United States Cellular Corporat (UZD) 10-Q 4 May 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information	3 Months Ended
	Mar. 31, 2018shares
Entity Registrant Name	United States Cellular Corporation
Entity Central Index Key	821,130
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	USM
Common Shares
Entity Common Stock, Shares Outstanding	52,210,981
Series A Common Shares
Entity Common Stock, Shares Outstanding	33,005,877

Consolidated Statement Of Opera

Consolidated Statement Of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating revenues
Service	$ 724	$ 746
Equipment sales	218	190
Total operating revenues	942	936
Operating expenses
System operations (excluding Depreciation, amortization and accretion reported below)	179	175
Cost of equipment sold	219	228
Selling, general and administrative (including charges from affiliates of $19 million and $21 million, respectively)	326	339
Depreciation, amortization and accretion	159	153
(Gain) loss on asset disposals, net	1	4
(Gain) loss on license sales and exchanges, net	(7)	(17)
Total operating expenses	877	882
Operating income	65	54
Investment and other income (expense)
Equity in earnings of unconsolidated entities	38	33
Interest and dividend income	4	3
Interest expense	(29)	(28)
Other, net	(1)	(1)
Total investment and other income	12	7
Income before income taxes	77	61
Income tax expense	22	33
Net income	55	28
Less: Net income attributable to noncontrolling interests, net of tax	10	2
Net income attributable to U.S. Cellular shareholders	$ 45	$ 26
Basic weighted average shares outstanding	85	85
Basic earnings per share attributable to U.S. Cellular shareholders	$ 0.52	$ 0.31
Diluted weighted average shares outstanding	86	86
Diluted earnings per share attributable to U.S. Cellular shareholders	$ 0.52	$ 0.31

Consolidated Statement Of Oper3

Consolidated Statement Of Operations Parenthetical - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating expenses
Selling, general and administrative, charges from affiliates	$ 19	$ 21

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income	$ 55	$ 28
Add (deduct) adjustments to reconcile net income to net cash flows from operating activities
Depreciation, amortization and accretion	159	153
Bad debts expense	19	24
Stock-based compensation expense	8	7
Deferred income taxes, net	15	1
Equity in earnings of unconsolidated entities	(38)	(33)
Distributions from unconsolidated entities	17	11
(Gain) loss on asset disposals, net	1	4
(Gain) loss on license sales and exchanges, net	(7)	(17)
Noncash interest	1
Changes in assets and liabilities from operations
Accounts receivable	69	26
Equipment installment plans receivable	(17)	(44)
Inventory	(2)	(3)
Accounts payable	(30)	(78)
Customer deposits and deferred revenues	(26)	(10)
Accrued taxes	5	22
Accrued interest	9	9
Other assets and liabilities	(50)	(39)
Net cash provided by operating activities	188	61
Cash flows from investing activities
Cash paid for additions to property, plant and equipment	(76)	(88)
Cash paid for licenses	(1)	(3)
Cash received for investments	50	0
Cash received from divestitures and exchanges	4	16
Net cash used in investing activities	(23)	(75)
Cash flows from financing activities
Repayment of long-term debt	(5)	(3)
Common shares reissued for benefit plans, net of tax payments	2	3
Other financing activities	(4)	0
Net cash used in financing activities	(7)
Net increase (decrease) in cash, cash equivalents and restricted cash	158	(14)
Cash, cash equivalents and restricted cash
Beginning of period	352	586
End of period	$ 510	$ 572

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents		$ 509	$ 352
Short-term investments		0	50
Accounts receivable
Customers and agents, less allowances of $56 and $55, respectively		789	775
Roaming		15	26
Affiliated		4	1
Other, less allowances of $1 and $1, respectively		35	41
Inventory, net		141	138
Prepaid expenses		66	79
Other current assets		32	21
Total current assets		1,591	1,483
Assets held for sale		6	10
Licenses		2,231	2,223
Investments in unconsolidated entities		450	415
Property, plant and equipment
In service and under construction		7,662	7,628
Less: Accumulated depreciation and amortization		5,429	5,308
Property, plant and equipment, net		2,233	2,320
Other assets and deferred charges		537	390
Total assets	[1]	7,048	6,841
Current liabilities
Current portion of long-term debt		18	18
Accounts payable
Affiliated		8	8
Trade		267	302
Customer deposits and deferred revenues		132	185
Accrued taxes		58	56
Accrued compensation		43	74
Other current liabilities		90	90
Total current liabilities		616	733
Deferred liabilities and credits
Deferred income tax liability, net		526	461
Other deferred liabilities and credits		359	337
Long-term debt, net		1,618	1,622
Commitments and contingencies
Noncontrolling interests with redemption features		11	1
U.S. Cellular shareholders' equity
Series A Common and Common Shares Authorized 190 shares (50 Series A Common and 140 Common Shares) Issued 88 shares (33 Series A Common and 55 Common Shares) Outstanding 85 shares (33 Series A Common and 52 Common Shares) Par Value ($1.00 per share) ($33 Series A Common and $55 Common Shares)		88	88
Additional paid-in capital		1,560	1,552
Treasury Shares, at cost, 3 Common Shares		(116)	(120)
Retained earnings		2,375	2,157
Total U.S. Cellular shareholders' equity		3,907	3,677
Noncontrolling interests		11	10
Total equity		3,918	3,687
Total liabilities and equity	[1]	$ 7,048	$ 6,841
[1]	The consolidated total assets as of March 31, 2018 and December 31, 2017, include assets held by consolidated variable interest entities (VIEs) of $793 million and $785 million, respectively, which are not available to be used to settle the obligations of U.S. Cellular. The consolidated total liabilities as of March 31, 2018 and December 31, 2017, include certain liabilities of consolidated VIEs of $21 million and $24 million, respectively, for which the creditors of the VIEs have no recourse to the general credit of U.S. Cellular. See Note 9 — Variable Interest Entities for additional information.

Consolidated Balance Sheet Pare

Consolidated Balance Sheet Parenthetical - USD ($) shares in Millions, $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accounts receivable
Customer and agent allowances	$ 56	$ 55
Other allowances	$ 1	$ 1
U.S. Cellular shareholders' equity
Authorized shares	190	190
Issued shares	88	88
Outstanding shares	85	85
Par value	$ 88	$ 88
Variable Interest Entities VIEs
Total VIE assets that can be used to settle only the VIEs' obligations	793	785
Total VIE liabilities for which creditors have no recourse	$ 21	$ 24
Series A Common Shares
U.S. Cellular shareholders' equity
Authorized shares	50	50
Issued shares	33	33
Outstanding shares	33	33
Par value per share	$ 1	$ 1
Par value	$ 33	$ 33
Common Shares
U.S. Cellular shareholders' equity
Authorized shares	140	140
Issued shares	55	55
Outstanding shares	52	52
Par value per share	$ 1	$ 1
Par value	$ 55	$ 55
Treasury shares	3	3

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity - USD ($) $ in Millions	Total	Series A Common and Common shares	Additional paid-in capital	Treasury shares	Retained earnings	Total U.S. Cellular shareholders' equity	Noncontrolling interests
Beginning balance at Dec. 31, 2016	$ 3,645	$ 88	$ 1,522	$ (136)	$ 2,160	$ 3,634	$ 11
Net income attributable to U.S. Cellular shareholders	26				26	26
Net income attributable to noncontrolling interests classified as equity	1						1
Incentive and compensation plans	3			4	(1)	3
Stock-based compensation awards	7		7			7
Ending balance at Mar. 31, 2017	3,682	88	1,529	(132)	2,185	3,670	12
Beginning balance at Dec. 31, 2017	3,687	88	1,552	(120)	2,157	3,677	10
Net income attributable to U.S. Cellular shareholders	45				45	45
Incentive and compensation plans	2			4	(2)	2
Stock-based compensation awards	8		8			8
Ending balance at Mar. 31, 2018	3,918	$ 88	$ 1,560	$ (116)	2,375	3,907	11
Cumulative effect of accounting change	$ 176				$ 175	$ 175	$ 1

