Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	$ 20,884		$ 20,884		$ 20,947
Payments to Acquire Productive Assets	317	$ 241	571	$ 404
Adjusted EBITDA by Segment	665	459	1,300	917
Revenue	2,061	1,625	4,114	3,234
Income Tax Expense	(18)	(12)	(23)	(19)
Other Expenses	(345)	(193)	(534)	(338)
Depreciation, Depletion and Amortization	(288)	(187)	(576)	(371)
Share-based Compensation	(27)	(16)	(58)	(26)
Net Income (Loss) Available to Common Stockholders, Basic	(13)	51	109	163
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	268		268		284
Payments to Acquire Productive Assets	35	64	66	83
Adjusted EBITDA by Segment	(238)	(167)	(479)	(333)
North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	16,294		16,294		16,242
Payments to Acquire Productive Assets	191	105	358	202
Adjusted EBITDA by Segment	767	480	1,507	968
Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	1,890		1,890		1,970
Payments to Acquire Productive Assets	45	29	73	48
Adjusted EBITDA by Segment	57	56	113	110
Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	2,432		2,432		$ 2,451
Payments to Acquire Productive Assets	46	43	74	71
Adjusted EBITDA by Segment	79	90	159	172
Core Network Service [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,941	1,479	3,868	2,936
Core Network Service [Member] | North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,551	1,051	3,086	2,094
Core Network Service [Member] | Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	204	229	411	454
Core Network Service [Member] | Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	186	199	371	388
Wholesale Voice Services and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	120	146	246	298
Wholesale Voice Services and Other [Member] | North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	115	137	233	282
Wholesale Voice Services and Other [Member] | Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	3	5	7	10
Wholesale Voice Services and Other [Member] | Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 2	$ 4	$ 6	$ 6