Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	$ 13,028		$ 13,028		$ 12,874
Payments to Acquire Productive Assets	241	208	404	377
Adjusted EBITDA by Segment	459	387	917	773
Revenue	1,625	1,565	3,234	3,142
Income Tax Expense (Benefit)	(12)	(11)	(19)	(25)
Other Income	(193)	(153)	(338)	(372)
Depreciation, Depletion and Amortization	(187)	(199)	(371)	(393)
Share-based Compensation	(16)	(48)	(26)	(85)
Net Income (Loss) Available to Common Stockholders, Basic	51	(24)	163	(102)
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	254		254		266
Payments to Acquire Productive Assets	64	34	83	55
Adjusted EBITDA by Segment	(167)	(181)	(333)	(353)
North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	8,239		8,239		8,133
Payments to Acquire Productive Assets	105	101	202	200
Adjusted EBITDA by Segment	480	434	968	862
Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	2,058		2,058		2,030
Payments to Acquire Productive Assets	29	43	48	69
Adjusted EBITDA by Segment	56	58	110	115
Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	2,477		2,477		2,445
Payments to Acquire Productive Assets	43	30	71	53
Adjusted EBITDA by Segment	90	76	172	149
Core Network Service [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,479	1,379	2,936	2,751
Core Network Service [Member] \| North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,051	970	2,094	1,937
Core Network Service [Member] \| Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	229	220	454	443
Core Network Service [Member] \| Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	199	189	388	371
Wholesale Voice Services and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	146	186	298	391
Wholesale Voice Services and Other [Member] \| North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	137	175	282	368
Wholesale Voice Services and Other [Member] \| Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	5	8	10	17
Wholesale Voice Services and Other [Member] \| Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 4	$ 3	$ 6	$ 6

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Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Reflects the sum of all other revenue and income recognized by the entity in the period not otherwise specified in the income statement.

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The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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