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Basis of Presentation [Abstract]
Basis of Presentation	Note 1 Basis of Presentation United States Cellular Corporation (U.S. Cellular), a Delaware corporation, is an 83% -owned subsidiary of Telephone and Data Systems, Inc. (TDS). The accounting policies of U.S. Cellular conform to accounting principles generally accepted in the United States of America (GAAP) as set forth in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC). The consolidated financial statements include the accounts of U.S. Cellular, subsidiaries in which it has a controlling financial interest, general partnerships in which U.S. Cellular has a majority partnership interest and certain entities in which U.S. Cellular has a variable interest that require consolidation under GAAP. All material intercompany accounts and transactions have been eliminated. The unaudited consolidated financial statements included herein have been prepared by U.S. Cellular pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, U.S. Cellular believes that the disclosures included herein are adequate to make the information presented not misleading. Certain numbers included herein are rounded to millions for ease of presentation; however, calculated amounts and percentages are determined using the unrounded numbers. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in U.S. Cellular’s Annual Report on Form 10-K (Form 10-K) for the year ended December 31, 2017 . The accompanying unaudited consolidated financial statements contain all adjustments (consisting of normal recurring items, unless otherwise disclosed) necessary for the fair statement of U.S. Cellular’s financial position as of March 31, 2018 and December 31, 2017 , and its results of operations, cash flows and changes in equity for the three months ended March 31, 2018 and 2017 . The Consolidated Statement of Comprehensive Income was not included because comprehensive income for the three months ended March 31, 2018 and 2017 , equaled net income. These results are not necessarily indicative of the results to be expected for the full year. U.S. Cellular has not changed its significant accounting and reporting policies from those disclosed in its Form 10-K for the year ended December 31, 2017 , except as described below and as disclosed in Note 2 — Revenue Recognition and Note 8 — Investments in Unconsolidated Entities . Restricted Cash U.S. Cellular presents restricted cash with cash and cash equivalents in the Consolidated Statement of Cash Flows. The following table provides a reconciliation of Cash and cash equivalents and restricted cash reported in the Consolidated Balance Sheet to the total of the amounts in the Consolidated Statement of Cash Flows as of March 31, 2018 and December 31, 2017 . March 31, December 31, 2018 2017 (Dollars in millions) Cash and cash equivalents $ 509 $ 352 Restricted cash included in: Other current assets 1 – Cash, cash equivalents and restricted cash in the statement of cash flows $ 510 $ 352 Recently Issued Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued Accounting Standards Update 2016-02, Leases (ASU 2016-02). ASU 2016-02 requires lessees to record a right-of-use asset and lease liability for almost all leases. This ASU does not substantially impact the lessor accounting model. However, some changes to the lessor accounting guidance were made to align with lessee accounting changes within Accounting Standards Codification (ASC) 842, Leases and certain key aspects of ASC 606, Revenue from Contracts with Customers . Early adoption is permitted; however, U.S. Cellular plans to adopt ASU 2016-02 on a modified retrospective basis when required on January 1, 2019. In January 2018, the FASB issued Accounting Standards Update 2018-01, Leases (ASU 2018-01), which permits an entity to elect an optional transition practical expedient to not evaluate land easements that exist or expired before the entities adoption of ASU 2016-02. U.S. Cellular plans to adopt ASU 2018-01 in conjunction with its adoption of ASU 2016-02. U.S. Cellular is evaluating the full effect that adoption of ASU 2016-02 and ASU 2018-01 will have on its financial condition, results of operations and disclosures. Upon adoption, U.S. Cellular expects a substantial increase to assets and liabilities on its balance sheet and is in the process of implementing a new lease management and accounting system to assist in the application of the new standard. In June 2016, the FASB issued Accounting Standards Update 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 requires entities to use a new forward-looking, expected loss model to estimate credit losses. It also requires additional disclosure relating to the credit quality of trade and other receivables, including information relating to management’s estimate of credit allowances. U.S. Cellular is required to adopt ASU 2016-13 on January 1, 2020, using the modified retrospective approach. Early adoption is permitted as of January 1, 2019. U.S. Cellular is evaluating the effects that adoption of ASU 2016-13 will have on its financial position, results of operations and disclosures. Amounts Collected from Customers and Remitted to Governmental Authorities U.S. Cellular records amounts collected from customers and remitted to governmental authorities on a net basis within a tax liability account if the tax is assessed upon the customer and U.S. Cellular merely acts as an agent in collecting the tax on behalf of the imposing governmental authority. If the tax is assessed upon U.S. Cellular, then amounts collected from customers as recovery of the tax are recorded in Service revenues and amounts remitted to governmental authorities are recorded in Selling, general and administrative expenses in the Consolidated Statement of Operations. The amounts recorded gross in revenues that are billed to customers and remitted to governmental authorities totaled $ 17 million and $ 14 million for the three months ended March 31, 2018 and 2017 , respectively.

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Note 2 Revenue Recognition Change in Accounting Policy In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers and has since amended the standard with Accounting Standards Update 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date , Accounting Standards Update 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net), Accounting Standards Update 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing , Accounting Standards Update 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients, and Accounting Standards Update 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, collectively referred to hereinafter as ASU 2014-09. These standards replace existing revenue recognition rules with a single comprehensive model to use in accounting for revenue arising from contracts with customers. In February 2017, the FASB issued Accounting Standards Update 2017-05, Other Income – Gains and Losses from the Derecognition of Nonfinancial Assets: Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (ASU 2017-05). ASU 2017-05 clarifies how entities account for the derecognition of a nonfinancial asset and adds guidance for partial sales of nonfinancial assets. U.S. Cellular adopted the provisions of ASU 2014-09 and ASU 2017-05 and applied them to all contracts as of January 1, 2018, using a modified retrospective method. Under this method, the new accounting standard is applied only to the most recent period presented, recognizing the cumulative effect of the accounting change as an adjustment to the beginning balance of retained earnings. Accordingly, prior periods have not been recast to reflect the new accounting standard. The cumulative effect of applying the provisions of ASU 2014-09 resulted in an increase of $ 175 million in retained earnings as of January 1, 2018. ASU 2017-05 had no impact to retained earnings as of January 1, 2018. As a practical expedient, U.S. Cellular groups similar contracts or similar performance obligations together into portfolios of contracts or performance obligations if doing so does not result in a significant difference from applying the new accounting standard to the individual contracts. U.S. Cellular applies this grouping method for the following types of transactions: device activation fees, contract acquisition costs, and certain customer promotions. Contract portfolios will be recognized over the respective expected customer lives or terms of the contracts. The line items impacted by the adoption of ASU 2014-09 and ASU 2017-05 in the Consolidated Statement of Operations and the Consolidated Balance Sheet are presented below. Consolidated Statement of Operations Results under prior accounting standards Adjustment As reported Three Months Ended March 31, 2018 (Dollars and shares in millions, except per share amounts) Operating revenues Service $ 754 $ (30) $ 724 Equipment sales 198 20 218 Total operating revenues 952 (10) 942 Cost of equipment sold 222 (3) 219 (Gain) loss on license sales and exchanges, net (6) (1) (7) Total operating expenses 882 (5) 877 Operating income (loss) 70 (5) 65 Income (loss) before income taxes 82 (5) 77 Income tax expense (benefit) 24 (2) 22 Net income (loss) 58 (3) 55 Net income (loss) attributable to U.S. Cellular shareholders 48 (3) 45 Basic earnings (loss) per share attributable to U.S. Cellular shareholders $ 0.56 $ (0.04) $ 0.52 Diluted earnings (loss) per share attributable to U.S. Cellular shareholders $ 0.56 $ (0.04) $ 0.52 The decrease in Service revenues and the increase in Equipment sales revenues are driven primarily by differences in the timing and classification of revenue recognized for certain arrangements with multiple performance obligations and ceasing to record deferred imputed interest and the resulting interest income on equipment installment contracts. Under prior accounting standards, revenues were allocated to deliverables using the relative selling price method, where consideration was allocated to each element on the basis of its relative selling price. Revenue recognized for the delivered items was limited to the amount due from the customer that was not contingent upon the delivery of additional products or services. Under ASU 2014-09, the revenue allocation of the transaction price is based on the relative standalone selling prices of the individual performance obligations in the customer’s contract, and the resulting revenue attributable to each is recognized as control over the performance obligation is transferred to the customer. This has resulted in increased Equipment sales revenues as more revenue is allocated to discounted equipment than under prior accounting standards. Under prior accounting standards, U.S. Cellular deferred imputed interest related to equipment installment plan receivable contracts that exceeded twelve months, and recognized the corresponding interest income over the contract period in Service revenues. Under the provisions of ASU 2014-09, U.S. Cellular has determined that equipment installment plan contracts do not contain a significant financing component, and accordingly U.S. Cellular ceased recording deferred imputed interest and the resulting interest income on equipment installment contracts upon the adoption of ASU 2014-09. Cost of equipment sold decreased due to a change in timing of recognition of cost of goods sold in the agent channel. Under prior accounting standards, Equipment sales to agents and the related Cost of equipment sold was recognized when equipment was sold through from the agent to end user customers. In accordance with the provisions of ASU 2014-09, such amounts are recognized when U.S. Cellular delivers the equipment to the agent. Under ASU 2017-05, (Gain) loss on license sales and exchanges, net is calculated by subtracting the carrying amount of the distinct asset being disposed from the consideration measured and allocated to that distinct asset. The consideration, or transaction price, is the fair value of the licenses received. Under prior accounting standards, the transaction price was typically the fair value of the licenses surrendered. This change in guidance has resulted in a decrease in (Gain) loss on license sales and exchanges, net. Consolidated Balance Sheet Results under prior accounting standards Adjustment As reported As of March 31, 2018 (Dollars in millions) Accounts receivable Customers and agents, less allowances $ 730 $ 59 $ 789 Roaming 26 (11) 15 Prepaid expenses 87 (21) 66 Other current assets 19 13 32 Total current assets 1,550 41 1,591 Licenses 2,230 1 2,231 Investments in unconsolidated entities 436 14 450 Other assets and deferred charges 383 154 537 Total assets 6,838 210 7,048 Customer deposits and deferred revenues 158 (26) 132 Accrued taxes 59 (1) 58 Other current liabilities 86 4 90 Total current liabilities 638 (22) 616 Deferred income tax liability, net 477 49 526 Other deferred liabilities and credits 349 10 359 Retained earnings 2,203 172 2,375 Total U.S. Cellular shareholders' equity 3,735 172 3,907 Noncontrolling interests 10 1 11 Total equity 3,745 173 3,918 Total liabilities and equity 6,838 210 7,048 As a result of adoption of ASU 2014-09, U.S. Cellular recorded short-term and long-term contract assets and contract liabilities in its Consolidated Balance Sheet as of March 31, 2018. Under ASU 2014-09, the timing of recognition of revenue for each performance obligation may differ from the timing of the customer billing, creating a contract asset or contract liability. See Contract Balances below for additional information. Contract assets are included in Other current assets if short-term in nature or Other assets and deferred charges if long-term in nature. Short-term contract liabilities are classified as Customer deposits and deferred revenues and long-term contract liabilities are included in Other deferred liabilities and credits. Accounts receivable increased as a result of U.S. Cellular ceasing to record deferred imputed interest. Certain prepaid expenses have been reclassified as contract cost assets, which are a component of Other assets and deferred charges. Investments in unconsolidated entities increased due to the cumulative effect of applying the provisions of ASU 2014-09 to certain of U.S. Cellular’s equity method investments as of January 1, 2018. Deferred income tax liabilities, net, increased due to the provisions of ASU 2014-09 increasing the net basis of assets on a U.S. GAAP basis, without a corresponding increase in tax basis. Contract cost assets have also been created as a result of ASU 2014-09 due to capitalization of costs to obtain a new contract. See Contract Cost Assets below for additional information. Nature of goods and services The following is a description of principal activities from which U.S. Cellular generates its revenues. Services and products Nature, timing of satisfaction of performance obligations, and significant payment terms Wireless services Wireless service includes voice, messaging and data services. Revenue is recognized in Service revenues as wireless service is provided to the customer. Wireless services are generally billed and paid in advance on a monthly basis. Wireless devices and accessories U.S. Cellular offers a comprehensive range of wireless devices such as handsets, modems, mobile hotspots, home phones and tablets for use by its customers, as well as accessories. U.S. Cellular also sells wireless devices to agents and other third-party distributors for resale. U.S. Cellular frequently discounts wireless devices sold to new and current customers. U.S. Cellular also offers customers the option to purchase certain devices under installment contracts over a specified time period. For certain equipment installment plans, after a specified period of time, the customer may have the right to upgrade to a new device. Such upgrades require the customer to enter into an equipment installment contract for the new device, and transfer the existing device to U.S. Cellular. U.S. Cellular recognizes revenue in Equipment sales revenues when control of the device or accessory is transferred to the customer, which is generally upon delivery. Wireless roaming U.S. Cellular receives roaming revenues when other wireless carriers’ customers use U.S. Cellular’s wireless systems. U.S. Cellular recognizes revenue in Service revenues when the roaming service is provided to the other carrier’s customer. Wireless Eligible Telecommunications Carrier (ETC) Revenues Telecommunications companies may be designated by states, or in some cases by the FCC, as an ETC to receive support payments from the Universal Service Fund if they provide specified services in “high cost” areas. ETC revenues recognized in the reporting period represent the amounts which U.S. Cellular is entitled to receive for such period, as determined and approved in connection with U.S. Cellular’s designation as an ETC in various states. Wireless tower rents U.S. Cellular receives tower rental revenues when another carrier leases tower space on a U.S. Cellular owned tower. U.S. Cellular recognizes revenue in Service revenues in the period during which the services are provided. Activation fees U.S. Cellular charges its end customers activation fees in connection with the sale of certain services and equipment. These fees are deferred and recognized over the period benefitted. Significant Judgments U.S. Cellular sells bundled service and equipment offerings. In these instances, U.S. Cellular recognizes its revenue based on the relative standalone selling prices for each distinct service or equipment performance obligation, or bundles thereof. Revenues from sales of equipment are recognized when control has transferred to the customer. Service revenues are recognized as the related service is provided. Services are deemed to be highly interrelated when the method and timing of transfer and performance risk are the same. Highly interrelated services that are determined to not be distinct have been grouped into a single performance obligation. Each month of services promised is a performance obligation. The series of monthly service performance obligations promised over the course of the contract are combined into a single performance obligation for purposes of the allocation. U.S. Cellular has made judgments regarding transaction price, including but not limited to issues relating to variable consideration, time value of money and returns. When determined to be significant in the context of the contract, these items are considered in the valuation of transaction price at contract inception or modification, as appropriate. Disaggregation of Revenue In the following table, revenue is disaggregated by type of service and timing of revenue recognition. Service revenues are recognized over time and Equipment sales are point in time. Three Months Ended March 31, 2018 (Dollars in millions) Revenues from contracts with customers: Retail service $ 649 Inbound roaming 27 Other service 32 Service revenues from contracts with customers 708 Equipment sales 218 Total revenues from contracts with customers 1 $ 926 1 These amounts do not include revenues outside the scope of ASU 2014-09; therefore, revenue line items in this table will not agree to amounts presented in the Consolidated Statement of Operations. Contract Balances For contracts that involve multiple element service and equipment offerings, the transaction price is allocated to each performance obligation based on its relative standalone selling price. When payment is collected in advance of delivery of goods or services, a contract liability is recorded. A contract asset is recorded when revenue is recognized in advance of U.S. Cellular’s right to receive consideration. Once there is an unconditional right to receive the consideration, U.S. Cellular bills the customer under the terms of the respective contract and the amounts are recorded as receivables. U.S. Cellular recognizes Equipment sales revenue when the equipment is delivered to the customer and a corresponding contract asset or liability is recorded for the difference between the amount of revenue recognized and the amount billed to the customer in cases where discounts are offered. The contract asset or liability is reduced over the contract term as service is provided and billed to the customer. The accounts receivable balance related to amounts billed and not paid on contracts with customers, net of allowances, is shown in the table below. Bad debts expense recognized for the three months ended March 31, 2018, related to receivables was $ 19 million. Three Months Ended March 31, 2018 (Dollars in millions) Accounts receivable Customer and agents $ 789 Roaming 15 Other 27 Total 1 $ 831 1 These amounts do not include accounts receivable related to revenues outside the scope of ASU 2014-09; therefore, accounts receivable line items presented in this table will not agree to amounts presented in the Consolidated Balance Sheet. The following table provides a rollforward of contract assets from contracts with customers, which are recorded in Other current assets and Other assets and deferred charges in the Consolidated Balance Sheet. Contract Assets (Dollars in millions) Balance at December 31, 2017 $ – Change in accounting policy 26 Contract additions 8 Terminated contracts (1) Bad debts expense – Revenue recognized (8) Balance at March 31, 2018 $ 25 The following table provides a rollforward of contract liabilities from contracts with customers, which are recorded in Customer deposits and deferred revenues and Other deferred liabilities and credits in the Consolidated Balance Sheet. Contract Liabilities (Dollars in millions) Balance at December 31, 2017 $ – Change in accounting policy - Deferred revenues reclassification 1 167 Change in accounting policy - Retained earnings impact (21) Contract additions 24 Terminated contracts – Revenue recognized (43) Balance at March 31, 2018 $ 127 1 This amount represents U.S. Cellular's obligation to transfer goods or services to customers for which it had received payment and classified as deferred revenue at December 31, 2017. Transaction price allocated to the remaining performance obligations The following table includes estimated service revenue expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period. These estimates are based on contracts in place as of March 31, 2018, and may vary from actual results due to future contract modifications. As a practical expedient, revenue related to contracts of less than one year, generally contracts with month-to-month customers, are excluded from these estimates. Service Revenue (Dollars in millions) Remainder of 2018 $ 244 2019 86 Thereafter 3 Total $ 333 U.S. Cellular has certain contracts in which it bills customers an amount equal to a fixed per-unit price multiplied by a variable quantity. Because U.S. Cellular invoices customers in an amount that corresponds directly with the value to the customer of the entity’s performance completed to date, U.S. Cellular may recognize revenue in that amount. As a practical expedient, these contracts will be excluded from the estimate of future revenues expected to be recognized related to performance obligations that are unsatisfied as of the end of a reporting period. Contract Cost Assets U.S. Cellular expects that incremental commission fees paid as a result of obtaining contracts are recoverable and therefore U.S. Cellular capitalizes these costs. As a practical expedient, costs with an amortization period of one year or less are not capitalized. The contract cost asset balance related to commission fees was $ 133 million at March 31, 2018, and was recorded in Other assets and deferred charges in the Consolidated Balance Sheet. Capitalized commission fees are amortized based on the transfer of the goods or services to which the assets relate, typically the contract term. Amortization of contract cost assets was $ 27 million for the three months ended March 31, 2018, and was included in Selling, general and administrative expense. There was no impairment loss recognized for the three months ended March 31, 2018, related to contract cost assets.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 3 Fair Value Measurements As of March 31, 2018 and December 31, 2017 , U.S. Cellular did not have any material financial or nonfinancial assets or liabilities that were required to be recorded at fair value in its Consolidated Balance Sheet in accordance with GAAP. The provisions of GAAP establish a fair value hierarchy that contains three levels for inputs used in fair value measurements. Level 1 inputs include quoted market prices for identical assets or liabilities in active markets. Level 2 inputs include quoted market prices for similar assets and liabilities in active markets or quoted market prices for identical assets and liabilities in inactive markets. Level 3 inputs are unobservable. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. A financial instrument’s level within the fair value hierarchy is not representative of its expected performance or its overall risk profile and, therefore, Level 3 assets are not necessarily higher risk than Level 2 assets or Level 1 assets. U.S. Cellular has applied the provisions of fair value accounting for purposes of computing the fair value of financial instruments for disclosure purposes as displayed below. Level within the Fair Value Hierarchy March 31, 2018 December 31, 2017 Book Value Fair Value Book Value Fair Value (Dollars in millions) Cash and cash equivalents 1 $ 509 $ 509 $ 352 $ 352 Short-term investments 1 – – 50 50 Long-term debt Retail 2 917 944 917 939 Institutional 2 534 555 534 522 Other 2 188 188 191 191 The fair values of Cash and cash equivalents and Short-term investments approximate their book values due to the short-term nature of these financial instruments. Long-term debt excludes capital lease obligations, other installment arrangements, the current portion of Long-term debt and debt financing costs. The fair value of “Retail” Long-term debt was estimated using market prices for the 6.95% Senior Notes, 7.25% 2063 Senior Notes and 7.25% 2064 Senior Notes. U.S. Cellular’s “Institutional” debt consists of the 6.7% Senior Notes which are traded over the counter. U.S. Cellular’s “Other” debt consists of a senior term loan credit facility. U.S. Cellular estimated the fair value of its Institutional and Other debt through a discounted cash flow analysis using the interest rates or estimated yield to maturity for each borrowing, which ranged from 4.58% to 6.34% and 4.74% to 7.13% at March 31, 2018 and December 31, 2017 , respectively.

