Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Segment Reporting Information by Segment (Parenthetical) (Detail) € in Millions, $ in Millions	3 Months Ended					6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2016 EUR (€)	Mar. 31, 2016 USD ($)	Mar. 31, 2016 EUR (€)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
European Commission charge		$ (109.6)				$ 0.0	$ 833.0
Truck, Parts and Other
Segment Reporting Information [Line Items]
European Commission charge	$ 0.0	$ (109.6)	€ (97.3)	$ 942.6	€ 850.0	$ 0.0	$ 833.0