Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	$ 21,303us-gaap_Assets		$ 20,947us-gaap_Assets
Payments to Acquire Productive Assets	254	163
Adjusted EBITDA by Segment	635lvlt_AdjustedEBITDAbySegment	458lvlt_AdjustedEBITDAbySegment
Revenue	2,053us-gaap_Revenues	1,609us-gaap_Revenues
Income Tax Expense (Benefit)	(5)us-gaap_IncomeTaxExpenseBenefit	(7)us-gaap_IncomeTaxExpenseBenefit
Other Income	(189)us-gaap_OtherIncome	(145)us-gaap_OtherIncome
Depreciation, Depletion and Amortization	(288)	(184)
Share-based Compensation	(31)us-gaap_ShareBasedCompensation	(10)us-gaap_ShareBasedCompensation
Net Income (Loss) Available to Common Stockholders, Basic	122	112
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	285		284
Payments to Acquire Productive Assets	31	19
Adjusted EBITDA by Segment	(241)	(166)
North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	16,781		16,242
Payments to Acquire Productive Assets	167	97
Adjusted EBITDA by Segment	740	488
Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	1,831		1,970
Payments to Acquire Productive Assets	28	19
Adjusted EBITDA by Segment	56	54
Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Assets	2,406		2,451
Payments to Acquire Productive Assets	28	28
Adjusted EBITDA by Segment	80	82
Core Network Service [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,927	1,457
Core Network Service [Member] \| North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	1,535	1,043
Core Network Service [Member] \| Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	207	225
Core Network Service [Member] \| Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	185	189
Wholesale Voice Services and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	126	152
Wholesale Voice Services and Other [Member] \| North America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	118	145
Wholesale Voice Services and Other [Member] \| Europe [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	4	5
Wholesale Voice Services and Other [Member] \| Latin America [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 4	$ 2

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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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