Business Segment Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Total operating revenues	$ 1,263		$ 1,261	$ 2,524		$ 2,518
Selling, general and administrative	398		421	809		819
Depreciation, amortization and accretion	236		234	470		460
(Gain) loss on asset disposals, net	4		5	8		0
(Gain) loss on sale of business and other exit costs, net	0		0	0		(2)
(Gain) loss on license sales and exchanges, net	0		0	0		(2)
Operating income	78		48	151		142
Equity in earnings of unconsolidated entities	44		41	90		85
Interest and dividend income	2		9	8		17
Interest expense	(38)		(43)	(75)		(86)
Other, net	0		0	(1)		1
Income before income taxes	86		55	173		159
Income tax expense (benefit)	8		16	12		50
Net income	78		39	161		109
Depreciation, amortization and accretion	236		234	470		460
(Gain) loss on asset disposals, net	4		5	8		0
(Gain) loss on sale of business and other exit costs, net	0		0	0		(2)
(Gain) loss on license sales and exchanges, net	0		0	0		(2)
Interest expense	38		43	75		86
Income tax expense	8		16	12		50
Adjusted EBITDA	364		337	726		701
Investments in unconsolidated entities	486		490	486		490	$ 488
Total assets	11,161	[1]	10,795	11,161	[1]	10,795	$ 10,781	[1]
Capital expenditures	247		264	539		411
Service
Segment Reporting Information [Line Items]
Total operating revenues	1,016		1,013	2,042		2,008
Cost of goods and services	306		304	599		588
Equipment and product sales
Segment Reporting Information [Line Items]
Total operating revenues	247		248	482		510
Cost of goods and services	241		249	487		513
U.S. Cellular
Segment Reporting Information [Line Items]
Total operating revenues	973		973	1,937		1,939
Selling, general and administrative	323		344	659		669
Depreciation, amortization and accretion	178		177	354		345
(Gain) loss on asset disposals, net	4		5	8		7
(Gain) loss on sale of business and other exit costs, net						(2)
(Gain) loss on license sales and exchanges, net						(2)
Operating income	53		30	104		95
Equity in earnings of unconsolidated entities	44		40	89		84
Interest and dividend income	1		5	5		11
Interest expense	(25)		(29)	(49)		(58)
Other, net				0		(1)
Income before income taxes	73		46	149		131
Income tax expense (benefit)	4		14	8		41
Net income	69		32	141		90
Depreciation, amortization and accretion	178		177	354		345
(Gain) loss on asset disposals, net	4		5	8		7
(Gain) loss on sale of business and other exit costs, net						(2)
(Gain) loss on license sales and exchanges, net						(2)
Interest expense	25		29	49		58
Income tax expense	4		14	8		41
Adjusted EBITDA	280		257	560		537
Investments in unconsolidated entities	445		450	445		450
Total assets	8,500		8,223	8,500		8,223
Capital expenditures	168		195	405		297
U.S. Cellular | Service
Segment Reporting Information [Line Items]
Total operating revenues	753		757	1,515		1,498
Cost of goods and services	197		193	377		369
U.S. Cellular | Equipment and product sales
Segment Reporting Information [Line Items]
Total operating revenues	220		216	422		441
Cost of goods and services	218		224	435		458
TDS Telecom Total
Segment Reporting Information [Line Items]
Total operating revenues	241		233	481		464
Selling, general and administrative	66		64	130		125
Depreciation, amortization and accretion	51		50	103		100
(Gain) loss on asset disposals, net	0		(1)	0		(8)
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Operating income	31		29	59		66
Equity in earnings of unconsolidated entities	0		0	0		0
Interest and dividend income	1		3	4		6
Interest expense	1		1	2		1
Other, net				(1)		0
Income before income taxes	33		33	64		74
Income tax expense (benefit)	5		8	8		18
Net income	28		25	56		56
Depreciation, amortization and accretion	51		50	103		100
(Gain) loss on asset disposals, net	0		(1)	0		(8)
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Interest expense	(1)		(1)	(2)		(1)
Income tax expense	5		8	8		18
Adjusted EBITDA	83		82	165		165
Investments in unconsolidated entities	4		4	4		4
Total assets	2,210		2,009	2,210		2,009
Capital expenditures	75		70	128		112
TDS Telecom Total | Service
Segment Reporting Information [Line Items]
Total operating revenues	240		233	480		463
Cost of goods and services	92		91	188		179
TDS Telecom Total | Equipment and product sales
Segment Reporting Information [Line Items]
Total operating revenues	0		0	1		1
Cost of goods and services	0		0	0		1
TDS Telecom Wireline
Segment Reporting Information [Line Items]
Total operating revenues	169		172	339		343
Selling, general and administrative	48		49	97		96
Depreciation, amortization and accretion	32		33	64		66
(Gain) loss on asset disposals, net	0		(1)	0		(8)
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Operating income	27		27	50		61
Equity in earnings of unconsolidated entities	0		0	0		0
Interest and dividend income	1		3	3		5
Interest expense	1		1	2		1
Other, net				(1)		0
Income before income taxes	28		30	55		68
Depreciation, amortization and accretion	32		33	64		66
(Gain) loss on asset disposals, net	0		(1)	0		(8)
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Interest expense	(1)		(1)	(2)		(1)
Adjusted EBITDA	59		62	116		125
Investments in unconsolidated entities	4		4	4		4
Total assets	1,495		1,377	1,495		1,377
Capital expenditures	58		55	97		84
TDS Telecom Wireline | Service
Segment Reporting Information [Line Items]
Total operating revenues	169		172	338		342
Cost of goods and services	63		64	128		127
TDS Telecom Wireline | Equipment and product sales
Segment Reporting Information [Line Items]
Total operating revenues	0		0	0		1
Cost of goods and services	0		0	0		1
TDS Telecom Cable
Segment Reporting Information [Line Items]
Total operating revenues	71		62	142		121
Selling, general and administrative	17		15	34		30
Depreciation, amortization and accretion	20		17	39		34
(Gain) loss on asset disposals, net	0		0	0		1
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Operating income	4		2	9		5
Equity in earnings of unconsolidated entities	0		0	0		0
Interest and dividend income	0		0	1		1
Interest expense	0		0	0		0
Other, net				0		0
Income before income taxes	4		3	10		6
Depreciation, amortization and accretion	20		17	39		34
(Gain) loss on asset disposals, net	0		0	0		1
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Interest expense	0		0	0		0
Adjusted EBITDA	24		20	49		40
Investments in unconsolidated entities	0		0	0		0
Total assets	725		641	725		641
Capital expenditures	17		15	31		28
TDS Telecom Cable | Service
Segment Reporting Information [Line Items]
Total operating revenues	71		62	142		121
Cost of goods and services	30		27	60		52
TDS Telecom Cable | Equipment and product sales
Segment Reporting Information [Line Items]
Total operating revenues	0		0	0		0
Cost of goods and services	0		0	0		0
Corporate, Eliminations and Other
Segment Reporting Information [Line Items]
Total operating revenues	49		55	106		115
Selling, general and administrative	9		13	20		25
Depreciation, amortization and accretion	7		7	13		15
(Gain) loss on asset disposals, net	0		1	0		1
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Operating income	(6)		(11)	(12)		(19)
Equity in earnings of unconsolidated entities	0		1	1		1
Interest and dividend income	0		1	(1)		0
Interest expense	(14)		(15)	(28)		(29)
Other, net				0		2
Income before income taxes	(20)		(24)	(40)		(46)
Income tax expense (benefit)	(1)		(6)	(4)		(9)
Net income	(19)		(18)	(36)		(37)
Depreciation, amortization and accretion	7		7	13		15
(Gain) loss on asset disposals, net	0		1	0		1
(Gain) loss on sale of business and other exit costs, net						0
(Gain) loss on license sales and exchanges, net						0
Interest expense	14		15	28		29
Income tax expense	(1)		(6)	(4)		(9)
Adjusted EBITDA	1		(2)	1		(1)
Investments in unconsolidated entities	37		36	37		36
Total assets	451		563	451		563
Capital expenditures	4		(1)	6		2
Corporate, Eliminations and Other | Service
Segment Reporting Information [Line Items]
Total operating revenues	23		23	47		47
Cost of goods and services	17		20	34		40
Corporate, Eliminations and Other | Equipment and product sales
Segment Reporting Information [Line Items]
Total operating revenues	27		32	59		68
Cost of goods and services	$ 23		$ 25	$ 52		$ 54

[1] The consolidated total assets as of June 30, 2020 and December 31, 2019, include assets held by consolidated variable interest entities (VIEs) of $1,085 million and $915 million, respectively, which are not available to be used to settle the obligations of TDS. The consolidated total liabilities as of June 30, 2020 and December 31, 2019, include certain liabilities of consolidated VIEs of $19 million and $20 million, respectively, for which the creditors of the VIEs have no recourse to the general credit of TDS. See Note 10 — Variable Interest Entities for additional information.