Carrying Value of Goodwill by Reporting Segment and the Activity (Detail) (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011
Goodwill [Line Items]
Beginning Balance	$ 482,019
Business Acquisitions
Currency Translation Adjustments	918
Other	1,695	[1]
Ending Balance	484,632
Thermal Vision and Measurement
Goodwill [Line Items]
Beginning Balance	236,181
Business Acquisitions
Currency Translation Adjustments	541
Other	(102)	[1]
Ending Balance	236,620
Raymarine
Goodwill [Line Items]
Beginning Balance	97,266
Business Acquisitions
Currency Translation Adjustments	419
Other	268	[1]
Ending Balance	97,953
Surveillance
Goodwill [Line Items]
Beginning Balance	88,052
Business Acquisitions
Currency Translation Adjustments	(42)
Other	2,552	[1]
Ending Balance	90,562
Detection
Goodwill [Line Items]
Beginning Balance	41,026
Business Acquisitions
Other	(1,697)	[1]
Ending Balance	39,329
Integrated Systems
Goodwill [Line Items]
Beginning Balance	19,494
Business Acquisitions
Other	674	[1]
Ending Balance	$ 20,168

[1] Primarily relates to adjustments for tax assets and liabilities recorded in relation to recent acquisitions.