Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 13,833	$ 10,701	$ 13,323
Currency translation adjustments, net of deferred taxes of $76, $(331) and $(66)	(664)	1,213	1,375
Cash flow hedges:
Deferred gains (losses), net of deferred taxes of $(36), $26 and $(4)	229	(101)	19
Realized (gains) losses reclassified to net income, net of deferred taxes of $(4), $31 and $(10)	(16)	(147)	65
Employee benefit obligations and other, net of deferred taxes of $(16), $20 and $16	54	(68)	(57)
Comprehensive income	13,436	11,598	14,725
Less: Net income (loss) attributable to noncontrolling interests and redeemable subsidiary preferred stock	(325)	167	266
Less: Other comprehensive income (loss) attributable to noncontrolling interests	7	60	(13)
Comprehensive income attributable to Comcast Corporation	$ 13,755	$ 11,371	$ 14,472