Industry Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013 Segment	Mar. 31, 2012
Segment Reporting Information [Line Items]
Number of reportable operating segments	2
Net sales	$ 230,708	$ 211,711
Intersegment revenue	0	0
Operating profit	16,030	9,703
Engine Management [Member]
Segment Reporting Information [Line Items]
Net sales	175,509	163,015
Intersegment revenue	5,453	4,488
Operating profit	20,784	13,688
Temperature Control [Member]
Segment Reporting Information [Line Items]
Net sales	52,728	45,291
Intersegment revenue	1,509	1,109
Operating profit	(454)	48
All Other [Member]
Segment Reporting Information [Line Items]
Net sales	2,471	3,405
Intersegment revenue	(6,962)	(5,597)
Operating profit	$ (4,300)	$ (4,033)

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

No definition available.

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

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- Definition

Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

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- Definition

Amount of revenue from transactions with other operating segments of the same entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 27

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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