Debt and Capital Lease Obligations (Non-cash Refinancing Transactions) (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Aggregate debt which resulted in non-cash borrowings and repayments	$ 5,418.8us-gaap_NotesAssumed1	$ 5,061.5us-gaap_NotesAssumed1	$ 3,793.4us-gaap_NotesAssumed1
Virgin Media Merger Agreement [Member]
Debt Instrument [Line Items]
Liabilities assumed		$ 3,557.5

The fair value of liabilities assumed in noncash investing or financing activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4313-108586

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

Name:	us-gaap_LiabilitiesAssumed1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration