Segment Information - Net Intangible Assets by Segment (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Goodwill and other intangible assets, net
Goodwill and other intangible assets, net	$ 25,065	$ 25,405
Operating Segments [Member] | SLPE [Member]
Goodwill and other intangible assets, net
Goodwill and other intangible assets, net	4,530	4,563
Operating Segments [Member] | High Power Group [Member]
Goodwill and other intangible assets, net
Goodwill and other intangible assets, net	15,102	15,343
Operating Segments [Member] | SL-MTI [Member]
Goodwill and other intangible assets, net
Goodwill and other intangible assets, net	115	140
Operating Segments [Member] | RFL [Member]
Goodwill and other intangible assets, net
Goodwill and other intangible assets, net	$ 5,318	$ 5,359