Revenue Recognition (Policy)	3 Months Ended
Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition, Deferred Revenue [Policy Text Block]	NOTE 5. REVENUE RECOGNITION As of January 1, 2018, we adopted FASB ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” as modified (ASC 606). With our adoption of ASC 606, we made a policy election to record certain regulatory fees, primarily Universal Service Fund (USF) fees, on a net basis. See the Notes to the Consolidated Financial Statements of our 2017 Annual Report on Form 10-K for additional information regarding our policies prior to adoption of ASC 606. When implementing ASC 606, we utilized the practical expedient allowing us to reflect the aggregate effect of all contract modifications occurring before the beginning of the earliest period presented when allocating the transaction price to performance obligations. Contracts with Customers Our products and services are offered to customers in service-only contracts and in contracts that bundle equipment used to access the services and/or with other service offerings. Service revenue is recognized when services are provided, based upon either usage (e.g., minutes of traffic/bytes of data processed) or period of time (e.g., monthly service fees). We record the sale of equipment when title has passed and the products are accepted by the customer. Some contracts have fixed terms and others are cancellable on a short-term basis (i.e., month-to-month arrangements). Revenues from transactions between us and our customers are recorded net of regulatory fees and taxes. Cash incentives given to customers are recorded as a reduction of revenue. Nonrefundable, upfront service activation and setup fees associated with service arrangements are deferred and recognized over the associated service contract period or customer life. We record the sale of equipment and services to customers as gross revenue when we are the principal in the arrangement and net of the associated costs incurred when we act as an agent in the arrangement. Our contracts allow for customers to frequently modify their arrangement, without incurring penalties in many cases. When a contract is modified, we evaluate the change in scope or price of the contract to determine if the modification should be treated as a new contract or if it should be considered a change of the existing contract. We generally do not have significant impacts from contract modifications. Service-Only Contracts and Standalone Equipment Sales Revenue is recognized as service is provided or when control has transferred. For devices sold through indirect channels (e.g., national dealers), revenue is recognized when the dealer accepts the device, not upon activation. Arrangements with Multiple Performance Obligations Revenue recognized from fixed term contracts that bundle services and/or equipment are allocated based on the standalone selling price of all required performance obligations of the contract (i.e., each item included in the bundle). Promotional discounts are attributed to each required component of the arrangement, resulting in recognition over the contract term. Standalone selling prices are determined by assessing prices paid for service-only contracts (e.g., arrangements where customers bring their own devices) and standalone device pricing. We offer the majority of our customers the option to purchase certain wireless devices in installments over a specified period of time, and, in many cases, they may be eligible to trade in the original equipment for a new device and have the remaining unpaid balance paid or settled. For customers that elect these equipment installment payment programs, at the point of sale, we recognize revenue for the entire amount of revenue allocated to the customer receivable net of fair value of the trade-in right guarantee. The difference between the revenue recognized and the consideration received is recorded as a note receivable when the devices are not discounted and our right to consideration is unconditional. When installment sales include promotional discounts (e.g., “buy one get one free”), the difference between revenue recognized and consideration received is recorded as a contract asset to be amortized over the contract term. Less commonly, we offer certain customers highly discounted devices when they enter into a minimum service agreement term. For these contracts, we recognize equipment revenue at the point of sale based on a standalone selling price allocation. The difference between the revenue recognized and the cash received is recorded as a contract asset that will amortize over the contract term. For contracts that require the use of certain equipment in order to receive service (e.g., AT&T U-verse® and DIRECTV linear video services), we allocate the total transaction price to service if the equipment does not meet the criteria to be a distinct performance obligation. Costs to fulfill customer contracts are deferred and amortized over periods ranging generally from four to five years, reflecting the estimated economic lives of the respective customer relationships, subject to an assessment of the recoverability of such costs. Costs to acquire customer contracts, including commissions on service activations, for our wireless and video entertainment services, are deferred and amortized over the contract period or expected customer life, which typically ranges from two to five years. For contracts with an estimated amortization period of less than one year, we expense incremental costs immediately. A contract asset is recorded when revenue is recognized in advance of our right to bill and receive consideration (i.e., we must perform additional services or satisfy another performance obligation in order to bill and receive additional consideration). The contract asset will decrease as services are provided and billed. When consideration is received in advance of the delivery of goods or services, a contract liability is recorded. Reductions in the contract liability will be recorded as we satisfy the performance obligations.

