Industry Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014 Segment		Jun. 30, 2013
Segment Reporting Information [Line Items]
Number of reportable operating segments					2
Net sales	$ 272,540		$ 270,126		$ 505,292		$ 500,834
Operating profit	17,620		27,220		38,025		43,250
Litigation charge	10,650		0		10,650		0
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	0		0		0		0
Engine Management [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	184,181		182,050		363,475		357,559
Operating profit	27,112		24,704		51,484		45,488
Engine Management [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	6,231		7,566		12,184		13,019
Temperature Control [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net sales	85,660		86,660		137,145		139,388
Operating profit	4,991		6,740		5,604		6,286
Temperature Control [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	2,133		1,546		4,367		3,055
All Other [Member]
Segment Reporting Information [Line Items]
Net sales	2,699		1,416		4,672		3,887
Operating profit	(14,483)	[1]	(4,224)	[1]	(19,063)	[1]	(8,524)	[1]
All Other [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net sales	$ (8,364)		$ (9,112)		$ (16,551)		$ (16,074)

[1] During the second quarter of 2014, we recorded a $10.6 million litigation charge in connection with a tentative settlement agreement in a legal proceeding with a third party (see Note 15 for additional details).