v3.24.4
Employee Compensation and Benefit Plans - Schedule of Pension Plan (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
Dec. 31, 2024
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Defined Benefit Plan, Plan Assets, Allocation [Line Items]        
Expected long-term rate of return on plan assets   7.00% 7.00%  
Actual rate of return on plan assets during period   6.00% 11.00%  
Expected long-term rate of return on investments   8.00%    
Interest on projected benefit obligations   $ 83 $ 86 $ 65
Gain on settlement and amortization of actuarial gain   (119) (59) 0
Expected return on pension plan assets   (99) (97) (71)
Net pension benefit   $ (135) $ (70) $ (6)
Percent at quoted price   26.00% 17.00%  
Percent at similar assets   62.00% 79.00%  
Percent supported at unobservable inputs   12.00% 4.00%  
Postretirement benefit plan assets $ 626 $ 626 $ 1,300  
Projected benefit obligations 895 895 1,600  
Underfunded plan $ 269 $ 269 $ 350  
Discount rate 6.00% 6.00% 5.00%  
Contributions to benefit plan   $ 52 $ 32  
Expected future contributions $ 66 66    
Expected payment, year one 51 51    
Expected payment, years two and three 110 110    
Expected payment, years four and five 119 119    
Expected payment, thereafter 320 $ 320    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]   Other income (expense), net Other income (expense), net Other income (expense), net
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]   Other income (expense), net Other income (expense), net Other income (expense), net
Sprint Retirement Pension Plan        
Defined Benefit Plan, Plan Assets, Allocation [Line Items]        
Settlement for a portion of retiree obligations 572      
Gain on settlement of pension plan obligation $ 80      
Defined Benefit Plan, Equity Securities, US        
Defined Benefit Plan, Plan Assets, Allocation [Line Items]        
Target allocation, percentage 48.00% 48.00%    
Fixed Income Securities        
Defined Benefit Plan, Plan Assets, Allocation [Line Items]        
Target allocation, percentage 39.00% 39.00%    
Defined Benefit Plan, Real Estate        
Defined Benefit Plan, Plan Assets, Allocation [Line Items]        
Target allocation, percentage 13.00% 13.00%