Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended
	Mar. 25, 2014 Defendant	Apr. 05, 2014 Complaints Manufacturers_Distributors	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Accrual for environmental loss contingencies, gross		$ 21.7	$ 22.9
Accrued environmental loss contingencies, current		6.2	6.9
Accrued environmental loss contingencies, noncurrent		15.5	16.0
Steel manufacturers, number of manufacturers		8
Additional complaints being filed in July and December of 2010		2
Complaints that are dismissed		2
Number of co-defendants	5
Damages against all defendants jointly and severally	$ 52.0