v3.3.1.900
Fair Value Measurements (Narrative) (Details) - USD ($)
$ in Millions
1 Months Ended 9 Months Ended 12 Months Ended
Jul. 31, 2014
Sep. 30, 2013
Dec. 31, 2014
Ziggo Acquisition [Member] | Customer Relationships [Member] | Level 3 [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Discount rate     8.50%
Virgin Media Acquisition [Member] | Customer Relationships [Member] | Level 3 [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Discount rate   9.00%  
ITV Collar [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Discount rate 0.00%    
ITV Collar [Member] | Minimum [Member] | Level 3 [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Estimated volatilities     23.80%
ITV Collar [Member] | Maximum [Member] | Level 3 [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Estimated volatilities     27.30%
Ziggo Collar [Member]      
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]      
Loss on derivative not included on consolidated balance sheet     $ 113.3