Commitments and Contingencies - Range of Environmental Liability and Number of Active Sites for Environmental Matters (Detail) (Environmental Related Matters [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2013 site	Dec. 31, 2012 site
Environmental Related Matters [Member]
Environmental Matters Range Of Estimated Liability And Active Sites Numbers [Line Items]
Low-end range	$ 73.3	$ 76.9
High end range	$ 168.0	$ 167.1
Number of active environmental investigation and remediation sites	60	58