Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Licenses
Balance, beginning of period	$ 1,401,126	$ 1,456,794
Acquisitions	41,707	16,540
Divestitures		(59,419)
Transferred to Assets held for sale	(56,809)	(16,027)
Exchanges, net	55,780usm_IncreaseDecreaseLicensesExchange
Other	1,634	3,238
Balance, end of period	1,443,438	1,401,126
Goodwill
Balance, beginning of year	387,524us-gaap_Goodwill	421,743us-gaap_Goodwill
Divestitures	(1,092)	(505)
Transferred to Assets held for sale	(16,281)
NY1 & NY2 Deconsolidation		(33,714)usm_GoodwillDeconsolidated
Balance, end of year	$ 370,151us-gaap_Goodwill	$ 387,524us-gaap_Goodwill

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

Name:	us-gaap_Goodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Definition

Amount of divestiture of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of increase in assets, excluding financial assets and goodwill, lacking physical substance with an indefinite life, resulting from a business combination.

+ References

No definition available.

+ Details

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

- Definition

Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Definition

Amount of write-off of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit associated with the sale of all or a portion of a reporting unit.

+ References

No definition available.

+ Details

Name:	us-gaap_IndefiniteLivedIntangibleAssetsWrittenOffRelatedToSaleOfBusinessUnit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Goodwill that is transferred to assets held for sale during the period.

+ References

No definition available.

+ Details

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

- Definition

Indefinite-lived intangible assets that were transferred to assets held for sale during the period.

+ References

No definition available.

+ Details

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

- Definition

The aggregate amount of goodwill that was deconsolidated in the period.

+ References

No definition available.

+ Details

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

- Definition

The net increase or decrease in Licenses (an indefinite lived intangible asset) carrying value as a result of exchanges that are primarily non-monetary in nature.

+ References

No definition available.

+ Details

Name:	usm_IncreaseDecreaseLicensesExchange
Namespace Prefix:	usm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Changes not otherwise specified in the taxonomy to the account balance of a major indefinite-lived intangible asset class during the period.

+ References

No definition available.

+ Details

Name:	usm_IndefiniteLivedIntangibleAssetsOtherChanges
Namespace Prefix:	usm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration