Subsequent Events (Narrative) (Details) In Millions, except Per Share data	12 Months Ended
Dec. 31, 2011 USD ($)	Dec. 31, 2011 MXN	Aug. 01, 2011
Subsequent Events
Agreement date between the Company and America Movil			August 1, 2011
Sales price per share (in Mexican pesos) of the company's investment in Telmex		10.50
Estimated total sales price (in U.S. dollars) of the company's investment in Telmex	$ 1,370
Estimated diluted earnings per share impact of the gain on the sale of the investment in Telmex - minimum	$ 0.01
Estimated diluted earnings per share impact of the gain on the sale of the investment in Telmex - maximum	$ 0.03

Date of the agreement between the registrant and the buyer of the registrant's interest in an equity method investment--not necessarily the same as the closing date of the transaction.

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- Definition

Consideration that the buyer will give to the registrant for its interest in an equity method investment.

+ Details

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- Definition

The estimated maximum (after-tax) diluted earnings per share impact of the gain on the pendng sale of the registrant's interest in an equity method investment.

+ Details

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- Definition

The estimated minimum (after-tax) diluted earnings per share impact of the gain on the pendng sale of the registrant's interest in an equity method investment.

+ Details

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- Definition

This item represents the amount of net sales proceeds received on disposal of an equity method investment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 35
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=6903645&loc=d3e32847-111569

+ Details

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- Details

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