Equipment Installment Plans

Equipment Installment Plans	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Equipment Installment Plans	Note 4 Equipment Installment Plans U.S. Cellular sells devices to customers under equipment installment plans over a specified time period. For certain equipment installment plans, after a specified period of time or amount of payments, the customer may have the right to upgrade to a new device and have the remaining unpaid equipment installment contract balance waived, subject to certain conditions, including trading in the original device in good working condition and signing a new equipment installment contract. U.S. Cellular values this trade-in right as a guarantee liability. The guarantee liability is initially measured at fair value and is determined based on assumptions including the probability and timing of the customer upgrading to a new device and the fair value of the device being traded-in at the time of trade-in. When a customer exercises the trade-in option, both the outstanding receivable and guarantee liability balances related to the respective device are reduced to zero, and the value of the used device that is received in the transaction is recognized as inventory. If the customer does not exercise the trade-in option at the time of eligibility, U.S. Cellular begins amortizing the liability and records this amortization as additional equipment revenue. As of March 31, 2018 and December 31, 2017 , the guarantee liability related to these plans was $ 13 million and $ 15 million, respectively, and is reflected in Customer deposits and deferred revenues in the Consolidated Balance Sheet. The following table summarizes equipment installment plan receivables as of March 31, 2018 and December 31, 2017 . March 31, 2018 December 31, 2017 (Dollars in millions) Equipment installment plan receivables, gross $ 871 $ 873 Deferred interest – (80) Equipment installment plan receivables, net of deferred interest 871 793 Allowance for credit losses (66) (65) Equipment installment plan receivables, net $ 805 $ 728 Net balance presented in the Consolidated Balance Sheet as: Accounts receivable — Customers and agents (Current portion) $ 496 $ 428 Other assets and deferred charges (Non-current portion) 309 300 Equipment installment plan receivables, net $ 805 $ 728 U.S. Cellular uses various inputs, including internal data, information from the credit bureaus and other sources, to evaluate the credit profiles of its customers. From this evaluation, a credit class is assigned to the customer that determines the number of eligible lines, the amount of credit available, and the down payment requirement, if any. Customers assigned to credit classes requiring no down payment represent a lower risk category, whereas those assigned to credit classes requiring a down payment represent a higher risk category. The balance and aging of the equipment installment plan receivables on a gross basis by credit category were as follows: March 31, 2018 December 31, 2017 Lower Risk Higher Risk Total Lower Risk Higher Risk Total (Dollars in millions) Unbilled $ 809 $ 19 $ 828 $ 807 $ 20 $ 827 Billed — current 28 1 29 31 1 32 Billed — past due 12 2 14 12 2 14 Equipment installment plan receivables, gross $ 849 $ 22 $ 871 $ 850 $ 23 $ 873 Activity for the three months ended March 31, 2018 and 2017 , in the allowance for credit losses balance for the equipment installment plan receivables was as follows: March 31, 2018 March 31, 2017 (Dollars in millions) Allowance for credit losses, beginning of period $ 65 $ 50 Bad debts expense 14 15 Write-offs, net of recoveries (13) (12) Allowance for credit losses, end of period $ 66 $ 53

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 5 Income Taxes In December 2017, the Tax Act was signed into law. Following the guidance of the FASB’s Accounting Standards Update 2018-05, Income Taxes: Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 , tax expense for the year ended December 31, 2017, included a provisional estimate for the impact of the Tax Act on U.S. Cellular’s 2017 depreciation deduction. Tax expense for the three months ended March 31, 2018, includes an income tax benefit of $3 million related to adjusting this provisional estimate. U.S. Cellular has not completed a full analysis of contracts and agreements related to fixed assets placed in service during 2017. U.S. Cellular expects any final adjustments to the provisional amounts to be recorded by the third quarter of 2018, which could be material to U.S. Cellular’s financial statements.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per Share	Note 6 Earnings Per Share Basic earnings per share attributable to U.S. Cellular shareholders is computed by dividing Net income attributable to U.S. Cellular shareholders by the weighted average number of common shares outstanding during the period. Diluted earnings per share attributable to U.S. Cellular shareholders is computed by dividing Net income attributable to U.S. Cellular shareholders by the weighted average number of common shares outstanding during the period adjusted to include the effects of potentially dilutive securities. Potentially dilutive securities primarily include incremental shares issuable upon the exercise of outstanding stock options and the vesting of performance and restricted stock units. The amounts used in computing earnings per common share and the effects of potentially dilutive securities on the weighted average number of common shares were as follows: Three Months Ended March 31, 2018 2017 (Dollars and shares in millions, except per share amounts) Net income attributable to U.S. Cellular shareholders $ 45 $ 26 Weighted average number of shares used in basic earnings per share 85 85 Effects of dilutive securities 1 1 Weighted average number of shares used in diluted earnings per share 86 86 Basic earnings per share attributable to U.S. Cellular shareholders $ 0.52 $ 0.31 Diluted earnings per share attributable to U.S. Cellular shareholders $ 0.52 $ 0.31 Certain Common Shares issuable upon the exercise of stock options or vesting of performance and restricted stock units were not included in average diluted shares outstanding for the calculation of Diluted earnings per share attributable to U.S. Cellular shareholders because their effects were antidilutive. The number of such Common Shares excluded was 2 million for both the three months ended March 31, 2018 and 2017 .

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Note 7 Intangible Assets Activity related to Licenses for the three months ended March 31, 2018 , is presented below: Licenses (Dollars in millions) Balance at December 31, 2017 $ 2,223 Acquisitions 1 Transferred to Assets held for sale (10) Exchanges - Licenses received 18 Exchanges - Licenses surrendered (1) Balance at March 31, 2018 $ 2,231

Investments in Unconsolidated E

Investments in Unconsolidated Entities	3 Months Ended
	Mar. 31, 2018
Investments in Unconsolidated Entities [Abstract]
Investments in Unconsolidated Entities	Note 8 Investments in Unconsolidated Entities Investments in unconsolidated entities consist of amounts invested in wireless entities in which U.S. Cellular holds a noncontrolling interest. On January 1, 2018, U.S. Cellular adopted Accounting Standards Update 2016-01, Financial Instruments – Overall: Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01) using the modified retrospective approach. The adoption of ASU 2016-01 did not have a significant impact on U.S. Cellular’s financial position or results of operations. U.S. Cellular’s Investments in unconsolidated entities are accounted for using either the equity method or measurement alternative method as shown in the table below. The measurement alternative method was elected for investments without readily determinable fair values formerly accounted for under the cost method. The measurement alternative fair value represents cost minus any impairments plus or minus any observable price changes. U.S. Cellular did not have an impairment or observable price change related to these investments for the three months ended March 31, 2018. March 31, December 31, 2018 2017 (Dollars in millions) Equity method investments $ 444 $ 411 Measurement alternative method investments 6 4 Total investments in unconsolidated entities $ 450 $ 415 The following table, which is based in part on information provided by third parties, summarizes the combined results of operations of U.S. Cellular’s equity method investments. Three Months Ended March 31, 2018 2017 (Dollars in millions) Revenues $ 1,657 $ 1,610 Operating expenses 1,208 1,212 Operating income 449 398 Other expense, net (1) – Net income $ 448 $ 398

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2018
Variable Interest Entities [Abstract]
Variable Interest Entities	Note 9 Variable Interest Entities Consolidated VIEs U.S. Cellular consolidates variable interest entities (VIEs) in which it has a controlling financial interest as defined by GAAP and is therefore deemed the primary beneficiary. A controlling financial interest will have both of the following characteristics: (a) the power to direct the VIE activities that most significantly impact economic performance; and (b) the obligation to absorb the VIE losses and the right to receive benefits that are significant to the VIE. U.S. Cellular reviews these criteria initially at the time it enters into agreements and subsequently when events warranting reconsideration occur. These VIEs have risks similar to those described in the “Risk Factors” in U.S. Cellular’s Form 10-K for the year ended December 31, 2017 . During 2017, U.S. Cellular formed USCC EIP LLC (Seller/Sub-Servicer), USCC Receivables Funding LLC (Transferor) and the USCC Master Note Trust (Trust), special purpose entities (SPEs), to facilitate a securitized borrowing using its equipment installment plan receivables. Under a Receivables Sale Agreement, U.S. Cellular wholly-owned, majority-owned and unconsolidated entities, collectively referred to as “affiliated entities”, will transfer device equipment installment plan contracts to the Seller/Sub-Servicer. The Seller/Sub-Servicer will aggregate device equipment installment plan contracts, and perform servicing, collection and all other administrative activities related to accounting for the equipment installment plan contracts. The Seller/Sub-Servicer will sell the eligible equipment installment plan receivables to the Transferor, a bankruptcy remote entity, which will subsequently sell the receivables to the Trust. The Trust, which is bankruptcy remote and isolated from the creditors of U.S. Cellular, will be responsible for issuing asset-backed variable funding notes (Notes), which are collateralized by the equipment installment plan receivables owned by the Trust. Given that U.S. Cellular has the power to direct the activities of these SPEs, and that these SPEs lack sufficient equity to finance their activities, U.S. Cellular is deemed to have a controlling financial interest in the SPEs and, therefore, consolidates them. All transactions with third parties (e.g., issuance of the asset-backed variable funding notes) will be accounted for as a secured borrowing due to the pledging of equipment installment plan contracts as collateral, significant continuing involvement in the transferred assets, subordinated interests of the cash flows, and continued evidence of control of the receivables. The following VIEs were formed to participate in FCC auctions of wireless spectrum and to fund, establish, and provide wireless service with respect to any FCC licenses won in the auctions: Advantage Spectrum, L.P. (Advantage Spectrum) and Sunshine Spectrum, Inc., the general partner of Advantage Spectrum; Aquinas Wireless, L.P. (Aquinas Wireless); and King Street Wireless, L.P. (King Street Wireless) and King Street Wireless, Inc., the general partner of King Street Wireless. These particular VIEs are collectively referred to as designated entities. The power to direct the activities that most significantly impact the economic performance of these VIEs is shared. Specifically, the general partner of these VIEs has the exclusive right to manage, operate and control the limited partnerships and make all decisions to carry on the business of the partnerships. The general partner of each partnership needs the consent of the limited partner, an indirect U.S. Cellular subsidiary, to sell or lease certain licenses, to make certain large expenditures, admit other partners or liquidate the limited partnerships. Although the power to direct the activities of these VIEs is shared, U.S. Cellular has the most significant level of exposure to the variability associated with the economic performance of the VIEs, indicating that U.S. Cellular is the primary beneficiary of the VIEs. Therefore, in accordance with GAAP, these VIEs are consolidated. In the first quarter of 2018, U.S. Cellular received an initial liquidating distribution of substantially all of the remaining assets of Aquinas Wireless. The final liquidating distribution is expected during the second quarter of 2018, and Aquinas Wireless will then be subsequently dissolved. U.S. Cellular also consolidates other VIEs that are limited partnerships that provide wireless service. A limited partnership is a variable interest entity unless the limited partners hold substantive participating rights or kick-out rights over the general partner. For certain limited partnerships, U.S. Cellular is the general partner and manages the operations. In these partnerships, the limited partners do not have substantive kick-out or participating rights and, further, such limited partners do not have the authority to remove the general partner. Therefore, these limited partnerships are also recognized as VIEs and are consolidated under the variable interest model. The following table presents the classification and balances of the consolidated VIEs’ assets and liabilities in U.S. Cellular’s Consolidated Balance Sheet. March 31, December 31, 2018 2017 (Dollars in millions) Assets Cash and cash equivalents $ 1 $ 3 Accounts receivable 543 476 Other current assets 8 8 Licenses 654 655 Property, plant and equipment, net 96 99 Other assets and deferred charges 321 303 Total assets $ 1,623 $ 1,544 Liabilities Current liabilities $ 32 $ 39 Deferred liabilities and credits 14 13 Total liabilities $ 46 $ 52 Unconsolidated VIEs U.S. Cellular manages the operations of and holds a variable interest in certain other limited partnerships, but is not the primary beneficiary of these entities and, therefore, does not consolidate them under the variable interest model. U.S. Cellular’s total investment in these unconsolidated entities was $ 5 million and $ 4 million at March 31, 2018 and December 31, 2017 , respectively, and is included in Investments in unconsolidated entities in U.S. Cellular’s Consolidated Balance Sheet. The maximum exposure from unconsolidated VIEs is limited to the investment held by U.S. Cellular in those entities. Other Related Matters During the three months ended March 31, 2018 and 2017 , U.S. Cellular made contributions, loans and/or advances to its VIEs totaling $ 19 million and $ 654 million, respectively; of these amounts $ 10 million and $ 650 million, respectively, are related to USCC EIP LLC as discussed above. U.S. Cellular may agree to make additional capital contributions and/or advances to these or other VIEs and/or to their general partners to provide additional funding for operations or the development of licenses granted in various auctions. U.S. Cellular may finance such amounts with a combination of cash on hand, borrowings under its revolving credit agreement and/or other long-term debt. There is no assurance that U.S. Cellular will be able to obtain additional financing on commercially reasonable terms or at all to provide such financial support. During the three months ended March 31, 2018, U.S. Cellular recorded out-of-period adjustments attributable to 2016 and 2017 due to errors in the application of accounting guidance applicable to the calculation of Noncontrolling interests with redemption features related to King Street Wireless, Inc. These out-of-period adjustments had the impact of increasing Net income attributable to noncontrolling interests, net of tax, by $ 8 million and decreasing Net income attributable to U.S. Cellular shareholders by $ 8 million for the three months ended March 31, 2018. U.S. Cellular determined that these adjustments were not material to any of the periods impacted.

Summary of Significant Accounti

Summary of Significant Accounting Policies and Recent Accounting Pronouncements (Significant Accounting Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Principles of Consolidation	The accounting policies of U.S. Cellular conform to accounting principles generally accepted in the United States of America (GAAP) as set forth in the Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC). The consolidated financial statements include the accounts of U.S. Cellular, subsidiaries in which it has a controlling financial interest, general partnerships in which U.S. Cellular has a majority partnership interest and certain entities in which U.S. Cellular has a variable interest that require consolidation under GAAP. All material intercompany accounts and transactions have been eliminated.
Basis of Accounting	The unaudited consolidated financial statements included herein have been prepared by U.S. Cellular pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, U.S. Cellular believes that the disclosures included herein are adequate to make the information presented not misleading. Certain numbers included herein are rounded to millions for ease of presentation; however, calculated amounts and percentages are determined using the unrounded numbers. These unaudited consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in U.S. Cellular’s Annual Report on Form 10-K (Form 10-K) for the year ended December 31, 2017 . The accompanying unaudited consolidated financial statements contain all adjustments (consisting of normal recurring items, unless otherwise disclosed) necessary for the fair statement of U.S. Cellular’s financial position as of March 31, 2018 and December 31, 2017 , and its results of operations, cash flows and changes in equity for the three months ended March 31, 2018 and 2017 . The Consolidated Statement of Comprehensive Income was not included because comprehensive income for the three months ended March 31, 2018 and 2017 , equaled net income. These results are not necessarily indicative of the results to be expected for the full year. U.S. Cellular has not changed its significant accounting and reporting policies from those disclosed in its Form 10-K for the year ended December 31, 2017 , except as described below and as disclosed in Note 2 — Revenue Recognition and Note 8 — Investments in Unconsolidated Entities .
Restricted Cash	Restricted Cash U.S. Cellular presents restricted cash with cash and cash equivalents in the Consolidated Statement of Cash Flows. The following table provides a reconciliation of Cash and cash equivalents and restricted cash reported in the Consolidated Balance Sheet to the total of the amounts in the Consolidated Statement of Cash Flows as of March 31, 2018 and December 31, 2017 . March 31, December 31, 2018 2017 (Dollars in millions) Cash and cash equivalents $ 509 $ 352 Restricted cash included in: Other current assets 1 – Cash, cash equivalents and restricted cash in the statement of cash flows $ 510 $ 352
New Accounting Pronouncements and Changes in Accounting Principles	In May 2014, the FASB issued Accounting Standards Update 2014-09, Revenue from Contracts with Customers and has since amended the standard with Accounting Standards Update 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date , Accounting Standards Update 2016-08, Revenue from Contracts with Customers: Principal versus Agent Considerations (Reporting Revenue Gross versus Net), Accounting Standards Update 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing , Accounting Standards Update 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients, and Accounting Standards Update 2016-20, Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers, collectively referred to hereinafter as ASU 2014-09. These standards replace existing revenue recognition rules with a single comprehensive model to use in accounting for revenue arising from contracts with customers. In February 2017, the FASB issued Accounting Standards Update 2017-05, Other Income – Gains and Losses from the Derecognition of Nonfinancial Assets: Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets (ASU 2017-05). ASU 2017-05 clarifies how entities account for the derecognition of a nonfinancial asset and adds guidance for partial sales of nonfinancial assets. U.S. Cellular adopted the provisions of ASU 2014-09 and ASU 2017-05 and applied them to all contracts as of January 1, 2018, using a modified retrospective method. Under this method, the new accounting standard is applied only to the most recent period presented, recognizing the cumulative effect of the accounting change as an adjustment to the beginning balance of retained earnings. Accordingly, prior periods have not been recast to reflect the new accounting standard. The cumulative effect of applying the provisions of ASU 2014-09 resulted in an increase of $ 175 million in retained earnings as of January 1, 2018. ASU 2017-05 had no impact to retained earnings as of January 1, 2018.
Recently Issued Accounting Pronouncements Not Yet Adopted	Recently Issued Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued Accounting Standards Update 2016-02, Leases (ASU 2016-02). ASU 2016-02 requires lessees to record a right-of-use asset and lease liability for almost all leases. This ASU does not substantially impact the lessor accounting model. However, some changes to the lessor accounting guidance were made to align with lessee accounting changes within Accounting Standards Codification (ASC) 842, Leases and certain key aspects of ASC 606, Revenue from Contracts with Customers . Early adoption is permitted; however, U.S. Cellular plans to adopt ASU 2016-02 on a modified retrospective basis when required on January 1, 2019. In January 2018, the FASB issued Accounting Standards Update 2018-01, Leases (ASU 2018-01), which permits an entity to elect an optional transition practical expedient to not evaluate land easements that exist or expired before the entities adoption of ASU 2016-02. U.S. Cellular plans to adopt ASU 2018-01 in conjunction with its adoption of ASU 2016-02. U.S. Cellular is evaluating the full effect that adoption of ASU 2016-02 and ASU 2018-01 will have on its financial condition, results of operations and disclosures. Upon adoption, U.S. Cellular expects a substantial increase to assets and liabilities on its balance sheet and is in the process of implementing a new lease management and accounting system to assist in the application of the new standard. In June 2016, the FASB issued Accounting Standards Update 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 requires entities to use a new forward-looking, expected loss model to estimate credit losses. It also requires additional disclosure relating to the credit quality of trade and other receivables, including information relating to management’s estimate of credit allowances. U.S. Cellular is required to adopt ASU 2016-13 on January 1, 2020, using the modified retrospective approach. Early adoption is permitted as of January 1, 2019. U.S. Cellular is evaluating the effects that adoption of ASU 2016-13 will have on its financial position, results of operations and disclosures.
Revenue Recognition	Nature of goods and services The following is a description of principal activities from which U.S. Cellular generates its revenues. Services and products Nature, timing of satisfaction of performance obligations, and significant payment terms Wireless services Wireless service includes voice, messaging and data services. Revenue is recognized in Service revenues as wireless service is provided to the customer. Wireless services are generally billed and paid in advance on a monthly basis. Wireless devices and accessories U.S. Cellular offers a comprehensive range of wireless devices such as handsets, modems, mobile hotspots, home phones and tablets for use by its customers, as well as accessories. U.S. Cellular also sells wireless devices to agents and other third-party distributors for resale. U.S. Cellular frequently discounts wireless devices sold to new and current customers. U.S. Cellular also offers customers the option to purchase certain devices under installment contracts over a specified time period. For certain equipment installment plans, after a specified period of time, the customer may have the right to upgrade to a new device. Such upgrades require the customer to enter into an equipment installment contract for the new device, and transfer the existing device to U.S. Cellular. U.S. Cellular recognizes revenue in Equipment sales revenues when control of the device or accessory is transferred to the customer, which is generally upon delivery. Wireless roaming U.S. Cellular receives roaming revenues when other wireless carriers’ customers use U.S. Cellular’s wireless systems. U.S. Cellular recognizes revenue in Service revenues when the roaming service is provided to the other carrier’s customer. Wireless Eligible Telecommunications Carrier (ETC) Revenues Telecommunications companies may be designated by states, or in some cases by the FCC, as an ETC to receive support payments from the Universal Service Fund if they provide specified services in “high cost” areas. ETC revenues recognized in the reporting period represent the amounts which U.S. Cellular is entitled to receive for such period, as determined and approved in connection with U.S. Cellular’s designation as an ETC in various states. Wireless tower rents U.S. Cellular receives tower rental revenues when another carrier leases tower space on a U.S. Cellular owned tower. U.S. Cellular recognizes revenue in Service revenues in the period during which the services are provided. Activation fees U.S. Cellular charges its end customers activation fees in connection with the sale of certain services and equipment. These fees are deferred and recognized over the period benefitted. Significant Judgments U.S. Cellular sells bundled service and equipment offerings. In these instances, U.S. Cellular recognizes its revenue based on the relative standalone selling prices for each distinct service or equipment performance obligation, or bundles thereof. Revenues from sales of equipment are recognized when control has transferred to the customer. Service revenues are recognized as the related service is provided. Services are deemed to be highly interrelated when the method and timing of transfer and performance risk are the same. Highly interrelated services that are determined to not be distinct have been grouped into a single performance obligation. Each month of services promised is a performance obligation. The series of monthly service performance obligations promised over the course of the contract are combined into a single performance obligation for purposes of the allocation. U.S. Cellular has made judgments regarding transaction price, including but not limited to issues relating to variable consideration, time value of money and returns. When determined to be significant in the context of the contract, these items are considered in the valuation of transaction price at contract inception or modification, as appropriate.
Revenue From Contract With Customer	U.S. Cellular adopted the provisions of ASU 2014-09 and ASU 2017-05 and applied them to all contracts as of January 1, 2018, using a modified retrospective method. Under this method, the new accounting standard is applied only to the most recent period presented, recognizing the cumulative effect of the accounting change as an adjustment to the beginning balance of retained earnings. As a practical expedient, U.S. Cellular groups similar contracts or similar performance obligations together into portfolios of contracts or performance obligations if doing so does not result in a significant difference from applying the new accounting standard to the individual contracts. U.S. Cellular applies this grouping method for the following types of transactions: device activation fees, contract acquisition costs, and certain customer promotions. Contract portfolios will be recognized over the respective expected customer lives or terms of the contracts. Transaction price allocated to the remaining performance obligations As a practical expedient, revenue related to contracts of less than one year, generally contracts with month-to-month customers, are excluded from these estimates. U.S. Cellular has certain contracts in which it bills customers an amount equal to a fixed per-unit price multiplied by a variable quantity. Because U.S. Cellular invoices customers in an amount that corresponds directly with the value to the customer of the entity’s performance completed to date, U.S. Cellular may recognize revenue in that amount. As a practical expedient, these contracts will be excluded from the estimate of future revenues expected to be recognized related to performance obligations that are unsatisfied as of the end of a reporting period. Contract Cost Assets As a practical expedient, costs with an amortization period of one year or less are not capitalized.
Variable Interest Entities	U.S. Cellular consolidates variable interest entities (VIEs) in which it has a controlling financial interest as defined by GAAP and is therefore deemed the primary beneficiary. A controlling financial interest will have both of the following characteristics: (a) the power to direct the VIE activities that most significantly impact economic performance; and (b) the obligation to absorb the VIE losses and the right to receive benefits that are significant to the VIE. U.S. Cellular reviews these criteria initially at the time it enters into agreements and subsequently when events warranting reconsideration occur. These VIEs have risks similar to those described in the “Risk Factors” in U.S. Cellular’s Form 10-K for the year ended December 31, 2017 .

