Segment Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	$ 20,883		$ 20,883		$ 20,947
Payments to Acquire Productive Assets	328	$ 204	899	$ 608
Adjusted EBITDA by Segment	657	471	1,957	1,388
Revenue	2,062	1,629	6,176	4,863
Income Tax Expense	(16)	(8)	(39)	(27)
Other Expenses	(310)	(169)	(844)	(507)
Depreciation, Depletion and Amortization	(296)	(187)	(872)	(558)
Share-based Compensation	(34)	(22)	(92)	(48)
Net Income (Loss) Available to Common Stockholders, Basic	1	85	110	248
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	262		262		284
Payments to Acquire Productive Assets	37	19	103	102
Adjusted EBITDA by Segment	(244)	(170)	(723)	(503)
North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	16,615		16,615		16,242
Payments to Acquire Productive Assets	202	116	560	318
Adjusted EBITDA by Segment	760	492	2,267	1,460
Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	1,859		1,859		1,970
Payments to Acquire Productive Assets	41	34	114	82
Adjusted EBITDA by Segment	63	57	176	167
Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	2,147		2,147		$ 2,451
Payments to Acquire Productive Assets	48	35	122	106
Adjusted EBITDA by Segment	78	92	237	264
Core Network Service [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,946	1,482	5,814	4,418
Core Network Service [Member] \| North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,551	1,063	4,637	3,157
Core Network Service [Member] \| Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	212	219	623	673
Core Network Service [Member] \| Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	183	200	554	588
Wholesale Voice Services and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	116	147	362	445
Wholesale Voice Services and Other [Member] \| North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	110	128	343	410
Wholesale Voice Services and Other [Member] \| Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	3	4	10	14
Wholesale Voice Services and Other [Member] \| Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 3	$ 15	$ 9	$ 21

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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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