Benefit Plans - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended			12 Months Ended
	Sep. 30, 2012	Nov. 30, 2011	Sep. 30, 2011	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2010
Defined Benefit Plan Disclosure [Line Items]
Defined pension plan discount rate		5.10%	4.90%
Expected change in net benefit cost due to change in discount rate	$ 5,300			$ 5,300
Expected change in net benefit cost due to change in plan assets	6,200			6,200
Net pension cost	40,200			40,200
Description of plan amendment for the defined benefit plan				Effective January 1, 2013, all plan participants' benefits in the defined benefit traditional pension plan will be converted to a defined benefit cash balance pension plan
Pension plan assets at fair value	83,160		89,291	83,160		89,291		71,997
Assumed Health care trend rate				7.50%		7.60%
Ultimate Health care trend rate beginning in 2024				5.00%		5.00%
Increase in accumulated post retirement benefit obligation due to one percentage point increase in assumed health care cost trend rates				11,526
Increase in Aggregate service cost and interest cost components retirement benefit obligation due to one percentage point increase in assumed health care cost trend rates				638
Decrease in accumulated post retirement benefit obligation due to one percentage point decrease in assumed health care cost trend rates				9,527
Decrease in Aggregate service cost and interest cost components retirement benefit obligation due to one percentage point decrease in assumed health care cost trend rates Decrease in Aggregate service cost and interest cost components retirement benefit obligation due to one percentage point decrease in assumed health care cost trend rates				480
Post retirement plan Expected Drug subsidy, 2013	1,417			1,417
Post retirement plan Expected Drug subsidy, 2014	1,404			1,404
Post retirement plan Expected Drug subsidy, 2015	1,382			1,382
Post retirement plan Expected Drug subsidy, 2016	1,353			1,353
Post retirement plan Expected Drug subsidy, 2017	1,315			1,315
Post retirement plan Expected Drug subsidy, 2018-2022	5,751			5,751
Percent of total assets domestic plans				70.00%
Amount recognized in Accumulated and other comprehensive income before income taxes for net actuarial loss	157,525		116,442	157,525		116,442
Accumulated and other comprehensive income into post employment benefit cost				19,210
Cost of the Savings Incentive Plan				36,281		36,535		34,097
Employers contribution				The Company matches contributions for eligible employees to 75% of employees' contributions, up to a maximum of 4.5% of each employee's eligible compensation.
Employers contribution to defined contribution plan as percentage of employees contribution				75.00%
Maximum employers contribution to Defined contribution plan as a percentage of employees salary				4.50%
Employees contribution guaranteed by the company to the fixed income fund of the Savings Incentive Plan	254,060			254,060
Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's Target allocation percentage for equity securities				65.00%
Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Company's Target allocation percentage for equity securities				35.00%
U.S. plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined pension plan discount rate	4.90%	5.10%	4.90%	4.90%	[1],[2]	5.20%	[1],[2]	5.90%	[1],[2]
Pension plan assets at fair value	1,106,892		933,278	1,106,892		933,278
Discretionary contribution to its U.S pension plan	100,000			100,000
Foreign plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined pension plan discount rate				5.26%		4.68%		5.63%
Net pension and postretirement cost				31,085		34,429		25,820
Pension plan assets at fair value	466,450		419,452	466,450		419,452
Pension plan projected benefit obligations	632,442		500,969	632,442		500,969
Percent of total plan assets foreign plans	30.00%			30.00%
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net pension and postretirement cost				127,939		134,342		104,808
Pension plan assets at fair value	1,573,342		1,352,730	1,573,342		1,352,730		1,413,848
Pension plan projected benefit obligations	(2,307,516)		(1,996,441)	(2,307,516)		(1,996,441)		(1,911,295)
Estimated net actuarial loss that will be amortized from accumulated other comprehensive income				(75,524)
Estimated Prior service credit costs that will be amortized from accumulated other comprehensive income				13,130
Other Postretirement Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net pension and postretirement cost				21,432		22,764		22,609
Pension plan projected benefit obligations	(267,201)		(269,458)	(267,201)		(269,458)		(260,124)
Estimated net actuarial loss that will be amortized from accumulated other comprehensive income				(3,911)
Estimated Prior service credit costs that will be amortized from accumulated other comprehensive income				$ 1,139

[1] Also used to determine other postretirement and postemployment benefit plan information.

[2] On November 30, 2011, the Company remeasured its U.S. defined benefit pension plan based upon a 5.10% discount rate compared to the discount rate of 4.90% used on September 30, 2011. All other U.S. plans remained at 4.90%.