Goodwill and Intangible Assets - Changes in Goodwill Balances by Segment (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012
Goodwill [Line Items]
Goodwill, beginning balance	$ 22,738,000
Foreign Exchange	(3,000)
Goodwill, ending balance	22,735,000
SLPE [Member]
Goodwill [Line Items]
Goodwill, beginning balance	4,245,000
Foreign Exchange	(3,000)
Goodwill, ending balance	4,242,000
MTE Corporation [Member]
Goodwill [Line Items]
Goodwill, beginning balance	8,189,000
Foreign Exchange
Goodwill, ending balance	8,189,000
TEAL Electronics Corp [Member]
Goodwill [Line Items]
Goodwill, beginning balance	5,055,000
Foreign Exchange
Goodwill, ending balance	5,055,000
RFL [Member]
Goodwill [Line Items]
Goodwill, beginning balance	5,249,000
Foreign Exchange
Goodwill, ending balance	$ 5,249,000