Basis Of Presentation (Table)

Basis Of Presentation (Table)	3 Months Ended
	Mar. 31, 2018
Basis of Presentation [Abstract]
Reconciliation of cash, cash equivalents and restricted cash	U.S. Cellular presents restricted cash with cash and cash equivalents in the Consolidated Statement of Cash Flows. The following table provides a reconciliation of Cash and cash equivalents and restricted cash reported in the Consolidated Balance Sheet to the total of the amounts in the Consolidated Statement of Cash Flows as of March 31, 2018 and December 31, 2017 . March 31, December 31, 2018 2017 (Dollars in millions) Cash and cash equivalents $ 509 $ 352 Restricted cash included in: Other current assets 1 – Cash, cash equivalents and restricted cash in the statement of cash flows $ 510 $ 352

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of new accounting pronouncements and changes in accounting principles	The line items impacted by the adoption of ASU 2014-09 and ASU 2017-05 on the Consolidated Statement of Operations and the Consolidated Balance Sheet are presented below. Consolidated Statement of Operations Results under prior accounting standards Adjustment As reported Three Months Ended March 31, 2018 (Dollars and shares in millions, except per share amounts) Operating revenues Service $ 754 $ (30) $ 724 Equipment sales 198 20 218 Total operating revenues 952 (10) 942 Cost of equipment sold 222 (3) 219 (Gain) loss on license sales and exchanges, net (6) (1) (7) Total operating expenses 882 (5) 877 Operating income (loss) 70 (5) 65 Income (loss) before income taxes 82 (5) 77 Income tax expense (benefit) 24 (2) 22 Net income (loss) 58 (3) 55 Net income (loss) attributable to U.S. Cellular shareholders 48 (3) 45 Basic earnings (loss) per share attributable to U.S. Cellular shareholders $ 0.56 $ (0.04) $ 0.52 Diluted earnings (loss) per share attributable to U.S. Cellular shareholders $ 0.56 $ (0.04) $ 0.52 Consolidated Balance Sheet Results under prior accounting standards Adjustment As reported As of March 31, 2018 (Dollars in millions) Accounts receivable Customers and agents, less allowances $ 730 $ 59 $ 789 Roaming 26 (11) 15 Prepaid expenses 87 (21) 66 Other current assets 19 13 32 Total current assets 1,550 41 1,591 Licenses 2,230 1 2,231 Investments in unconsolidated entities 436 14 450 Other assets and deferred charges 383 154 537 Total assets 6,838 210 7,048 Customer deposits and deferred revenues 158 (26) 132 Accrued taxes 59 (1) 58 Other current liabilities 86 4 90 Total current liabilities 638 (22) 616 Deferred income tax liability, net 477 49 526 Other deferred liabilities and credits 349 10 359 Retained earnings 2,203 172 2,375 Total U.S. Cellular shareholders' equity 3,735 172 3,907 Noncontrolling interests 10 1 11 Total equity 3,745 173 3,918 Total liabilities and equity 6,838 210 7,048
Disaggregation of revenue	In the following table, revenue is disaggregated by type of service and timing of revenue recognition. Service revenues are recognized over time and Equipment sales are point in time. Three Months Ended March 31, 2018 (Dollars in millions) Revenues from contracts with customers: Retail service $ 649 Inbound roaming 27 Other service 32 Service revenues from contracts with customers 708 Equipment sales 218 Total revenues from contracts with customers 1 $ 926 1 These amounts do not include revenues outside the scope of ASU 2014-09; therefore, revenue line items in this table will not agree to amounts presented in the Consolidated Statement of Operations.
Contract with customer, Assets and Liabilities	The accounts receivable balance related to amounts billed and not paid on contracts with customers, net of allowances, is shown in the table below. Bad debts expense recognized for the three months ended March 31, 2018, related to receivables was $ 19 million. Three Months Ended March 31, 2018 (Dollars in millions) Accounts receivable Customer and agents $ 789 Roaming 15 Other 27 Total 1 $ 831 1 These amounts do not include accounts receivable related to revenues outside the scope of ASU 2014-09; therefore, accounts receivable line items presented in this table will not agree to amounts presented in the Consolidated Balance Sheet. The following table provides a rollforward of contract assets from contracts with customers, which are recorded in Other current assets and Other assets and deferred charges in the Consolidated Balance Sheet. Contract Assets (Dollars in millions) Balance at December 31, 2017 $ – Change in accounting policy 26 Contract additions 8 Terminated contracts (1) Bad debts expense – Revenue recognized (8) Balance at March 31, 2018 $ 25 The following table provides a rollforward of contract liabilities from contracts with customers, which are recorded in Customer deposits and deferred revenues and Other deferred liabilities and credits in the Consolidated Balance Sheet. Contract Liabilities (Dollars in millions) Balance at December 31, 2017 $ – Change in accounting policy - Deferred revenues reclassification 1 167 Change in accounting policy - Retained earnings impact (21) Contract additions 24 Terminated contracts – Revenue recognized (43) Balance at March 31, 2018 $ 127 1 This amount represents U.S. Cellular's obligation to transfer goods or services to customers for which it had received payment and classified as deferred revenue at December 31, 2017.
Remaining performance obligation	The following table includes estimated service revenue expected to be recognized in the future related to performance obligations that are unsatisfied (or partially unsatisfied) at the end of the reporting period. These estimates are based on contracts in place as of March 31, 2018, and may vary from actual results due to future contract modifications. As a practical expedient, revenue related to contracts of less than one year, generally contracts with month-to-month customers, are excluded from these estimates. Service Revenue (Dollars in millions) Remainder of 2018 $ 244 2019 86 Thereafter 3 Total $ 333

Fair Value Measurements (Table)

Fair Value Measurements (Table)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair value measurements	U.S. Cellular has applied the provisions of fair value accounting for purposes of computing the fair value of financial instruments for disclosure purposes as displayed below. Level within the Fair Value Hierarchy March 31, 2018 December 31, 2017 Book Value Fair Value Book Value Fair Value (Dollars in millions) Cash and cash equivalents 1 $ 509 $ 509 $ 352 $ 352 Short-term investments 1 – – 50 50 Long-term debt Retail 2 917 944 917 939 Institutional 2 534 555 534 522 Other 2 188 188 191 191

