Goodwill and Other Identifiable Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Balance beginning	$ 75.6	$ 72.1
Acquisitions		2.6
Currency translation	(2.9)	0.9
Balance ending	72.7	75.6
Carbon Materials and Chemicals [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Balance beginning	70.2	69.4
Acquisitions		0
Currency translation	(2.2)	0.8
Balance ending	68.0	70.2
Railroad and Utility Products and Services [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Balance beginning	5.4	2.7
Acquisitions		2.6
Currency translation	(0.7)	0.1
Balance ending	$ 4.7	$ 5.4