Receivables and Related Allowance for Credit Losses - Schedule of Equipment Installment Plan Receivables by Credit Category (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
EIP receivables, net of unamortized imputed discount	$ 6,766	$ 7,997
Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	3,955
Originated in 2022	1,148
Originated prior to 2022	257
EIP receivables, net of unamortized imputed discount	5,360
Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	1,039
Originated in 2022	323
Originated prior to 2022	44
EIP receivables, net of unamortized imputed discount	1,406
Current - 30 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
EIP receivables, net of unamortized imputed discount	6,638
Current - 30 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	3,925
Originated in 2022	1,129
Originated prior to 2022	253
EIP receivables, net of unamortized imputed discount	5,307
Current - 30 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	987
Originated in 2022	304
Originated prior to 2022	40
EIP receivables, net of unamortized imputed discount	1,331
31 - 60 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
EIP receivables, net of unamortized imputed discount	52
31 - 60 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	13
Originated in 2022	7
Originated prior to 2022	1
EIP receivables, net of unamortized imputed discount	21
31 - 60 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	23
Originated in 2022	7
Originated prior to 2022	1
EIP receivables, net of unamortized imputed discount	31
61 - 90 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
EIP receivables, net of unamortized imputed discount	38
61 - 90 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	9
Originated in 2022	6
Originated prior to 2022	1
EIP receivables, net of unamortized imputed discount	16
61 - 90 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	16
Originated in 2022	5
Originated prior to 2022	1
EIP receivables, net of unamortized imputed discount	22
More than 90 days past due
Financing Receivable, Credit Quality Indicator [Line Items]
EIP receivables, net of unamortized imputed discount	38
More than 90 days past due \| Prime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	8
Originated in 2022	6
Originated prior to 2022	2
EIP receivables, net of unamortized imputed discount	16
More than 90 days past due \| Subprime
Financing Receivable, Credit Quality Indicator [Line Items]
Originated in 2023	13
Originated in 2022	7
Originated prior to 2022	2
EIP receivables, net of unamortized imputed discount	$ 22

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Amortized cost of financing receivable originated in current fiscal year. Excludes net investment in lease.

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

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