Comprehensive Income (Schedule Of Accumulated Other Comprehensive Income (Loss) Net Of Taxes) (Details) (GBP £) In Millions, unless otherwise specified	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended	2 Months Ended	3 Months Ended		2 Months Ended	3 Months Ended	1 Months Ended
	Jun. 07, 2013	Mar. 31, 2013	Jun. 07, 2013 Foreign exchange gain	Mar. 31, 2013 Foreign exchange gain	Mar. 31, 2013 Interest expense	Jun. 07, 2013 Selling, general and administrative expenses	Mar. 31, 2013 Selling, general and administrative expenses	Jun. 07, 2013 Derivatives	Mar. 31, 2013 Derivatives	Jun. 07, 2013 Derivatives Interest rate swaps	Mar. 31, 2013 Derivatives Interest rate swaps	Jun. 07, 2013 Derivatives Interest rate swaps Foreign exchange gain	Mar. 31, 2013 Derivatives Interest rate swaps Foreign exchange gain	Mar. 31, 2013 Derivatives Interest rate swaps Interest expense	Jun. 07, 2013 Derivatives Interest rate swaps Selling, general and administrative expenses	Mar. 31, 2013 Derivatives Interest rate swaps Selling, general and administrative expenses	Jun. 07, 2013 Derivatives Cross-currency interest rate swaps	Mar. 31, 2013 Derivatives Cross-currency interest rate swaps	Jun. 07, 2013 Derivatives Cross-currency interest rate swaps Foreign exchange gain	Mar. 31, 2013 Derivatives Cross-currency interest rate swaps Foreign exchange gain	Mar. 31, 2013 Derivatives Cross-currency interest rate swaps Interest expense	Jun. 07, 2013 Derivatives Cross-currency interest rate swaps Selling, general and administrative expenses	Mar. 31, 2013 Derivatives Cross-currency interest rate swaps Selling, general and administrative expenses	Jun. 07, 2013 Pension	Mar. 31, 2013 Pension	Jun. 07, 2013 Pension Foreign exchange gain	Mar. 31, 2013 Pension Foreign exchange gain	Mar. 31, 2013 Pension Interest expense	Jun. 07, 2013 Pension Selling, general and administrative expenses	Mar. 31, 2013 Pension Selling, general and administrative expenses	Jun. 07, 2013 Foreign currency translation	Mar. 31, 2013 Foreign currency translation	Jun. 07, 2013 Foreign currency translation Foreign exchange gain	Mar. 31, 2013 Foreign currency translation Foreign exchange gain	Mar. 31, 2013 Foreign currency translation Interest expense	Jun. 07, 2013 Foreign currency translation Selling, general and administrative expenses	Mar. 31, 2013 Foreign currency translation Selling, general and administrative expenses	Jun. 07, 2013 VMIH and VMIL	Mar. 31, 2013 VMIH and VMIL	Jun. 07, 2013 VMIH and VMIL Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Interest expense	Jun. 07, 2013 VMIH and VMIL Selling, general and administrative expenses	Mar. 31, 2013 VMIH and VMIL Selling, general and administrative expenses	Jun. 07, 2013 VMIH and VMIL Derivatives	Mar. 31, 2013 VMIH and VMIL Derivatives	Jun. 07, 2013 VMIH and VMIL Derivatives Interest rate swaps	Mar. 31, 2013 VMIH and VMIL Derivatives Interest rate swaps	Jun. 07, 2013 VMIH and VMIL Derivatives Interest rate swaps Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Derivatives Interest rate swaps Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Derivatives Interest rate swaps Interest expense	Jun. 07, 2013 VMIH and VMIL Derivatives Interest rate swaps Selling, general and administrative expenses	Mar. 31, 2013 VMIH and VMIL Derivatives Interest rate swaps Selling, general and administrative expenses	Jun. 07, 2013 VMIH and VMIL Derivatives Cross-currency interest rate swaps	Mar. 31, 2013 VMIH and VMIL Derivatives Cross-currency interest rate swaps	Jun. 07, 2013 VMIH and VMIL Derivatives Cross-currency interest rate swaps Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Derivatives Cross-currency interest rate swaps Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Derivatives Cross-currency interest rate swaps Interest expense	Jun. 07, 2013 VMIH and VMIL Derivatives Cross-currency interest rate swaps Selling, general and administrative expenses	Mar. 31, 2013 VMIH and VMIL Derivatives Cross-currency interest rate swaps Selling, general and administrative expenses	Jun. 07, 2013 VMIH and VMIL Pension	Mar. 31, 2013 VMIH and VMIL Pension	Jun. 07, 2013 VMIH and VMIL Pension Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Pension Foreign exchange gain	Mar. 31, 2013 VMIH and VMIL Pension Interest expense	Jun. 07, 2013 VMIH and VMIL Pension Selling, general and administrative expenses	Mar. 31, 2013 VMIH and VMIL Pension Selling, general and administrative expenses	Jun. 30, 2013 Successor
Increase (Decrease) in AOCI [Roll Forward]
AOCI balance at the beginning of the period										£ 3.3	£ 3.3						£ (78.8)	£ (72.8)						£ (107.9)	£ (108.4)																						£ 3.3	£ 3.3						£ (78.8)	£ (72.8)						£ (107.9)	£ (108.4)
AOCI tax effect at the beginning of the period								4.5	1.0															9.8	9.9																				4.5	1.0															9.8	9.9
AOCI total at the beginning of the period	(20.9)	(5.8)																													148.2	161.2						(169.1)	(167.0)
Amounts recognized in other comprehensive income	(41.5)	95.3								0	0						(44.7)	108.3						0	0						3.2	(13.0)						(44.7)	108.3								0	0						(44.7)	108.3						0	0
Amounts reclassified to earnings impacting			39.9	(114.8)	0.5	0.3	0.5					0	0	0	0	0			39.9	(114.8)	0.5	0	0			0	0	0	0.3	0.5			0	0	0	0	0			39.9	(114.8)	0.5	0.3	0.5					0	0	0	0	0			39.9	(114.8)	0.5	0	0			0	0	0	0.3	0.5
Tax effect recognzied	(0.4)	3.4						(0.3)	3.5															(0.1)	(0.1)													(0.4)	3.4						(0.3)	3.5															(0.1)	(0.1)
AOCI balance at the end of the period										3.3	3.3						(83.6)	(78.8)						(107.6)	(107.9)																						3.3	3.3						(83.6)	(78.8)						(107.6)	(107.9)
AOCI tax effect at the end of the period								4.2	4.5															9.7	9.8																				4.2	4.5															9.7	9.8
AOCI total at the end of the period	(22.6)	(20.9)																													151.4	148.2						(174.0)	(169.1)																													(68.4)
Pension liability recognized in other comprehensive income																																																																				£ 0

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e681-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14A

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669686-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 14, 17, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

+ Details

- Definition

Tax effect of other comprehensive income (loss) attributable to both parent entity and noncontrolling interest.

+ References

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 20

-Section 45

-Paragraph 11

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=18498875&loc=d3e39076-109324

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 36

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph 38

-Subparagraph c(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 12

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e640-108580

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 24

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

VIRGIN MEDIA INC. 10-Q