Other Noncurrent Assets - Future Minimum Payments under Non-cancellable Operating Leases (Parenthetical) (Detail) $ in Millions	Dec. 31, 2018 USD ($)
Future Minimum Payments Under Non Cancelable Operating Leases With Initial Terms Of One Year Or More [Line Items]
Future minimum lease payments	$ 42.8
Leverkusen TiO2 production facility \| Chemicals
Future Minimum Payments Under Non Cancelable Operating Leases With Initial Terms Of One Year Or More [Line Items]
Future minimum lease payments	$ 17.0

Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 3)
-URI http://asc.fasb.org/extlink&oid=82846649&loc=d3e38371-112697

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77902758&loc=d3e41502-112717

Name:	us-gaap_OperatingLeasesFutureMinimumPaymentsDue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant