CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Total Charter Shareholders’ Equity	Noncontrolling Interests
Balance at Dec. 31, 2017	$ 47,531	$ 0	$ 0	$ 35,253	$ 3,832	$ 0	$ (1)	$ 39,084	$ 8,447
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	223	0	0	0	168	0	0	168	55
Stock compensation expense	72	0	0	72	0	0	0	72	0
Accelerated vesting of equity awards	5	0	0	5	0	0	0	5	0
Exercise of stock options	36	0	0	36	0	0	0	36	0
Cumulative effect of accounting change	38	0	0	0	34	0	0	34	4
Purchases of treasury stock	(617)	0	0	0	0	(617)	0	(617)	0
Purchase of noncontrolling interest, net of tax	(118)	0	0	(28)	0	0	0	(28)	(90)
Change in noncontrolling interest ownership, net of tax	(6)	0	0	14	0	0	0	14	(20)
Distributions to noncontrolling interest	(39)	0	0	0	0	0	0	0	(39)
Balance at Mar. 31, 2018	47,125	0	0	35,352	4,034	(617)	(1)	38,768	8,357
Balance at Dec. 31, 2017	47,531	0	0	35,253	3,832	0	(1)	39,084	8,447
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	1,146
Purchases of treasury stock	(3,214)
Change in noncontrolling interest ownership, net of tax				39					(53)
Balance at Sep. 30, 2018	45,228	0	0	35,493	4,828	(3,214)	(2)	37,105	8,123
Balance at Mar. 31, 2018	47,125	0	0	35,352	4,034	(617)	(1)	38,768	8,357
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	339	0	0	0	273	0	0	273	66
Stock compensation expense	70	0	0	70	0	0	0	70	0
Exercise of stock options	7	0	0	7	0	0	0	7	0
Changes in accumulated other comprehensive loss	(1)	0	0	0	0	0	(1)	(1)	0
Purchases of treasury stock	(1,664)	0	0	0	0	(1,664)	0	(1,664)	0
Purchase of noncontrolling interest, net of tax	(192)	0	0	(28)	0	0	0	(28)	(164)
Change in noncontrolling interest ownership, net of tax	(5)	0	0	18	0	0	0	18	(23)
Distributions to noncontrolling interest	(37)	0	0	0	0	0	0	0	(37)
Balance at Jun. 30, 2018	45,642	0	0	35,419	4,307	(2,281)	(2)	37,443	8,199
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	584	0	0	0	493	0	0	493	91
Stock compensation expense	71	0	0	71	0	0	0	71	0
Exercise of stock options	13	0	0	13	0	0	0	13	0
Cumulative effect of accounting change	31	0	0	0	28	0	0	28	3
Purchases of treasury stock	(933)	0	0	0	0	(933)	0	(933)	0
Purchase of noncontrolling interest, net of tax	(139)	0	0	(17)	0	0	0	(17)	(122)
Change in noncontrolling interest ownership, net of tax	(3)	0	0	7	0	0	0	7	(10)
Distributions to noncontrolling interest	(38)	0	0	0	0	0	0	0	(38)
Balance at Sep. 30, 2018	45,228	0	0	35,493	4,828	(3,214)	(2)	37,105	8,123
Balance at Dec. 31, 2018	44,272	0	0	33,507	2,780	0	(2)	36,285	7,987
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	317	0	0	0	253	0	0	253	64
Stock compensation expense	85	0	0	85	0	0	0	85	0
Exercise of stock options	44	0	0	44	0	0	0	44	0
Purchases of treasury stock	(940)	0	0	0	0	(940)	0	(940)	0
Purchase of noncontrolling interest, net of tax	(89)	0	0	(15)	0	0	0	(15)	(74)
Change in noncontrolling interest ownership, net of tax	(7)	0	0	22	0	0	0	22	(29)
Distributions to noncontrolling interest	(39)	0	0	0	0	0	0	0	(39)
Balance at Mar. 31, 2019	43,643	0	0	33,643	3,033	(940)	(2)	35,734	7,909
Balance at Dec. 31, 2018	44,272	0	0	33,507	2,780	0	(2)	36,285	7,987
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	1,170
Purchases of treasury stock	(4,568)
Change in noncontrolling interest ownership, net of tax				104					(139)
Balance at Sep. 30, 2019	40,522	0	0	33,810	3,734	(4,568)	(2)	32,974	7,548
Balance at Mar. 31, 2019	43,643	0	0	33,643	3,033	(940)	(2)	35,734	7,909
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	386	0	0	0	314	0	0	314	72
Stock compensation expense	82	0	0	82	0	0	0	82	0
Exercise of stock options	37	0	0	37	0	0	0	37	0
Purchases of treasury stock	(861)	0	0	0	0	(861)	0	(861)	0
Purchase of noncontrolling interest, net of tax	(148)	0	0	(37)	0	0	0	(37)	(111)
Change in noncontrolling interest ownership, net of tax	(6)	0	0	17	0	0	0	17	(23)
Distributions to noncontrolling interest	(39)	0	0	0	0	0	0	0	(39)
Balance at Jun. 30, 2019	43,094	0	0	33,742	3,347	(1,801)	(2)	35,286	7,808
Rollforward of Consolidated Shareholders' Equity:
Consolidated net income	467	0	0	0	387	0	0	387	80
Stock compensation expense	71	0	0	71	0	0	0	71	0
Exercise of stock options	25	0	0	25	0	0	0	25	0
Purchases of treasury stock	(2,767)	0	0	0	0	(2,767)	0	(2,767)	0
Purchase of noncontrolling interest, net of tax	(308)	0	0	(93)	0	0	0	(93)	(215)
Change in noncontrolling interest ownership, net of tax	(22)	0	0	65	0	0	0	65	(87)
Distributions to noncontrolling interest	(38)	0	0	0	0	0	0	0	(38)
Balance at Sep. 30, 2019	$ 40,522	$ 0	$ 0	$ 33,810	$ 3,734	$ (4,568)	$ (2)	$ 32,974	$ 7,548