Receivables and Expected Credit Losses - Gross EIP Receivables by Credit Category (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	$ 4,855	$ 4,283
Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	985
Originated in 2019	1,064
Originated prior to 2019	297
Total EIP Receivables, net of unamortized imputed discounts	2,346
Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	1,253
Originated in 2019	1,097
Originated prior to 2019	159
Total EIP Receivables, net of unamortized imputed discounts	2,509
Current - 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	4,707
Current - 30 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	973
Originated in 2019	1,041
Originated prior to 2019	291
Total EIP Receivables, net of unamortized imputed discounts	2,305
Current - 30 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	1,222
Originated in 2019	1,034
Originated prior to 2019	146
Total EIP Receivables, net of unamortized imputed discounts	2,402
31 - 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	73
31 - 60 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	7
Originated in 2019	12
Originated prior to 2019	3
Total EIP Receivables, net of unamortized imputed discounts	22
31 - 60 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	17
Originated in 2019	29
Originated prior to 2019	5
Total EIP Receivables, net of unamortized imputed discounts	51
61 - 90 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	34
61 - 90 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	3
Originated in 2019	5
Originated prior to 2019	1
Total EIP Receivables, net of unamortized imputed discounts	9
61 - 90 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	8
Originated in 2019	15
Originated prior to 2019	2
Total EIP Receivables, net of unamortized imputed discounts	25
More than 90 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
Total EIP Receivables, net of unamortized imputed discounts	41
More than 90 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	2
Originated in 2019	6
Originated prior to 2019	2
Total EIP Receivables, net of unamortized imputed discounts	10
More than 90 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2020	6
Originated in 2019	19
Originated prior to 2019	6
Total EIP Receivables, net of unamortized imputed discounts	$ 31

Financing Receivable, Originated, More than Two Years before Current Fiscal Year

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- Definition

Amount of financing receivable originated in current fiscal year.

+ References

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- Definition

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+ References

No definition available.

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- Definition

The receivable or note face amount less the unamortized discount or premium.

+ References

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