Changes in Carrying Amount of Wireless Licenses (Detail) (USD $) In Millions, unless otherwise specified			3 Months Ended
Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Wireless Licenses
Wireless Licenses, Goodwill and Other Intangible Assets [Line Items]
Beginning balance	$ 75,645	$ 77,744	$ 77,744
Capitalized interest on wireless licenses			133
Reclassifications, adjustments and other			(2,232)
Ending balance	$ 75,645	$ 77,744	$ 75,645

Amount of interest capitalized during the period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Allowance for Funds Used during Construction

-URI http://asc.fasb.org/extlink&oid=6504829

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 34

-Paragraph 21

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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