T-Mobile US (TMUS) 10-Q 1 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 27, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	T-MOBILE US, INC.
Trading Symbol	TMUS
Entity Central Index Key	1,283,699
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		846,845,766

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 2,527	$ 1,219
Accounts receivable, net of allowances of $76 and $86	1,689	1,915
Equipment installment plan receivables, net	2,281	2,290
Accounts receivable from affiliates	13	22
Inventories	1,311	1,566
Other current assets	1,788	1,903
Total current assets	9,609	8,915
Property and equipment, net	22,308	22,196
Goodwill	1,901	1,683
Spectrum licenses	35,504	35,366
Other intangible assets, net	291	217
Equipment installment plan receivables due after one year, net	1,234	1,274
Other assets	1,157	912
Total assets	72,004	70,563
Current liabilities
Accounts payable and accrued liabilities	7,157	8,528
Payables to affiliates	291	182
Short-term debt	3,320	1,612
Short-term debt to affiliates	445	0
Deferred revenue	791	779
Other current liabilities	353	414
Total current liabilities	12,357	11,515
Long-term debt	12,127	12,121
Long-term debt to affiliates	14,586	14,586
Tower obligations	2,582	2,590
Deferred tax liabilities	3,813	3,537
Deferred rent expense	2,730	2,720
Other long-term liabilities	933	935
Total long-term liabilities	36,771	36,489
Commitments and contingencies (Note 13)
Stockholders' equity
Common Stock, par value $0.00001 per share, 1,000,000,000 shares authorized; 854,576,971 and 860,861,998 shares issued, 853,066,229 and 859,406,651 shares outstanding	0	0
Additional paid-in capital	38,057	38,629
Treasury stock, at cost, 1,510,742 and 1,455,347 shares issued	(7)	(4)
Accumulated other comprehensive income	5	8
Accumulated deficit	(15,179)	(16,074)
Total stockholders' equity	22,876	22,559
Total liabilities and stockholders' equity	$ 72,004	$ 70,563

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowances	$ 76	$ 86
Common stock, par value (in USD per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	1,000,000,000	1,000,000,000
Common stock, shares issued (in shares)	854,576,971	860,861,998
Common stock, shares outstanding (in shares)	853,066,229	859,406,651
Treasury stock, at cost (in shares)	1,510,742	1,455,347

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues
Branded postpaid revenues	$ 5,070	$ 4,725
Branded prepaid revenues	2,402	2,299
Wholesale revenues	266	270
Roaming and other service revenues	68	35
Total service revenues	7,806	7,329
Equipment revenues	2,353	2,043
Other revenues	296	241
Total revenues	10,455	9,613
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	1,589	1,408
Cost of equipment sales	2,845	2,686
Selling, general and administrative	3,164	2,955
Depreciation and amortization	1,575	1,564
Gains on disposal of spectrum licenses	0	(37)
Total operating expense	9,173	8,576
Operating income	1,282	1,037
Other income (expense)
Interest expense	(251)	(339)
Interest expense to affiliates	(166)	(100)
Interest income	6	7
Other income, net	10	2
Total other expense, net	(401)	(430)
Income before income taxes	881	607
Income tax (expense) benefit	(210)	91
Net income	671	698
Dividends on preferred stock	0	(14)
Net income attributable to common stockholders	671	684
Net income	671	698
Other comprehensive (loss) income, net of tax
Unrealized (loss) gain on available-for-sale securities, net of tax effect of $(1) and $1	(3)	1
Other comprehensive (loss) income	(3)	1
Total comprehensive income	$ 668	$ 699
Earnings per share
Basic (in USD per share)	$ 0.78	$ 0.83
Diluted (in USD per share)	$ 0.78	$ 0.80
Weighted average shares outstanding
Basic (in shares)	855,222,664	827,723,034
Diluted (in shares)	862,244,084	869,395,984

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Unrealized (loss) gain on available-for-sale securities, tax	$ (1)	$ 1

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities
Net income	$ 671	$ 698
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	1,575	1,564
Stock-based compensation expense	97	67
Deferred income tax expense (benefit)	206	(97)
Bad debt expense	54	93
Losses from sales of receivables	52	95
Deferred rent expense	4	20
Gains on disposal of spectrum licenses	0	(37)
Changes in operating assets and liabilities
Accounts receivable	(873)	(1,025)
Equipment installment plan receivables	(222)	(209)
Inventories	33	44
Other current and long-term assets	132	(11)
Accounts payable and accrued liabilities	(1,028)	(651)
Other current and long-term liabilities	45	45
Other, net	24	12
Net cash provided by operating activities	770	608
Investing activities
Purchases of property and equipment, including capitalized interest of $43 and $48	(1,366)	(1,528)
Purchases of spectrum licenses and other intangible assets, including deposits	(51)	(14)
Proceeds related to beneficial interests in securitization transactions	1,295	1,134
Acquisition of companies, net of cash acquired	(333)	0
Other, net	(7)	(8)
Net cash used in investing activities	(462)	(416)
Financing activities
Proceeds from issuance of long-term debt	2,494	5,495
Proceeds from borrowing on revolving credit facility	2,170	0
Repayments of revolving credit facility	(1,725)	0
Repayments of capital lease obligations	(172)	(90)
Repayments of long-term debt	(999)	(3,480)
Repurchases of common stock	(666)	0
Tax withholdings on share-based awards	(74)	(92)
Dividends on preferred stock	0	(14)
Other, net	(28)	(10)
Net cash provided by financing activities	1,000	1,809
Change in cash and cash equivalents	1,308	2,001
Cash and cash equivalents
Beginning of period	1,219	5,500
End of period	2,527	7,501
Supplemental disclosure of cash flow information
Interest payments, net of amounts capitalized	378	495
Income tax payments	1	15
Noncash beneficial interest obtained in exchange for securitized receivables	1,128	1,016
Noncash investing and financing activities
Changes in accounts payable for purchases of property and equipment	(364)	(325)
Leased devices transferred from inventory to property and equipment	304	243
Returned leased devices transferred from property and equipment to inventory	(82)	(197)
Issuance of short-term debt for financing of property and equipment	237	288
Assets acquired under capital lease obligations	$ 142	$ 284

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows Condensed Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Cash Flows [Abstract]
Capitalized interest	$ (43)	$ (48)

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies	Note 1 – Summary of Significant Accounting Policies Basis of Presentation The unaudited condensed consolidated financial statements of T-Mobile US, Inc. (“T-Mobile,” “we,” “our,” “us” or the “Company”) include all adjustments of a normal recurring nature necessary for the fair presentation of the results for the interim periods presented. The results for the interim periods are not necessarily indicative of those for the full year. The condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2017 . The condensed consolidated financial statements include the balances and results of operations of T-Mobile and our consolidated subsidiaries. We consolidate majority-owned subsidiaries over which we exercise control, as well as variable interest entities (“VIE”) where we are deemed to be the primary beneficiary and VIEs which cannot be deconsolidated, such as those related to Tower obligations (Tower obligations are included in VIEs related to the 2012 Tower Transaction. See Note 8 - Tower Obligations included in our Annual Report on Form 10-K for the year ended December 31, 2017 ). Intercompany transactions and balances have been eliminated in consolidation. The preparation of financial statements in conformity with United States (“U.S.”) generally accepted accounting principles (“GAAP”) requires our management to make estimates and assumptions which affect the financial statements and accompanying notes. Estimates are based on historical experience, where applicable, and other assumptions which our management believes are reasonable under the circumstances. These estimates are inherently subject to judgment and actual results could differ from those estimates. Accounting Pronouncements Adopted During the Current Year Revenue In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”, and has since modified the standard with several ASUs (collectively, the “new revenue standard”). The new revenue standard requires entities to recognize revenue through the application of a five-step model, which includes: identification of the contract; identification of the performance obligations; determination of the transaction price; allocation of the transaction price to the performance obligations; and recognition of revenue as the entity satisfies the performance obligations. We adopted the new revenue standard on January 1, 2018, using the modified retrospective method with the cumulative effect of initially applying the guidance recognized at the date of initial application. Comparative information has not been restated and continues to be reported under the standards in effect for those periods. We have applied the new revenue standard only to contracts not completed as of the date of initial application, referred to as open contracts. We have elected the practical expedient that permits an entity to reflect the aggregate effect of all of the modifications (on a contract-by-contract basis) that occurred before the date of initial application in determining the transaction price, identifying the satisfied and unsatisfied performance obligations, and allocating the transaction price to the performance obligations. Electing this practical expedient does not have a significant impact on our financial statements due to the short-term duration of most of our contracts and the nature of our contract modifications. We have implemented significant new revenue accounting systems, processes and internal controls over revenue recognition to assist us in the application of the new revenue standard. Revenue Recognition We primarily generate our revenue from providing wireless services to customers and selling or leasing devices and accessories. Our contracts with customers may involve multiple performance obligations, which include wireless services, wireless devices or a combination thereof, and we allocate the transaction price between each performance obligation based on its relative standalone selling price. Significant Judgments The most significant judgments affecting the amount and timing of revenue from contracts with our customers include the following items: • For transactions where we recognize a significant financing component, judgment is required to determine the discount rate. For equipment installment plan (“EIP”) sales, the discount rate used to adjust the transaction price primarily reflects current market interest rates and the estimated credit risk of the customer. • Our products are generally sold with a right of return, which is accounted for as variable consideration when estimating the amount of revenue to recognize. Expected device returns are estimated based on historical experience. • Promotional bill credits offered to a customer on an equipment sale that are paid over time and are contingent on the customer maintaining a service contract may result in an extended service contract based on whether a substantive penalty is deemed to exist. Determining whether contingent bill credits result in a substantive termination penalty, and determining the term over which a substantive termination penalty exists, may require significant judgment. • For capitalized contract costs, determining the amortization period as well as assessing the indicators of impairment may require significant judgment. • The determination of the standalone selling price for contracts that involve more than one product or service (or performance obligation) may require significant judgment. • The identification of distinct performance obligations within our service plans may require significant judgment. Wireless Services Revenue We generate our wireless services revenues from providing access to, and usage of, our wireless communications network. Service revenues also include revenues earned for providing value added services to customers, such as handset insurance services. Service contracts are billed monthly either in advance or arrears, or are prepaid. Generally, service revenue is recognized as we satisfy our performance obligation to transfer service to our customers. We typically satisfy our stand-ready-performance obligations, including unlimited wireless services, evenly over the contract term. For usage-based and prepaid wireless services, we satisfy our performance obligations when services are rendered. Revenue for service contracts that we assess are not probable of collection is not recognized until the contract is completed and cash is received. Collectibility is re-assessed when there is a significant change in facts or circumstances. Our assessment of collectibility considers whether we may limit our exposure to credit risk through our right to stop transferring additional service in the event the customer is delinquent. Consideration payable to a customer is treated as a reduction of the total transaction price, unless the payment is in exchange for a distinct good or service, such as certain commissions paid to dealers. Revenue is recorded net of costs paid to another party for performance obligations where we arrange for the other party to transfer goods or services to the customer (i.e., when we are acting as an agent). For example, performance obligations relating to services provided by third-party content providers where T-Mobile neither controls a right to the content provider’s service nor controls the underlying service itself are presented net because T-Mobile is acting as an agent. Federal Universal Service Fund (“USF”) and other regulatory fees are assessed by various governmental authorities in connection with the services we provide to our customers and included in Cost of services. When we separately bill and collect these regulatory fees from customers, they are recorded in Total service revenues in our Condensed Consolidated Statements of Comprehensive Income . We have made an accounting policy election to exclude from the measurement of the transaction price all taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction and collected by T-Mobile from a customer (for example, sales, use, value added, and some excise taxes). Equipment Revenues We generate equipment revenues from the sale or lease of mobile communication devices and accessories. For performance obligations related to equipment contracts, we typically transfer control at a point in time when the device or accessory is delivered to, and accepted by, the customer or dealer. We have elected to account for shipping and handling activities that occur after control of the related good transfers as fulfillment activities instead of assessing such activities as performance obligations. We establish provisions for estimated device returns based on historical experience. Equipment sales not probable of collection are generally recorded as payments are received. Our assessment of collectibility considers payment terms such as down payments that reduce our exposure to credit risk. We offer certain customers the option to pay for devices and accessories in installments using an EIP. Generally, we recognize as a reduction of the total transaction price the effects of a financing component in contracts where customers purchase their devices and accessories on an EIP with a term of more than one year, including those financing components that are not considered to be significant to the contract. However, we have elected the practical expedient to not recognize the effects of a significant financing component for contracts where we expect, at contract inception, that the period between the transfer of a performance obligation to a customer and the customer’s payment for that performance obligation will be one year or less. In addition, for customers who enroll in our Just Upgrade My Phone (“JUMP!” ® ) program, we recognize a liability based on the estimated fair value of the specified-price trade-in right guarantee. The fair value of the guarantee is deducted from the transaction price under the new revenue standard, and the remaining transaction price is allocated to other elements of the contract, including service and equipment performance obligations. See “Guarantee Liabilities” in Note 1 - Summary of Significant Accounting Policies included in our Annual Report on Form 10-K for the year ended December 31, 2017. In 2015, we introduced JUMP! On Demand, which allows customers to lease a device and upgrade their leased wireless device for a new device up to one time per month. To date, all of our leased wireless devices are accounted for as operating leases and estimated contract consideration is allocated between lease elements and non-lease elements (such as service and equipment performance obligations) based on the relative standalone selling price of each performance obligation in the contract. Lease revenues are recorded as equipment revenues and recognized as earned on a straight-line basis over the lease term. Lease revenues on contracts not probable of collection are limited to the amount of payments received. See “Property and Equipment” in Note 1 - Summary of Significant Accounting Policies included in our Annual Report on Form 10-K for the year ended December 31, 2017. Contract Balances Generally, T-Mobile devices and service plans are available at standard prices, which are maintained on price lists and published on our website and/or within our retail stores. For contracts that involve more than one product or service that are identified as separate performance obligations, the transaction price is generally allocated to the performance obligations based on their relative standalone selling prices. Standalone selling price is the price that T-Mobile would sell the good or service separately to a customer and is best evidenced by the price that T-Mobile sells that good or service separately in similar circumstances and to similar customers. A contract asset is recorded when revenue is recognized in advance of our right to receive consideration (e.g., we must perform additional services in order to receive consideration). Amounts are recorded as receivables when our right to consideration is unconditional. When consideration is received or we have an unconditional right to consideration in advance of delivery of goods or services, a contract liability is recorded. The transaction price can include non-refundable upfront fees, which are allocated to the identifiable performance obligations. Contract assets are included in Other current assets and Other assets and contract liabilities are included in Deferred revenue in our Condensed Consolidated Balance Sheets . Contract Modifications Our service contracts allow customers to frequently modify their contracts without incurring penalties in many cases. Each time 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 separate contract, as if there is a termination of the existing contract and creation of a new contract, or if the modification should be considered a change associated with the existing contract. We typically do not have significant impacts from contract modifications. Contract Costs We incur certain incremental costs to obtain a contract that we expect to recover, such as sales commissions. We record an asset when these incremental costs to obtain a contract are incurred and amortize them on a systematic basis that is consistent with the transfer to the customer of the goods or services to which the asset relates. We amortize deferred costs incurred to obtain service contracts on a straight-line basis over the term of the initial contract and anticipated renewal contracts to which the costs relate. However, we have elected the practical expedient permitting expensing of costs to obtain a contract when the expected amortization period is one year or less. Incremental costs to obtain equipment contracts (e.g., commissions paid on device and accessory sales) are recognized when the equipment is transferred to the customer. Financial Statement Impacts of Applying the New Revenue Standard The cumulative effect of initially applying the new revenue standard to all open contracts as of January 1, 2018 is as follows: January 1, 2018 (in millions) Beginning Balance Cumulative Effect Adjustment Beginning Balance, As Adjusted Assets Other current assets $ 1,903 $ 140 $ 2,043 Other assets 912 150 1,062 Liabilities and Stockholders’ Equity Deferred revenue $ 779 $ 4 $ 783 Deferred tax liabilities 3,537 73 3,610 Accumulated deficit (16,074 ) 213 (15,861 ) The most significant impacts upon adoption of the new revenue standard on January 1, 2018 include the following items: • A deferred contract cost asset of $150 million was recorded at transition in Other assets in our Condensed Consolidated Balance Sheets for incremental contract acquisition costs paid on open contracts, which consists primarily of commissions paid to acquire branded postpaid service contracts; and • A contract asset of $140 million was recorded at transition in Other current assets in our Condensed Consolidated Balance Sheets primarily for contracts with promotional bill credits offered to customers on equipment sales that are paid over time and are contingent on the customer maintaining a service contract. Financial statement results as reported under the new revenue standard as compared to the previous revenue standard for the three months ended and as of March 31, 2018 are as follows: Three Months Ended March 31, 2018 (in millions, except per share amounts) Previous Revenue Standard New Revenue Standard Change Revenues Branded postpaid revenues $ 5,099 $ 5,070 $ (29 ) Branded prepaid revenues 2,403 2,402 (1 ) Wholesale revenues 266 266 — Roaming and other service revenues 68 68 — Total service revenues 7,836 7,806 (30 ) Equipment revenues 2,276 2,353 77 Other revenues 296 296 — Total revenues 10,408 10,455 47 Operating expenses Cost of services, exclusive of depreciation and amortization shown separately below 1,589 1,589 — Cost of equipment sales 2,845 2,845 — Selling, general and administrative 3,212 3,164 (48 ) Depreciation and amortization 1,575 1,575 — Total operating expenses 9,221 9,173 (48 ) Operating income 1,187 1,282 95 Total other expense, net (401 ) (401 ) — Income before income taxes 786 881 95 Income tax expense (186 ) (210 ) (24 ) Net income $ 600 $ 671 $ 71 Earnings per share Basic earnings per share $ 0.70 $ 0.78 $ 0.08 Diluted earnings per share $ 0.70 $ 0.78 $ 0.08 March 31, 2018 (in millions) Previous Revenue Standard New Revenue Standard Change Assets Other current assets $ 1,684 $ 1,788 $ 104 Other assets 866 1,157 291 Liabilities and Stockholders’ Equity Deferred revenue $ 777 $ 791 $ 14 Deferred tax liabilities 3,716 3,813 97 Accumulated deficit (15,463 ) (15,179 ) 284 The most significant impacts to financial statement results as reported under the new revenue standard as compared to the previous revenue standard for the current reporting period are as follows: • Under the new revenue standard, certain commissions paid to dealers previously recognized as a reduction to Equipment revenues in our Condensed Consolidated Statements of Comprehensive Income are now recorded as commission costs in Selling, general and administrative expense. • Contract costs capitalized for new contracts will accumulate in Other assets in our Condensed Consolidated Balance Sheets during 2018. As a result, there will be a net benefit to Operating income in our Condensed Consolidated Statements of Comprehensive Income during 2018 as capitalization of costs exceed amortization. As capitalized costs amortize into expense over time, the accretive benefit to Operating income anticipated in 2018 is expected to moderate in 2019 and normalize in 2020. • For contracts with promotional bill credits that are contingent on the customer maintaining a service contract that result in an extended service contract, a contract asset is recorded when control of the equipment transfers to the customer and is subsequently recognized as a reduction to Total service revenues in our Condensed Consolidated Statements of Comprehensive Income over the extended contract term. See disclosures related to Contracts with Customers under the new revenue standard in Note 10 - Revenue from Contracts with Customers . Statement of Cash Flows In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” (the “new cash flow standard”). The new cash flow standard is intended to reduce current diversity in practice and provides guidance on how certain cash receipts and payments are presented and classified in the statement of cash flows. We adopted the new cash flow standard on January 1, 2018, which was the date it became effective for us. We have applied the new cash flow standard retrospectively to all periods presented. The new cash flow standard impacted the presentation of cash flows related to our beneficial interests in securitization transactions, which is the deferred purchase price, resulting in a reclassification of cash inflows from Operating activities to Investing activities of approximately $1.3 billion and $1.1 billion for the three months ended March 31, 2018 and 2017 , respectively, in our Condensed Consolidated Statements of Cash Flows . The new cash flow standard also impacted the presentation of our cash payments for debt prepayment and debt extinguishment costs, resulting in a reclassification of cash outflows from Operating activities to Financing activities of $31 million and $29 million for the three months ended March 31, 2018 and 2017 , respectively, in our Condensed Consolidated Statements of Cash Flows . Income Taxes In October 2016, the FASB issued ASU 2016-16, “Accounting for Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory.” The standard requires that the income tax impact of intra-entity sales and transfers of property, except for inventory, be recognized when the transfer occurs. The standard became effective for us, and we adopted the standard, on January 1, 2018. The standard requires any deferred taxes not yet recognized on intra-entity transfers to be recorded to retained earnings under a modified retrospective approach. The implementation of this standard did not have a material impact on our condensed consolidated financial statements . Accounting Pronouncements Not Yet Adopted Leases In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (the “new lease standard”). The new lease standard requires all lessees to report a right-of-use asset and a lease liability for most leases. The income statement recognition is similar to existing lease accounting and is based on lease classification. The new lease standard requires lessees and lessors to classify most leases using principles similar to existing lease accounting. For lessors, the new lease standard modifies the classification criteria and the accounting for sales-type and direct financing leases. We are currently evaluating the new lease standard, which will require recognizing and measuring leases at the beginning of the earliest period presented using a modified retrospective approach. Our evaluation includes assessing which of our arrangements qualify as a lease, and aggregating lease data and related information as well as determining whether previous conclusions for certain transactions, such as failed sale leaseback arrangements under the previous lease standard, Leases (Topic 840), would change under the new lease standard. We plan to adopt the new lease standard when it becomes effective for us beginning January 1, 2019, and expect the adoption of the new lease standard will result in the recognition of right-of-use assets and lease liabilities that have not previously been recorded, which will have a material impact on our condensed consolidated financial statements . We are in the process of implementing significant new lease accounting systems, processes and internal controls over lease recognition, which will ultimately assist in the application of the new lease standard. Financial Instruments In June 2016, the FASB issued ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The standard requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions and reasonable and supportable forecasts that affect the collectibility of the reported amount. The standard will become effective for us beginning January 1, 2020, and will require a cumulative-effect adjustment to Accumulated deficit as of the beginning of the first reporting period in which the guidance is effective (that is, a modified-retrospective approach). Early adoption is permitted for us as of January 1, 2019. We are currently evaluating the impact this guidance will have on our condensed consolidated financial statements and the timing of adoption. Other recent accounting pronouncements issued by the FASB (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission (“SEC”) did not have, or are not believed by management to have, a significant impact on our present or future consolidated financial statements.

Significant Transactions

Significant Transactions	3 Months Ended
	Mar. 31, 2018
Significant Transactions Disclosure [Abstract]
Significant Transactions	Note 2 - Significant Transactions Business Combinations During the three months ended March 31, 2018 , we completed the following acquisitions which were accounted for as business combinations: • On January 1, 2018, we closed on our previously announced Unit Purchase Agreement to acquire the remaining equity in Iowa Wireless Services, LLC (“IWS”), a 54% owned unconsolidated subsidiary, for a purchase price of $25 million . • On January 22, 2018, we completed our acquisition of television innovator Layer3 TV, Inc. (“Layer3 TV”) for cash consideration of $318 million , subject to customary working capital and other post-closing adjustments. See Note 3 - Business Combinations for further information. Hurricane Impacts During the three months ended March 31, 2018 , our operations in Puerto Rico continued to experience losses related to hurricanes. The negative impacts to Operating income and Net income for the three months ended March 31, 2018 , primarily from incremental costs to maintain our services in Puerto Rico, were $36 million and $23 million , respectively. We expect additional expenses to be incurred in 2018, primarily related to our operations in Puerto Rico. We continue to assess the damage of the hurricanes and work with our insurance carriers to submit claims for property damage and business interruption. During the three months ended March 31, 2018 , we received $94 million in reimbursement from our insurance carriers, which eliminated the $93 million receivable we accrued for reimbursements as of December 31, 2017 . No additional reimbursements were recorded during the three months ended March 31, 2018 , however, we expect to record additional insurance recoveries related to these hurricanes in future periods. Debt During the three months ended March 31, 2018 , we completed significant transactions with both third parties and affiliates related to the issuance, borrowing and redemption of debt. See Note 9 - Debt for further information. Sales of Certain Receivables In February 2018, the service receivable sale agreement was amended to extend the scheduled expiration date to March 2019. See Note 5 – Sales of Certain Receivables for further information. Repurchases of Common Stock During the three months ended March 31, 2018 , we made additional repurchases of our common stock. Additionally, during the three months ended March 31, 2018 , Deutsche Telekom AG (“DT”), our majority stockholder and an affiliated purchaser, made additional repurchases of our common stock. See Note 11 – Repurchases of Common Stock for further information. Corporate Headquarters Leases In February 2018, we extended the leases related to our corporate headquarters facility. See Note 13 – Commitments and Contingencies for further information.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Business Combinations	Note 3 - Business Combinations Acquisition of Layer3 TV On January 22, 2018, we completed our acquisition of television innovator Layer3 TV for cash consideration of $318 million , subject to customary working capital and other post-closing adjustments. The consideration includes a $5 million payment that was made after the closing date. Upon closing of the transaction, Layer3 TV became a wholly-owned consolidated subsidiary. Layer3 TV acquires and distributes digital entertainment programming primarily through the internet to residential subscribers, offering direct to home digital television and multi-channel video programming distribution services. This transaction represented an opportunity to acquire a complementary service to our existing wireless service to advance our video strategy. We accounted for the purchase of Layer3 TV as a business combination. Costs related to this acquisition were immaterial to our Condensed Consolidated Statements of Comprehensive Income . The grant-date fair value of cash-based and share-based incentive compensation awards attributable to post-combination services was approximately $37 million . The following table shows the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed and the resultant purchase price allocation: (in millions) January 22, Assets acquired Cash and cash equivalents $ 2 Other current assets 14 Property and equipment, net 11 Intangible assets 100 Goodwill 218 Deferred tax assets 2 Total assets acquired $ 347 Liabilities assumed Accounts payable and accrued liabilities $ 27 Short-term debt 2 Total liabilities assumed 29 Total consideration transferred $ 318 We recognized a liability of $21 million within Accounts payable and accrued liabilities in our Condensed Consolidated Balance Sheets and an associated indemnification asset of $12 million in our Condensed Consolidated Balance Sheets related to minimum commitments under acquired content agreements. The maximum amount that would be received under the indemnification agreement is $12 million . Goodwill of $218 million is calculated as the excess of the purchase price paid over the net assets acquired. The goodwill recorded as part of the Layer3 TV acquisition primarily reflects industry knowledge of the retained management team, as well as intangible assets that do not qualify for separate recognition. None of the goodwill is deductible for tax purposes. See Note 6 - Goodwill for further information. As part of the transaction, we acquired an identifiable intangible asset of developed technology with an estimated fair value of $100 million , which is being amortized on a straight-line basis over a useful life of 5 years . The financial results from the acquisition of Layer3 TV since the closing date through March 31, 2018 were not material to our Condensed Consolidated Statements of Comprehensive Income . Acquisition of Iowa Wireless On January 1, 2018 (the “acquisition date”), we closed on our previously announced Unit Purchase Agreement to acquire the remaining equity in IWS, a 54% owned unconsolidated subsidiary, for a purchase price of $25 million . We accounted for our acquisition of IWS as a business combination. Prior to the acquisition date, we accounted for our previously-held investment in IWS under the equity method as we had significant influence, but not control. Authoritative guidance on accounting for business combinations requires that an acquirer re-measure its previously held equity interest in the acquiree at its acquisition date fair value and recognize the resulting gain or loss in earnings. As such, we valued our previously held equity interest in IWS at $56 million as of the acquisition date and recognized a gain of $15 million . The following table highlights the consideration transferred, the fair value of our previously held equity interest and bargain purchase: (in millions) January 1, Consideration transferred: Cash paid $ 25 Previously held equity interest: Acquisition date fair value of previously held equity interest 56 Bargain purchase gain 25 Net assets acquired $ 106 As part of the acquisition of IWS, we recognized a bargain purchase gain of approximately $25 million , which represents the fair value of the identifiable net assets acquired, primarily IWS spectrum licenses, in excess of the purchase price and fair value of our previously held equity interest. We were in a favorable position to acquire the remaining shares of IWS as a result of our previously held 54% equity interest in IWS, an unprofitable business with valuable spectrum holdings. The following table shows the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed and the resultant purchase price allocation: (in millions) January 1, Assets acquired Current assets Cash and cash equivalents $ 3 Accounts receivables, net 6 Equipment installment plan receivables, net 3 Inventories 1 Other current assets 2 Total current assets 15 Property and equipment, net 36 Spectrum licenses 87 Total assets acquired $ 138 Liabilities assumed Accounts payable and accrued liabilities $ 6 Deferred revenue 2 Total current liabilities 8 Deferred tax liabilities 17 Other long-term liabilities 7 Total long-term liabilities 24 Net assets acquired $ 106 We included both the gain on our previously held equity interest in IWS and the bargain purchase gain within Other income, net in our Condensed Consolidated Statements of Comprehensive Income for the three months ended March 31, 2018 . Pro forma information The acquisitions of Layer3 TV and IWS were not material to our prior period consolidated results on a pro forma basis.

Receivables and Allowance for C

Receivables and Allowance for Credit Losses	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Receivables and Allowance for Credit Losses	Note 4 – Receivables and Allowance for Credit Losses Our portfolio of receivables is comprised of two portfolio segments, accounts receivable and EIP receivables. Our accounts receivable segment primarily consists of amounts currently due from customers, including service and leased device receivables, other carriers and third-party retail channels. Based upon customer credit profiles, we classify the EIP receivables segment into two customer classes of “Prime” and “Subprime.” Prime customer receivables are those with lower delinquency risk and Subprime customer receivables are those with higher delinquency risk. Customers may be required to make a down payment on their equipment purchases. In addition, certain customers within the Subprime category are required to pay an advance deposit. To determine a customer’s credit profile, we use a proprietary credit scoring model that measures the credit quality of a customer at the time of application for wireless communications service using several factors, such as credit bureau information, consumer credit risk scores and service plan characteristics. The following table summarizes the EIP receivables, including imputed discounts and related allowance for credit losses: (in millions) March 31, December 31, EIP receivables, gross $ 3,896 $ 3,960 Unamortized imputed discount (267 ) (264 ) EIP receivables, net of unamortized imputed discount 3,629 3,696 Allowance for credit losses (114 ) (132 ) EIP receivables, net $ 3,515 $ 3,564 Classified on the balance sheet as: Equipment installment plan receivables, net $ 2,281 $ 2,290 Equipment installment plan receivables due after one year, net 1,234 1,274 EIP receivables, net $ 3,515 $ 3,564 To determine the appropriate level of the allowance for credit losses, we consider a number of credit quality indicators, including historical credit losses and timely payment experience as well as current collection trends such as write-off frequency and severity, aging of the receivable portfolio, credit quality of the customer base and other qualitative factors such as macro-economic conditions. We write off account balances if collection efforts are unsuccessful and the receivable balance is deemed uncollectible, based on customer credit quality and the aging of the receivable. For EIP receivables, subsequent to the initial determination of the imputed discount, we assess the need for and, if necessary, recognize an allowance for credit losses to the extent the amount of estimated probable losses on the gross EIP receivable balances exceed the remaining unamortized imputed discount balances. The EIP receivables had weighted average effective imputed interest rates of 9.9% and 9.6% as of March 31, 2018 and December 31, 2017 , respectively. Activity for the three months ended March 31, 2018 and 2017 , in the allowance for credit losses and unamortized imputed discount balances for the accounts receivable and EIP receivable segments were as follows: March 31, 2018 March 31, 2017 (in millions) Accounts Receivable Allowance EIP Receivables Allowance Total Accounts Receivable Allowance EIP Receivables Allowance Total Allowance for credit losses and imputed discount, beginning of period $ 86 $ 396 $ 482 $ 102 $ 316 $ 418 Bad debt expense 4 50 54 37 56 93 Write-offs, net of recoveries (14 ) (67 ) (81 ) (39 ) (75 ) (114 ) Change in imputed discount on short-term and long-term EIP receivables N/A 53 53 N/A 48 48 Impact on the imputed discount from sales of EIP receivables N/A (51 ) (51 ) N/A (41 ) (41 ) Allowance for credit losses and imputed discount, end of period $ 76 $ 381 $ 457 $ 100 $ 304 $ 404 Management considers the aging of receivables to be an important credit indicator. The following table provides delinquency status for the unpaid principal balance for receivables within the EIP portfolio segment, which we actively monitor as part of our current credit risk management practices and policies: March 31, 2018 December 31, 2017 (in millions) Prime Subprime Total EIP Receivables, gross Prime Subprime Total EIP Receivables, gross Current - 30 days past due $ 1,648 $ 2,168 $ 3,816 $ 1,727 $ 2,133 $ 3,860 31 - 60 days past due 14 24 38 17 29 46 61 - 90 days past due 5 13 18 6 16 22 More than 90 days past due 7 17 24 8 24 32 Total receivables, gross $ 1,674 $ 2,222 $ 3,896 $ 1,758 $ 2,202 $ 3,960

Sales of Certain Receivables

Sales of Certain Receivables	3 Months Ended
	Mar. 31, 2018
Transfers and Servicing [Abstract]
Sales of Certain Receivables	Note 5 – Sales of Certain Receivables We have entered into transactions to sell certain service and EIP accounts receivable. The transactions, including our continuing involvement with the sold receivables and the respective impacts to our condensed consolidated financial statements , are described below. Sales of Service Receivables Overview of the Transaction In 2014, we entered into an arrangement to sell certain service accounts receivable on a revolving basis and in November 2016, the arrangement was amended to increase the maximum funding commitment to $950 million (the “service receivable sale arrangement”) and extend the scheduled expiration date to March 2018. In February 2018, the service receivable sale arrangement was again amended to extend the scheduled expiration date to March 2019. In April 2018, the service receivable sale arrangement was again amended to update certain terms and covenants contained therein to make them consistent with analogous terms and covenants in documents of our other financing arrangements. As of March 31, 2018 and December 31, 2017 , the service receivable sale arrangement provided funding of $802 million and $880 million , respectively. Sales of receivables occur daily and are settled on a monthly basis. The receivables consist of service charges currently due from customers and are short-term in nature. In connection with the service receivable sale arrangement, we formed a wholly-owned subsidiary, which qualifies as a bankruptcy remote entity, to sell service accounts receivable (the “Service BRE”). The Service BRE does not qualify as a VIE, and due to the significant level of control we exercise over the entity, it is consolidated. Pursuant to the arrangement, certain of our wholly-owned subsidiaries transfer selected receivables to the Service BRE. The Service BRE then sells the receivables to an unaffiliated entity (the “Service VIE”), which was established to facilitate the sale of beneficial ownership interests in the receivables to certain third parties. Variable Interest Entity We determined that the Service VIE qualifies as a VIE as it lacks sufficient equity to finance its activities. We have a variable interest in the Service VIE, but are not the primary beneficiary as we lack the power to direct the activities that most significantly impact the Service VIE’s economic performance. Those activities include committing the Service VIE to legal agreements to purchase or sell assets, selecting which receivables are purchased in the service receivable sale arrangement, determining whether the Service VIE will sell interests in the purchased service receivables to other parties, funding of the entity and servicing of receivables. We do not hold the power to direct the key decisions underlying these activities. For example, while we act as the servicer of the sold receivables, which is considered a significant activity of the Service VIE, we are acting as an agent in our capacity as the servicer and the counterparty to the service receivable sale arrangement has the ability to remove us as the servicing agent of the receivables at will with no recourse available to us. As we have determined we are not the primary beneficiary, the balances and results of the Service VIE are not included in our condensed consolidated financial statements . The following table summarizes the carrying amounts and classification of assets, which consists primarily of the deferred purchase price and liabilities included in our Condensed Consolidated Balance Sheets that relate to our variable interest in the Service VIE: (in millions) March 31, December 31, Other current assets $ 266 $ 236 Accounts payable and accrued liabilities — 25 Other current liabilities 118 180 Sales of EIP Receivables Overview of the Transaction In 2015, we entered into an arrangement to sell certain EIP accounts receivables on a revolving basis and in August 2017, the EIP sale arrangement was amended to reduce the maximum funding commitment to $1.2 billion (the “EIP sale arrangement”) and extend the scheduled expiration date to November 2018. In December 2017, the EIP sale arrangement was again amended to increase the maximum funding commitment to $1.3 billion . In April 2018, the EIP sale arrangement was again amended to update certain terms and covenants contained therein to make them consistent with analogous terms and covenants in the documentation of our other financing arrangements. As of both March 31, 2018 and December 31, 2017 , the EIP sale arrangement provided funding of $1.3 billion . Sales of EIP receivables occur daily and are settled on a monthly basis. The receivables consist of customer EIP balances, which require monthly customer payments for up to 24 months. In connection with this EIP sale arrangement, we formed a wholly-owned subsidiary, which qualifies as a bankruptcy remote entity (the “EIP BRE”). Pursuant to the EIP sale arrangement, our wholly-owned subsidiary transfers selected receivables to the EIP BRE. The EIP BRE then sells the receivables to a non-consolidated and unaffiliated third-party entity for which we do not exercise any level of control, nor does the entity qualify as a VIE. Variable Interest Entity We determined that the EIP BRE is a VIE as its equity investment at risk lacks the obligation to absorb a certain portion of its expected losses. We have a variable interest in the EIP BRE and determined that we are the primary beneficiary based on our ability to direct the activities which most significantly impact the EIP BRE’s economic performance. Those activities include selecting which receivables are transferred into the EIP BRE and sold in the EIP sale arrangement and funding of the EIP BRE. Additionally, our equity interest in the EIP BRE obligates us to absorb losses and gives us the right to receive benefits from the EIP BRE that could potentially be significant to the EIP BRE. Accordingly, we determined that we are the primary beneficiary, and include the balances and results of operations of the EIP BRE in our condensed consolidated financial statements . The following table summarizes the carrying amounts and classification of assets, which consists primarily of the deferred purchase price and liabilities included in our Condensed Consolidated Balance Sheets that relate to the EIP BRE: (in millions) March 31, December 31, Other current assets $ 370 $ 403 Other assets 93 109 Other long-term liabilities 10 3 In addition, the EIP BRE is a separate legal entity with its own separate creditors who will be entitled, prior to any liquidation of the EIP BRE, to be satisfied prior to any value in the EIP BRE becoming available to us. Accordingly, the assets of the EIP BRE may not be used to settle our general obligations and creditors of the EIP BRE have limited recourse to our general credit. Sales of Receivables The transfers of service receivables and EIP receivables to the non-consolidated entities are accounted for as sales of financial assets. Once identified for sale, the receivable is recorded at the lower of cost or fair value. Upon sale, we derecognize the net carrying amount of the receivables. We recognize the cash proceeds received upon sale in Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows . We recognize proceeds net of the deferred purchase price, consisting of a receivable from the purchasers that entitles us to certain collections on the receivables. We recognize the collection of the deferred purchase price in Net cash provided by investing activities in our Condensed Consolidated Statements of Cash Flows as Proceeds related to beneficial interests in securitization transactions. The deferred purchase price represents a financial asset that is primarily tied to the creditworthiness of the customers and which can be settled in such a way that we may not recover substantially all of our recorded investment, due to default by the customers on the underlying receivables. We elected, at inception, to measure the deferred purchase price at fair value with changes in fair value included in Selling, general and administrative expense in our Condensed Consolidated Statements of Comprehensive Income . The fair value of the deferred purchase price is determined based on a discounted cash flow model which uses primarily unobservable inputs (Level 3 inputs), including customer default rates. As of March 31, 2018 and December 31, 2017 , our deferred purchase price related to the sales of service receivables and EIP receivables was $728 million and $745 million , respectively. The following table summarizes the impacts of the sale of certain service receivables and EIP receivables in our Condensed Consolidated Balance Sheets : (in millions) March 31, December 31, Derecognized net service receivables and EIP receivables $ 2,663 $ 2,725 Other current assets 636 639 of which, deferred purchase price 635 636 Other long-term assets 93 109 of which, deferred purchase price 93 109 Accounts payable and accrued liabilities — 25 Other current liabilities 118 180 Other long-term liabilities 10 3 Net cash proceeds since inception 1,908 2,058 Of which: Change in net cash proceeds during the year-to-date period (150 ) 28 Net cash proceeds funded by reinvested collections 2,058 2,030 We recognized losses from sales of receivables of $52 million and $95 million for the three months ended March 31, 2018 and 2017 , respectively. These losses from sales of receivables were recognized in Selling, general and administrative expense in our Condensed Consolidated Statements of Comprehensive Income . Losses from sales of receivables include adjustments to the receivables’ fair values and changes in fair value of the deferred purchase price. Continuing Involvement Pursuant to the sale arrangements described above, we have continuing involvement with the service receivables and EIP receivables we sell as we service the receivables and are required to repurchase certain receivables, including ineligible receivables, aged receivables and receivables where write-off is imminent. We continue to service the customers and their related receivables, including facilitating customer payment collection, in exchange for a monthly servicing fee. As the receivables are sold on a revolving basis, the customer payment collections on sold receivables may be reinvested in new receivable sales. While servicing the receivables, we apply the same policies and procedures to the sold receivables as we apply to our owned receivables, and we continue to maintain normal relationships with our customers. Pursuant to the EIP sale arrangement, under certain circumstances, we are required to deposit cash or replacement EIP receivables primarily for contracts terminated by customers under our JUMP! Program. In addition, we have continuing involvement with the sold receivables as we may be responsible for absorbing additional credit losses pursuant to the sale arrangements. Our maximum exposure to loss related to the involvement with the service receivables and EIP receivables sold under the sale arrangements was $1.3 billion as of March 31, 2018 . The maximum exposure to loss, which is a required disclosure under GAAP, represents an estimated loss that would be incurred under severe, hypothetical circumstances whereby we would not receive the deferred purchase price portion of the contractual proceeds withheld by the purchasers and would also be required to repurchase the maximum amount of receivables pursuant to the sale arrangements without consideration for any recovery. As we believe the probability of these circumstances occurring is remote, the maximum exposure to loss is not an indication of our expected loss.

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Note 6 - Goodwill The changes in the carrying amount of goodwill for the three months ended March 31, 2018 , are as follows: (in millions) Historical goodwill $ 12,449 Accumulated impairment losses at December 31, 2017 (10,766 ) Balance as of December 31, 2017 1,683 Goodwill from acquisition of Layer3 TV 218 Balance as of March 31, 2018 $ 1,901 Accumulated impairment losses at March 31, 2018 $ (10,766 ) On January 22, 2018, we completed our acquisition of television innovator Layer3 TV. This purchase was accounted for as a business combination resulting in $218 million in goodwill. Layer3 TV is a separate reporting unit and the acquired goodwill will be tested for impairment at this level. See Note 3 - Business Combinations for additional information.

Spectrum License Transactions

Spectrum License Transactions	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Spectrum License Transactions	Note 7 – Spectrum License Transactions The following table summarizes our spectrum license activity for the three months ended March 31, 2018 : (in millions) Spectrum Licenses Balance at December 31, 2017 $ 35,366 Spectrum license acquisitions 125 Costs to clear spectrum 13 Balance at March 31, 2018 $ 35,504 We had the following spectrum license transactions for the three months ended March 31, 2018 : • We recorded spectrum licenses received as part of our acquisition of the remaining equity interest in IWS at their estimated fair value of approximately $87 million . See Note 3 - Business Combinations for further information. • We closed on multiple spectrum purchase agreements in which we acquired total spectrum licenses of approximately $38 million for cash consideration. No gains or losses were recognized on the spectrum license purchases .

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 8 – Fair Value Measurements The carrying values of cash and cash equivalents, accounts receivable, accounts receivable from affiliates, accounts payable, and borrowings under our senior secured revolving credit facility with DT, our majority stockholder, approximate fair value due to the short-term maturities of these instruments. Deferred Purchase Price Assets In connection with the sales of certain service and EIP receivables pursuant to the sale arrangements, we have deferred purchase price assets measured at fair value that are based on a discounted cash flow model using unobservable Level 3 inputs, including customer default rates. See Note 5 – Sales of Certain Receivables for further information . The carrying amounts and fair values of our assets measured at fair value on a recurring basis included in our Condensed Consolidated Balance Sheets were as follows: Level within the Fair Value Hierarchy March 31, 2018 December 31, 2017 (in millions) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Deferred purchase price assets 3 $ 728 $ 728 $ 745 $ 745 Long-term Debt The fair value of our Senior Notes to third parties was determined based on quoted market prices in active markets, and therefore was classified as Level 1 within the fair value hierarchy. The fair values of our Senior Notes to affiliates , Incremental Term Loan Facility to affiliates , and Senior Reset Notes to affiliates were determined based on a discounted cash flow approach using market interest rates of instruments with similar terms and maturities and an estimate for our standalone credit risk. Accordingly, our Senior Notes to affiliates , Incremental Term Loan Facility to affiliates , and Senior Reset Notes to affiliates were classified as Level 2 within the fair value hierarchy. Although we have determined the estimated fair values using available market information and commonly accepted valuation methodologies, considerable judgment was required in interpreting market data to develop fair value estimates for the Senior Notes to affiliates , Incremental Term Loan Facility to affiliates , and Senior Reset Notes to affiliates . The fair value estimates were based on information available as of March 31, 2018 and December 31, 2017 . As such, our estimates are not necessarily indicative of the amount we could realize in a current market exchange. The carrying amounts and fair values of our short-term and long-term debt included in our Condensed Consolidated Balance Sheets were as follows: Level within the Fair Value Hierarchy March 31, 2018 December 31, 2017 (in millions) Carrying Amount Fair Value Carrying Amount Fair Value Liabilities: Senior Notes to third parties 1 $ 13,402 $ 13,732 $ 11,910 $ 12,540 Senior Notes to affiliates 2 7,486 7,659 7,486 7,852 Incremental Term Loan Facility to affiliates 2 4,000 4,000 4,000 4,020 Senior Reset Notes to affiliates 2 3,100 3,223 3,100 3,260

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	Note 9 – Debt The following table sets forth the debt balances and activity as of, and for the three months ended , March 31, 2018 : (in millions) December 31, Issuances and Borrowings (1) Note Redemptions (1) Repayments Reclassifications (1) Other (2) March 31, Short-term debt $ 1,612 $ — $ (999 ) $ — $ 2,425 $ 282 $ 3,320 Long-term debt 12,121 2,494 — — (2,425 ) (63 ) 12,127 Total debt to third parties 13,733 2,494 (999 ) — — 219 15,447 Short-term debt to affiliates — 2,170 — (1,725 ) — — 445 Long-term debt to affiliates 14,586 — — — — — 14,586 Total debt $ 28,319 $ 4,664 $ (999 ) $ (1,725 ) $ — $ 219 $ 30,478 (1) Issuances and borrowings, note redemptions, and reclassifications are recorded net of related issuance costs, discounts and premiums. Issuances and borrowings and repayments for Short-term debt to affiliates represent net outstanding borrowings and net repayments on our senior secured revolving credit facility. (2) Other includes: $246 million of issuances of short-term debt related to vendor financing arrangements, of which $237 million related to financing of property and equipment. During the three months ended March 31, 2018 , we did not have any repayments under the vendor financing arrangements. Vendor financing arrangements are included in Short-term debt within Total current liabilities in our Condensed Consolidated Balance Sheets. Other also includes capital leases and the amortization of discounts and premiums. Capital lease liabilities totaled $1.8 billion at both March 31, 2018 and December 31, 2017 . Debt to Third Parties Issuances and Borrowings During the three months ended March 31, 2018 , we issued the following Senior Notes: (in millions) Principal Issuances Issuance Costs Net Proceeds from Issuance of Long-Term Debt 4.500% Senior Notes due 2026 $ 1,000 $ 2 $ 998 4.750% Senior Notes due 2028 1,500 4 1,496 Total of Senior Notes issued $ 2,500 $ 6 $ 2,494 On January 25, 2018, T-Mobile USA, Inc. (“T-Mobile USA”) and certain of its affiliates, as guarantors, issued (i) $1.0 billion of public 4.500% Senior Notes due 2026 and (ii) $1.5 billion of public 4.750% Senior Notes due 2028. Issuance costs related to the public debt issuance totaled approximately $6 million . Subsequent to March 31, 2018 , we used the net proceeds of $2.494 billion from the transaction to redeem our $1.75 billion of 6.625% Senior Notes due 2023, on April 1, 2018, and to redeem our $600 million of 6.836% Senior Notes due 2023 on April 28, 2018, as further discussed below, and for general corporate purposes, including the partial repayment of borrowings under our revolving credit facility with DT. Notes Redemptions During the three months ended March 31, 2018 , we made the following note redemption: (in millions) Principal Amount Write-off of Premiums, Discounts and Issuance Costs (1) Call Penalties (1) (2) Redemption Redemption Price 6.125% Senior Notes due 2022 $ 1,000 $ 1 $ 31 January 15, 2018 103.063 % (1) Write-off of premiums, discounts, issuance costs and call penalties are included in Other income, net in our Condensed Consolidated Statements of Comprehensive Income . Write-off of premiums, discounts and issuance costs are included in Other, net within Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows . (2) The call penalty is the excess paid over the principal amount. Call penalties are included within Net cash provided by financing activities in our Condensed Consolidated Statements of Cash Flows . Prior to March 31, 2018, we delivered a notice of redemption on $1.75 billion aggregate principal amount of our 6.625% Senior Notes due 2023. The notes were redeemed on April 1, 2018 at a redemption price equal to 103.313% of the principal amount of the notes (plus accrued and unpaid interest thereon), payable on April 2, 2018. The redemption premium was approximately $58 million , the write-off of issuance costs was less than $1 million , and the write-off of premiums was approximately $75 million . The outstanding principal amount was reclassified from Long-term debt to Short-term debt in our Condensed Consolidated Balance Sheets as of March 31, 2018 . Prior to March 31, 2018, we delivered a notice of redemption on $600 million aggregate principal amount of our 6.836% Senior Notes due 2023. The notes were redeemed on April 28, 2018 at a redemption price equal to 103.418% of the principal amount of the notes (plus accrued and unpaid interest thereon), payable on April 30, 2018. The redemption premium was approximately $21 million and the write-off of issuance costs was less than $1 million . The outstanding principal amount was reclassified from Long-term debt to Short-term debt in our Condensed Consolidated Balance Sheets as of March 31, 2018 . Debt to Affiliates Issuances and Borrowings On January 22, 2018, DT agreed to purchase (i) $1.0 billion in aggregate principal amount of 4.500% Senior Notes due 2026 and (ii) $1.5 billion in aggregate principal amount of 4.750% Senior Notes due 2028 directly from T-Mobile USA and certain of its affiliates, as guarantors, with no underwriting discount (the “DT Notes”). As of March 31, 2018 , there were no outstanding balances on the DT Notes. Prior to March 31, 2018, we delivered a notice of redemption on (i) $1.25 billion in aggregate principal amount of 8.097% Senior Reset Notes due 2021 and (ii) $1.25 billion in aggregate principal amount of 8.195% Senior Reset Notes due 2022 (collectively, the “DT Senior Reset Notes”) held by DT. Subsequent to March 31, 2018 , through net settlement on April 30, 2018, we issued to DT a total of $2.5 billion in aggregate principal amount of DT Notes and redeemed the DT Senior Reset Notes. The 8.097% Senior Reset Notes due 2021 were redeemed on April 28, 2018 at a redemption price equal to 104.0485% of the principal amount of the notes (plus accrued and unpaid interest thereon), payable on April 30, 2018. The 8.195% Senior Reset Notes due 2022 were redeemed on April 28, 2018 at a redemption price equal to 104.0975% of the principal amount of the notes (plus accrued and unpaid interest thereon), payable on April 30, 2018. In connection with the net settlement, we paid DT $102 million in cash for the premium portion of the redemption price set forth in the indenture governing the DT Senior Reset Notes, plus accrued but unpaid interest on the DT Senior Reset Notes to, but not including, the exchange date. Incremental Term Loan Facility In March 2018, we amended the terms of the Incremental Term Loan Facility. Following this amendment, the applicable margin payable on LIBOR indexed loans is 1.50% under the $2.0 billion Incremental Term Loan Facility maturing on November 9, 2022 and 1.75% under the $2.0 billion Incremental Term Loan Facility maturing on January 31, 2024. The amendment also modified the Incremental Term Loan Facility to (i) include a soft-call prepayment premium of 1.00% of the outstanding principal amount of the loans under the Incremental Term Loan Facility payable to DT upon certain refinancings of such loans by us with lower priced debt prior to a date that is six months after March 29, 2018 and (ii) update certain covenants and other provisions to make them substantially consistent, subject to certain additional carve outs, with our most recently publicly issued notes. No issuance fees were incurred related to this debt agreement for the three months ended March 31, 2018 . Revolving Credit Facility In January 2018, we utilized proceeds under our revolving credit facility with DT to redeem $1.0 billion in aggregate principal amount of our 6.125% Senior Notes due 2022 and for general corporate purposes. On January 29, 2018, the proceeds utilized under our revolving credit facility with DT were repaid. The proceeds and borrowings from the revolving credit facility are presented in Proceeds from borrowing on revolving credit facility and Repayments of revolving credit facility within Net cash provided by financing activities in our Condensed Consolidated Statements of Cash Flows . As of March 31, 2018 , there was $445 million in outstanding borrowings under the revolving credit facility. As of December 31, 2017 , there were no outstanding borrowings under the revolving credit facility. In March 2018, we amended the terms of (a) our Secured Revolving Credit Facility and (b) our Unsecured Revolving Credit Facility. Following these amendments, (i) the range of applicable margin payable under the Secured Revolving Credit Facility is 1.05% to 1.80% , (ii) the range of the applicable margin payable under the Unsecured Revolving Credit Facility is 2.05% to 3.05% , (iii) the range of the undrawn commitment fee applicable to the Secured Revolving Credit Facility is 0.25% to 0.45% , (iv) the range of the undrawn commitment fee applicable to the Unsecured Revolving Credit Facility is 0.20% to 0.575% and (v) the maturity date of the revolving credit facility with DT is December 29, 2020. The amendments also modify the facility to update certain covenants and other provisions to make them substantially consistent, subject to certain additional carve outs, with our most recently publicly issued notes.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Note 10 - Revenue from Contracts with Customers Disaggregation of revenue We provide wireless communication services to three primary categories of customers: • Branded postpaid customers generally include customers that are qualified to pay after receiving wireless communication services utilizing phones, mobile broadband devices (including tablets), DIGITS or other devices; • Branded prepaid customers generally include customers who pay for wireless communication services in advance. Our branded prepaid customers include customers of T-Mobile and MetroPCS; and • Wholesale customers include Machine-to-Machine (“M2M”) and Mobile Virtual Network Operator (“MVNO”) customers that operate on our network, but are managed by wholesale partners. Branded postpaid service revenues include branded postpaid phone revenues and branded postpaid other revenues, which were $4.8 billion and $259 million , respectively, for the three months ended March 31, 2018 and $4.5 billion and $225 million , respectively, for the three months ended March 31, 2017 . We operate as a single operating segment. The balances presented within each revenue line item in our Condensed Consolidated Statements of Comprehensive Income represent categories of revenue from contracts with customers disaggregated by type of product and service. Service revenues also include revenues earned for providing value added services to customers, such as handset insurance services. Revenue generated from the lease of mobile communication devices and accessories is included within Equipment revenues in our Condensed Consolidated Statements of Comprehensive Income . For the three months ended March 31, 2018 , and 2017 , we recorded approximately $171 million and $324 million , respectively, of Equipment revenues from the lease of mobile communication devices and accessories. Contract balances The opening and closing balances of T-Mobile’s contract asset, contract liability and receivables balances from contracts with customers for the three months ended March 31, 2018 are as follows: (in millions) Contract Assets Included in Other Current Assets Contract Liabilities Included in Deferred Revenue Balance as of January 1, 2018 $ 140 $ 718 Balance as of March 31, 2018 104 718 Change (36 ) — Contract assets primarily represent revenue recognized for equipment sales with promotional bill credits offered to customers that are paid over time and are contingent on the customer maintaining a service contract. The change in the contract asset balance includes customer activity related to new promotions, customers that churn and forfeit their bill credits and impairment of bill credits which are recognized as bad debt expense. Contract liabilities are recorded when fees are collected or we have an unconditional right to consideration (a receivable) in advance of delivery of goods or services. The change in contract liabilities is related to customer activity associated with our prepaid plans including the receipt of cash payments and the satisfaction of our performance obligations. Revenues for the three months ended March 31, 2018 , include the following: Three Months Ended March 31, (in millions) 2018 Amounts included in the beginning of period contract liability balance $ 528 Amounts associated with performance obligations satisfied in previous periods — Remaining performance obligations As of March 31, 2018 , the aggregate amount of the transaction price allocated to remaining service performance obligations for branded postpaid contracts is $694 million . We expect to recognize this revenue as service is provided over the next 12 months . Certain of our wholesale, roaming and other service contracts include variable consideration based on usage. This variable consideration has been excluded from the disclosure of remaining performance obligations. As of March 31, 2018 , the aggregate amount of the guaranteed minimum consideration allocated to remaining service performance obligations for wholesale, roaming and other service contracts is $879 million , $1.1 billion and $901 million for 2018 , 2019 and 2020 and beyond, respectively. These contracts have a remaining duration of less than one year to six years . Information about remaining performance obligations that are part of a contract that has an original expected duration of one year or less have been excluded from the above, which primarily consists of monthly service contracts. The aggregate amount of the transaction price allocated to remaining service performance obligations includes the estimated amount to be invoiced to the customer. Contract costs Deferred contract cost balances at March 31, 2018 were as follows: (in millions) At March 31, 2018 Total deferred incremental costs to obtain contracts $ 290 Deferred contract costs incurred to obtain postpaid service contracts have an average amortization period of approximately 24 months . The amortization period is monitored every period to reflect any significant change in assumptions. Amortization of deferred costs was $35 million for the three months ended March 31, 2018 . The deferred contract cost asset is assessed for impairment on a periodic basis. There were no impairment losses recognized on deferred contract cost assets for the three months ended March 31, 2018 .

Repurchases of Common Stock

Repurchases of Common Stock	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Repurchases of Common Stock	Note 11 – Repurchases of Common Stock 2017 Stock Repurchase Program On December 6, 2017, our Board of Directors authorized a stock repurchase program for up to $1.5 billion of our common stock through December 31, 2018 (the “2017 Stock Repurchase Program”). During the three months ended March 31, 2018 , we repurchased a total of 10.5 million shares of our common stock for $666 million . From the inception of the 2017 Stock Repurchase Program through April 27, 2018, we repurchased 23.7 million shares of our common stock at an average price per share of $63.07 for a total purchase price of $1.5 billion . Repurchased shares are retired. For the three months ended March 31, 2018 , DT, our majority stockholder and an affiliated purchaser, purchased 3.3 million additional shares of our common stock at an aggregate market value of $200 million in the public market or from other parties, in accordance with the rules of the SEC and other applicable legal requirements. We do not receive proceeds from these purchases. 2018 Stock Repurchase Program On April 27, 2018, our Board of Directors authorized an increase in the total stock repurchase program to $9.0 billion , consisting of the $1.5 billion in repurchases previously completed and for up to an additional $7.5 billion of repurchases of our common stock, allocated as up to $500 million of shares of common stock through December 31, 2018, up to $3.0 billion of shares of common stock for the year ending December 31, 2019 and up to $4.0 billion of shares of common stock for the year ending December 31, 2020, with any authorized but unutilized repurchase capacity for any of the foregoing periods increasing the authorized repurchase capacity for the succeeding period by the amount of such unutilized repurchase capacity. The additional $7.5 billion repurchase authorization is contingent upon the termination of the Business Combination Agreement with Sprint (the “Business Combination Agreement”) and the abandonment of the transactions contemplated under the agreement. Under the repurchase program, repurchases can be made from time to time using a variety of methods, which may include open market purchases, privately negotiated transactions or otherwise, all in accordance with the rules of the Securities and Exchange Commission and other applicable legal requirements. The specific timing, price and size of purchases will depend on prevailing stock prices, general economic and market conditions, and other considerations. The repurchase program does not obligate us to acquire any particular amount of common stock, and the repurchase program may be suspended or discontinued at any time at our discretion. Repurchased shares are retired.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Note 12 – Earnings Per Share The computation of basic and diluted earnings per share was as follows: Three Months Ended March 31, (in millions, except shares and per share amounts) 2018 2017 Net income $ 671 $ 698 Less: Dividends on mandatory convertible preferred stock — (14 ) Net income attributable to common stockholders - basic 671 684 Add: Dividends related to mandatory convertible preferred stock — 14 Net income attributable to common stockholders - diluted $ 671 $ 698 Weighted average shares outstanding - basic 855,222,664 827,723,034 Effect of dilutive securities: Outstanding stock options and unvested stock awards 7,021,420 9,434,950 Mandatory convertible preferred stock — 32,238,000 Weighted average shares outstanding - diluted 862,244,084 869,395,984 Earnings per share - basic $ 0.78 $ 0.83 Earnings per share - diluted $ 0.78 $ 0.80 Potentially dilutive securities: Outstanding stock options and unvested stock awards 67,580 9,993 As of March 31, 2018 , we had authorized 100 million shares of 5.50% mandatory convertible preferred stock series A, with a par value of $0.00001 per share. There were no preferred shares outstanding as of March 31, 2018 . On December 15, 2017, 20 million shares of our preferred stock converted to approximately 32 million shares of our common stock at a conversion rate of 1.6119 shares of common stock for each share of previously outstanding preferred stock and certain cash-in-lieu of fractional shares. Potentially dilutive securities were not included in the computation of diluted earnings per share if to do so would have been anti-dilutive.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 13 – Commitments and Contingencies Commitments Operating Leases In February 2018, we extended the leases related to our corporate headquarters facility. These agreements, increased our minimum lease payments by approximately $400 million in the aggregate. In February 2018, we amended an agreement related to the lease of certain wireless communication tower sites. This agreement increased our minimum lease payments by approximately $385 million in the aggregate. Contingencies and Litigation We are involved in various lawsuits, claims, government agency investigations and enforcement actions, and other proceedings (“Litigation Matters”) that arise in the ordinary course of business, which include claims of patent infringement (most of which are asserted by non-practicing entities primarily seeking monetary damages), class actions, and proceedings to enforce Federal Communications Commission (“FCC”) rules and regulations. The Litigation Matters described above have progressed to various stages and some of them may proceed to trial, arbitration, hearing or other adjudication that could result in fines, penalties, or awards of monetary or injunctive relief in the coming 12 months, if they are not otherwise resolved. We have established an accrual with respect to certain of these matters, where appropriate, which is reflected in the condensed consolidated financial statements but that we do not consider, individually or in the aggregate, material. An accrual is established when we believe it is both probable that a loss has been incurred and an amount can be reasonably estimated. For other matters, where we have not determined that a loss is probable or because the amount of loss cannot be reasonably estimated, we have not recorded an accrual due to various factors typical in contested proceedings, including but not limited to: uncertainty concerning legal theories and their resolution by courts or regulators; uncertain damage theories and demands; and a less than fully developed factual record. While we do not expect that the ultimate resolution of these proceedings, individually or in the aggregate, will have a material adverse effect on our financial position, an unfavorable outcome of some or all of these proceedings could have a material adverse impact on results of operations or cash flows for a particular period. This assessment is based on our current understanding of relevant facts and circumstances. As such, our view of these matters is subject to inherent uncertainties and may change in the future.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Note 14 – Subsequent Events Note Redemptions In April 2018, we redeemed $1.75 billion of 6.625% Senior Notes due 2023 and $600 million of 6.836% Senior Notes due 2023. Additionally, through net settlement in April 2018, we issued to DT a total of $2.5 billion in aggregate principal amount of DT Notes and redeemed $1.25 billion in aggregate principal amount of 8.097% Senior Reset Notes due 2021 and $1.25 billion in aggregate principal amount of 8.195% Senior Reset Notes due 2022 held by DT. See Note 9 - Debt for further information. Repurchases of Common Stock We made common stock repurchases through April 27, 2018, under the stock repurchase program authorized by our Board of Directors on December 6, 2017. On April 27, 2018, our Board of Directors authorized an increase in the total stock repurchase program to $9.0 billion , consisting of the $1.5 billion in repurchases previously authorized and for up to an additional $7.5 billion of our common stock. See Note 11- Repurchases of Common Stock for further information. Business Combination Agreement On April 29, 2018, we entered into a Business Combination Agreement with Sprint Corporation (“Sprint”), Huron Merger Sub LLC (“T-Mobile Merger Company”), Superior Merger Sub Corporation (“Merger Sub”), Starburst I, Inc., (“Starburst”), Galaxy Investment Holdings, Inc., (“Galaxy,” and together with Starburst, the “SoftBank US HoldCos”) and for the limited purposes set forth therein, DT, Deutsche Telekom Holding B.V. (“DT Holding”), and SoftBank Group Corp. (“SoftBank”). Pursuant to the Business Combination Agreement and upon the terms and subject to the conditions described therein, the SoftBank US HoldCos will merge with and into T-Mobile Merger Company, with T-Mobile Merger Company continuing as the surviving entity and our wholly owned subsidiary (the “HoldCo Mergers”). Immediately following the HoldCo Mergers, Merger Sub will merge with and into Sprint, with Sprint continuing as the surviving corporation and our wholly owned indirect subsidiary (the “Merger” and, together with the HoldCo Mergers, the “Merger Transactions”). Pursuant to the Business Combination Agreement, (i) at the effective time of the HoldCo Mergers, all the issued and outstanding shares of common stock of Galaxy and Starburst held by SoftBank Group Capital Limited, a wholly owned subsidiary of SoftBank and the sole stockholder of Galaxy and Starburst (“Softbank UK”), will be converted such that SoftBank UK will receive an aggregate number of shares of our common stock equal to the product of (x) 0.10256 (the “Exchange Ratio”) and (y) the aggregate number of shares of common stock of Sprint (“Sprint Common Stock”), held by the SoftBank US HoldCos, collectively, immediately prior to the effective time of the HoldCo Mergers, and (ii) at the effective time of the Merger, each share of Sprint Common Stock issued and outstanding immediately prior to the effective time of the Merger (other than shares of Sprint Common Stock that were held by the SoftBank US HoldCos or are held by Sprint as treasury stock) will be converted into the right to receive a number of shares of our common stock equal to the Exchange Ratio. SoftBank and its affiliates will receive the same amount of our common stock per share of Sprint Common Stock as all other Sprint stockholders. Immediately following the Merger Transactions, DT and SoftBank are expected to hold approximately 42% and 27% of the fully diluted shares of the combined company, respectively, with the remaining approximately 31% of the fully-diluted shares of the combined company held by public stockholders. The consummation of the Merger Transactions and the other transactions contemplated by the Business Combination Agreement (collectively, the “Transactions”) is subject to obtaining the consent of the holders of a majority of the outstanding shares of Sprint Common Stock in favor of the adoption of the Business Combination Agreement (the “Sprint Stockholder Approval”). Subsequent to the execution of the Business Combination Agreement, SoftBank entered into a support agreement (the “SoftBank Support Agreement”), pursuant to which it has agreed to cause SoftBank UK, Galaxy and Starburst to deliver a written consent in favor of the adoption of the Business Combination Agreement, which will constitute receipt by Sprint of the Sprint Stockholder Approval. As of April 25, 2018, SoftBank beneficially owned approximately 84.8% of Sprint Common Stock outstanding. Under the terms of the SoftBank Support Agreement, SoftBank and its affiliates are generally prohibited from transferring ownership of Sprint Common Stock prior to the earlier of the consummation of the Merger and the termination of the Business Combination Agreement in accordance with its terms. The consummation of the Transactions is also subject to obtaining the consent of the holders of a majority of the outstanding shares of our common stock in favor of the issuance of our common stock in the Merger Transactions (the “T-Mobile Stock Issuance Approval”) and in favor of the amendment and restatement of our certificate of incorporation (the “T-Mobile Charter Amendment”) (collectively, the “T-Mobile Stockholder Approval”). Subsequent to the execution of the Business Combination Agreement, DT entered into a support agreement (the “DT Support Agreement”), pursuant to which it has agreed to deliver a written consent in favor of the T-Mobile Stock Issuance Approval and the T-Mobile Charter Amendment, which will constitute receipt by T-Mobile of the T-Mobile Stockholder Approval. As of April 25, 2018, DT beneficially owned approximately 63.5% of our outstanding common stock. Under the terms of the DT Support Agreement, DT and its affiliates are generally prohibited from transferring ownership of our common stock prior to the earlier of the consummation of the Merger and the termination of the Business Combination Agreement in accordance with its terms. The consummation of the Transactions is also subject to the satisfaction or waiver, if legally permitted, of certain other conditions, including, among other things, (i) the accuracy of representations and warranties and performance of covenants of the parties, (ii) the effectiveness of the registration statement for the shares of our common stock to be issued in the Merger Transactions, and the approval of the listing of such shares on the NASDAQ Global Select Market (“NASDAQ”), (iii) receipt of certain regulatory approvals, including approvals of the Federal Communications Commission, applicable state public utility commissions and expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 and favorable completion of review by the Committee on Foreign Investments in the United States, (iv) specified minimum credit ratings for the combined company on the closing date of the Merger Transaction (after giving effect to the Merger) from at least two of the three credit rating agencies, subject to certain qualifications and (v) no material adverse effect with respect to Sprint or us since the date of the Business Combination Agreement. The Business Combination Agreement contains representations and warranties and covenants customary for a transaction of this nature. Sprint and SoftBank, and we and DT, are each subject to restrictions on the ability to solicit alternative acquisition proposals and to provide information to, and engage in discussion with, third parties regarding such proposals, except under limited circumstances to permit Sprint’s and our boards of directors to comply with fiduciary duties. Subject to certain exceptions, each of the parties to the Business Combination Agreement has agreed to use its reasonable best efforts to take or cause to be taken actions necessary to consummate the Transactions, including with respect to obtaining required government approvals. The Business Combination Agreement also contains certain termination rights for both Sprint and us. If we terminate the Business Combination Agreement in connection with a failure to satisfy the closing condition related to the specified minimum credit ratings noted above, then in certain circumstances, we may be required to pay Sprint $600 million . Pursuant to the terms of the Business Combination Agreement, we, SoftBank and DT will also enter into an amended and restated stockholders’ agreement (the “Stockholders Agreement”), which will become effective upon the closing of the Transactions and will provide that the board of directors of the combined company will consist of fourteen members, comprising nine directors designated by DT (of which at least two will be independent), four directors designated by SoftBank (of which at least two will be independent), and the combined company’s chief executive officer. The Stockholders Agreement will also set forth certain consent rights for each of SoftBank and DT over certain material transactions of the combined company and will contain a non-compete which will apply to SoftBank, DT and their respective affiliates, subject to certain exceptions, until such time as SoftBank’s or DT’s ownership in the combined company has been reduced below an agreed threshold. In addition, pursuant to the terms of the Business Combination Agreement, SoftBank and DT will enter into a proxy, lock-up and right of first refusal agreement (the “PLR Agreement”), which will become effective upon the closing of the Transactions, and which will set forth certain rights and obligations in respect to the shares of our common stock owned by each of SoftBank, DT and their respective affiliates to enable DT to consolidate us into DT’s financial statements following the consummation of the Transactions. Among other terms, these rights and obligations will require SoftBank to agree to vote its shares of our common stock as directed by DT and will restrict SoftBank from transferring its shares of our common stock in a manner that would prevent DT from consolidating us into DT’s financial statements following the consummation of the Transactions, subject in each case to certain exceptions set forth in the PLR Agreement. In addition, the PLR Agreement will impose certain restrictions on SoftBank’s and DT’s ability to transfer their shares of our common stock in the four year period following the closing of the Transactions and will provide each of SoftBank and DT with a right of first refusal with respect to proposed transfers of shares of our common stock by the other party, subject in each case to certain exceptions and limitations set forth in the PLR Agreement. As a result of the PLR Agreement, we are expected to continue to be a “Controlled Company” for purposes of NASDAQ rules following consummation of the Merger, which provides us with exemptions from certain corporate governance requirements under the NASDAQ rules. Commitment Letter In connection with entry into the Business Combination Agreement, T-Mobile USA entered into a commitment letter, dated as of April 29, 2018 (the “Commitment Letter”), with Barclays Bank PLC, Credit Suisse AG, Deutsche Bank AG, Goldman Sachs Bank USA, Morgan Stanley Senior Funding, Inc., RBC Capital Markets, and certain of their affiliates (collectively, the “Commitment Parties”), pursuant to which, subject to the terms and conditions set forth therein, certain of the Commitment Parties have committed to provide up to $38.0 billion in secured and unsecured debt financing, including a $4.0 billion secured revolving credit facility, a $7.0 billion secured term loan facility, a $19.0 billion secured bridge loan facility and an $8.0 billion unsecured bridge loan facility. The funding of the debt facilities provided for in the Commitment Letter is subject to the satisfaction of the conditions set forth therein, including consummation of the proposed merger with Sprint. The proceeds of the debt financing provided for in the Commitment Letter will be used to refinance certain existing debt of us, Sprint and our and Sprint’s respective subsidiaries and for post-closing working capital needs of the combined company. Financing Matters Agreement In connection with the entry into the Business Combination Agreement, DT and T-Mobile USA entered into a Financing Matters Agreement, dated as of April 29, 2018 (the “Financing Matters Agreement”). Pursuant to the Financing Matters Agreement, DT agreed, among other things, to consent to the incurrence by T-Mobile USA of secured debt in connection with and after the consummation of the Merger, and to provide a lock up on sales thereby as to certain senior notes of T-Mobile USA held thereby. In addition, T-Mobile USA agreed, among other things, to repay and terminate, upon closing of the Merger, the existing credit facilities of T-Mobile USA which are provided by DT, as well as $2.0 billion of T-Mobile USA’s 5.300% senior notes due 2021 and $2.0 billion of T-Mobile USA’s 6.000% senior notes due 2024. In addition, T-Mobile USA and DT agreed, upon closing of the Merger, to amend the $1.25 billion of T-Mobile USA’s 5.125% senior notes due 2025 and $1.25 billion of T-Mobile USA’s 5.375% senior notes due 2027 to change the maturity dates thereof to April 15, 2021 and April 15, 2022, respectively.

Guarantor Financial Information

Guarantor Financial Information	3 Months Ended
	Mar. 31, 2018
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Guarantor Financial Information	Note 15 – Guarantor Financial Information Pursuant to the applicable indentures and supplemental indentures, the long-term debt to affiliates and third parties issued by T-Mobile USA (“Issuer”) is fully and unconditionally guaranteed, jointly and severally, on a senior unsecured basis by T-Mobile (“Parent”) and certain of the Issuer’s 100% owned subsidiaries (“Guarantor Subsidiaries”). In January 2018, T-Mobile USA and certain of its affiliates, as guarantors, issued (i) $1.0 billion of public 4.500% Senior Notes due 2026 and (ii) $1.5 billion of public 4.750% Senior Notes due 2028. In April 2018, T-Mobile USA and certain of its affiliates, as guarantors, issued (i) $1.0 billion in aggregate principal amount of 4.500% Senior Notes due 2026 and (ii) $1.5 billion in aggregate principal amount of 4.750% Senior Notes due 2028. Additionally, T-Mobile USA and certain of its affiliates, as guarantors, redeemed through net settlement, (i) the $1.25 billion in aggregate principal amount of 8.097% Senior Reset Notes due 2021 and (ii) $1.25 billion in aggregate principal amount of 8.195% Senior Reset Notes due 2022. See Note 9 - Debt for further information. The guarantees of the Guarantor Subsidiaries are subject to release in limited circumstances only upon the occurrence of certain customary conditions. The indentures and credit facilities governing the long-term debt contain covenants that, among other things, limit the ability of the Issuer and the Guarantor Subsidiaries to: incur more debt; pay dividends and make distributions; make certain investments; repurchase stock; create liens or other encumbrances; enter into transactions with affiliates; enter into transactions that restrict dividends or distributions from subsidiaries; and merge, consolidate, or sell, or otherwise dispose of, substantially all of their assets. Certain provisions of each of the credit facilities, indentures and supplemental indentures relating to the long-term debt restrict the ability of the Issuer to loan funds or make payments to Parent. However, the Issuer and Guarantor Subsidiaries are allowed to make certain permitted payments to the Parent under the terms of the indentures and the supplemental indentures. During the preparation of the condensed consolidating financial information of T-Mobile US, Inc. and Subsidiaries for the year ended December 31, 2017, it was determined that certain intercompany advances were misclassified in Net cash provided by (used in) operating activities and Net cash provided by (used in) financing activities in the Condensed Consolidating Statement of Cash Flows Information for the three months ended March 31, 2017 , as filed in our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2017. We have revised the Issuer, Guarantor Subsidiaries and Non-Guarantor Subsidiaries columns of the Condensed Consolidating Statement of Cash Flows Information to reclassify Intercompany advances, net from Net cash provided by (used in) operating activities to Net cash provided by (used in) financing activities. The impacts to the Issuer, Guarantor Subsidiaries and Non-Guarantor Subsidiaries columns for the three months ended March 31, 2017 were $5.0 billion , $5.0 billion and $11 million , respectively. The revisions, which we have determined are not material, are eliminated upon consolidation and have no impact on our Condensed Consolidating Statement of Cash Flows Information . Presented below is the condensed consolidating financial information as of March 31, 2018 and December 31, 2017 , and for the three months ended March 31, 2018 and 2017 . Condensed Consolidating Balance Sheet Information March 31, 2018 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Assets Current assets Cash and cash equivalents $ 1 $ 1 $ 2,395 $ 130 $ — $ 2,527 Accounts receivable, net — — 1,469 220 — 1,689 Equipment installment plan receivables, net — — 2,281 — — 2,281 Accounts receivable from affiliates — 5 13 — (5 ) 13 Inventories — — 1,311 — — 1,311 Other current assets — — 1,144 644 — 1,788 Total current assets 1 6 8,613 994 (5 ) 9,609 Property and equipment, net (1) — — 22,008 300 — 22,308 Goodwill — — 1,683 218 — 1,901 Spectrum licenses — — 35,504 — — 35,504 Other intangible assets, net — — 194 97 — 291 Investments in subsidiaries, net 23,426 42,581 — — (66,007 ) — Intercompany receivables and note receivables — 10,039 — — (10,039 ) — Equipment installment plan receivables due after one year, net — — 1,234 — — 1,234 Other assets — 3 1,074 225 (145 ) 1,157 Total assets $ 23,427 $ 52,629 $ 70,310 $ 1,834 $ (76,196 ) $ 72,004 Liabilities and Stockholders' Equity Current liabilities Accounts payable and accrued liabilities $ — $ 211 $ 6,679 $ 267 $ — $ 7,157 Payables to affiliates — 256 35 — — 291 Short-term debt — 2,670 648 2 — 3,320 Short-term debt to affiliates — 445 5 — (5 ) 445 Deferred revenue — — 791 — — 791 Other current liabilities 17 18 176 142 — 353 Total current liabilities 17 3,600 8,334 411 (5 ) 12,357 Long-term debt — 10,978 1,149 — — 12,127 Long-term debt to affiliates — 14,586 — — — 14,586 Tower obligations (1) — — 391 2,191 — 2,582 Deferred tax liabilities — — 3,958 — (145 ) 3,813 Deferred rent expense — — 2,730 — — 2,730 Negative carrying value of subsidiaries, net — — 590 — (590 ) — Intercompany payables and debt 534 — 9,244 261 (10,039 ) — Other long-term liabilities — 39 884 10 — 933 Total long-term liabilities 534 25,603 18,946 2,462 (10,774 ) 36,771 Total stockholders' equity (deficit) 22,876 23,426 43,030 (1,039 ) (65,417 ) 22,876 Total liabilities and stockholders' equity $ 23,427 $ 52,629 $ 70,310 $ 1,834 $ (76,196 ) $ 72,004 (1) Assets and liabilities for Non-Guarantor Subsidiaries are primarily included in VIEs related to the 2012 Tower Transaction. See Note 8 – Tower Obligations included in our Annual Report on Form 10-K for the year ended December 31, 2017 for further information. Condensed Consolidating Balance Sheet Information December 31, 2017 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Assets Current assets Cash and cash equivalents $ 74 $ 1 $ 1,086 $ 58 $ — $ 1,219 Accounts receivable, net — — 1,659 256 — 1,915 Equipment installment plan receivables, net — — 2,290 — — 2,290 Accounts receivable from affiliates — — 22 — — 22 Inventories — — 1,566 — — 1,566 Other current assets — — 1,275 628 — 1,903 Total current assets 74 1 7,898 942 — 8,915 Property and equipment, net (1) — — 21,890 306 — 22,196 Goodwill — — 1,683 — — 1,683 Spectrum licenses — — 35,366 — — 35,366 Other intangible assets, net — — 217 — — 217 Investments in subsidiaries, net 22,534 40,988 — — (63,522 ) — Intercompany receivables and note receivables — 8,503 — — (8,503 ) — Equipment installment plan receivables due after one year, net — — 1,274 — — 1,274 Other assets — 2 814 236 (140 ) 912 Total assets $ 22,608 $ 49,494 $ 69,142 $ 1,484 $ (72,165 ) $ 70,563 Liabilities and Stockholders' Equity Current liabilities Accounts payable and accrued liabilities $ — $ 253 $ 8,014 $ 261 $ — $ 8,528 Payables to affiliates — 146 36 — — 182 Short-term debt — 999 613 — — 1,612 Deferred revenue — — 779 — — 779 Other current liabilities 17 — 192 205 — 414 Total current liabilities 17 1,398 9,634 466 — 11,515 Long-term debt — 10,911 1,210 — — 12,121 Long-term debt to affiliates — 14,586 — — — 14,586 Tower obligations (1) — — 392 2,198 — 2,590 Deferred tax liabilities — — 3,677 — (140 ) 3,537 Deferred rent expense — — 2,720 — — 2,720 Negative carrying value of subsidiaries, net — — 629 — (629 ) — Intercompany payables and debt 32 — 8,201 270 (8,503 ) — Other long-term liabilities — 65 866 4 — 935 Total long-term liabilities 32 25,562 17,695 2,472 (9,272 ) 36,489 Total stockholders' equity (deficit) 22,559 22,534 41,813 (1,454 ) (62,893 ) 22,559 Total liabilities and stockholders' equity $ 22,608 $ 49,494 $ 69,142 $ 1,484 $ (72,165 ) $ 70,563 (1) Assets and liabilities for Non-Guarantor Subsidiaries are primarily included in VIEs related to the 2012 Tower Transaction. See Note 8 – Tower Obligations included in our Annual Report on Form 10-K for the year ended December 31, 2017, for further information. Condensed Consolidating Statement of Comprehensive Income Information Three Months Ended March 31, 2018 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Revenues Service revenues $ — $ — $ 7,487 $ 540 $ (221 ) $ 7,806 Equipment revenues — — 2,407 — (54 ) 2,353 Other revenues — 1 249 55 (9 ) 296 Total revenues — 1 10,143 595 (284 ) 10,455 Operating expenses Cost of services, exclusive of depreciation and amortization shown separately below — — 1,580 9 — 1,589 Cost of equipment sales — — 2,664 236 (55 ) 2,845 Selling, general and administrative — — 3,157 236 (229 ) 3,164 Depreciation and amortization — — 1,554 21 — 1,575 Total operating expense — — 8,955 502 (284 ) 9,173 Operating income — 1 1,188 93 — 1,282 Other income (expense) Interest expense — (174 ) (29 ) (48 ) — (251 ) Interest expense to affiliates — (166 ) (5 ) — 5 (166 ) Interest income — 6 5 — (5 ) 6 Other (expense) income, net — (32 ) 42 — — 10 Total other (expense) income, net — (366 ) 13 (48 ) — (401 ) Income (loss) before income taxes — (365 ) 1,201 45 — 881 Income tax expense — — (199 ) (11 ) — (210 ) Earnings (loss) of subsidiaries 671 1,036 (6 ) — (1,701 ) — Net income 671 671 996 34 (1,701 ) 671 Net Income $ 671 $ 671 $ 996 $ 34 $ (1,701 ) $ 671 Other comprehensive loss, net of tax Other comprehensive loss, net of tax (3 ) (3 ) (3 ) — 6 (3 ) Total comprehensive income $ 668 $ 668 $ 993 $ 34 $ (1,695 ) $ 668 Condensed Consolidating Statement of Comprehensive Income Information Three Months Ended March 31, 2017 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Revenues Service revenues $ — $ — $ 7,018 $ 525 $ (214 ) $ 7,329 Equipment revenues — — 2,143 — (100 ) 2,043 Other revenues — — 194 52 (5 ) 241 Total revenues — — 9,355 577 (319 ) 9,613 Operating expenses Cost of services, exclusive of depreciation and amortization shown separately below — — 1,402 6 — 1,408 Cost of equipment sales — — 2,540 246 (100 ) 2,686 Selling, general and administrative — — 2,928 246 (219 ) 2,955 Depreciation and amortization — — 1,546 18 — 1,564 Gains on disposal of spectrum licenses — — (37 ) — — (37 ) Total operating expenses — — 8,379 516 (319 ) 8,576 Operating income — — 976 61 — 1,037 Other income (expense) Interest expense — (264 ) (27 ) (48 ) — (339 ) Interest expense to affiliates — (99 ) (7 ) — 6 (100 ) Interest income — 9 4 — (6 ) 7 Other income (expense), net — 3 (1 ) — — 2 Total other expense, net — (351 ) (31 ) (48 ) — (430 ) Income (loss) before income taxes — (351 ) 945 13 — 607 Income tax benefit (expense) — — 96 (5 ) — 91 Earnings (loss) of subsidiaries 698 1,049 (31 ) — (1,716 ) — Net income 698 698 1,010 8 (1,716 ) 698 Dividends on preferred stock (14 ) — — — — (14 ) Net income attributable to common stockholders $ 684 $ 698 $ 1,010 $ 8 $ (1,716 ) $ 684 Net income $ 698 $ 698 $ 1,010 $ 8 $ (1,716 ) $ 698 Other comprehensive income, net of tax Other comprehensive income, net of tax 1 1 1 1 (3 ) 1 Total comprehensive income $ 699 $ 699 $ 1,011 $ 9 $ (1,719 ) $ 699 Condensed Consolidating Statement of Cash Flows Information Three Months Ended March 31, 2018 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Operating activities Net cash provided by (used in) operating activities $ 1 $ (404 ) $ 2,374 $ (1,201 ) $ — $ 770 Investing activities Purchases of property and equipment — — (1,366 ) — — (1,366 ) Purchases of spectrum licenses and other intangible assets, including deposits — — (51 ) — — (51 ) Proceeds related to beneficial interests in securitization transactions — — 13 1,282 — 1,295 Acquisition of companies, net of cash acquired — — (333 ) — — (333 ) Other, net — — (7 ) — — (7 ) Net cash provided by (used in) investing activities — — (1,744 ) 1,282 — (462 ) Financing activities Proceeds from issuance of long-term debt — 2,494 — — — 2,494 Proceeds from borrowing on revolving credit facility, net — 2,170 — — — 2,170 Repayments of revolving credit facility — — (1,725 ) — — (1,725 ) Repayments of capital lease obligations — — (172 ) — — (172 ) Repayments of long-term debt — — (999 ) — — (999 ) Repurchases of common stock (666 ) — — — — (666 ) Intercompany advances, net 590 (4,260 ) 3,679 (9 ) — — Tax withholdings on share-based awards — — (74 ) — — (74 ) Other, net 2 — (30 ) — — (28 ) Net cash (used in) provided by financing activities (74 ) 404 679 (9 ) — 1,000 Change in cash and cash equivalents (73 ) — 1,309 72 — 1,308 Cash and cash equivalents Beginning of period 74 1 1,086 58 — 1,219 End of period $ 1 $ 1 $ 2,395 $ 130 $ — $ 2,527 Condensed Consolidating Statement of Cash Flows Information Three Months Ended March 31, 2017 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Operating activities Net cash provided by (used in) operating activities $ 1 $ (134 ) $ 1,855 $ (1,114 ) $ — $ 608 Investing activities Purchases of property and equipment — — (1,528 ) — — (1,528 ) Purchases of spectrum licenses and other intangible assets, including deposits — — (14 ) — — (14 ) Proceeds related to beneficial interests in securitization transactions — — 10 1,124 — 1,134 Other, net — — (8 ) — — (8 ) Net cash (used in) provided by investing activities — — (1,540 ) 1,124 — (416 ) Financing activities Proceeds from issuance of long-term debt — 5,495 — — — 5,495 Repayments of capital lease obligations — — (90 ) — — (90 ) Repayments of long-term debt — — (3,480 ) — — (3,480 ) Intercompany advances, net — (4,956 ) 4,967 (11 ) — — Tax withholdings on share-based awards — — (92 ) — — (92 ) Dividends on preferred stock (14 ) — — — — (14 ) Other, net 15 — (25 ) — — (10 ) Net cash provided by (used in) financing activities 1 539 1,280 (11 ) — 1,809 Change in cash and cash equivalents 2 405 1,595 (1 ) — 2,001 Cash and cash equivalents Beginning of period 358 2,733 2,342 67 — 5,500 End of period $ 360 $ 3,138 $ 3,937 $ 66 $ — $ 7,501 Balances have been revised based on the guidance in ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” See Note 1 - Summary of Significant Accounting Policies of the Notes to the Condensed Consolidated Financial Statements, for further information.

Summary of Significant Accoun23

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The unaudited condensed consolidated financial statements of T-Mobile US, Inc. (“T-Mobile,” “we,” “our,” “us” or the “Company”) include all adjustments of a normal recurring nature necessary for the fair presentation of the results for the interim periods presented. The results for the interim periods are not necessarily indicative of those for the full year. The condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2017 . The condensed consolidated financial statements include the balances and results of operations of T-Mobile and our consolidated subsidiaries. We consolidate majority-owned subsidiaries over which we exercise control, as well as variable interest entities (“VIE”) where we are deemed to be the primary beneficiary and VIEs which cannot be deconsolidated, such as those related to Tower obligations (Tower obligations are included in VIEs related to the 2012 Tower Transaction. See Note 8 - Tower Obligations included in our Annual Report on Form 10-K for the year ended December 31, 2017 ). Intercompany transactions and balances have been eliminated in consolidation.
Basis of Accounting	The preparation of financial statements in conformity with United States (“U.S.”) generally accepted accounting principles (“GAAP”) requires our management to make estimates and assumptions which affect the financial statements and accompanying notes.
Use of Estimates	Estimates are based on historical experience, where applicable, and other assumptions which our management believes are reasonable under the circumstances. These estimates are inherently subject to judgment and actual results could differ from those estimates.
Accounting Pronouncements Adopted During the Current Year and Accounting Pronouncements Not Yet Adopted	The most significant impacts to financial statement results as reported under the new revenue standard as compared to the previous revenue standard for the current reporting period are as follows: • Under the new revenue standard, certain commissions paid to dealers previously recognized as a reduction to Equipment revenues in our Condensed Consolidated Statements of Comprehensive Income are now recorded as commission costs in Selling, general and administrative expense. • Contract costs capitalized for new contracts will accumulate in Other assets in our Condensed Consolidated Balance Sheets during 2018. As a result, there will be a net benefit to Operating income in our Condensed Consolidated Statements of Comprehensive Income during 2018 as capitalization of costs exceed amortization. As capitalized costs amortize into expense over time, the accretive benefit to Operating income anticipated in 2018 is expected to moderate in 2019 and normalize in 2020. • For contracts with promotional bill credits that are contingent on the customer maintaining a service contract that result in an extended service contract, a contract asset is recorded when control of the equipment transfers to the customer and is subsequently recognized as a reduction to Total service revenues in our Condensed Consolidated Statements of Comprehensive Income over the extended contract term. See disclosures related to Contracts with Customers under the new revenue standard in Note 10 - Revenue from Contracts with Customers . Statement of Cash Flows In August 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” (the “new cash flow standard”). The new cash flow standard is intended to reduce current diversity in practice and provides guidance on how certain cash receipts and payments are presented and classified in the statement of cash flows. We adopted the new cash flow standard on January 1, 2018, which was the date it became effective for us. We have applied the new cash flow standard retrospectively to all periods presented. The new cash flow standard impacted the presentation of cash flows related to our beneficial interests in securitization transactions, which is the deferred purchase price, resulting in a reclassification of cash inflows from Operating activities to Investing activities of approximately $1.3 billion and $1.1 billion for the three months ended March 31, 2018 and 2017 , respectively, in our Condensed Consolidated Statements of Cash Flows . The new cash flow standard also impacted the presentation of our cash payments for debt prepayment and debt extinguishment costs, resulting in a reclassification of cash outflows from Operating activities to Financing activities of $31 million and $29 million for the three months ended March 31, 2018 and 2017 , respectively, in our Condensed Consolidated Statements of Cash Flows . Income Taxes In October 2016, the FASB issued ASU 2016-16, “Accounting for Income Taxes: Intra-Entity Transfers of Assets Other Than Inventory.” The standard requires that the income tax impact of intra-entity sales and transfers of property, except for inventory, be recognized when the transfer occurs. The standard became effective for us, and we adopted the standard, on January 1, 2018. The standard requires any deferred taxes not yet recognized on intra-entity transfers to be recorded to retained earnings under a modified retrospective approach. The implementation of this standard did not have a material impact on our condensed consolidated financial statements . Accounting Pronouncements Not Yet Adopted Leases In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” (the “new lease standard”). The new lease standard requires all lessees to report a right-of-use asset and a lease liability for most leases. The income statement recognition is similar to existing lease accounting and is based on lease classification. The new lease standard requires lessees and lessors to classify most leases using principles similar to existing lease accounting. For lessors, the new lease standard modifies the classification criteria and the accounting for sales-type and direct financing leases. We are currently evaluating the new lease standard, which will require recognizing and measuring leases at the beginning of the earliest period presented using a modified retrospective approach. Our evaluation includes assessing which of our arrangements qualify as a lease, and aggregating lease data and related information as well as determining whether previous conclusions for certain transactions, such as failed sale leaseback arrangements under the previous lease standard, Leases (Topic 840), would change under the new lease standard. We plan to adopt the new lease standard when it becomes effective for us beginning January 1, 2019, and expect the adoption of the new lease standard will result in the recognition of right-of-use assets and lease liabilities that have not previously been recorded, which will have a material impact on our condensed consolidated financial statements . We are in the process of implementing significant new lease accounting systems, processes and internal controls over lease recognition, which will ultimately assist in the application of the new lease standard. Financial Instruments In June 2016, the FASB issued ASU 2016-13, “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The standard requires a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions and reasonable and supportable forecasts that affect the collectibility of the reported amount. The standard will become effective for us beginning January 1, 2020, and will require a cumulative-effect adjustment to Accumulated deficit as of the beginning of the first reporting period in which the guidance is effective (that is, a modified-retrospective approach). Early adoption is permitted for us as of January 1, 2019. We are currently evaluating the impact this guidance will have on our condensed consolidated financial statements and the timing of adoption. Other recent accounting pronouncements issued by the FASB (including its Emerging Issues Task Force), the American Institute of Certified Public Accountants, and the Securities and Exchange Commission (“SEC”) did not have, or are not believed by management to have, a significant impact on our present or future consolidated financial statements. Accounting Pronouncements Adopted During the Current Year Revenue In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606)”, and has since modified the standard with several ASUs (collectively, the “new revenue standard”). The new revenue standard requires entities to recognize revenue through the application of a five-step model, which includes: identification of the contract; identification of the performance obligations; determination of the transaction price; allocation of the transaction price to the performance obligations; and recognition of revenue as the entity satisfies the performance obligations. We adopted the new revenue standard on January 1, 2018, using the modified retrospective method with the cumulative effect of initially applying the guidance recognized at the date of initial application. Comparative information has not been restated and continues to be reported under the standards in effect for those periods. We have applied the new revenue standard only to contracts not completed as of the date of initial application, referred to as open contracts. We have elected the practical expedient that permits an entity to reflect the aggregate effect of all of the modifications (on a contract-by-contract basis) that occurred before the date of initial application in determining the transaction price, identifying the satisfied and unsatisfied performance obligations, and allocating the transaction price to the performance obligations. Electing this practical expedient does not have a significant impact on our financial statements due to the short-term duration of most of our contracts and the nature of our contract modifications. We have implemented significant new revenue accounting systems, processes and internal controls over revenue recognition to assist us in the application of the new revenue standard.
Revenue Recognition	Revenue Recognition We primarily generate our revenue from providing wireless services to customers and selling or leasing devices and accessories. Our contracts with customers may involve multiple performance obligations, which include wireless services, wireless devices or a combination thereof, and we allocate the transaction price between each performance obligation based on its relative standalone selling price. Significant Judgments The most significant judgments affecting the amount and timing of revenue from contracts with our customers include the following items: • For transactions where we recognize a significant financing component, judgment is required to determine the discount rate. For equipment installment plan (“EIP”) sales, the discount rate used to adjust the transaction price primarily reflects current market interest rates and the estimated credit risk of the customer. • Our products are generally sold with a right of return, which is accounted for as variable consideration when estimating the amount of revenue to recognize. Expected device returns are estimated based on historical experience. • Promotional bill credits offered to a customer on an equipment sale that are paid over time and are contingent on the customer maintaining a service contract may result in an extended service contract based on whether a substantive penalty is deemed to exist. Determining whether contingent bill credits result in a substantive termination penalty, and determining the term over which a substantive termination penalty exists, may require significant judgment. • For capitalized contract costs, determining the amortization period as well as assessing the indicators of impairment may require significant judgment. • The determination of the standalone selling price for contracts that involve more than one product or service (or performance obligation) may require significant judgment. • The identification of distinct performance obligations within our service plans may require significant judgment. Wireless Services Revenue We generate our wireless services revenues from providing access to, and usage of, our wireless communications network. Service revenues also include revenues earned for providing value added services to customers, such as handset insurance services. Service contracts are billed monthly either in advance or arrears, or are prepaid. Generally, service revenue is recognized as we satisfy our performance obligation to transfer service to our customers. We typically satisfy our stand-ready-performance obligations, including unlimited wireless services, evenly over the contract term. For usage-based and prepaid wireless services, we satisfy our performance obligations when services are rendered. Revenue for service contracts that we assess are not probable of collection is not recognized until the contract is completed and cash is received. Collectibility is re-assessed when there is a significant change in facts or circumstances. Our assessment of collectibility considers whether we may limit our exposure to credit risk through our right to stop transferring additional service in the event the customer is delinquent. Consideration payable to a customer is treated as a reduction of the total transaction price, unless the payment is in exchange for a distinct good or service, such as certain commissions paid to dealers. Revenue is recorded net of costs paid to another party for performance obligations where we arrange for the other party to transfer goods or services to the customer (i.e., when we are acting as an agent). For example, performance obligations relating to services provided by third-party content providers where T-Mobile neither controls a right to the content provider’s service nor controls the underlying service itself are presented net because T-Mobile is acting as an agent. Federal Universal Service Fund (“USF”) and other regulatory fees are assessed by various governmental authorities in connection with the services we provide to our customers and included in Cost of services. When we separately bill and collect these regulatory fees from customers, they are recorded in Total service revenues in our Condensed Consolidated Statements of Comprehensive Income . We have made an accounting policy election to exclude from the measurement of the transaction price all taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction and collected by T-Mobile from a customer (for example, sales, use, value added, and some excise taxes). Equipment Revenues We generate equipment revenues from the sale or lease of mobile communication devices and accessories. For performance obligations related to equipment contracts, we typically transfer control at a point in time when the device or accessory is delivered to, and accepted by, the customer or dealer. We have elected to account for shipping and handling activities that occur after control of the related good transfers as fulfillment activities instead of assessing such activities as performance obligations. We establish provisions for estimated device returns based on historical experience. Equipment sales not probable of collection are generally recorded as payments are received. Our assessment of collectibility considers payment terms such as down payments that reduce our exposure to credit risk. We offer certain customers the option to pay for devices and accessories in installments using an EIP. Generally, we recognize as a reduction of the total transaction price the effects of a financing component in contracts where customers purchase their devices and accessories on an EIP with a term of more than one year, including those financing components that are not considered to be significant to the contract. However, we have elected the practical expedient to not recognize the effects of a significant financing component for contracts where we expect, at contract inception, that the period between the transfer of a performance obligation to a customer and the customer’s payment for that performance obligation will be one year or less. In addition, for customers who enroll in our Just Upgrade My Phone (“JUMP!” ® ) program, we recognize a liability based on the estimated fair value of the specified-price trade-in right guarantee. The fair value of the guarantee is deducted from the transaction price under the new revenue standard, and the remaining transaction price is allocated to other elements of the contract, including service and equipment performance obligations. See “Guarantee Liabilities” in Note 1 - Summary of Significant Accounting Policies included in our Annual Report on Form 10-K for the year ended December 31, 2017. In 2015, we introduced JUMP! On Demand, which allows customers to lease a device and upgrade their leased wireless device for a new device up to one time per month. To date, all of our leased wireless devices are accounted for as operating leases and estimated contract consideration is allocated between lease elements and non-lease elements (such as service and equipment performance obligations) based on the relative standalone selling price of each performance obligation in the contract. Lease revenues are recorded as equipment revenues and recognized as earned on a straight-line basis over the lease term. Lease revenues on contracts not probable of collection are limited to the amount of payments received. See “Property and Equipment” in Note 1 - Summary of Significant Accounting Policies included in our Annual Report on Form 10-K for the year ended December 31, 2017. Contract Balances Generally, T-Mobile devices and service plans are available at standard prices, which are maintained on price lists and published on our website and/or within our retail stores. For contracts that involve more than one product or service that are identified as separate performance obligations, the transaction price is generally allocated to the performance obligations based on their relative standalone selling prices. Standalone selling price is the price that T-Mobile would sell the good or service separately to a customer and is best evidenced by the price that T-Mobile sells that good or service separately in similar circumstances and to similar customers. A contract asset is recorded when revenue is recognized in advance of our right to receive consideration (e.g., we must perform additional services in order to receive consideration). Amounts are recorded as receivables when our right to consideration is unconditional. When consideration is received or we have an unconditional right to consideration in advance of delivery of goods or services, a contract liability is recorded. The transaction price can include non-refundable upfront fees, which are allocated to the identifiable performance obligations. Contract assets are included in Other current assets and Other assets and contract liabilities are included in Deferred revenue in our Condensed Consolidated Balance Sheets . Contract Modifications Our service contracts allow customers to frequently modify their contracts without incurring penalties in many cases. Each time 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 separate contract, as if there is a termination of the existing contract and creation of a new contract, or if the modification should be considered a change associated with the existing contract. We typically do not have significant impacts from contract modifications. Contract Costs We incur certain incremental costs to obtain a contract that we expect to recover, such as sales commissions. We record an asset when these incremental costs to obtain a contract are incurred and amortize them on a systematic basis that is consistent with the transfer to the customer of the goods or services to which the asset relates. We amortize deferred costs incurred to obtain service contracts on a straight-line basis over the term of the initial contract and anticipated renewal contracts to which the costs relate. However, we have elected the practical expedient permitting expensing of costs to obtain a contract when the expected amortization period is one year or less. Incremental costs to obtain equipment contracts (e.g., commissions paid on device and accessory sales) are recognized when the equipment is transferred to the customer.

Summary of Significant Accoun24

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Statement Impacts of Applying New Accounting Standard	The cumulative effect of initially applying the new revenue standard to all open contracts as of January 1, 2018 is as follows: January 1, 2018 (in millions) Beginning Balance Cumulative Effect Adjustment Beginning Balance, As Adjusted Assets Other current assets $ 1,903 $ 140 $ 2,043 Other assets 912 150 1,062 Liabilities and Stockholders’ Equity Deferred revenue $ 779 $ 4 $ 783 Deferred tax liabilities 3,537 73 3,610 Accumulated deficit (16,074 ) 213 (15,861 ) The most significant impacts upon adoption of the new revenue standard on January 1, 2018 include the following items: • A deferred contract cost asset of $150 million was recorded at transition in Other assets in our Condensed Consolidated Balance Sheets for incremental contract acquisition costs paid on open contracts, which consists primarily of commissions paid to acquire branded postpaid service contracts; and • A contract asset of $140 million was recorded at transition in Other current assets in our Condensed Consolidated Balance Sheets primarily for contracts with promotional bill credits offered to customers on equipment sales that are paid over time and are contingent on the customer maintaining a service contract. Financial statement results as reported under the new revenue standard as compared to the previous revenue standard for the three months ended and as of March 31, 2018 are as follows: Three Months Ended March 31, 2018 (in millions, except per share amounts) Previous Revenue Standard New Revenue Standard Change Revenues Branded postpaid revenues $ 5,099 $ 5,070 $ (29 ) Branded prepaid revenues 2,403 2,402 (1 ) Wholesale revenues 266 266 — Roaming and other service revenues 68 68 — Total service revenues 7,836 7,806 (30 ) Equipment revenues 2,276 2,353 77 Other revenues 296 296 — Total revenues 10,408 10,455 47 Operating expenses Cost of services, exclusive of depreciation and amortization shown separately below 1,589 1,589 — Cost of equipment sales 2,845 2,845 — Selling, general and administrative 3,212 3,164 (48 ) Depreciation and amortization 1,575 1,575 — Total operating expenses 9,221 9,173 (48 ) Operating income 1,187 1,282 95 Total other expense, net (401 ) (401 ) — Income before income taxes 786 881 95 Income tax expense (186 ) (210 ) (24 ) Net income $ 600 $ 671 $ 71 Earnings per share Basic earnings per share $ 0.70 $ 0.78 $ 0.08 Diluted earnings per share $ 0.70 $ 0.78 $ 0.08 March 31, 2018 (in millions) Previous Revenue Standard New Revenue Standard Change Assets Other current assets $ 1,684 $ 1,788 $ 104 Other assets 866 1,157 291 Liabilities and Stockholders’ Equity Deferred revenue $ 777 $ 791 $ 14 Deferred tax liabilities 3,716 3,813 97 Accumulated deficit (15,463 ) (15,179 ) 284

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Schedule of Amounts Recognized as of Acquisition Date	The following table shows the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed and the resultant purchase price allocation: (in millions) January 1, Assets acquired Current assets Cash and cash equivalents $ 3 Accounts receivables, net 6 Equipment installment plan receivables, net 3 Inventories 1 Other current assets 2 Total current assets 15 Property and equipment, net 36 Spectrum licenses 87 Total assets acquired $ 138 Liabilities assumed Accounts payable and accrued liabilities $ 6 Deferred revenue 2 Total current liabilities 8 Deferred tax liabilities 17 Other long-term liabilities 7 Total long-term liabilities 24 Net assets acquired $ 106 The following table shows the amounts recognized as of the acquisition date for each major class of assets acquired and liabilities assumed and the resultant purchase price allocation: (in millions) January 22, Assets acquired Cash and cash equivalents $ 2 Other current assets 14 Property and equipment, net 11 Intangible assets 100 Goodwill 218 Deferred tax assets 2 Total assets acquired $ 347 Liabilities assumed Accounts payable and accrued liabilities $ 27 Short-term debt 2 Total liabilities assumed 29 Total consideration transferred $ 318
Schedule of Consideration Transferred	The following table highlights the consideration transferred, the fair value of our previously held equity interest and bargain purchase: (in millions) January 1, Consideration transferred: Cash paid $ 25 Previously held equity interest: Acquisition date fair value of previously held equity interest 56 Bargain purchase gain 25 Net assets acquired $ 106

Receivables and Allowance for26

Receivables and Allowance for Credit Losses (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Schedule of Equipment Installment Plan Receivables	The following table summarizes the EIP receivables, including imputed discounts and related allowance for credit losses: (in millions) March 31, December 31, EIP receivables, gross $ 3,896 $ 3,960 Unamortized imputed discount (267 ) (264 ) EIP receivables, net of unamortized imputed discount 3,629 3,696 Allowance for credit losses (114 ) (132 ) EIP receivables, net $ 3,515 $ 3,564 Classified on the balance sheet as: Equipment installment plan receivables, net $ 2,281 $ 2,290 Equipment installment plan receivables due after one year, net 1,234 1,274 EIP receivables, net $ 3,515 $ 3,564
Schedule of Unamortized Imputed Discount and Allowance for Credit Losses for Equipment Installment Plan Receivables	Activity for the three months ended March 31, 2018 and 2017 , in the allowance for credit losses and unamortized imputed discount balances for the accounts receivable and EIP receivable segments were as follows: March 31, 2018 March 31, 2017 (in millions) Accounts Receivable Allowance EIP Receivables Allowance Total Accounts Receivable Allowance EIP Receivables Allowance Total Allowance for credit losses and imputed discount, beginning of period $ 86 $ 396 $ 482 $ 102 $ 316 $ 418 Bad debt expense 4 50 54 37 56 93 Write-offs, net of recoveries (14 ) (67 ) (81 ) (39 ) (75 ) (114 ) Change in imputed discount on short-term and long-term EIP receivables N/A 53 53 N/A 48 48 Impact on the imputed discount from sales of EIP receivables N/A (51 ) (51 ) N/A (41 ) (41 ) Allowance for credit losses and imputed discount, end of period $ 76 $ 381 $ 457 $ 100 $ 304 $ 404
Schedule of Equipment Installment Plan Receivables by Credit Category	The following table provides delinquency status for the unpaid principal balance for receivables within the EIP portfolio segment, which we actively monitor as part of our current credit risk management practices and policies: March 31, 2018 December 31, 2017 (in millions) Prime Subprime Total EIP Receivables, gross Prime Subprime Total EIP Receivables, gross Current - 30 days past due $ 1,648 $ 2,168 $ 3,816 $ 1,727 $ 2,133 $ 3,860 31 - 60 days past due 14 24 38 17 29 46 61 - 90 days past due 5 13 18 6 16 22 More than 90 days past due 7 17 24 8 24 32 Total receivables, gross $ 1,674 $ 2,222 $ 3,896 $ 1,758 $ 2,202 $ 3,960

Sales of Certain Receivables (T

Sales of Certain Receivables (Tables)	3 Months Ended
	Mar. 31, 2018
Transfers and Servicing [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the carrying amounts and classification of assets, which consists primarily of the deferred purchase price and liabilities included in our Condensed Consolidated Balance Sheets that relate to our variable interest in the Service VIE: (in millions) March 31, December 31, Other current assets $ 266 $ 236 Accounts payable and accrued liabilities — 25 Other current liabilities 118 180
Schedule of variable interest entities - EIP	The following table summarizes the carrying amounts and classification of assets, which consists primarily of the deferred purchase price and liabilities included in our Condensed Consolidated Balance Sheets that relate to the EIP BRE: (in millions) March 31, December 31, Other current assets $ 370 $ 403 Other assets 93 109 Other long-term liabilities 10 3
Schedule of Factoring Arrangement	The following table summarizes the impacts of the sale of certain service receivables and EIP receivables in our Condensed Consolidated Balance Sheets : (in millions) March 31, December 31, Derecognized net service receivables and EIP receivables $ 2,663 $ 2,725 Other current assets 636 639 of which, deferred purchase price 635 636 Other long-term assets 93 109 of which, deferred purchase price 93 109 Accounts payable and accrued liabilities — 25 Other current liabilities 118 180 Other long-term liabilities 10 3 Net cash proceeds since inception 1,908 2,058 Of which: Change in net cash proceeds during the year-to-date period (150 ) 28 Net cash proceeds funded by reinvested collections 2,058 2,030

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill for the three months ended March 31, 2018 , are as follows: (in millions) Historical goodwill $ 12,449 Accumulated impairment losses at December 31, 2017 (10,766 ) Balance as of December 31, 2017 1,683 Goodwill from acquisition of Layer3 TV 218 Balance as of March 31, 2018 $ 1,901 Accumulated impairment losses at March 31, 2018 $ (10,766 )

Spectrum License Transactions (

Spectrum License Transactions (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Spectrum Licenses	The following table summarizes our spectrum license activity for the three months ended March 31, 2018 : (in millions) Spectrum Licenses Balance at December 31, 2017 $ 35,366 Spectrum license acquisitions 125 Costs to clear spectrum 13 Balance at March 31, 2018 $ 35,504

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Carrying Values and Fair Values of Long-term Debt	The carrying amounts and fair values of our short-term and long-term debt included in our Condensed Consolidated Balance Sheets were as follows: Level within the Fair Value Hierarchy March 31, 2018 December 31, 2017 (in millions) Carrying Amount Fair Value Carrying Amount Fair Value Liabilities: Senior Notes to third parties 1 $ 13,402 $ 13,732 $ 11,910 $ 12,540 Senior Notes to affiliates 2 7,486 7,659 7,486 7,852 Incremental Term Loan Facility to affiliates 2 4,000 4,000 4,000 4,020 Senior Reset Notes to affiliates 2 3,100 3,223 3,100 3,260 The carrying amounts and fair values of our assets measured at fair value on a recurring basis included in our Condensed Consolidated Balance Sheets were as follows: Level within the Fair Value Hierarchy March 31, 2018 December 31, 2017 (in millions) Carrying Amount Fair Value Carrying Amount Fair Value Assets: Deferred purchase price assets 3 $ 728 $ 728 $ 745 $ 745

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule of Debt	During the three months ended March 31, 2018 , we issued the following Senior Notes: (in millions) Principal Issuances Issuance Costs Net Proceeds from Issuance of Long-Term Debt 4.500% Senior Notes due 2026 $ 1,000 $ 2 $ 998 4.750% Senior Notes due 2028 1,500 4 1,496 Total of Senior Notes issued $ 2,500 $ 6 $ 2,494 The following table sets forth the debt balances and activity as of, and for the three months ended , March 31, 2018 : (in millions) December 31, Issuances and Borrowings (1) Note Redemptions (1) Repayments Reclassifications (1) Other (2) March 31, Short-term debt $ 1,612 $ — $ (999 ) $ — $ 2,425 $ 282 $ 3,320 Long-term debt 12,121 2,494 — — (2,425 ) (63 ) 12,127 Total debt to third parties 13,733 2,494 (999 ) — — 219 15,447 Short-term debt to affiliates — 2,170 — (1,725 ) — — 445 Long-term debt to affiliates 14,586 — — — — — 14,586 Total debt $ 28,319 $ 4,664 $ (999 ) $ (1,725 ) $ — $ 219 $ 30,478 (1) Issuances and borrowings, note redemptions, and reclassifications are recorded net of related issuance costs, discounts and premiums. Issuances and borrowings and repayments for Short-term debt to affiliates represent net outstanding borrowings and net repayments on our senior secured revolving credit facility. (2) Other includes: $246 million of issuances of short-term debt related to vendor financing arrangements, of which $237 million related to financing of property and equipment. During the three months ended March 31, 2018 , we did not have any repayments under the vendor financing arrangements. Vendor financing arrangements are included in Short-term debt within Total current liabilities in our Condensed Consolidated Balance Sheets. Other also includes capital leases and the amortization of discounts and premiums. Capital lease liabilities totaled $1.8 billion at both March 31, 2018 and December 31, 2017 .
Debt Instrument Redemption	During the three months ended March 31, 2018 , we made the following note redemption: (in millions) Principal Amount Write-off of Premiums, Discounts and Issuance Costs (1) Call Penalties (1) (2) Redemption Redemption Price 6.125% Senior Notes due 2022 $ 1,000 $ 1 $ 31 January 15, 2018 103.063 % (1) Write-off of premiums, discounts, issuance costs and call penalties are included in Other income, net in our Condensed Consolidated Statements of Comprehensive Income . Write-off of premiums, discounts and issuance costs are included in Other, net within Net cash provided by operating activities in our Condensed Consolidated Statements of Cash Flows . (2) The call penalty is the excess paid over the principal amount. Call penalties are included within Net cash provided by financing activities in our Condensed Consolidated Statements of Cash Flows .

