v3.6.0.2
Business and Basis of Presentation (Details)
customer in Millions
12 Months Ended
Jan. 24, 2017
Dec. 31, 2016
customer
segment
Nov. 30, 2015
Business And Basis Of Presentation [Line Items]      
Number of reportable segments | segment   5  
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 | customer   28.6  
NBCUniversal [Member]      
Business And Basis Of Presentation [Line Items]      
Number of reportable segments | segment   4  
Video Customers [Member] | Cable Communications [Member]      
Business And Basis Of Presentation [Line Items]      
Number of customers | customer   22.5  
High-speed Internet Customers [Member] | Cable Communications [Member]      
Business And Basis Of Presentation [Line Items]      
Number of customers | customer   24.7  
Voice Customers [Member] | Cable Communications [Member]      
Business And Basis Of Presentation [Line Items]      
Number of customers | customer   11.7  
Universal Studios Japan [Member] | Theme Parks [Member]      
Business And Basis Of Presentation [Line Items]      
Ownership percentage     51.00%
Universal Studios Japan [Member] | Theme Parks [Member] | NBCUniversal Media LLC [Member]      
Business And Basis Of Presentation [Line Items]      
Ownership percentage     51.00%
Subsequent Event [Member]      
Business And Basis Of Presentation [Line Items]      
Stockholders' Equity Note, Stock Split, Conversion Ratio 2