XML 106 R89.htm IDEA: XBRL DOCUMENT v3.8.0.1
Pension and Other Benefit Programs - One Percentage Point (ppt) Change on Projected Benefit Obligations (Detail)
$ in Millions
12 Months Ended
Sep. 30, 2017
USD ($)
Compensation and Retirement Disclosure [Abstract]  
Impact of 1 ppt Discount Rate decrease on Benefit Expense $ 263
Impact of 1 ppt Discount Rate increase on Benefit Expense (242)
Impact of 1 ppt Discount Rate decrease on Projected Benefit Obligations 2,778
Impact of 1 ppt Discount Rate increase on Projected Benefit Obligations (2,349)
Impact of 1 ppt Expected Long-Term Rate of Return on Assets Decrease on Benefit Expense 127
Impact of 1 ppt Expected Long-Term Rate of Return on Assets Increase on Benefit Expense (127)
Impact of 1 ppt Healthcare Cost Trend Rate decrease on Net Periodic Postretirement Medical Cost (29)
Impact of 1 ppt Healthcare Cost Trend Rate increase on Net Periodic Postretirement Medical Cost 44
Impact of 1 ppt Healthcare Cost Trend Rate decrease on Projected Benefit Obligations (239)
Impact of 1 ppt Healthcare Cost Trend Rate increase on Projected Benefit Obligations $ 316