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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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-Section 50
-Paragraph 1
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472

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Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

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Acquisition (Schedule of Intangibles Acquired) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	May 30, 2017
Uniwheels Acquisition [Member]
Business Acquisition [Line Items]
Intangible assets	$ 205,000	$ 205,000
Uniwheels Acquisition [Member] \| Brand Name [Member]
Business Acquisition [Line Items]
Finite-lived intangibles acquired	9,000
Uniwheels Acquisition [Member] \| Technology [Member]
Business Acquisition [Line Items]
Finite-lived intangibles acquired	15,000
Uniwheels Acquisition [Member] \| Customer Relationships [Member]
Business Acquisition [Line Items]
Finite-lived intangibles acquired	167,000
Uniwheels Acquisition [Member] \| Trade Names [Member]
Business Acquisition [Line Items]
Indefinite-lived intangibles acquired	$ 14,000
Minimum [Member] \| Brand Name [Member]
Business Acquisition [Line Items]
Acquired intangible useful lives	5 years
Minimum [Member] \| Technology [Member]
Business Acquisition [Line Items]
Acquired intangible useful lives	4 years
Minimum [Member] \| Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired intangible useful lives	6 years
Maximum [Member] \| Brand Name [Member]
Business Acquisition [Line Items]
Acquired intangible useful lives	6 years
Maximum [Member] \| Technology [Member]
Business Acquisition [Line Items]
Acquired intangible useful lives	6 years
Maximum [Member] \| Customer Relationships [Member]
Business Acquisition [Line Items]
Acquired intangible useful lives	11 years