Business Acquisitions and Investments, Pensacola Fuel Injection Inc Acquisition and Annex Manufacturing (Details) (USD $)	3 Months Ended		6 Months Ended			6 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Pensacola Fuel Injection Inc. [Member]	Jun. 30, 2014 Annex Manufacturing [Member]	Jun. 30, 2014 Annex Manufacturing [Member]	Dec. 31, 2013 Annex Manufacturing [Member]	Jun. 30, 2014 Annex Manufacturing [Member] Customer Relationships [Member]	Jun. 30, 2014 Annex Manufacturing [Member] Non-compete Agreements [Member]
Allocation of purchase price to the assets acquired and liabilities assumed [Abstract]
Purchase price:						$ 12,225,000		$ 11,500,000
Assets acquired and liabilities assumed [Abstract]
Receivables						0	2,581,000	2,581,000
Inventory						2,815,000	2,630,000	2,630,000
Property, plant and equipment, net						466,000	128,000	128,000
Intangible assets						0	4,760,000	4,760,000
Goodwill	55,173,000		55,173,000		38,005,000	12,528,000	4,567,000	4,567,000
Current liabilities						(3,584,000)	(3,166,000)	(3,166,000)
Net assets acquired						12,225,000	11,500,000	11,500,000
Revenue reported by acquired entity for last annual period									22,000,000
Percentage of volume from acquired business sold to parent (in hundredths)									40.00%
Intangible assets acquired in business acquisition										4,700,000	100,000
Estimated useful life of intangible assets										7 years	5 years
Revenues	$ 272,540,000	$ 270,126,000	$ 505,292,000	$ 500,834,000			$ 2,600,000