Net Fair Value of Commodity Price Risk (Detail) (USD $) In Millions, unless otherwise specified	Oct. 06, 2012
Derivatives, Fair Value [Line Items]
Assets	$ 6.7
Liabilities	(1.1)
Net Fair Value	5.6
Other Current Assets
Derivatives, Fair Value [Line Items]
Assets	6.6
Other Long Term Assets
Derivatives, Fair Value [Line Items]
Assets	0.1
Other Current Liabilities
Derivatives, Fair Value [Line Items]
Liabilities	(1.0)
Other LongTerm Liabilities
Derivatives, Fair Value [Line Items]
Liabilities	(0.1)
Level 1
Derivatives, Fair Value [Line Items]
Assets	5.6
Liabilities	(0.5)
Net Fair Value	5.1
Level 1 | Other Current Assets
Derivatives, Fair Value [Line Items]
Assets	5.6
Level 1 | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Liabilities	(0.4)
Level 1 | Other LongTerm Liabilities
Derivatives, Fair Value [Line Items]
Liabilities	(0.1)
Level 2
Derivatives, Fair Value [Line Items]
Assets	1.1
Liabilities	(0.6)
Net Fair Value	0.5
Level 2 | Other Current Assets
Derivatives, Fair Value [Line Items]
Assets	1.0
Level 2 | Other Long Term Assets
Derivatives, Fair Value [Line Items]
Assets	0.1
Level 2 | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Liabilities	$ (0.6)