Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

Name:	us-gaap_LongTermCommitmentExcludingUnconditionalPurchaseObligationAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Describes the terms of a significant arrangement with a supplier (excluding an unconditional purchase obligation) to acquire goods or services over a period of time beyond one year or the normal operating cycle, if longer, which may include identification of the goods or services to be purchased, pricing, effects on pricing of failing to reach minimum quantities required to be purchased, cancellation rights, and termination provisions.

No definition available.

Name:	us-gaap_LongTermPurchaseCommitmentDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Amount of loss contingency liability.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_LossContingencyEstimateAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	us-gaap_OperatingLeasesRentExpenseAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The remaining estimated amount the entity agreed to spend under the long-term purchase commitment.

No definition available.

Name:	usm_RemainingLongTermPurchaseCommitmentEstimate
Namespace Prefix:	usm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_InventoriesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=usm_SoftwareAndSoftwareDevelopmentCosts3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=usm_SoftwareAndSoftwareDevelopmentCosts2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: