Goodwill, Customer Relationships and Other Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 segment	Sep. 30, 2011	Apr. 02, 2012	Dec. 31, 2011
Intangible assets
Goodwill	$ 21,732		$ 21,732		$ 21,732	$ 21,732
Total other intangible assets, net	1,859		1,859			2,243
Other intangible assets subject to amortization
Increase (decrease) in amortization expense	409	459	1,268	967
Indefinite-lived intangible assets
Indefinite-life intangible assets	268		268			422
Reclassification from Other intangible assets, net to current assets-other	154		154
Discrete projection period			9 years
Weighted average cost of capital to calculate discount rate as of the measurement date (as a percent)			6.00%
Pre-tax cost component of weighted average cost of capital, cost of debt (as a percent)	3.20%		3.20%
Cost of debt component of weighted average cost of capital, cost of equity (as a percent)	8.40%		8.40%
Percentage of reasonable implied control premium	14.00%		14.00%
Number of operating segments			4
Previously allocated amounts
Intangible assets
Goodwill					21,732
Regional markets
Intangible assets
Goodwill					15,170
Regional markets | Previously allocated amounts
Intangible assets
Goodwill					13,816
Wholesale markets
Intangible assets
Goodwill					3,283
Wholesale markets | Previously allocated amounts
Intangible assets
Goodwill					3,287
Enterprise markets - network
Intangible assets
Goodwill					1,788
Enterprise markets - network | Previously allocated amounts
Intangible assets
Goodwill					3,320
Enterprise markets - data hosting
Intangible assets
Goodwill					1,491
Indefinite-lived intangible assets
Weighted average cost of capital to calculate discount rate as of the measurement date (as a percent)			11.00%
Pre-tax cost component of weighted average cost of capital, cost of debt (as a percent)	3.20%		3.20%
Cost of debt component of weighted average cost of capital, cost of equity (as a percent)	12.00%		12.00%
Enterprise markets - data hosting | Previously allocated amounts
Intangible assets
Goodwill					1,309
Capitalized software
Intangible assets
Finite-life intangible assets, less accumulated amortization	1,447		1,447			1,622
Accumulated amortization	749		749			441
Capitalized software | Maximum
Other intangible assets subject to amortization
Estimated life			7 years
Development costs, integrated billing and customer care system
Intangible assets
Finite-life intangible assets, less accumulated amortization	237		237
Other intangible assets subject to amortization
Estimated life			20 years
Tradenames and patents
Intangible assets
Finite-life intangible assets, less accumulated amortization	144		144			199
Accumulated amortization	126		126			71
Other intangible assets subject to amortization
Estimated life			4 years
Customer relationships
Intangible assets
Finite-life intangible assets, less accumulated amortization	7,341		7,341			8,239
Accumulated amortization	$ 2,235		$ 2,235			$ 1,337
Customer relationships | Minimum
Other intangible assets subject to amortization
Estimated life			10 years
Customer relationships | Maximum
Other intangible assets subject to amortization
Estimated life			12 years 6 months