Condensed Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Preferred stock, authorized	20,000,000	20,000,000
Preferred stock, issued	0	0
Accumulated depreciation	$ 49,119	$ 48,100
Accumulated amortization	10,299	9,868
NBCUniversal Media LLC [Member]
Accumulated depreciation	3,108	2,779
Accumulated amortization	$ 6,121	$ 5,654
Class A Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	7,500,000,000	7,500,000,000
Common stock, issued	2,838,776,825	2,869,349,502
Common stock, outstanding	2,402,381,311	2,432,953,988
Treasury stock common shares	436,395,514	436,395,514
Class B Common Stock [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized	75,000,000	75,000,000
Common stock, issued	9,444,375	9,444,375
Common stock, outstanding	9,444,375	9,444,375