XML 185 R97.htm IDEA: XBRL DOCUMENT v3.22.2.2
Benefit Plans Obligations and Funded Status (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 30, 2022
Sep. 30, 2021
Sep. 30, 2020
Pension Benefits      
Change in benefit obligation      
Benefit obligation $ 13,348 $ 13,675  
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation 10,536 13,348  
Service cost 53 57 $ 55
Plan participants' contributions 5 5  
Change in Plan Assets due to Collections 0 0  
Collections [1] 0 0  
Actuarial loss (gain) (2,509) (25)  
Net transfers from variable fund/401(k) plan 11 2  
Expenses paid (6) (6)  
Benefits paid 744 728  
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets 8,094 9,110  
Change in plan assets      
Fair value of net plan assets 9,110 7,959  
Actual return on plan assets (590) 1,572  
Employer contributions 308 306  
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]      
Funded status $ (2,442) $ (4,238)  
Discount rate 5.60% 2.90% 2.75%
Amount of defined benefit plan actuarial gain (loss) from discount rate change $ (3,500) $ (248)  
Amount of defined benefit plan actuarial gain (loss) from change in mortality assumption (527) (28)  
Amount of defined benefit plan actuarial gain (loss) from change in demograhic and plan experience 78 104  
Amount of defined benefit plan actuarial gain (loss) from assumption change in elections 411 91  
Other Post-retirement Benefits      
Change in benefit obligation      
Benefit obligation 388 498  
Postconfirmation, Other Postretirement Obligations 498 544  
Service cost 17 18 $ 16
Plan participants' contributions 0 0  
Change in Plan Assets due to Collections 15 17  
Collections [1] 15 17  
Actuarial loss (gain) (114) (53)  
Net transfers from variable fund/401(k) plan 0 0  
Expenses paid 0 0  
Benefits paid 43 44  
Change in plan assets      
Fair value of net plan assets 0 0  
Actual return on plan assets 0 0  
Employer contributions 28 27  
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]      
Funded status $ (388) $ (498)  
Discount rate 5.65% 3.05%  
Amount of defined benefit plan actuarial gain (loss) from updated capita claims costs and retiree contributions   $ (47)  
Amount of change related to actual   1  
Amount of defined benefit plan actuarial gain (loss) from change in demograhic and plan experience   $ 7  
[1] Collections include retiree contributions as well as provider discounts and rebates.