Common Stock (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended						9 Months Ended
Common Stock (Details) - USD ($) $ in Millions	Oct. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Treasury stock acquired (shares)		4,960,752			5,833,667			16,627,760	13,328,430
Value of treasury stock shares repurchased/withheld		$ 3,666	$ 3,516	$ 3,652	$ 3,361	$ 1,155	$ 2,352	$ 10,834	$ 6,868
Remaining authorized repurchase amount		$ 1,500						$ 1,500
Issuance of equity							$ 23		$ 23
Liberty Broadband
Class of Stock [Line Items]
Issuance of equity, shares									35,112
A/N
Class of Stock [Line Items]
Issuance of equity, shares									20,182
Share buybacks
Class of Stock [Line Items]
Treasury stock acquired (shares)		4,738,842			5,466,295			15,442,417	11,947,078
Value of treasury stock shares repurchased/withheld		$ 3,584			$ 3,250			$ 10,450	$ 6,452
Share buybacks \| Liberty Broadband
Class of Stock [Line Items]
Treasury stock acquired (shares)		1,200,547						3,962,155
Value of treasury stock shares repurchased/withheld		$ 880						$ 2,642
Share buybacks \| Liberty Broadband \| Subsequent Event
Class of Stock [Line Items]
Treasury stock acquired (shares)	700,000
Value of treasury stock shares repurchased/withheld	$ 561
Income tax withholding
Class of Stock [Line Items]
Treasury stock acquired (shares)		104,949			186,548			572,869	769,853
Value of treasury stock shares repurchased/withheld		$ 82			$ 111			$ 384	$ 416
Exercise cost
Class of Stock [Line Items]
Treasury stock acquired (shares)		116,961			180,824			612,474	611,499