Segment Reporting Information by Segment (Parenthetical) (Detail) € in Millions, $ in Millions	3 Months Ended
Mar. 31, 2016 USD ($)	Mar. 31, 2016 EUR (€)	Mar. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
European Commission charge	$ 942.6		$ 0.0
Truck, Parts and Other
Segment Reporting Information [Line Items]
European Commission charge	$ 942.6	€ 850.0	$ 0.0

Amount of other expense that is infrequent in occurrence or unusual in nature.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 20
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6365513&loc=d3e15122-107781

Name:	us-gaap_OtherNonrecurringExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration