting for revenue arising from contracts with customers. TDS is required to adopt ASU 2014-09, as amended, on January 1, 2018. Early adoption as of January 1, 2017 is permitted; however, TDS does not intend to adopt early. ASU 2014-09, as amended, impacts TDS’ revenue recognition related to the allocation of contract revenues between various services and equipment, and the timing of when those revenues are recognized. In addition, the new requirements require deferral of incremental contract acquisition and fulfillment costs and subsequent expense recognition over the contract period or expected customer life. TDS expects to transition to the new standard under the modified retrospective transition method whereby a cumulative effect adjustment is recognized upon adoption and the guidance is applied prospectively. TDS is currently evaluating the guidance, developing its implementation plan, and evaluating the effects ASU 2014-09, as amended, will have on its financial position and results of operations upon adoption.

In August 2014, the FASB issued Accounting Standards Update 2014-15, Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). ASU 2014-15 requires TDS to assess its ability to continue as a going concern each interim and annual reporting period and provide certain disclosures if there is substantial doubt about the entity’s ability to continue as a going concern, including management’s plan to alleviate the substantial doubt. TDS is required to adopt the provisions of ASU 2014-15 for the annual period ending December 31, 2016. The adoption of ASU 2014-15 will not impact TDS’ financial position or results of operations but may impact future disclosures.

In July 2015, the FASB issued Accounting Standards Update 2015-11, Inventory: Simplifying the Measurement of Inventory (“ASU 2015-11”), which requires inventory to be measured at the lower of cost or net realizable value. TDS is required to adopt ASU 2015-11 on January 1, 2017. Early adoption is permitted. The adoption of ASU 2015-11 is not expected to have a significant impact on TDS’ financial position or results of operations.

In January 2016, the FASB issued Accounting Standards Update 2016-01, Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). This ASU introduces changes to current accounting for equity investments and financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. TDS is required to adopt ASU 2016-01 on January 1, 2018. Certain provisions are eligible for early adoption. The adoption of ASU 2016-01 is not expected to have a significant impact on TDS’ financial position or results of operations.

In February 2016, the FASB issued Accounting Standards Update 2016-02, Leases (“ASU 2016-02”). ASU 2016-02 requires lessees to record a right-of-use asset and lease liability for almost all leases. This ASU does not substantially impact lessor accounting. TDS is required to adopt ASU 2016-02 on January 1, 2019. Early adoption is permitted. Upon adoption of ASU 2016-02, TDS expects a substantial increase to assets and liabilities on its balance sheet. TDS is evaluating the full effects that adoption of ASU 2016-02 will have on its financial position and results of operations.

In March 2016, the FASB issued Accounting Standards Update 2016-04, Liabilities – Extinguishments of Liabilities: Recognition of Breakage from Certain Prepaid Stored-Value Products (“ASU 2016-04”). ASU 2016-04 requires companies that sell prepaid stored-value products redeemable for goods, services or cash at third-party merchants to recognize breakage (i.e., the value that is ultimately not redeemed by the consumer) in a way that is consistent with how it will be recognized under the new revenue recognition standard. TDS is required to adopt ASU 2016-04 on January 1, 2018. Early adoption is permitted. The adoption of ASU 2016-04 is not expected to have a significant impact on TDS’ financial position or results of operations.

In March 2016, the FASB issued Accounting Standards Update 2016-09, Compensation – Stock Compensation: Improvements to Employee Share-Based Payment Accounting (“ASU 2016-09”). ASU 2016-09 intends to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. TDS will adopt ASU 2016-09 on January 1, 2017. The adoption of ASU 2016-09 is not expected to have a significant impact on TDS’ financial position, results of operations, or cash flows.

In June 2016, the FASB issued Accounting Standards Update 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). ASU 2016-13 requires entities to use a new forward-looking, expected loss model to estimate credit losses. It also requires additional disclosure relating to the credit quality of trade and other receivables, including information relating to management’s estimate of credit allowances. TDS is required to adopt ASU 2016-13 on January 1, 2020. Early adoption as of January 1, 2019 is permitted. TDS is evaluating the effects that adoption of ASU 2016-13 will have on its financial position, results of operations and disclosures.

In August 2016, the FASB issued Accounting Standards Update 2016-15, Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments (“ASU 2016-15”). ASU 2016-15 provides guidance on eight targeted cash flow classification issues. TDS is required to adopt ASU 2016-15 on January 1, 2018. TDS is evaluating the effects that adoption of ASU 2016-15 will have on its statement of cash flows.

In October 2016, the FASB issued Accounting Standards Update 2016-16, Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory (“ASU 2016-16”). ASU 2016-16 impacts the accounting for the income tax consequences of intra-entity transfers of assets other than inventory when the transfer occurs between entities in different tax jurisdictions. TDS is required to adopt ASU 2016-16 on January 1, 2018. Early adoption is permitted. The adoption of ASU 2016-16 is not expected to have a significant impact on TDS’ financial position or results of operations.

In October 2016, the FASB issued Accounting Standards Update 2016-17, Consolidation: Interests Held through Related Parties That Are under Common Control (“ASU 2016-17”). ASU 2016-17 provides guidance on how a reporting entity that is the single decision maker of a VIE should treat indirect interests in an entity held through related parties that are under common control. TDS is required to adopt ASU 2016-17 on January 1, 2017. Early adoption is permitted. TDS is evaluating the effects that adoption of ASU 2016-17 will have on its financial position, results of operations and disclosures.

Variable Interest Entities

TDS consolidates variable interest entities (“VIEs”) in which it has a controlling financial interest as defined by GAAP and is therefore deemed the primary beneficiary. A controlling financial interest will have both of the following characteristics: (a) the power to direct the VIE activities that most significantly impact economic performance and (b) the obligation to absorb the VIE losses and right to receive benefits that are significant to the VIE. TDS reviews these criteria initially at the time it enters into agreements and subsequently when events warranting reconsideration occur. These VIEs have risks similar to those described in the “Risk Factors” in TDS’ Form 10-K for the year ended December 31, 2015.