Equipment Installment Plans (Ta

Equipment Installment Plans (Table)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Equipment installment plans	The following table summarizes equipment installment plan receivables as of March 31, 2018 and December 31, 2017 . March 31, 2018 December 31, 2017 (Dollars in millions) Equipment installment plan receivables, gross $ 871 $ 873 Deferred interest – (80) Equipment installment plan receivables, net of deferred interest 871 793 Allowance for credit losses (66) (65) Equipment installment plan receivables, net $ 805 $ 728 Net balance presented in the Consolidated Balance Sheet as: Accounts receivable — Customers and agents (Current portion) $ 496 $ 428 Other assets and deferred charges (Non-current portion) 309 300 Equipment installment plan receivables, net $ 805 $ 728
Equipment installment plan receivables credit categories	The balance and aging of the equipment installment plan receivables on a gross basis by credit category were as follows: March 31, 2018 December 31, 2017 Lower Risk Higher Risk Total Lower Risk Higher Risk Total (Dollars in millions) Unbilled $ 809 $ 19 $ 828 $ 807 $ 20 $ 827 Billed — current 28 1 29 31 1 32 Billed — past due 12 2 14 12 2 14 Equipment installment plan receivables, gross $ 849 $ 22 $ 871 $ 850 $ 23 $ 873
Equipment installment plans allowance for credit losses	Activity for the three months ended March 31, 2018 and 2017 , in the allowance for credit losses balance for the equipment installment plan receivables was as follows: March 31, 2018 March 31, 2017 (Dollars in millions) Allowance for credit losses, beginning of period $ 65 $ 50 Bad debts expense 14 15 Write-offs, net of recoveries (13) (12) Allowance for credit losses, end of period $ 66 $ 53

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per share	The amounts used in computing earnings per common share and the effects of potentially dilutive securities on the weighted average number of common shares were as follows: Three Months Ended March 31, 2018 2017 (Dollars and shares in millions, except per share amounts) Net income attributable to U.S. Cellular shareholders $ 45 $ 26 Weighted average number of shares used in basic earnings per share 85 85 Effects of dilutive securities 1 1 Weighted average number of shares used in diluted earnings per share 86 86 Basic earnings per share attributable to U.S. Cellular shareholders $ 0.52 $ 0.31 Diluted earnings per share attributable to U.S. Cellular shareholders $ 0.52 $ 0.31

Intangible Assets (Tables)

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Licenses
Licenses	Activity related to Licenses for the three months ended March 31, 2018 , is presented below: Licenses (Dollars in millions) Balance at December 31, 2017 $ 2,223 Acquisitions 1 Transferred to Assets held for sale (10) Exchanges - Licenses received 18 Exchanges - Licenses surrendered (1) Balance at March 31, 2018 $ 2,231

Investment in Unconsolidated En

Investment in Unconsolidated Entities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments in Unconsolidated Entities [Abstract]
Equity and measurement alternative method investments	U.S. Cellular’s Investments in unconsolidated entities are accounted for using either the equity method or measurement alternative method as shown in the table below. The measurement alternative method was elected for investments without readily determinable fair values formerly accounted for under the cost method. The measurement alternative fair value represents cost minus any impairments plus or minus any observable price changes. U.S. Cellular did not have an impairment or observable price change related to these investments for the three months ended March 31, 2018. March 31, December 31, 2018 2017 (Dollars in millions) Equity method investments $ 444 $ 411 Measurement alternative method investments 6 4 Total investments in unconsolidated entities $ 450 $ 415
Equity method investments, summarized results of operations	The following table, which is based in part on information provided by third parties, summarizes the combined results of operations of U.S. Cellular’s equity method investments. Three Months Ended March 31, 2018 2017 (Dollars in millions) Revenues $ 1,657 $ 1,610 Operating expenses 1,208 1,212 Operating income 449 398 Other expense, net (1) – Net income $ 448 $ 398

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2018
Variable Interest Entities [Abstract]
Consolidated VIE assets and liabilities	The following table presents the classification and balances of the consolidated VIEs’ assets and liabilities in U.S. Cellular’s Consolidated Balance Sheet. March 31, December 31, 2018 2017 (Dollars in millions) Assets Cash and cash equivalents $ 1 $ 3 Accounts receivable 543 476 Other current assets 8 8 Licenses 654 655 Property, plant and equipment, net 96 99 Other assets and deferred charges 321 303 Total assets $ 1,623 $ 1,544 Liabilities Current liabilities $ 32 $ 39 Deferred liabilities and credits 14 13 Total liabilities $ 46 $ 52

Basis Of Presentation, Restrict

Basis Of Presentation, Restricted Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Basis of Presentation [Abstract]
Cash and cash equivalents	$ 509	$ 352
Other current assets	1
Cash, cash equivalents and restricted cash in the statement of cash flows	$ 510	$ 352	$ 572	$ 586

Basis of Presentation, Narrativ

Basis of Presentation, Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basis of Presentation [Line Items]
Amounts recorded gross in revenues that are billed to customers and remitted to governmental authorities	$ 17	$ 14
TDS
Basis of Presentation [Line Items]
TDS ownership of U.S. Cellular	83.00%

Revenue Recognition, Consolidat

Revenue Recognition, Consolidated Statement Of Operations (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating revenues
Service	$ 724	$ 746
Equipment sales	218	190
Total operating revenues	942	936
Cost of equipment sold	219	228
(Gain) loss on license sales and exchanges, net	(7)	(17)
Total operating expenses	877	882
Operating income (loss)	65	54
Income (loss) before income taxes	77	61
Income tax expense (benefit)	22	33
Net income (loss)	55	28
Net income (loss) attributable to U.S. Cellular shareholders	$ 45	$ 26
Basic earnings (loss) per share attributable to U.S. Cellular shareholders	$ 0.52	$ 0.31
Diluted earnings (loss) per share attributable to U.S. Cellular shareholders	$ 0.52	$ 0.31
Results under prior accounting standards
Operating revenues
Service	$ 754
Equipment sales	198
Total operating revenues	952
Cost of equipment sold	222
(Gain) loss on license sales and exchanges, net	(6)
Total operating expenses	882
Operating income (loss)	70
Income (loss) before income taxes	82
Income tax expense (benefit)	24
Net income (loss)	58
Net income (loss) attributable to U.S. Cellular shareholders	$ 48
Basic earnings (loss) per share attributable to U.S. Cellular shareholders	$ 0.56
Diluted earnings (loss) per share attributable to U.S. Cellular shareholders	$ 0.56
Adjustment
Operating revenues
Service	$ (30)
Equipment sales	20
Total operating revenues	(10)
Cost of equipment sold	(3)
(Gain) loss on license sales and exchanges, net	(1)
Total operating expenses	(5)
Operating income (loss)	(5)
Income (loss) before income taxes	(5)
Income tax expense (benefit)	(2)
Net income (loss)	(3)
Net income (loss) attributable to U.S. Cellular shareholders	$ (3)
Basic earnings (loss) per share attributable to U.S. Cellular shareholders	$ (0.04)
Diluted earnings (loss) per share attributable to U.S. Cellular shareholders	$ (0.04)

Revenue Recognition, Consolid29

Revenue Recognition, Consolidated Balance Sheet (Details) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounts receivable
Customers and agents, less allowances		$ 789	$ 775
Roaming		15	26
Prepaid expenses		66	79
Other current assets		32	21
Total current assets		1,591	1,483
Licenses		2,231	2,223
Investments in unconsolidated entities		450	415
Other assets and deferred charges		537	390
Total assets	[1]	7,048	6,841
Customer deposits and deferred revenues		132	185
Accrued taxes		58	56
Other current liabilities		90	90
Total current liabilities		616	733
Deferred income tax liability, net		526	461
Other deferred liabilities and credits		359	337
Retained earnings		2,375	2,157
Total U.S. Cellular shareholders' equity		3,907	3,677
Noncontrolling interests		11	10
Total equity		3,918	3,687	$ 3,682	$ 3,645
Total liabilities and equity	[1]	7,048	$ 6,841
Results under prior accounting standards
Accounts receivable
Customers and agents, less allowances		730
Roaming		26
Prepaid expenses		87
Other current assets		19
Total current assets		1,550
Licenses		2,230
Investments in unconsolidated entities		436
Other assets and deferred charges		383
Total assets		6,838
Customer deposits and deferred revenues		158
Accrued taxes		59
Other current liabilities		86
Total current liabilities		638
Deferred income tax liability, net		477
Other deferred liabilities and credits		349
Retained earnings		2,203
Total U.S. Cellular shareholders' equity		3,735
Noncontrolling interests		10
Total equity		3,745
Total liabilities and equity		6,838
Adjustment
Accounts receivable
Customers and agents, less allowances		59
Roaming		(11)
Prepaid expenses		(21)
Other current assets		13
Total current assets		41
Licenses		1
Investments in unconsolidated entities		14
Other assets and deferred charges		154
Total assets		210
Customer deposits and deferred revenues		(26)
Accrued taxes		(1)
Other current liabilities		4
Total current liabilities		(22)
Deferred income tax liability, net		49
Other deferred liabilities and credits		10
Retained earnings		172
Total U.S. Cellular shareholders' equity		172
Noncontrolling interests		1
Total equity		173
Total liabilities and equity		$ 210
[1]	The consolidated total assets as of March 31, 2018 and December 31, 2017, include assets held by consolidated variable interest entities (VIEs) of $793 million and $785 million, respectively, which are not available to be used to settle the obligations of U.S. Cellular. The consolidated total liabilities as of March 31, 2018 and December 31, 2017, include certain liabilities of consolidated VIEs of $21 million and $24 million, respectively, for which the creditors of the VIEs have no recourse to the general credit of U.S. Cellular. See Note 9 — Variable Interest Entities for additional information.

Revenue Recognition, Disaggrega

Revenue Recognition, Disaggregation Of Revenue (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Revenue from contracts with customers
Revenue from contracts with customers	$ 926	[1]
Transferred over time
Revenue from contracts with customers
Revenue from contracts with customers	708
Transferred over time | Retail service
Revenue from contracts with customers
Revenue from contracts with customers	649
Transferred over time | Inbound roaming
Revenue from contracts with customers
Revenue from contracts with customers	27
Transferred over time | Other service
Revenue from contracts with customers
Revenue from contracts with customers	32
Transferred at point in time
Revenue from contracts with customers
Revenue from contracts with customers	$ 218
[1]	These amounts do not include revenues outside the scope of ASU 2014-09; therefore, revenue line items in this table will not agree to amounts presented in the Consolidated Statement of Operations.

Revenue Recognition, Accounts R

Revenue Recognition, Accounts Receivable (Details) - USD ($) $ in Millions		Mar. 31, 2018	Dec. 31, 2017
Accounts receivable
Customer and agents		$ 789	$ 775
Roaming		15	26
Other		35	$ 41
Accounts receivable from contract with customer
Accounts receivable
Customer and agents		789
Roaming		15
Other		27
Total	[1]	$ 831
[1]	These amounts do not include accounts receivable related to revenues outside the scope of ASU 2014-09; therefore, accounts receivable line items presented in this table will not agree to amounts presented in the Consolidated Balance Sheet.

Revenue Recognition, Contract A

Revenue Recognition, Contract Asset (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Contract Assets
Change in accounting policy	$ 176
Contract assets
Contract Assets
Balance, beginning of period	0
Change in accounting policy	26
Contract additions	8
Terminated contracts	(1)
Revenue recognized	(8)
Balance, end of period	$ 25

Revenue Recognition, Contract L

Revenue Recognition, Contract Liabilities (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Contract Liabilities
Balance, beginning of period	$ 0
Change in accounting policy - Deferred revenues reclassification	167	[1]
Change in accounting policy - Retained earnings impact	(21)
Contract additions	24
Revenue recognized	(43)
Balance, end of period	$ 127
[1]	This amount represents U.S. Cellular's obligation to transfer goods or services to customers for which it had received payment and classified as deferred revenue at December 31, 2017.

Revenue Recognition, Performanc

Revenue Recognition, Performance Obligations (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 333
Revenue recognition, remaining performance obligation, optional practical expedient	true
Remainder of 2018
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 244
2,019
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	86
Thereafter
Revenue Remaining Performance Obligation Expected Timing Of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 3

Revenue Recognition, Narrative

Revenue Recognition, Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue recognition [Line Items]
Cumulative effect of accounting change	$ 176
Bad debts expense	$ 19	$ 24
Revenue recognition, practical expedient	false
Capitalized contract cost
Capitalized contract cost related to commission fees	$ 133
Amortization of contract cost assets	27
Impairment of capitalized contract cost	$ 0
Contract cost practical expedient	true
Retained Earnings [Member]
Revenue recognition [Line Items]
Cumulative effect of accounting change	$ 175
Revenue from contract with customer
Revenue recognition [Line Items]
Bad debts expense	19
Revenue recognition | Retained Earnings [Member]
Revenue recognition [Line Items]
Cumulative effect of accounting change	$ 175

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Financial Instruments
Cash and cash equivalents	$ 509	$ 352
Short-term investments	$ 0	$ 50
Institutional and Other | Minimum
Financial Instruments
Fair value assumption, interest rate	4.58%	4.74%
Institutional and Other | Maximum
Financial Instruments
Fair value assumption, interest rate	6.34%	7.13%
Fair Value | Level 1
Financial Instruments
Cash and cash equivalents	$ 509	$ 352
Short-term investments	0	50
Fair Value | Level 2 | Retail
Financial Instruments
Long-term debt	944	939
Fair Value | Level 2 | Institutional
Financial Instruments
Long-term debt	555	522
Fair Value | Level 2 | Other
Financial Instruments
Long-term debt	188	191
Book Value
Financial Instruments
Cash and cash equivalents	509	352
Short-term investments	0	50
Book Value | Retail
Financial Instruments
Long-term debt	917	917
Book Value | Institutional
Financial Instruments
Long-term debt	534	534
Book Value | Other
Financial Instruments
Long-term debt	$ 188	$ 191

Equipment Installment Plan Rece

Equipment Installment Plan Receivables, EIP Receivables (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Equipment installment plans [Line Items]
Equipment installment plan receivables, gross	$ 871	$ 873
Deferred interest	0	(80)
Equipment installment plan receivables, net of deferred interest	871	793
Allowance for credit losses	(66)	(65)
Equipment installment plan receivables, net	805	728
Accounts receivable - Customers and agents
Equipment installment plans [Line Items]
Equipment installment plan receivables, net	496	428
Other assets and deferred charges
Equipment installment plans [Line Items]
Equipment installment plan receivables, net	$ 309	$ 300

Equipment Installment Plan Re38

Equipment Installment Plan Receivables, Gross Receivables by Credit Category (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables, gross	$ 871	$ 873
Unbilled
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables	828	827
Billed
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables	29	32
Equipment installment plan receivables, past due	14	14
Lower Risk
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables, gross	849	850
Lower Risk | Unbilled
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables	809	807
Lower Risk | Billed
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables	28	31
Equipment installment plan receivables, past due	12	12
Higher Risk
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables, gross	22	23
Higher Risk | Unbilled
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables	19	20
Higher Risk | Billed
Financing Receivable, Recorded Investment [Line Items]
Equipment installment plan receivables	1	1
Equipment installment plan receivables, past due	$ 2	$ 2

Equipment Installment Plan Re39

Equipment Installment Plan Receivables, Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance for credit losses
Allowance for credit losses, beginning of period	$ 65
Allowance for credit losses, end of period	66
Equipment Installment Plan Receivable
Allowance for credit losses
Allowance for credit losses, beginning of period	65	$ 50
Bad debts expense	14	15
Write-offs, net of recoveries	(13)	(12)
Allowance for credit losses, end of period	$ 66	$ 53

Equipment Installment Plan Re40

Equipment Installment Plan Receivables, Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Equipment installment plans [Line Items]
Guarantee liability	$ 13	$ 15

Income Taxes, Narrative (Detail

Income Taxes, Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Income Tax Disclosure [Abstract]
Income tax benefit, adjustment	$ 3

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings per share
Net income attributable to U.S. Cellular shareholders	$ 45	$ 26
Weighted average number of shares used in basic earnings per share	85	85
Effects of dilutive securities	1	1
Weighted average number of shares used in diluted earnings per share	86	86
Basic earnings per share attributable to U.S. Cellular shareholders	$ 0.52	$ 0.31
Diluted earnings per share attributable to U.S. Cellular shareholders	$ 0.52	$ 0.31

Earnings Per Share, Narrative (

Earnings Per Share, Narrative (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings per share, Other disclosures
Antidilutive securities	2	2

Intangible Assets (Details)

Intangible Assets (Details) - Licenses $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Licenses
Balance, beginning of period	$ 2,223
Acquisitions	1
Transferred to Assets held for sale	(10)
Exchanges - Licenses received	18
Exchanges - Licenses surrendered	(1)
Balance, end of period	$ 2,231

Investments in Unconsolidated45

Investments in Unconsolidated Entities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Equity and measurement alternative method investments
Equity method investments	$ 444		$ 411
Measurement alternative method investments	6		4
Total investments in unconsolidated entities	450		$ 415
Equity method investments, combined income statements
Revenues	1,657	$ 1,610
Operating expenses	1,208	1,212
Operating income	449	398
Other expense, net	(1)
Net income	$ 448	$ 398

Investments in Unconsolidated46

Investments in Unconsolidated Entities, Narrative (Details) $ in Millions	Mar. 31, 2018USD ($)
Equity Securities without Readily Determinable Fair Value [Line Items]
Measurement alternative, impairment	$ 0
Measurement alternative, observable price change	$ 0

Variable Interest Entities, Con

Variable Interest Entities, Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 509	$ 352
Accounts receivable	789	775
Other current assets	32	21
Licenses	2,231	2,223
Property, plant and equipment, net	2,233	2,320
Other assets and deferred charges	537	390
Liabilities
Current liabilities	616	733
Consolidated Variable Interest Entities
Assets
Cash and cash equivalents	1	3
Accounts receivable	543	476
Other current assets	8	8
Licenses	654	655
Property, plant and equipment, net	96	99
Other assets and deferred charges	321	303
Total assets	1,623	1,544
Liabilities
Current liabilities	32	39
Deferred liabilities and credits	14	13
Total liabilities	$ 46	$ 52

Variable Interest Entities, Nar

Variable Interest Entities, Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Variable Interest Entities, Other Disclosures
Capital contributions, loans or advances	$ 19	$ 654
Investments in unconsolidated entities, maximum exposure	$ 5		$ 4
Out-of-period adjustment description	During the three months ended March 31, 2018, U.S. Cellular recorded out-of-period adjustments attributable to 2016 and 2017 due to errors in the application of accounting guidance applicable to the calculation of Noncontrolling interests with redemption features related to King Street Wireless, Inc.  These out-of-period adjustments had the impact of increasing Net income attributable to noncontrolling interests, net of tax, by $8 million and decreasing Net income attributable to U.S. Cellular shareholders by $8 million for the three months ended March 31, 2018. U.S. Cellular determined that these adjustments were not material to any of the periods impacted.
Net income attributable to noncontrolling interests, net of tax
Variable Interest Entities, Other Disclosures
Out-of-period adjustment	$ 8
Net income attributable to U.S. Cellular shareholders
Variable Interest Entities, Other Disclosures
Out-of-period adjustment	(8)
USCC EIP LLC
Variable Interest Entities, Other Disclosures
Capital contributions, loans or advances	$ 10	$ 650