NOTE 5. REVENUE RECOGNITION

As of January 1, 2018, we adopted FASB ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” as modified (ASC 606). With our adoption of ASC 606, we made a policy election to record certain regulatory fees, primarily Universal Service Fund (USF) fees, on a net basis. See the Notes to the Consolidated Financial Statements of our 2017 Annual Report on Form 10-K for additional information regarding our policies prior to adoption of ASC 606.

When implementing ASC 606, we utilized the practical expedient allowing us to reflect the aggregate effect of all contract modifications occurring before the beginning of the earliest period presented when allocating the transaction price to performance obligations.

Contracts with Customers

Our products and services are offered to customers in service-only contracts and in contracts that bundle equipment used to access the services and/or with other service offerings. Service revenue is recognized when services are provided, based upon either usage (e.g., minutes of traffic/bytes of data processed) or period of time (e.g., monthly service fees). We record the sale of equipment when title has passed and the products are accepted by the customer. Some contracts have fixed terms and others are cancellable on a short-term basis (i.e., month-to-month arrangements).

Revenues from transactions between us and our customers are recorded net of regulatory fees and taxes. Cash incentives given to customers are recorded as a reduction of revenue. Nonrefundable, upfront service activation and setup fees associated with service arrangements are deferred and recognized over the associated service contract period or customer life. We record the sale of equipment and services to customers as gross revenue when we are the principal in the arrangement and net of the associated costs incurred when we act as an agent in the arrangement.

Our contracts allow for customers to frequently modify their arrangement, without incurring penalties in many cases. When a contract is modified, we evaluate the change in scope or price of the contract to determine if the modification should be treated as a new contract or if it should be considered a change of the existing contract. We generally do not have significant impacts from contract modifications.

Service-Only Contracts and Standalone Equipment Sales

Revenue is recognized as service is provided or when control has transferred. For devices sold through indirect channels (e.g., national dealers), revenue is recognized when the dealer accepts the device, not upon activation.

Arrangements with Multiple Performance Obligations

Revenue recognized from fixed term contracts that bundle services and/or equipment are allocated based on the standalone selling price of all required performance obligations of the contract (i.e., each item included in the bundle). Promotional discounts are attributed to each required component of the arrangement, resulting in recognition over the contract term. Standalone selling prices are determined by assessing prices paid for service-only contracts (e.g., arrangements where customers bring their own devices) and standalone device pricing.

We offer the majority of our customers the option to purchase certain wireless devices in installments over a specified period of time, and, in many cases, they may be eligible to trade in the original equipment for a new device and have the remaining unpaid balance paid or settled. For customers that elect these equipment installment payment programs, at the point of sale, we recognize revenue for the entire amount of revenue allocated to the customer receivable net of fair value of the trade-in right guarantee. The difference between the revenue recognized and the consideration received is recorded as a note receivable when the devices are not discounted and our right to consideration is unconditional. When installment sales include promotional discounts (e.g., “buy one get one free”), the difference between revenue recognized and consideration received is recorded as a contract asset to be amortized over the contract term.

Less commonly, we offer certain customers highly discounted devices when they enter into a minimum service agreement term. For these contracts, we recognize equipment revenue at the point of sale based on a standalone selling price allocation. The difference between the revenue recognized and the cash received is recorded as a contract asset that will amortize over the contract term.

For contracts that require the use of certain equipment in order to receive service (e.g., AT&T U-verse® and DIRECTV linear video services), we allocate the total transaction price to service if the equipment does not meet the criteria to be a distinct performance obligation.