Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Line Items]

Property and Equipment

December 31 (in millions)	Weighted-Average Original Useful Life as of December 31, 2017	2017		2016
Cable distribution system	11 years	$	36,046	$	34,028
Customer premise equipment	6 years	26,392		28,621
Other equipment	9 years	10,518		9,471
Buildings and leasehold improvements	30 years	12,346		10,653
Construction in process	N/A	1,752		1,901
Land	N/A	1,332		1,273
Property and equipment, at cost		88,386		85,947
Less: Accumulated depreciation		49,916		49,694
Property and equipment, net		$	38,470	$	36,253

NBCUniversal Media LLC [Member]

Property, Plant and Equipment [Line Items]

Property and Equipment

December 31 (in millions)	Weighted-Average Original Useful Life as of December 31, 2017	2017		2016
Buildings and leasehold improvements	31 years	$	8,124	$	7,543
Furniture, fixtures and equipment	11 years	4,843		4,158
Construction in process	N/A	1,506		1,176
Land	N/A	1,039		984
Property and equipment, at cost		15,512		13,861
Less: Accumulated depreciation		4,166		3,350
Property and equipment, net		$	11,346	$	10,511