XML 60 R37.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Variable Interest Entities, Narrative (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016
Variable Interest Entities, Other Disclosures |  |  |
Capital contributions, loans or advances | $ 724 | $ 100 |
Investments in unconsolidated entities, maximum exposure | 4 |  | $ 6
Transfer of net equipment installment plan receivables | 1,093 |  | $ 0
USCC EIP LLC |  |  |
Variable Interest Entities, Other Disclosures |  |  |
Capital contributions, loans or advances | $ 701 |  |

X
- Definition Amount of derecognized financial assets from transactions which comprise an initial transfer and an agreement entered into in contemplation of the initial transfer resulting in retention of substantially all of the exposure to the economic return throughout the term of the transaction, at the date of derecognition. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82924980&loc=SL51823488-111719 + Details
Name: | us-gaap_TransferOfFinancialAssetsAccountedForAsSalesAmountDerecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5728-111685 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5747-111685 + Details
Name: | us-gaap_VariableInterestEntityEntityMaximumLossExposureAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of financial or other support the reporting entity has provided (explicitly or implicitly) to the Variable Interest Entity (VIE) that it was not previously contractually required to provide or that the reporting entity intends to provide, including, for example, situations in which the reporting entity assisted the VIE in obtaining another type of support. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=77990344&loc=SL6759159-111685 + Details
Name: | us-gaap_VariableInterestEntityFinancialOrOtherSupportAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_VariableInterestEntityMeasureOfActivityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=usm_VariableInterestEntityUsccEipLlcMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |