Schedule of Assumptions used to Determine Net Periodic Benefit Cost and to Compute Expected Long Term Return on Assets (Detail)	12 Months Ended
	Sep. 28, 2012	Sep. 30, 2011	Oct. 01, 2010
Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.38%	3.45%	4.17%
Rates of compensation increase	2.48%	2.44%	2.99%
Expected long-term return on assets	4.02%	4.13%	4.87%
Post-Retirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.90%	4.40%	5.30%