Defined Benefit Plans - Components of Consolidated Net Periodic Benefit and Deferred Compensation Benefit Costs and Contributions Made (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Apr. 01, 2012	Mar. 31, 2013	Apr. 01, 2012
Defined Benefit Plan Disclosure [Line Items]
Number of separate contributory plans			2
Net periodic benefit cost [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$ 0.9	$ 0.7	$ 1.7	$ 1.3
Interest cost	2.7	2.7	5.3	4.9
Expected return on assets	(2.4)	(2.3)	(4.9)	(3.8)
Recognized net actuarial loss	0.6	0.3	1.1	0.3
Employee contributions	(0.1)	(0.1)	(0.1)	(0.1)
Net periodic benefit expense	1.7	1.3	3.1	2.6
Contributions made during period	$ 1.2	$ 1.7	$ 1.9	$ 2.6