Retirement Plans (Details Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2011 Plan Business Segment Entity Person Age Plant lb MetricTon	Sep. 30, 2010	Sep. 30, 2009
Retirement Plans (Textuals)
Defined benefit plan, pension plans with accumulated benefit obligations in excess of plan assets, aggregate projected benefit obligation	$ 4,339	$ 3,942
Defined benefit plan, pension plans with accumulated benefit obligations in excess of plan assets, aggregate accumulated benefit obligation	4,185	3,804
Defined benefit plan, pension plans with accumulated benefit obligations in excess of plan assets, aggregate fair value of plan assets	3,346	3,169
Modification in salaried plans to limit company's cost of future annual retiree medical benefits	150.00%
Threshold age for retirement calculations	65
Projected prescription drug subsidy receipts per year over the next ten years	3
Matching contributions charged to expense for defined contribution savings plans	67	42	35
Employer contributions to multiemployer pension plans	51	46	47
Pension Plans, Defined Benefit [Member]
Retirement Plans (Textuals)
Total employer and employee contributions to defined benefit plans	280
Voluntary contributions made by the company to defined benefit plans	183
Estimated future employer contributions to defined benefit plans in next fiscal year	350
Postretirement Health and Other Benefits [Member]
Retirement Plans (Textuals)
Total employer and employee contributions to defined benefit plans	183
Voluntary contributions made by the company to defined benefit plans	156
Estimated future employer contributions to defined benefit plans in next fiscal year	60
Postretirement health and other benefit plan assets held	$ 15	$ 0
U.S. Postretirement Health and Other Benefits - Medical [Member]
Retirement Plans (Textuals)
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost trend rates	7.50%	7.00%
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost ultimate trend rates	5.00%	5.00%
Defined benefit plan, description of direction and pattern of change for assumed health care cost trend rate	Decreasing one half percent each year to an ultimate rate	Decreasing one half percent each year to an ultimate rate
Non-U.S. Postretirement Health and Other Benefits - Medical [Member]
Retirement Plans (Textuals)
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost trend rates	7.50%	8.00%
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost ultimate trend rates	5.00%	5.00%
Defined benefit plan, description of direction and pattern of change for assumed health care cost trend rate	Decreasing one half percent each year to an ultimate rate	Decreasing one half percent each year to an ultimate rate
U.S. Postretirement Health and Other Benefits - Prescription Drug [Member]
Retirement Plans (Textuals)
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost trend rates	7.50%	9.00%
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost ultimate trend rates	5.00%	6.00%
Defined benefit plan, description of direction and pattern of change for assumed health care cost trend rate	Decreasing one half percent each year to an ultimate rate	Decreasing one half percent each year to an ultimate rate
Non-U.S. Postretirement Health and Other Benefits - Prescription Drug [Member]
Retirement Plans (Textuals)
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost trend rates	7.50%	8.00%
Accumulated postretirement benefit obligation for both pre-65 and post-65, assumed health care cost ultimate trend rates	5.00%	5.00%
Defined benefit plan, description of direction and pattern of change for assumed health care cost trend rate	Decreasing one half percent each year to an ultimate rate	Decreasing one half percent each year to an ultimate rate