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Business and Basis of Presentation (Details)
customer in Millions
12 Months Ended
Jan. 24, 2017
Dec. 31, 2017
segment
customer
business
Business And Basis Of Presentation [Line Items]    
Number of primary businesses | business   2
Number of reportable segments | segment   5
Stock split, conversion ratio 2  
NBCUniversal Media LLC [Member]    
Business And Basis Of Presentation [Line Items]    
Number of reportable segments | segment   4
Cable Communications [Member]    
Business And Basis Of Presentation [Line Items]    
Number of reportable segments | segment   1
Total customer relationships   29.3
Cable Communications [Member] | Video Customers [Member]    
Business And Basis Of Presentation [Line Items]    
Number of customers   22.4
Cable Communications [Member] | High-speed Internet Customers [Member]    
Business And Basis Of Presentation [Line Items]    
Number of customers   25.9
Cable Communications [Member] | Voice Customers [Member]    
Business And Basis Of Presentation [Line Items]    
Number of customers   11.6
Cable Communications [Member] | Residential Customers [Member]    
Business And Basis Of Presentation [Line Items]    
Total customer relationships   27.2
Cable Communications [Member] | Business Customers [Member]    
Business And Basis Of Presentation [Line Items]    
Total customer relationships   2.2
NBCUniversal Segments [Member]    
Business And Basis Of Presentation [Line Items]    
Number of reportable segments | segment   4