v3.3.1.900
Acquisitions (2012 Acquisitions) (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Nov. 08, 2012
Nov. 08, 2012
Dec. 31, 2014
OneLink [Member]      
Business Acquisition [Line Items]      
Closing adjustments $ 1.8 $ 1.8  
Estimated useful life 10 years    
Searchlight [Member] | Leo Cable [Member]      
Business Acquisition [Line Items]      
Cash contribution to fund acquisition $ 94.7 $ 94.7  
Business acquisition percentage of voting interests acquired 40.00% 40.00%  
LGI Broadband Operations [Member]      
Business Acquisition [Line Items]      
Portion of purchase price retained to satisfy claims $ 20.0 $ 20.0  
LGI Broadband Operations [Member] | Old Liberty Puerto Rico [Member]      
Business Acquisition [Line Items]      
Ownership percentage 100.00% 100.00%  
LGI Broadband Operations [Member] | OneLink [Member]      
Business Acquisition [Line Items]      
Ownership percentage 100.00% 100.00%  
Cost of acquired entity   $ 96.5  
Fair value of debt and capital lease obligations $ 496.0 496.0  
Total consideration before transaction cost 592.5 592.5  
Acquisition costs $ 18.1 $ 18.1  
Liberty Cablevision of Puerto Rico LLC [Member]      
Business Acquisition [Line Items]      
Percentage ownership in subsidiary     60.00%