Subsequent Events (Preferred Interest) (Details) shares in Millions, $ in Millions	3 Months Ended
	Apr. 04, 2023 USD ($) shares	Mar. 31, 2023 USD ($) period	Apr. 18, 2023 USD ($)
Subsequent Event [Line Items]
Option to require redemption, certain contingent events, failure of Telco LLC to pay preferred distributions, minimum number of periods | period		2
Telco LLC | Subsequent Event
Subsequent Event [Line Items]
Nonconvertible cumulative preferred interests issued			$ 7,250
Telco LLC | Class A-2 And Class A-3 | Subsequent Event
Subsequent Event [Line Items]
Nonconvertible cumulative preferred interests issued			$ 5,250
Initial preferred distribution percentage	6.85%
Distribution reset period	7 years
AT&T Mobility II, LLC | Preferred Stock - Series A
Subsequent Event [Line Items]
Put or redemption option, minimum exercise price calculation, value added to accrued and unpaid distributions in the aggregate		$ 5,320
AT&T Mobility II, LLC | Preferred Stock - Series A | Subsequent Event
Subsequent Event [Line Items]
Stock Redeemed or Called During Period, Shares | shares	213
Stock Redeemed or Called During Period, Value	$ 5,414
AT&T Mobility II, LLC | Accounts payable and accrued liabilities | Preferred Stock - Series A
Subsequent Event [Line Items]
Put or redemption option, minimum exercise price calculation, value added to accrued and unpaid distributions in the aggregate		2,650
AT&T Mobility II, LLC | Other Noncurrent Liabilities [Member] | Preferred Stock - Series A
Subsequent Event [Line Items]
Put or redemption option, minimum exercise price calculation, value added to accrued and unpaid distributions in the aggregate		$ 2,670