Goodwill - Changes in Carrying Amount of Goodwill (Detail) (USD $) In Thousands, unless otherwise specified																	6 Months Ended								12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2012 ACS	Jun. 30, 2012 ACS	Jun. 30, 2011 ACS	Dec. 31, 2012 MFS	Jun. 30, 2012 MFS	Jun. 30, 2011 MFS	Jun. 30, 2013 MCE	Dec. 31, 2012 MCE	Jun. 30, 2013 MDS	Dec. 31, 2012 MDS	Jun. 30, 2013 MIS	Dec. 31, 2012 MIS	Jun. 30, 2013 Micronetics	Dec. 31, 2012 Micronetics	Dec. 31, 2012 Micronetics ACS	Dec. 31, 2012 Micronetics MFS	Jun. 30, 2013 Micronetics MCE	Jun. 30, 2013 Micronetics MDS	Jun. 30, 2013 Micronetics MIS	Dec. 31, 2012 KOR Electronics	Jun. 30, 2012 KOR Electronics	Dec. 31, 2012 KOR Electronics ACS	Jun. 30, 2012 KOR Electronics ACS	Dec. 31, 2012 KOR Electronics MFS	Jun. 30, 2012 KOR Electronics MFS
Goodwill [Roll Forward]
Beginning Balance	$ 176,521	$ 178,429	$ 132,621	$ 79,558	$ 159,279	$ 113,471	$ 79,558	$ 19,150	$ 19,150	$ 0	$ 133,783	$ 135,691	$ 33,768	$ 33,768	$ 8,970	$ 8,970
Goodwill arising from acquistion																		46,509	46,509	0					53,063		33,913		19,150
Subsequent recognition of deferred tax assets from the Micronetics acquisition																	(376)				(376)	0	0
Subsequent decrease of deferred tax liabilities from the Micronetics acquisition																	(414)				(414)	0	0
Goodwill adjustment																	(1,118)				(1,118)	0	0	(701)		(701)		0
Ending Balance	$ 176,521	$ 178,429	$ 132,621	$ 79,558	$ 159,279	$ 113,471	$ 79,558	$ 19,150	$ 19,150	$ 0	$ 133,783	$ 135,691	$ 33,768	$ 33,768	$ 8,970	$ 8,970