Segment Reporting Information by Segment (Parenthetical) (Detail) € in Millions, $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2016 EUR (€)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Truck, Parts and Other
Segment Reporting Information [Line Items]
European Commission charge	$ (109.6)	$ 942.6	$ 833.0	€ 752.7	$ 0.0	$ 833.0	$ 0.0

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.

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