Revenue from Contracts with C32

Revenue from Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Contract Liability and Receivable Balances	Revenues for the three months ended March 31, 2018 , include the following: Three Months Ended March 31, (in millions) 2018 Amounts included in the beginning of period contract liability balance $ 528 Amounts associated with performance obligations satisfied in previous periods — The opening and closing balances of T-Mobile’s contract asset, contract liability and receivables balances from contracts with customers for the three months ended March 31, 2018 are as follows: (in millions) Contract Assets Included in Other Current Assets Contract Liabilities Included in Deferred Revenue Balance as of January 1, 2018 $ 140 $ 718 Balance as of March 31, 2018 104 718 Change (36 ) —
Schedule of Contract Costs	Deferred contract cost balances at March 31, 2018 were as follows: (in millions) At March 31, 2018 Total deferred incremental costs to obtain contracts $ 290

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share	The computation of basic and diluted earnings per share was as follows: Three Months Ended March 31, (in millions, except shares and per share amounts) 2018 2017 Net income $ 671 $ 698 Less: Dividends on mandatory convertible preferred stock — (14 ) Net income attributable to common stockholders - basic 671 684 Add: Dividends related to mandatory convertible preferred stock — 14 Net income attributable to common stockholders - diluted $ 671 $ 698 Weighted average shares outstanding - basic 855,222,664 827,723,034 Effect of dilutive securities: Outstanding stock options and unvested stock awards 7,021,420 9,434,950 Mandatory convertible preferred stock — 32,238,000 Weighted average shares outstanding - diluted 862,244,084 869,395,984 Earnings per share - basic $ 0.78 $ 0.83 Earnings per share - diluted $ 0.78 $ 0.80 Potentially dilutive securities: Outstanding stock options and unvested stock awards 67,580 9,993

Guarantor Financial Informati34

Guarantor Financial Information (Tables)	3 Months Ended
	Mar. 31, 2018
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Consolidating Balance Sheet Information	Condensed Consolidating Balance Sheet Information March 31, 2018 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Assets Current assets Cash and cash equivalents $ 1 $ 1 $ 2,395 $ 130 $ — $ 2,527 Accounts receivable, net — — 1,469 220 — 1,689 Equipment installment plan receivables, net — — 2,281 — — 2,281 Accounts receivable from affiliates — 5 13 — (5 ) 13 Inventories — — 1,311 — — 1,311 Other current assets — — 1,144 644 — 1,788 Total current assets 1 6 8,613 994 (5 ) 9,609 Property and equipment, net (1) — — 22,008 300 — 22,308 Goodwill — — 1,683 218 — 1,901 Spectrum licenses — — 35,504 — — 35,504 Other intangible assets, net — — 194 97 — 291 Investments in subsidiaries, net 23,426 42,581 — — (66,007 ) — Intercompany receivables and note receivables — 10,039 — — (10,039 ) — Equipment installment plan receivables due after one year, net — — 1,234 — — 1,234 Other assets — 3 1,074 225 (145 ) 1,157 Total assets $ 23,427 $ 52,629 $ 70,310 $ 1,834 $ (76,196 ) $ 72,004 Liabilities and Stockholders' Equity Current liabilities Accounts payable and accrued liabilities $ — $ 211 $ 6,679 $ 267 $ — $ 7,157 Payables to affiliates — 256 35 — — 291 Short-term debt — 2,670 648 2 — 3,320 Short-term debt to affiliates — 445 5 — (5 ) 445 Deferred revenue — — 791 — — 791 Other current liabilities 17 18 176 142 — 353 Total current liabilities 17 3,600 8,334 411 (5 ) 12,357 Long-term debt — 10,978 1,149 — — 12,127 Long-term debt to affiliates — 14,586 — — — 14,586 Tower obligations (1) — — 391 2,191 — 2,582 Deferred tax liabilities — — 3,958 — (145 ) 3,813 Deferred rent expense — — 2,730 — — 2,730 Negative carrying value of subsidiaries, net — — 590 — (590 ) — Intercompany payables and debt 534 — 9,244 261 (10,039 ) — Other long-term liabilities — 39 884 10 — 933 Total long-term liabilities 534 25,603 18,946 2,462 (10,774 ) 36,771 Total stockholders' equity (deficit) 22,876 23,426 43,030 (1,039 ) (65,417 ) 22,876 Total liabilities and stockholders' equity $ 23,427 $ 52,629 $ 70,310 $ 1,834 $ (76,196 ) $ 72,004 (1) Assets and liabilities for Non-Guarantor Subsidiaries are primarily included in VIEs related to the 2012 Tower Transaction. See Note 8 – Tower Obligations included in our Annual Report on Form 10-K for the year ended December 31, 2017 for further information. Condensed Consolidating Balance Sheet Information December 31, 2017 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Assets Current assets Cash and cash equivalents $ 74 $ 1 $ 1,086 $ 58 $ — $ 1,219 Accounts receivable, net — — 1,659 256 — 1,915 Equipment installment plan receivables, net — — 2,290 — — 2,290 Accounts receivable from affiliates — — 22 — — 22 Inventories — — 1,566 — — 1,566 Other current assets — — 1,275 628 — 1,903 Total current assets 74 1 7,898 942 — 8,915 Property and equipment, net (1) — — 21,890 306 — 22,196 Goodwill — — 1,683 — — 1,683 Spectrum licenses — — 35,366 — — 35,366 Other intangible assets, net — — 217 — — 217 Investments in subsidiaries, net 22,534 40,988 — — (63,522 ) — Intercompany receivables and note receivables — 8,503 — — (8,503 ) — Equipment installment plan receivables due after one year, net — — 1,274 — — 1,274 Other assets — 2 814 236 (140 ) 912 Total assets $ 22,608 $ 49,494 $ 69,142 $ 1,484 $ (72,165 ) $ 70,563 Liabilities and Stockholders' Equity Current liabilities Accounts payable and accrued liabilities $ — $ 253 $ 8,014 $ 261 $ — $ 8,528 Payables to affiliates — 146 36 — — 182 Short-term debt — 999 613 — — 1,612 Deferred revenue — — 779 — — 779 Other current liabilities 17 — 192 205 — 414 Total current liabilities 17 1,398 9,634 466 — 11,515 Long-term debt — 10,911 1,210 — — 12,121 Long-term debt to affiliates — 14,586 — — — 14,586 Tower obligations (1) — — 392 2,198 — 2,590 Deferred tax liabilities — — 3,677 — (140 ) 3,537 Deferred rent expense — — 2,720 — — 2,720 Negative carrying value of subsidiaries, net — — 629 — (629 ) — Intercompany payables and debt 32 — 8,201 270 (8,503 ) — Other long-term liabilities — 65 866 4 — 935 Total long-term liabilities 32 25,562 17,695 2,472 (9,272 ) 36,489 Total stockholders' equity (deficit) 22,559 22,534 41,813 (1,454 ) (62,893 ) 22,559 Total liabilities and stockholders' equity $ 22,608 $ 49,494 $ 69,142 $ 1,484 $ (72,165 ) $ 70,563 (1) Assets and liabilities for Non-Guarantor Subsidiaries are primarily included in VIEs related to the 2012 Tower Transaction. See Note 8 – Tower Obligations included in our Annual Report on Form 10-K for the year ended December 31, 2017, for further information.
Schedule of Condensed Consolidating Statement of Comprehensive Income Information	Condensed Consolidating Statement of Comprehensive Income Information Three Months Ended March 31, 2018 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Revenues Service revenues $ — $ — $ 7,487 $ 540 $ (221 ) $ 7,806 Equipment revenues — — 2,407 — (54 ) 2,353 Other revenues — 1 249 55 (9 ) 296 Total revenues — 1 10,143 595 (284 ) 10,455 Operating expenses Cost of services, exclusive of depreciation and amortization shown separately below — — 1,580 9 — 1,589 Cost of equipment sales — — 2,664 236 (55 ) 2,845 Selling, general and administrative — — 3,157 236 (229 ) 3,164 Depreciation and amortization — — 1,554 21 — 1,575 Total operating expense — — 8,955 502 (284 ) 9,173 Operating income — 1 1,188 93 — 1,282 Other income (expense) Interest expense — (174 ) (29 ) (48 ) — (251 ) Interest expense to affiliates — (166 ) (5 ) — 5 (166 ) Interest income — 6 5 — (5 ) 6 Other (expense) income, net — (32 ) 42 — — 10 Total other (expense) income, net — (366 ) 13 (48 ) — (401 ) Income (loss) before income taxes — (365 ) 1,201 45 — 881 Income tax expense — — (199 ) (11 ) — (210 ) Earnings (loss) of subsidiaries 671 1,036 (6 ) — (1,701 ) — Net income 671 671 996 34 (1,701 ) 671 Net Income $ 671 $ 671 $ 996 $ 34 $ (1,701 ) $ 671 Other comprehensive loss, net of tax Other comprehensive loss, net of tax (3 ) (3 ) (3 ) — 6 (3 ) Total comprehensive income $ 668 $ 668 $ 993 $ 34 $ (1,695 ) $ 668 Condensed Consolidating Statement of Comprehensive Income Information Three Months Ended March 31, 2017 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Revenues Service revenues $ — $ — $ 7,018 $ 525 $ (214 ) $ 7,329 Equipment revenues — — 2,143 — (100 ) 2,043 Other revenues — — 194 52 (5 ) 241 Total revenues — — 9,355 577 (319 ) 9,613 Operating expenses Cost of services, exclusive of depreciation and amortization shown separately below — — 1,402 6 — 1,408 Cost of equipment sales — — 2,540 246 (100 ) 2,686 Selling, general and administrative — — 2,928 246 (219 ) 2,955 Depreciation and amortization — — 1,546 18 — 1,564 Gains on disposal of spectrum licenses — — (37 ) — — (37 ) Total operating expenses — — 8,379 516 (319 ) 8,576 Operating income — — 976 61 — 1,037 Other income (expense) Interest expense — (264 ) (27 ) (48 ) — (339 ) Interest expense to affiliates — (99 ) (7 ) — 6 (100 ) Interest income — 9 4 — (6 ) 7 Other income (expense), net — 3 (1 ) — — 2 Total other expense, net — (351 ) (31 ) (48 ) — (430 ) Income (loss) before income taxes — (351 ) 945 13 — 607 Income tax benefit (expense) — — 96 (5 ) — 91 Earnings (loss) of subsidiaries 698 1,049 (31 ) — (1,716 ) — Net income 698 698 1,010 8 (1,716 ) 698 Dividends on preferred stock (14 ) — — — — (14 ) Net income attributable to common stockholders $ 684 $ 698 $ 1,010 $ 8 $ (1,716 ) $ 684 Net income $ 698 $ 698 $ 1,010 $ 8 $ (1,716 ) $ 698 Other comprehensive income, net of tax Other comprehensive income, net of tax 1 1 1 1 (3 ) 1 Total comprehensive income $ 699 $ 699 $ 1,011 $ 9 $ (1,719 ) $ 699
Schedule of Condensed Consolidating Statement of Cash Flows Information	Condensed Consolidating Statement of Cash Flows Information Three Months Ended March 31, 2018 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Operating activities Net cash provided by (used in) operating activities $ 1 $ (404 ) $ 2,374 $ (1,201 ) $ — $ 770 Investing activities Purchases of property and equipment — — (1,366 ) — — (1,366 ) Purchases of spectrum licenses and other intangible assets, including deposits — — (51 ) — — (51 ) Proceeds related to beneficial interests in securitization transactions — — 13 1,282 — 1,295 Acquisition of companies, net of cash acquired — — (333 ) — — (333 ) Other, net — — (7 ) — — (7 ) Net cash provided by (used in) investing activities — — (1,744 ) 1,282 — (462 ) Financing activities Proceeds from issuance of long-term debt — 2,494 — — — 2,494 Proceeds from borrowing on revolving credit facility, net — 2,170 — — — 2,170 Repayments of revolving credit facility — — (1,725 ) — — (1,725 ) Repayments of capital lease obligations — — (172 ) — — (172 ) Repayments of long-term debt — — (999 ) — — (999 ) Repurchases of common stock (666 ) — — — — (666 ) Intercompany advances, net 590 (4,260 ) 3,679 (9 ) — — Tax withholdings on share-based awards — — (74 ) — — (74 ) Other, net 2 — (30 ) — — (28 ) Net cash (used in) provided by financing activities (74 ) 404 679 (9 ) — 1,000 Change in cash and cash equivalents (73 ) — 1,309 72 — 1,308 Cash and cash equivalents Beginning of period 74 1 1,086 58 — 1,219 End of period $ 1 $ 1 $ 2,395 $ 130 $ — $ 2,527 Condensed Consolidating Statement of Cash Flows Information Three Months Ended March 31, 2017 (in millions) Parent Issuer Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating and Eliminating Adjustments Consolidated Operating activities Net cash provided by (used in) operating activities $ 1 $ (134 ) $ 1,855 $ (1,114 ) $ — $ 608 Investing activities Purchases of property and equipment — — (1,528 ) — — (1,528 ) Purchases of spectrum licenses and other intangible assets, including deposits — — (14 ) — — (14 ) Proceeds related to beneficial interests in securitization transactions — — 10 1,124 — 1,134 Other, net — — (8 ) — — (8 ) Net cash (used in) provided by investing activities — — (1,540 ) 1,124 — (416 ) Financing activities Proceeds from issuance of long-term debt — 5,495 — — — 5,495 Repayments of capital lease obligations — — (90 ) — — (90 ) Repayments of long-term debt — — (3,480 ) — — (3,480 ) Intercompany advances, net — (4,956 ) 4,967 (11 ) — — Tax withholdings on share-based awards — — (92 ) — — (92 ) Dividends on preferred stock (14 ) — — — — (14 ) Other, net 15 — (25 ) — — (10 ) Net cash provided by (used in) financing activities 1 539 1,280 (11 ) — 1,809 Change in cash and cash equivalents 2 405 1,595 (1 ) — 2,001 Cash and cash equivalents Beginning of period 358 2,733 2,342 67 — 5,500 End of period $ 360 $ 3,138 $ 3,937 $ 66 $ — $ 7,501 Balances have been revised based on the guidance in ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” See Note 1 - Summary of Significant Accounting Policies of the Notes to the Condensed Consolidated Financial Statements, for further information.

Summary of Significant Accoun35

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) operating activities	$ 770	$ 608
Net cash used in investing activities	(462)	(416)
Net cash (used in) provided by financing activities	1,000	1,809
Accounting Standards Update 2014-09 | Contract acquisition costs paid on open contracts
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred contract cost asset			$ 150
Accounting Standards Update 2014-09 | Contracts with promotional bill credits
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred contract cost asset			$ 140
Accounting Standards Update 2016-15 | Adjustments for New Accounting Principle, Early Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) operating activities	(1,300)	(1,100)
Net cash used in investing activities	1,300	1,100
Accounting Standards Update 2016-15 | Adjustment for Debt Prepayments and Debt Extinguishment Costs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) operating activities	(31)	(29)
Net cash (used in) provided by financing activities	$ (31)	$ (29)

Summary of Significant Accoun36

Summary of Significant Accounting Policies - Schedule of Cumulative Impact of Adoption (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets
Other current assets	$ 1,788	$ 2,043	$ 1,903
Other assets	1,157	1,062	912
Liabilities and Stockholders' Equity
Deferred revenue	791	783	779
Deferred tax liabilities	3,813	3,610	3,537
Accumulated deficit	(15,179)	(15,861)	$ (16,074)
Calculated under Revenue Guidance in Effect before Topic 606
Assets
Other current assets	1,684	1,903
Other assets	866	912
Liabilities and Stockholders' Equity
Deferred revenue	777	779
Deferred tax liabilities	3,716	3,537
Accumulated deficit	(15,463)	(16,074)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Assets
Other current assets	104	140
Other assets	291	150
Liabilities and Stockholders' Equity
Deferred revenue	14	4
Deferred tax liabilities	97	73
Accumulated deficit	$ 284	$ 213

Summary of Significant Accoun37

Summary of Significant Accounting Policies - Schedule of Impact of Adoption on Condensed Consolidated Financial Statements (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Revenues
Branded postpaid revenues	$ 5,070	$ 4,725
Branded prepaid revenues	2,402	2,299
Wholesale revenues	266	270
Roaming and other service revenues	68	35
Total service revenues	7,806	7,329
Equipment revenues	2,353	2,043
Other revenues	296	241
Total revenues	10,455	9,613
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	1,589	1,408
Cost of equipment sales	2,845	2,686
Selling, general and administrative	3,164	2,955
Depreciation and amortization	1,575	1,564
Total operating expenses	9,173	8,576
Operating income	1,282	1,037
Total other expense, net	(401)	(430)
Income before income taxes	881	607
Income tax expense	(210)	91
Net income	$ 671	$ 698
Earnings per share
Basic (in USD per share)	$ 0.78	$ 0.83
Diluted (in USD per share)	$ 0.78	$ 0.80
Assets
Other current assets	$ 1,788		$ 2,043	$ 1,903
Other assets	1,157		1,062	912
Liabilities and Stockholders' Equity
Deferred revenue	791		783	779
Deferred tax liabilities	3,813		3,610	3,537
Accumulated deficit	(15,179)		(15,861)	$ (16,074)
Calculated under Revenue Guidance in Effect before Topic 606
Revenues
Branded postpaid revenues	5,099
Branded prepaid revenues	2,403
Wholesale revenues	266
Roaming and other service revenues	68
Total service revenues	7,836
Equipment revenues	2,276
Other revenues	296
Total revenues	10,408
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	1,589
Cost of equipment sales	2,845
Selling, general and administrative	3,212
Depreciation and amortization	1,575
Total operating expenses	9,221
Operating income	1,187
Total other expense, net	(401)
Income before income taxes	786
Income tax expense	(186)
Net income	$ 600
Earnings per share
Basic (in USD per share)	$ 0.70
Diluted (in USD per share)	$ 0.70
Assets
Other current assets	$ 1,684		1,903
Other assets	866		912
Liabilities and Stockholders' Equity
Deferred revenue	777		779
Deferred tax liabilities	3,716		3,537
Accumulated deficit	(15,463)		(16,074)
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenues
Branded postpaid revenues	(29)
Branded prepaid revenues	(1)
Wholesale revenues	0
Roaming and other service revenues	0
Total service revenues	(30)
Equipment revenues	77
Other revenues	0
Total revenues	47
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	0
Cost of equipment sales	0
Selling, general and administrative	(48)
Depreciation and amortization	0
Total operating expenses	(48)
Operating income	95
Total other expense, net	0
Income before income taxes	95
Income tax expense	(24)
Net income	$ 71
Earnings per share
Basic (in USD per share)	$ 0.08
Diluted (in USD per share)	$ 0.08
Assets
Other current assets	$ 104		140
Other assets	291		150
Liabilities and Stockholders' Equity
Deferred revenue	14		4
Deferred tax liabilities	97		73
Accumulated deficit	$ 284		$ 213

Significant Transactions - Narr

Significant Transactions - Narrative (Details) - USD ($) $ in Millions	Jan. 22, 2018	Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Significant Transactions [Line Items]
Operating income			$ 1,282	$ 1,037
Net income			671	$ 698
Hurricane
Significant Transactions [Line Items]
Operating income			(36)
Net income			(23)
Reimbursement from insurance carriers			$ (94)
Elimination of receivable for insurance reimbursements					$ 93
Iowa Wireless
Significant Transactions [Line Items]
Unconsolidated subsidiary ownership percentage		54.00%
Purchase price of unconsolidated subsidiary		$ 25
Cash consideration		$ 25
Layer3 TV
Significant Transactions [Line Items]
Cash consideration	$ 318

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Millions	Jan. 22, 2018	Jan. 01, 2018	Mar. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill			$ 1,901	$ 1,683
Layer3 TV
Business Acquisition [Line Items]
Cash consideration	$ 318
Payment included in consideration after closing of transaction	5
Grant-date fair value of cash-based and share-based incentive compensation awards	37
Liability recognized	21
Indemnification assets	12
Maximum amount that would be received under the indemnification asset	12
Goodwill	218
Intangible assets	$ 100
Layer3 TV | Developed Technology
Business Acquisition [Line Items]
Estimated useful life (in years)	5 years
Intangible assets	$ 100
Iowa Wireless
Business Acquisition [Line Items]
Cash consideration		$ 25
Purchase price of unconsolidated subsidiary		25
Fair value of equity interest held		56
Gain on remeasurement of equity interest		15
Bargain purchase gain		$ 25
Unconsolidated subsidiary ownership percentage		54.00%

Business Combinations - Schedul

Business Combinations - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 22, 2018	Jan. 01, 2018	Dec. 31, 2017
Assets acquired
Goodwill	$ 1,901			$ 1,683
Iowa Wireless
Assets acquired
Cash and cash equivalents			$ 3
Accounts receivables, net			6
Equipment installment plan receivables, net			3
Inventories			1
Other current assets			2
Total current assets			15
Property and equipment, net			36
Spectrum licenses	$ 87		87
Total assets acquired			138
Liabilities assumed
Accounts payable and accrued liabilities			6
Deferred revenue			2
Total current liabilities			8
Deferred tax liabilities			17
Other long-term liabilities			7
Total long-term liabilities			24
Total consideration transferred			$ 106
Layer3 TV
Assets acquired
Cash and cash equivalents		$ 2
Other current assets		14
Property and equipment, net		11
Intangible assets		100
Goodwill		218
Deferred tax assets		2
Total assets acquired		347
Liabilities assumed
Accounts payable and accrued liabilities		27
Short-term debt		2
Total liabilities assumed		29
Total consideration transferred		$ 318

Business Combinations - Conside

Business Combinations - Consideration Transferred - Iowa Wireless (Details) - Iowa Wireless $ in Millions	Jan. 01, 2018USD ($)
Business Acquisition [Line Items]
Cash paid	$ 25
Acquisition date fair value of previously held equity interest	56
Bargain purchase gain	25
Net assets acquired	$ 106

Receivables and Allowance for42

Receivables and Allowance for Credit Losses - EIP Receivables (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)classessegments	Dec. 31, 2017USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Portfolio segments | segments	2
Customer classes | classes	2
EIP receivables, gross	$ 3,896	$ 3,960
Unamortized imputed discount	(267)	(264)
EIP receivables, net of unamortized imputed discount	3,629	3,696
Allowance for credit losses	(114)	(132)
Equipment installment plan receivables, net	3,515	3,564
Equipment installment plan receivables, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Equipment installment plan receivables, net	2,281	2,290
Equipment installment plan receivables due after one year, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Equipment installment plan receivables, net	$ 1,234	$ 1,274

Receivables and Allowance for43

Receivables and Allowance for Credit Losses - Unamortized Imputed Discount and Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	$ 482	$ 418	$ 418
Bad debt expense	54	93
Write-offs, net of recoveries	(81)	(114)
Change in imputed discount on short-term and long-term EIP receivables	53	48
Impact on the imputed discount from sales of EIP receivables	(51)	(41)
Allowance for credit losses and imputed discount, end of period	457	404	482
Accounts Receivable Allowance
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	86	102	102
Bad debt expense	4	37
Write-offs, net of recoveries	(14)	(39)
Allowance for credit losses and imputed discount, end of period	$ 76	100	$ 86
EIP Receivables Allowance
Financing Receivable, Allowance for Credit Losses [Line Items]
Weighted average effective imputed interest rate	9.90%		9.60%
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit losses and imputed discount, beginning of period	$ 396	316	$ 316
Bad debt expense	50	56
Write-offs, net of recoveries	(67)	(75)
Change in imputed discount on short-term and long-term EIP receivables	53	48
Impact on the imputed discount from sales of EIP receivables	(51)	(41)
Allowance for credit losses and imputed discount, end of period	$ 381	$ 304	$ 396

Receivables and Allowance for44

Receivables and Allowance for Credit Losses - Gross EIP Receivables by Credit Category (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	$ 3,896	$ 3,960
Prime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	1,674	1,758
Subprime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	2,222	2,202
Current - 30 days past due
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	3,816	3,860
Current - 30 days past due | Prime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	1,648	1,727
Current - 30 days past due | Subprime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	2,168	2,133
31 - 60 days past due
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	38	46
31 - 60 days past due | Prime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	14	17
31 - 60 days past due | Subprime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	24	29
61 - 90 days past due
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	18	22
61 - 90 days past due | Prime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	5	6
61 - 90 days past due | Subprime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	13	16
More than 90 days past due
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	24	32
More than 90 days past due | Prime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	7	8
More than 90 days past due | Subprime
Financing Receivable, Recorded Investment [Line Items]
EIP receivables, gross	$ 17	$ 24

Sales of Certain Receivables -

Sales of Certain Receivables - Sales of Service Receivables (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Nov. 30, 2016
Variable Interest Entity [Line Items]
Other current assets	$ 1,788	$ 2,043	$ 1,903
Accounts payable and accrued liabilities	7,157		8,528
Other current liabilities	353		414
Factoring Arrangement | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Revolving receivables facility, maximum borrowing capacity				$ 950
Revolving receivables facility, outstanding borrowings	802		880
Other current assets	266		236
Accounts payable and accrued liabilities	0		25
Other current liabilities	$ 118		$ 180

Sales of Certain Receivables 46

Sales of Certain Receivables - Sales of EIP Receivables (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Aug. 31, 2017
Variable Interest Entity [Line Items]
Other current assets	$ 1,788	$ 2,043	$ 1,903
Other assets	1,157	$ 1,062	912
EIP Securitization Arrangement
Variable Interest Entity [Line Items]
Revolving receivables facility, maximum borrowing capacity			1,300	$ 1,200
Revolving receivables facility, outstanding borrowings	$ 1,300		1,300
Equipment installment plan, maximum payment term	24 months
Other current assets	$ 370		403
Other assets	93		109
Other long-term liabilities	$ 10		$ 3

Sales of Certain Receivables 47

Sales of Certain Receivables - Sales of Receivables and Continuing Involvement (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017	Jan. 01, 2018
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Other current assets	$ 1,788		$ 1,903	$ 2,043
Other long-term assets	1,157		912	$ 1,062
Accounts payable and accrued liabilities	7,157		8,528
Other current liabilities	353		414
Other long-term liabilities	933		935
Of which:
Losses from sales of receivables	52	$ 95
Factoring and EIP Securitization Arrangement | Transferor's Continuing Involvement in Transferred Financial Assets, Transfer Description
Of which:
Maximum exposure to loss, Factoring VIE	1,300
Factoring and EIP Securitization Arrangement
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Derecognized net service receivables and EIP receivables	2,663		2,725
Other current assets	636		639
Deferred purchase price assets	728		745
Other long-term assets	93		109
Accounts payable and accrued liabilities	0		25
Other current liabilities	118		180
Other long-term liabilities	10		3
Net cash proceeds since inception	1,908		2,058
Of which:
Change in net cash proceeds during the year-to-date period	(150)		28
Net cash proceeds funded by reinvested collections	2,058		2,030
Losses from sales of receivables	52	$ 95
Factoring and EIP Securitization Arrangement | Other current assets - of which, deferred purchase price
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Deferred purchase price assets	635		636
Factoring and EIP Securitization Arrangement | Other long-term assets - of which, deferred purchase price
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Deferred purchase price assets	$ 93		$ 109

Goodwill - Schedule of Changes

Goodwill - Schedule of Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Historical goodwill		$ 12,449
Accumulated impairment losses at December 31, 2017	$ (10,766)
Balance as of December 31, 2017	1,683
Goodwill from acquisition of Layer3 TV	218
Balance as of March 31, 2018	1,901
Accumulated impairment losses at March 31, 2018	$ (10,766)

Goodwill - Narrative (Details)

Goodwill - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 22, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill	$ 1,901		$ 1,683
Layer3 TV
Goodwill [Line Items]
Goodwill		$ 218

Spectrum License Transactions -

Spectrum License Transactions - Schedule of Spectrum License Activity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018
Indefinite-lived Intangible Assets [Roll Forward]
Purchase of spectrum licenses	$ 51,000,000	$ 14,000,000
Gains or losses recognized on spectrum license purchase	0	$ 37,000,000
Licensing Agreements
Indefinite-lived Intangible Assets [Roll Forward]
Spectrum licenses, beginning of year	35,366,000,000
Spectrum license acquisitions	125,000,000
Costs to clear spectrum	13,000,000
Spectrum licenses, end of year	35,504,000,000
Purchase of spectrum licenses	38,000,000
Gains or losses recognized on spectrum license purchase	0
Iowa Wireless
Indefinite-lived Intangible Assets [Roll Forward]
Spectrum licenses	$ 87,000,000		$ 87,000,000

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Short-term Investments and Long-term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Level 1 | Reported Value Measurement | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	$ 13,402	$ 11,910
Level 1 | Fair Value | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	13,732	12,540
Level 2 | Reported Value Measurement | Secured Term Loan [$4.0B]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loans	4,000	4,000
Level 2 | Reported Value Measurement | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,100	3,100
Level 2 | Reported Value Measurement | Affiliated Entity | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	7,486	7,486
Level 2 | Fair Value | Secured Term Loan [$4.0B]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Term loans	4,000	4,020
Level 2 | Fair Value | Affiliated Entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	3,223	3,260
Level 2 | Fair Value | Affiliated Entity | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt	7,659	7,852
Level 3 | Reported Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred purchase price assets	728	745
Level 3 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deferred purchase price assets	$ 728	$ 745

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term debt, beginning balance	$ 12,121
Total debt to third parties, beginning balance	13,733
Short-term debt to affiliates, beginning balance	0
Total debt, beginning balance	28,319
Issuances and Borrowings	2,170	$ 0
Issuances and Borrowings	2,494
Issuances and Borrowings	4,664
Note Redemptions	(999)
Repayments	(999)	(3,480)
Repayments	0
Repayments	(1,725)
Reclassifications	0
Other	246
Other	219
Long-term debt, ending balance	12,127
Total debt to third parties, ending balance	15,447
Short-term debt to affiliates, ending balance	445
Total debt, ending balance	30,478
Issuance of short-term debt for financing of property and equipment	237	$ 288
Capital leases outstanding	1,800		$ 1,800
Short-term Debt
Debt Instrument [Line Items]
Short-term debt, beginning balance	1,612
Issuances and Borrowings	0
Note Redemptions	(999)
Repayments	0
Reclassifications	2,425
Other	282
Short-term debt, ending balance	3,320
Short-term Debt | Affiliated Entity
Debt Instrument [Line Items]
Short-term debt to affiliates, beginning balance	0
Issuances and Borrowings	2,170
Note Redemptions	0
Repayments	(1,725)
Reclassifications	0
Other	0
Short-term debt to affiliates, ending balance	445
Long-term Debt
Debt Instrument [Line Items]
Long-term debt, beginning balance	12,121
Issuances and Borrowings	2,494
Note Redemptions	0
Repayments	0
Reclassifications	(2,425)
Other	(63)
Long-term debt, ending balance	12,127
Long-term Debt | Affiliated Entity
Debt Instrument [Line Items]
Long-term debt to affiliates, beginning balance	14,586
Issuances and Borrowings	0
Note Redemptions	0
Repayments	0
Reclassifications	0
Other	0
Long-term debt to affiliates, ending balance	$ 14,586

Debt - Debt to Third Parties -

Debt - Debt to Third Parties - Issuances and Borrowings (Details) - USD ($)	Apr. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Apr. 30, 2018	Apr. 28, 2018	Jan. 31, 2018	Jan. 25, 2018
Debt Instrument [Line Items]
Principal Issuances		$ 2,500,000,000
Issuance Costs		6,000,000
Net Proceeds from Issuance of Long-Term Debt		2,494,000,000
Proceeds from issuance of long-term debt		2,494,000,000	$ 5,495,000,000
4.500% Senior Notes due 2026
Debt Instrument [Line Items]
Principal Issuances		1,000,000,000
Issuance Costs		2,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 998,000,000
Interest rate, stated percentage		4.50%
4.500% Senior Notes due 2026 | Issuer
Debt Instrument [Line Items]
Principal Issuances						$ 1,000,000,000	$ 1,000,000,000
Interest rate, stated percentage						4.50%	4.50%
4.750% Senior Notes due 2028
Debt Instrument [Line Items]
Principal Issuances		$ 1,500,000,000
Issuance Costs		4,000,000
Net Proceeds from Issuance of Long-Term Debt		$ 1,496,000,000
Interest rate, stated percentage		4.75%
4.750% Senior Notes due 2028 | Issuer
Debt Instrument [Line Items]
Principal Issuances						$ 1,500,000,000	$ 1,500,000,000
Interest rate, stated percentage						4.75%	4.75%
4.500% Senior Notes due 2026 and 4.750% Senior Notes due 2028 | Issuer | Subsequent Event
Debt Instrument [Line Items]
Proceeds from issuance of long-term debt	$ 2,494,000,000
6.625% Senior Notes due 2023 | Issuer | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances	$ 1,750,000,000
Interest rate, stated percentage	6.625%
6.836% Senior Notes due 2023 | Issuer | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances					$ 600,000,000
Interest rate, stated percentage				6.836%	6.836%

Debt - Debt to Third Parties 54

Debt - Debt to Third Parties - Notes Redemption (Details) - USD ($)	Apr. 28, 2018	Apr. 01, 2018	Jan. 15, 2018	Mar. 31, 2018	Apr. 30, 2018	Jan. 31, 2018
Debt Instrument [Line Items]
Principal Amount				$ 999,000,000
6.125% Senior Notes due 2022
Debt Instrument [Line Items]
Redemption price (as a percent)			103.063%
Senior Notes | 6.125% Senior Notes due 2022
Debt Instrument [Line Items]
Principal Amount				1,000,000,000		$ 1,000,000,000
Write-off of Premiums, Discounts and Issuance Costs				1,000,000
Call Penalties				$ 31,000,000
Interest rate, stated percentage				6.125%		6.125%
Senior Notes | 6.625% Senior Notes due 2023 | Subsequent Event
Debt Instrument [Line Items]
Principal Amount		$ 1,750,000,000			$ 1,750,000,000
Redemption price (as a percent)		103.313%
Interest rate, stated percentage		6.625%			6.625%
Redemption premium		$ 58,000,000
Write-off of issuance costs (less than)		1,000,000
Write-off of premiums		$ (75,000,000)
Senior Notes | 6.836% Senior Notes due 2023 | Subsequent Event
Debt Instrument [Line Items]
Principal Amount	$ 600,000,000
Redemption price (as a percent)	103.418%
Interest rate, stated percentage	6.836%
Redemption premium	$ 21,000,000
Write-off of issuance costs (less than)	$ 1,000,000

Debt - Debt to Affiliates - Iss

Debt - Debt to Affiliates - Issuances and Borrowings (Details) - USD ($)	Apr. 28, 2018	Apr. 30, 2018	Mar. 31, 2018	Jan. 31, 2018	Jan. 25, 2018	Jan. 22, 2018
Debt Instrument [Line Items]
Principal Issuances			$ 2,500,000,000
4.500% Senior Notes due 2026
Debt Instrument [Line Items]
Principal Issuances			$ 1,000,000,000
Interest rate, stated percentage			4.50%
4.750% Senior Notes due 2028
Debt Instrument [Line Items]
Principal Issuances			$ 1,500,000,000
Interest rate, stated percentage			4.75%
Senior Notes | Affiliated Entity | Deutsche Telekom AG | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances	$ 2,500,000,000	$ 2,500,000,000
Senior Reset Notes | Affiliated Entity | Deutsche Telekom AG | Subsequent Event
Debt Instrument [Line Items]
Payment of redemption premium	102,000,000
Senior Reset Notes | 8.097% Senior Reset Notes to affiliates due 2021 | Affiliated Entity | Deutsche Telekom AG | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances	$ 1,250,000,000
Interest rate, stated percentage	8.097%	8.097%
Redemption price (as a percent)	104.0485%
Senior Reset Notes | 8.195% Senior Reset Notes to affiliates due 2022 | Affiliated Entity | Deutsche Telekom AG | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances	$ 1,250,000,000
Interest rate, stated percentage	8.195%	8.195%
Redemption price (as a percent)	104.0975%
Issuer | Affiliated Entity | Deutsche Telekom AG
Debt Instrument [Line Items]
Outstanding balance on DT Notes			$ 0
Issuer | 4.500% Senior Notes due 2026
Debt Instrument [Line Items]
Principal Issuances				$ 1,000,000,000	$ 1,000,000,000
Interest rate, stated percentage				4.50%	4.50%
Issuer | 4.500% Senior Notes due 2026 | Affiliated Entity | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances		$ 1,000,000,000
Interest rate, stated percentage		4.50%
Issuer | 4.500% Senior Notes due 2026 | Affiliated Entity | Deutsche Telekom AG
Debt Instrument [Line Items]
Principal Issuances						$ 1,000,000,000
Interest rate, stated percentage						4.50%
Issuer | 4.750% Senior Notes due 2028
Debt Instrument [Line Items]
Principal Issuances				$ 1,500,000,000	$ 1,500,000,000
Interest rate, stated percentage				4.75%	4.75%
Issuer | 4.750% Senior Notes due 2028 | Affiliated Entity | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances		$ 1,500,000,000
Interest rate, stated percentage		4.75%
Issuer | 4.750% Senior Notes due 2028 | Affiliated Entity | Deutsche Telekom AG
Debt Instrument [Line Items]
Principal Issuances						$ 1,500,000,000
Interest rate, stated percentage						4.75%
Issuer | 8.097% Senior Reset Notes to affiliates due 2021 | Affiliated Entity | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances		$ 1,250,000,000
Interest rate, stated percentage		8.097%
Issuer | 8.195% Senior Reset Notes to affiliates due 2022 | Affiliated Entity | Subsequent Event
Debt Instrument [Line Items]
Principal Issuances		$ 1,250,000,000
Interest rate, stated percentage		8.195%

Debt - Debt to Affiliates - Inc

Debt - Debt to Affiliates - Incremental Term Loan Facility (Details)	3 Months Ended
	Mar. 31, 2018USD ($)
Short-term Debt [Line Items]
Issuance Costs	$ 6,000,000
Deutsche Telekom AG | Affiliated Entity
Short-term Debt [Line Items]
Soft-call prepayment premium (percent)	1.00%
Issuance Costs	$ 0
Deutsche Telekom AG | LIBOR plus 1.50% Senior Secured Term Loan due 2022 | Affiliated Entity
Short-term Debt [Line Items]
Applicable margin, percentage	1.50%
Senior Secured Term Loans	$ 2,000,000,000
Deutsche Telekom AG | LIBOR plus 1.75% Senior Secured Term Loan due 2024 | Affiliated Entity
Short-term Debt [Line Items]
Applicable margin, percentage	1.75%
Senior Secured Term Loans	$ 2,000,000,000

Debt - Debt to Affiliates - Rev

Debt - Debt to Affiliates - Revolving Credit Facility (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Jan. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Principal Amount	$ 999,000,000
6.125% Senior Notes due 2022 | Senior Notes
Debt Instrument [Line Items]
Principal Amount	$ 1,000,000,000	$ 1,000,000,000
Interest rate, stated percentage	6.125%	6.125%
Revolving Credit Facility [$2.5B] | Affiliated Entity | Secured Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Applicable margin, percentage	1.05%
Undrawn commitment fee, percentage	0.25%
Revolving Credit Facility [$2.5B] | Affiliated Entity | Secured Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Applicable margin, percentage	1.80%
Undrawn commitment fee, percentage	0.45%
Revolving Credit Facility [$2.5B] | Affiliated Entity | Unsecured Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Applicable margin, percentage	2.05%
Undrawn commitment fee, percentage	0.20%
Revolving Credit Facility [$2.5B] | Affiliated Entity | Unsecured Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Applicable margin, percentage	3.05%
Undrawn commitment fee, percentage	0.575%
Revolving Credit Facility [$2.5B] | Line of Credit | Affiliated Entity | Secured Revolving Credit Facility | Deutsche Telekom AG
Debt Instrument [Line Items]
Short-term debt to affiliates	$ 445,000,000		$ 0

Revenue from Contracts with C58

Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Branded postpaid phone revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 4,800	$ 4,500
Branded postpaid other revenue
Disaggregation of Revenue [Line Items]
Revenue	259	225
Lease of mobile communication devices and accessories
Disaggregation of Revenue [Line Items]
Revenue	$ 171	$ 324

Revenue from Contracts with C59

Revenue from Contracts with Customers - Contract Balances (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Change in Contract with Customer, Asset and Liability [Abstract]
Contract assets included in other current assets	$ 104	$ 140
Contract liabilities included in deferred revenue	718	$ 718
Change in contract assets included in other current assets	(36)
Change in contracts liabilities included in deferred revenue	0
Amounts included in the beginning of period contract liability balance	528
Amounts associated with performance obligations satisfied in previous periods	$ 0

Revenue from Contracts with C60

Revenue from Contracts with Customers - Remaining Performance Obligations, Branded Postpaid Contracts (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Branded postpaid contracts
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 694
Remaining contract duration	12 months
Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining contract duration	1 year
Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining contract duration	6 years

Revenue from Contracts with C61

Revenue from Contracts with Customers - Remaining Performance Obligations (Details) $ in Millions	Mar. 31, 2018USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 879
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	1,100
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 901

Revenue from Contracts with C62

Revenue from Contracts with Customers - Contract Costs (Details)	3 Months Ended
	Mar. 31, 2018USD ($)
Capitalized Contract Cost [Abstract]
Total deferred incremental costs to obtain contracts	$ 290,000,000
Average amortization period, deferred contract costs	24 months
Amortization of deferred costs	$ 35,000,000
Impairment losses recognized on deferred contract cost assets	$ 0

Repurchases of Common Stock - N

Repurchases of Common Stock - Narrative (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended	5 Months Ended
	Mar. 31, 2018	Apr. 27, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 06, 2017
Affiliated Entity | Deutsche Telekom AG
Equity, Class of Treasury Stock [Line Items]
Additional shares purchased (in shares)	3.3
Aggregate market value of shares purchased	$ 200,000,000
2017 Stock Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount						$ 1,500,000,000
Common stock repurchased (in shares)	10.5
Common stock repurchased	$ 666,000,000
2017 Stock Repurchase Program | Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount		$ 9,000,000,000
Common stock repurchased (in shares)		23.7
Common stock repurchased		$ 1,500,000,000
Average price paid per share (usd per share)		$ 63.07
2018 Stock Repurchase Program | Scenario, Forecast
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount			$ 4,000,000,000	$ 3,000,000,000	$ 500,000,000
2018 Stock Repurchase Program | Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, increase in authorized amount		$ 7,500,000,000

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Net income	$ 671	$ 698
Less: Dividends on mandatory convertible preferred stock	0	(14)
Net income attributable to common stockholders	671	684
Add: Dividends related to mandatory convertible preferred stock	0	14
Net income attributable to common stockholders - diluted	$ 671	$ 698
Weighted average shares outstanding - basic (in shares)	855,222,664	827,723,034
Effect of dilutive securities:
Outstanding stock options and unvested stock awards (in shares)	7,021,420	9,434,950
Mandatory convertible preferred stock (in shares)	0	32,238,000
Weighted average shares outstanding - diluted (in shares)	862,244,084	869,395,984
Earnings per share - basic (in USD per share)	$ 0.78	$ 0.83
Earnings per share - diluted (in USD per share)	$ 0.78	$ 0.80
Outstanding stock options and unvested stock awards (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	67,580	9,993

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Details) - $ / shares	Dec. 15, 2017	Mar. 31, 2018
Mandatory Convertible Preferred Stock Series A
Class of Stock [Line Items]
Preferred shares authorized (in shares)		100,000,000
Preferred stock rate (percent)		5.50%
Preferred stock, par value (in USD per share)		$ 0.00001
Preferred shares outstanding (in shares)		0
Stock converted (in shares)	20,000,000
Common Stock
Class of Stock [Line Items]
Stock issued upon conversion (in shares)	32,000,000
Stock conversion ratio (in shares)	1.6119

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	1 Months Ended
	Feb. 28, 2018USD ($)
Corporate Headquarters Facility
Operating Leased Assets [Line Items]
Increase in minimum lease payments	$ 400
Tower Obligations
Operating Leased Assets [Line Items]
Increase in minimum lease payments	$ 385

Subsequent Events - Narrative (

Subsequent Events - Narrative (Details)	Apr. 29, 2018USD ($)	Apr. 25, 2018	Mar. 31, 2018USD ($)	Apr. 30, 2018USD ($)	Apr. 28, 2018USD ($)	Apr. 27, 2018USD ($)	Apr. 01, 2018USD ($)	Dec. 06, 2017USD ($)
Subsequent Event [Line Items]
Redemption of aggregate principal amount			$ 999,000,000
Principal Issuances			2,500,000,000
Repaid and terminated			1,725,000,000
Senior notes, amended			$ 2,500,000,000
2017 Stock Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program, authorized amount								$ 1,500,000,000
Subsequent Event | Sprint
Subsequent Event [Line Items]
Exchange ratio	0.10256
Fully-diluted shares of combined company held by public stockholders (percent)	31.00%
Required payment resulting from failure to satisfy closing condition of business combination agreement (up to)	$ 600,000,000
Subsequent Event | Deutsche Telekom AG | Sprint
Subsequent Event [Line Items]
Fully-diluted shares expected to be held immediately following merger (percent)	42.00%
Amount of outstanding common stock beneficially owned before merger (percent)		63.50%
Subsequent Event | SoftBank | Sprint
Subsequent Event [Line Items]
Fully-diluted shares expected to be held immediately following merger (percent)	27.00%
Amount of outstanding common stock beneficially owned before merger (percent)		84.80%
Subsequent Event | 2017 Stock Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program, authorized amount						$ 9,000,000,000
Subsequent Event | 2018 Stock Repurchase Program
Subsequent Event [Line Items]
Stock repurchase program, increase in authorized amount						$ 7,500,000,000
Subsequent Event | Senior Notes | Affiliated Entity | Deutsche Telekom AG
Subsequent Event [Line Items]
Principal Issuances				$ 2,500,000,000	$ 2,500,000,000
Senior notes, amended				2,500,000,000	$ 2,500,000,000
Subsequent Event | 6.625% Senior Notes due 2023 | Issuer
Subsequent Event [Line Items]
Interest rate, stated percentage							6.625%
Principal Issuances							$ 1,750,000,000
Senior notes, amended							1,750,000,000
Subsequent Event | 6.625% Senior Notes due 2023 | Senior Notes
Subsequent Event [Line Items]
Redemption of aggregate principal amount				$ 1,750,000,000			$ 1,750,000,000
Interest rate, stated percentage				6.625%			6.625%
Subsequent Event | 6.836% Senior Notes due 2023 | Issuer
Subsequent Event [Line Items]
Redemption of aggregate principal amount				$ 600,000,000
Interest rate, stated percentage				6.836%	6.836%
Principal Issuances					$ 600,000,000
Senior notes, amended					600,000,000
Subsequent Event | 6.836% Senior Notes due 2023 | Senior Notes
Subsequent Event [Line Items]
Redemption of aggregate principal amount					$ 600,000,000
Interest rate, stated percentage					6.836%
Subsequent Event | 8.097% Senior Reset Notes to affiliates due 2021 | Issuer | Affiliated Entity
Subsequent Event [Line Items]
Interest rate, stated percentage				8.097%
Principal Issuances				$ 1,250,000,000
Senior notes, amended				1,250,000,000
Subsequent Event | 8.097% Senior Reset Notes to affiliates due 2021 | Senior Reset Notes | Affiliated Entity | Deutsche Telekom AG
Subsequent Event [Line Items]
Redemption of aggregate principal amount				$ 1,250,000,000
Interest rate, stated percentage				8.097%	8.097%
Principal Issuances					$ 1,250,000,000
Senior notes, amended					$ 1,250,000,000
Subsequent Event | 8.195% Senior Reset Notes to affiliates due 2022 | Issuer | Affiliated Entity
Subsequent Event [Line Items]
Interest rate, stated percentage				8.195%
Principal Issuances				$ 1,250,000,000
Senior notes, amended				1,250,000,000
Subsequent Event | 8.195% Senior Reset Notes to affiliates due 2022 | Senior Reset Notes | Affiliated Entity | Deutsche Telekom AG
Subsequent Event [Line Items]
Redemption of aggregate principal amount				$ 1,250,000,000
Interest rate, stated percentage				8.195%	8.195%
Principal Issuances					$ 1,250,000,000
Senior notes, amended					$ 1,250,000,000
Subsequent Event | Secured and Unsecured Debt Financing | Sprint
Subsequent Event [Line Items]
Financing commitment, amount	$ 38,000,000,000
Subsequent Event | Secured Revolving Credit Facility | Sprint
Subsequent Event [Line Items]
Financing commitment, amount	4,000,000,000
Subsequent Event | Secured Term Loan Facility | Sprint
Subsequent Event [Line Items]
Financing commitment, amount	7,000,000,000
Subsequent Event | Secured Bridge Loan Facility | Sprint
Subsequent Event [Line Items]
Financing commitment, amount	19,000,000,000
Subsequent Event | Unsecured Bridge Loan Facility | Sprint
Subsequent Event [Line Items]
Financing commitment, amount	$ 8,000,000,000
Subsequent Event | 5.300% Senior Notes due 2021 | Senior Notes | Deutsche Telekom AG | Sprint
Subsequent Event [Line Items]
Interest rate, stated percentage	5.30%
Repaid and terminated	$ 2,000,000,000
Subsequent Event | 6.000% Senior Notes due 2024 | Senior Notes | Deutsche Telekom AG | Sprint
Subsequent Event [Line Items]
Interest rate, stated percentage	6.00%
Repaid and terminated	$ 2,000,000,000
Subsequent Event | 5.125% Senior Notes Due April 2021 | Senior Notes | Deutsche Telekom AG | Sprint
Subsequent Event [Line Items]
Interest rate, stated percentage	5.125%
Principal Issuances	$ 1,250,000,000
Senior notes, amended	$ 1,250,000,000
Subsequent Event | 5.375% Senior Notes Due April 2022 | Senior Notes | Deutsche Telekom AG | Sprint
Subsequent Event [Line Items]
Interest rate, stated percentage	5.375%
Principal Issuances	$ 1,250,000,000
Senior notes, amended	$ 1,250,000,000

Guarantor Financial Informati68

Guarantor Financial Information - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Apr. 30, 2018	Jan. 31, 2018	Jan. 25, 2018
Condensed Financial Statements, Captions [Line Items]
Principal Issuances	$ 2,500,000,000
Net cash provided by (used in) operating activities	770,000,000	$ 608,000,000
Net cash (used in) provided by financing activities	1,000,000,000	1,809,000,000
Issuer | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(404,000,000)	(134,000,000)
Net cash (used in) provided by financing activities	404,000,000	539,000,000
Issuer | Reportable Legal Entities | Reclassification Adjustment
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities		5,000,000
Net cash (used in) provided by financing activities		5,000,000,000
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	2,374,000,000	1,855,000,000
Net cash (used in) provided by financing activities	679,000,000	1,280,000,000
Guarantor Subsidiaries | Reportable Legal Entities | Reclassification Adjustment
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities		5,000,000
Net cash (used in) provided by financing activities		(5,000,000,000)
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(1,201,000,000)	(1,114,000,000)
Net cash (used in) provided by financing activities	(9,000,000)	(11,000,000)
Non-Guarantor Subsidiaries | Reportable Legal Entities | Reclassification Adjustment
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities		11,000,000
Net cash (used in) provided by financing activities		$ 11,000,000
4.500% Senior Notes due 2026
Condensed Financial Statements, Captions [Line Items]
Principal Issuances	$ 1,000,000,000
Interest rate, stated percentage	4.50%
4.500% Senior Notes due 2026 | Issuer
Condensed Financial Statements, Captions [Line Items]
Principal Issuances				$ 1,000,000,000	$ 1,000,000,000
Interest rate, stated percentage				4.50%	4.50%
4.500% Senior Notes due 2026 | Issuer | Affiliated Entity | Subsequent Event
Condensed Financial Statements, Captions [Line Items]
Principal Issuances			$ 1,000,000,000
Interest rate, stated percentage			4.50%
4.750% Senior Notes due 2028
Condensed Financial Statements, Captions [Line Items]
Principal Issuances	$ 1,500,000,000
Interest rate, stated percentage	4.75%
4.750% Senior Notes due 2028 | Issuer
Condensed Financial Statements, Captions [Line Items]
Principal Issuances				$ 1,500,000,000	$ 1,500,000,000
Interest rate, stated percentage				4.75%	4.75%
4.750% Senior Notes due 2028 | Issuer | Affiliated Entity | Subsequent Event
Condensed Financial Statements, Captions [Line Items]
Principal Issuances			$ 1,500,000,000
Interest rate, stated percentage			4.75%
8.097% Senior Reset Notes to affiliates due 2021 | Issuer | Affiliated Entity | Subsequent Event
Condensed Financial Statements, Captions [Line Items]
Principal Issuances			$ 1,250,000,000
Interest rate, stated percentage			8.097%
8.195% Senior Reset Notes to affiliates due 2022 | Issuer | Affiliated Entity | Subsequent Event
Condensed Financial Statements, Captions [Line Items]
Principal Issuances			$ 1,250,000,000
Interest rate, stated percentage			8.195%

Guarantor Financial Informati69

Guarantor Financial Information - Condensed Consolidating Balance Sheet Information (Details) - USD ($) $ in Millions	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 2,527		$ 1,219	$ 7,501	$ 5,500
Accounts receivable, net	1,689		1,915
Equipment installment plan receivables, net	2,281		2,290
Accounts receivable from affiliates	13		22
Inventories	1,311		1,566
Other current assets	1,788	$ 2,043	1,903
Total current assets	9,609		8,915
Property and equipment, net	22,308		22,196
Goodwill	1,901		1,683
Spectrum licenses	35,504		35,366
Other intangible assets, net	291		217
Investments in subsidiaries, net	0		0
Intercompany receivables and note receivables	0		0
Equipment installment plan receivables due after one year, net	1,234		1,274
Other assets	1,157	1,062	912
Total assets	72,004		70,563
Current liabilities
Accounts payable and accrued liabilities	7,157		8,528
Payables to affiliates	291		182
Short-term debt	3,320		1,612
Short-term debt to affiliates	445		0
Deferred revenue	791	783	779
Other current liabilities	353		414
Total current liabilities	12,357		11,515
Long-term debt	12,127		12,121
Long-term debt to affiliates	14,586		14,586
Tower obligations	2,582		2,590
Deferred tax liabilities	3,813	$ 3,610	3,537
Deferred rent expense	2,730		2,720
Negative carrying value of subsidiaries, net	0		0
Intercompany payables and debt	0		0
Other long-term liabilities	933		935
Total long-term liabilities	36,771		36,489
Total stockholders' equity (deficit)	22,876		22,559
Total liabilities and stockholders' equity	72,004		70,563
Consolidating and Eliminating Adjustments
Current assets
Cash and cash equivalents	0		0	0	0
Accounts receivable, net	0		0
Equipment installment plan receivables, net	0		0
Accounts receivable from affiliates	(5)		0
Inventories	0		0
Other current assets	0		0
Total current assets	(5)		0
Property and equipment, net	0		0
Goodwill	0		0
Spectrum licenses	0		0
Other intangible assets, net	0		0
Investments in subsidiaries, net	(66,007)		(63,522)
Intercompany receivables and note receivables	(10,039)		(8,503)
Equipment installment plan receivables due after one year, net	0		0
Other assets	(145)		(140)
Total assets	(76,196)		(72,165)
Current liabilities
Accounts payable and accrued liabilities	0		0
Payables to affiliates	0		0
Short-term debt	0		0
Short-term debt to affiliates	(5)
Deferred revenue	0		0
Other current liabilities	0		0
Total current liabilities	(5)		0
Long-term debt	0		0
Long-term debt to affiliates	0		0
Tower obligations	0		0
Deferred tax liabilities	(145)		(140)
Deferred rent expense	0		0
Negative carrying value of subsidiaries, net	(590)		(629)
Intercompany payables and debt	(10,039)		(8,503)
Other long-term liabilities	0		0
Total long-term liabilities	(10,774)		(9,272)
Total stockholders' equity (deficit)	(65,417)		(62,893)
Total liabilities and stockholders' equity	(76,196)		(72,165)
Parent | Reportable Legal Entities
Current assets
Cash and cash equivalents	1		74	360	358
Accounts receivable, net	0		0
Equipment installment plan receivables, net	0		0
Accounts receivable from affiliates	0		0
Inventories	0		0
Other current assets	0		0
Total current assets	1		74
Property and equipment, net	0		0
Goodwill	0		0
Spectrum licenses	0		0
Other intangible assets, net	0		0
Investments in subsidiaries, net	23,426		22,534
Intercompany receivables and note receivables	0		0
Equipment installment plan receivables due after one year, net	0		0
Other assets	0		0
Total assets	23,427		22,608
Current liabilities
Accounts payable and accrued liabilities	0		0
Payables to affiliates	0		0
Short-term debt	0		0
Short-term debt to affiliates	0
Deferred revenue	0		0
Other current liabilities	17		17
Total current liabilities	17		17
Long-term debt	0		0
Long-term debt to affiliates	0		0
Tower obligations	0		0
Deferred tax liabilities	0		0
Deferred rent expense	0		0
Negative carrying value of subsidiaries, net	0		0
Intercompany payables and debt	534		32
Other long-term liabilities	0		0
Total long-term liabilities	534		32
Total stockholders' equity (deficit)	22,876		22,559
Total liabilities and stockholders' equity	23,427		22,608
Issuer | Reportable Legal Entities
Current assets
Cash and cash equivalents	1		1	3,138	2,733
Accounts receivable, net	0		0
Equipment installment plan receivables, net	0		0
Accounts receivable from affiliates	5		0
Inventories	0		0
Other current assets	0		0
Total current assets	6		1
Property and equipment, net	0		0
Goodwill	0		0
Spectrum licenses	0		0
Other intangible assets, net	0		0
Investments in subsidiaries, net	42,581		40,988
Intercompany receivables and note receivables	10,039		8,503
Equipment installment plan receivables due after one year, net	0		0
Other assets	3		2
Total assets	52,629		49,494
Current liabilities
Accounts payable and accrued liabilities	211		253
Payables to affiliates	256		146
Short-term debt	2,670		999
Short-term debt to affiliates	445
Deferred revenue	0		0
Other current liabilities	18		0
Total current liabilities	3,600		1,398
Long-term debt	10,978		10,911
Long-term debt to affiliates	14,586		14,586
Tower obligations	0		0
Deferred tax liabilities	0		0
Deferred rent expense	0		0
Negative carrying value of subsidiaries, net	0		0
Intercompany payables and debt	0		0
Other long-term liabilities	39		65
Total long-term liabilities	25,603		25,562
Total stockholders' equity (deficit)	23,426		22,534
Total liabilities and stockholders' equity	52,629		49,494
Guarantor Subsidiaries | Reportable Legal Entities
Current assets
Cash and cash equivalents	2,395		1,086	3,937	2,342
Accounts receivable, net	1,469		1,659
Equipment installment plan receivables, net	2,281		2,290
Accounts receivable from affiliates	13		22
Inventories	1,311		1,566
Other current assets	1,144		1,275
Total current assets	8,613		7,898
Property and equipment, net	22,008		21,890
Goodwill	1,683		1,683
Spectrum licenses	35,504		35,366
Other intangible assets, net	194		217
Investments in subsidiaries, net	0		0
Intercompany receivables and note receivables	0		0
Equipment installment plan receivables due after one year, net	1,234		1,274
Other assets	1,074		814
Total assets	70,310		69,142
Current liabilities
Accounts payable and accrued liabilities	6,679		8,014
Payables to affiliates	35		36
Short-term debt	648		613
Short-term debt to affiliates	5
Deferred revenue	791		779
Other current liabilities	176		192
Total current liabilities	8,334		9,634
Long-term debt	1,149		1,210
Long-term debt to affiliates	0		0
Tower obligations	391		392
Deferred tax liabilities	3,958		3,677
Deferred rent expense	2,730		2,720
Negative carrying value of subsidiaries, net	590		629
Intercompany payables and debt	9,244		8,201
Other long-term liabilities	884		866
Total long-term liabilities	18,946		17,695
Total stockholders' equity (deficit)	43,030		41,813
Total liabilities and stockholders' equity	70,310		69,142
Non-Guarantor Subsidiaries | Reportable Legal Entities
Current assets
Cash and cash equivalents	130		58	$ 66	$ 67
Accounts receivable, net	220		256
Equipment installment plan receivables, net	0		0
Accounts receivable from affiliates	0		0
Inventories	0		0
Other current assets	644		628
Total current assets	994		942
Property and equipment, net	300		306
Goodwill	218		0
Spectrum licenses	0		0
Other intangible assets, net	97		0
Investments in subsidiaries, net	0		0
Intercompany receivables and note receivables	0		0
Equipment installment plan receivables due after one year, net	0		0
Other assets	225		236
Total assets	1,834		1,484
Current liabilities
Accounts payable and accrued liabilities	267		261
Payables to affiliates	0		0
Short-term debt	2		0
Short-term debt to affiliates	0
Deferred revenue	0		0
Other current liabilities	142		205
Total current liabilities	411		466
Long-term debt	0		0
Long-term debt to affiliates	0		0
Tower obligations	2,191		2,198
Deferred tax liabilities	0		0
Deferred rent expense	0		0
Negative carrying value of subsidiaries, net	0		0
Intercompany payables and debt	261		270
Other long-term liabilities	10		4
Total long-term liabilities	2,462		2,472
Total stockholders' equity (deficit)	(1,039)		(1,454)
Total liabilities and stockholders' equity	$ 1,834		$ 1,484

Guarantor Financial Informati70

Guarantor Financial Information - Condensed Consolidating Statement of Comprehensive Income Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues
Service revenues	$ 7,806	$ 7,329
Equipment revenues	2,353	2,043
Other revenues	296	241
Total revenues	10,455	9,613
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	1,589	1,408
Cost of equipment sales	2,845	2,686
Selling, general and administrative	3,164	2,955
Depreciation and amortization	1,575	1,564
Gains on disposal of spectrum licenses	0	(37)
Total operating expense	9,173	8,576
Operating income	1,282	1,037
Other income (expense)
Interest expense	(251)	(339)
Interest expense to affiliates	(166)	(100)
Interest income	6	7
Other income, net	10	2
Total other expense, net	(401)	(430)
Income before income taxes	881	607
Income tax (expense) benefit	(210)	91
Earnings (loss) of subsidiaries	0	0
Net income	671	698
Dividends on preferred stock	0	(14)
Net income attributable to common stockholders	671	684
Other comprehensive income (loss), net of tax	(3)	1
Total comprehensive income	668	699
Consolidating and Eliminating Adjustments
Revenues
Service revenues	(221)	(214)
Equipment revenues	(54)	(100)
Other revenues	(9)	(5)
Total revenues	(284)	(319)
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	0	0
Cost of equipment sales	(55)	(100)
Selling, general and administrative	(229)	(219)
Depreciation and amortization	0	0
Gains on disposal of spectrum licenses		0
Total operating expense	(284)	(319)
Operating income	0	0
Other income (expense)
Interest expense	0	0
Interest expense to affiliates	5	6
Interest income	(5)	(6)
Other income, net	0	0
Total other expense, net	0	0
Income before income taxes	0	0
Income tax (expense) benefit	0	0
Earnings (loss) of subsidiaries	(1,701)	(1,716)
Net income	(1,701)	(1,716)
Dividends on preferred stock		0
Net income attributable to common stockholders		(1,716)
Other comprehensive income (loss), net of tax	6	(3)
Total comprehensive income	(1,695)	(1,719)
Parent | Reportable Legal Entities
Revenues
Service revenues	0	0
Equipment revenues	0	0
Other revenues	0	0
Total revenues	0	0
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	0	0
Cost of equipment sales	0	0
Selling, general and administrative	0	0
Depreciation and amortization	0	0
Gains on disposal of spectrum licenses		0
Total operating expense	0	0
Operating income	0	0
Other income (expense)
Interest expense	0	0
Interest expense to affiliates	0	0
Interest income	0	0
Other income, net	0	0
Total other expense, net	0	0
Income before income taxes	0	0
Income tax (expense) benefit	0	0
Earnings (loss) of subsidiaries	671	698
Net income	671	698
Dividends on preferred stock		(14)
Net income attributable to common stockholders		684
Other comprehensive income (loss), net of tax	(3)	1
Total comprehensive income	668	699
Issuer | Reportable Legal Entities
Revenues
Service revenues	0	0
Equipment revenues	0	0
Other revenues	1	0
Total revenues	1	0
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	0	0
Cost of equipment sales	0	0
Selling, general and administrative	0	0
Depreciation and amortization	0	0
Gains on disposal of spectrum licenses		0
Total operating expense	0	0
Operating income	1	0
Other income (expense)
Interest expense	(174)	(264)
Interest expense to affiliates	(166)	(99)
Interest income	6	9
Other income, net	(32)	3
Total other expense, net	(366)	(351)
Income before income taxes	(365)	(351)
Income tax (expense) benefit	0	0
Earnings (loss) of subsidiaries	1,036	1,049
Net income	671	698
Dividends on preferred stock		0
Net income attributable to common stockholders		698
Other comprehensive income (loss), net of tax	(3)	1
Total comprehensive income	668	699
Guarantor Subsidiaries | Reportable Legal Entities
Revenues
Service revenues	7,487	7,018
Equipment revenues	2,407	2,143
Other revenues	249	194
Total revenues	10,143	9,355
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	1,580	1,402
Cost of equipment sales	2,664	2,540
Selling, general and administrative	3,157	2,928
Depreciation and amortization	1,554	1,546
Gains on disposal of spectrum licenses		(37)
Total operating expense	8,955	8,379
Operating income	1,188	976
Other income (expense)
Interest expense	(29)	(27)
Interest expense to affiliates	(5)	(7)
Interest income	5	4
Other income, net	42	(1)
Total other expense, net	13	(31)
Income before income taxes	1,201	945
Income tax (expense) benefit	(199)	96
Earnings (loss) of subsidiaries	(6)	(31)
Net income	996	1,010
Dividends on preferred stock		0
Net income attributable to common stockholders		1,010
Other comprehensive income (loss), net of tax	(3)	1
Total comprehensive income	993	1,011
Non-Guarantor Subsidiaries | Reportable Legal Entities
Revenues
Service revenues	540	525
Equipment revenues	0	0
Other revenues	55	52
Total revenues	595	577
Operating expenses
Cost of services, exclusive of depreciation and amortization shown separately below	9	6
Cost of equipment sales	236	246
Selling, general and administrative	236	246
Depreciation and amortization	21	18
Gains on disposal of spectrum licenses		0
Total operating expense	502	516
Operating income	93	61
Other income (expense)
Interest expense	(48)	(48)
Interest expense to affiliates	0	0
Interest income	0	0
Other income, net	0	0
Total other expense, net	(48)	(48)
Income before income taxes	45	13
Income tax (expense) benefit	(11)	(5)
Earnings (loss) of subsidiaries	0	0
Net income	34	8
Dividends on preferred stock		0
Net income attributable to common stockholders		8
Other comprehensive income (loss), net of tax	0	1
Total comprehensive income	$ 34	$ 9

Guarantor Financial Informati71

Guarantor Financial Information - Condensed Consolidating Statement of Cash Flows Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating activities
Net cash provided by (used in) operating activities	$ 770	$ 608
Investing activities
Purchases of property and equipment	(1,366)	(1,528)
Purchases of spectrum licenses and other intangible assets, including deposits	(51)	(14)
Proceeds related to beneficial interests in securitization transactions	1,295	1,134
Acquisition of companies, net of cash acquired	(333)	0
Other, net	(7)	(8)
Net cash used in investing activities	(462)	(416)
Financing activities
Proceeds from issuance of long-term debt	2,494	5,495
Proceeds from borrowing on revolving credit facility	2,170	0
Repayments of revolving credit facility	(1,725)	0
Repayments of capital lease obligations	(172)	(90)
Repayments of long-term debt	(999)	(3,480)
Repurchases of common stock	(666)	0
Intercompany advances, net	0	0
Tax withholdings on share-based awards	(74)	(92)
Dividends on preferred stock	0	(14)
Other, net	(28)	(10)
Net cash provided by financing activities	1,000	1,809
Change in cash and cash equivalents	1,308	2,001
Beginning of period	1,219	5,500
End of period	2,527	7,501
Consolidating and Eliminating Adjustments
Operating activities
Net cash provided by (used in) operating activities	0	0
Investing activities
Purchases of property and equipment	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0
Proceeds related to beneficial interests in securitization transactions	0	0
Acquisition of companies, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	0	0
Financing activities
Proceeds from issuance of long-term debt	0	0
Proceeds from borrowing on revolving credit facility	0
Repayments of revolving credit facility	0
Repayments of capital lease obligations	0	0
Repayments of long-term debt	0	0
Repurchases of common stock	0
Intercompany advances, net	0	0
Tax withholdings on share-based awards	0	0
Dividends on preferred stock		0
Other, net	0	0
Net cash provided by financing activities	0	0
Change in cash and cash equivalents	0	0
Beginning of period	0	0
End of period	0	0
Parent | Reportable Legal Entities
Operating activities
Net cash provided by (used in) operating activities	1	1
Investing activities
Purchases of property and equipment	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0
Proceeds related to beneficial interests in securitization transactions	0	0
Acquisition of companies, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	0	0
Financing activities
Proceeds from issuance of long-term debt	0	0
Proceeds from borrowing on revolving credit facility	0
Repayments of revolving credit facility	0
Repayments of capital lease obligations	0	0
Repayments of long-term debt	0	0
Repurchases of common stock	(666)
Intercompany advances, net	590	0
Tax withholdings on share-based awards	0	0
Dividends on preferred stock		(14)
Other, net	2	15
Net cash provided by financing activities	(74)	1
Change in cash and cash equivalents	(73)	2
Beginning of period	74	358
End of period	1	360
Issuer | Reportable Legal Entities
Operating activities
Net cash provided by (used in) operating activities	(404)	(134)
Investing activities
Purchases of property and equipment	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0
Proceeds related to beneficial interests in securitization transactions	0	0
Acquisition of companies, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	0	0
Financing activities
Proceeds from issuance of long-term debt	2,494	5,495
Proceeds from borrowing on revolving credit facility	2,170
Repayments of revolving credit facility	0
Repayments of capital lease obligations	0	0
Repayments of long-term debt	0	0
Repurchases of common stock	0
Intercompany advances, net	(4,260)	(4,956)
Tax withholdings on share-based awards	0	0
Dividends on preferred stock		0
Other, net	0	0
Net cash provided by financing activities	404	539
Change in cash and cash equivalents	0	405
Beginning of period	1	2,733
End of period	1	3,138
Guarantor Subsidiaries | Reportable Legal Entities
Operating activities
Net cash provided by (used in) operating activities	2,374	1,855
Investing activities
Purchases of property and equipment	(1,366)	(1,528)
Purchases of spectrum licenses and other intangible assets, including deposits	(51)	(14)
Proceeds related to beneficial interests in securitization transactions	13	10
Acquisition of companies, net of cash acquired	(333)
Other, net	(7)	(8)
Net cash used in investing activities	(1,744)	(1,540)
Financing activities
Proceeds from issuance of long-term debt	0	0
Proceeds from borrowing on revolving credit facility	0
Repayments of revolving credit facility	(1,725)
Repayments of capital lease obligations	(172)	(90)
Repayments of long-term debt	(999)	(3,480)
Repurchases of common stock	0
Intercompany advances, net	3,679	4,967
Tax withholdings on share-based awards	(74)	(92)
Dividends on preferred stock		0
Other, net	(30)	(25)
Net cash provided by financing activities	679	1,280
Change in cash and cash equivalents	1,309	1,595
Beginning of period	1,086	2,342
End of period	2,395	3,937
Non-Guarantor Subsidiaries | Reportable Legal Entities
Operating activities
Net cash provided by (used in) operating activities	(1,201)	(1,114)
Investing activities
Purchases of property and equipment	0	0
Purchases of spectrum licenses and other intangible assets, including deposits	0	0
Proceeds related to beneficial interests in securitization transactions	1,282	1,124
Acquisition of companies, net of cash acquired	0
Other, net	0	0
Net cash used in investing activities	1,282	1,124
Financing activities
Proceeds from issuance of long-term debt	0	0
Proceeds from borrowing on revolving credit facility	0
Repayments of revolving credit facility	0
Repayments of capital lease obligations	0	0
Repayments of long-term debt	0	0
Repurchases of common stock	0
Intercompany advances, net	(9)	(11)
Tax withholdings on share-based awards	0	0
Dividends on preferred stock		0
Other, net	0	0
Net cash provided by financing activities	(9)	(11)
Change in cash and cash equivalents	72	(1)
Beginning of period	58	67
End of period	$ 130	$ 66