Other Noncurrent Assets - Other Noncurrent Assets (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Other Noncurrent Assets [Line Items]
Investment in affiliates	$ 110.7	$ 126.1
Other assets:
Restricted cash	21.7	20.9
Deferred financing costs	3.7	7.0
IBNR receivables	6.9	6.7
Capital lease deposit	6.2	6.2
Pension asset	5.9	5.1
Assets held for sale	1.0	2.6
Other	48.9	46.9
Total	157.1	161.1
TiO2 manufacturing joint venture, Louisiana Pigment Company, L.P. ("LPC")
Other Noncurrent Assets [Line Items]
Investment in affiliates	95.2	109.9
Other
Other Noncurrent Assets [Line Items]
Investment in affiliates	15.5	16.2
Capitalized Operating Permits
Other assets:
Waste disposal site operating permits, net	$ 62.8	$ 65.7