Operating Segments and Related Information Operating Segments and Related Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011		Jun. 30, 2012	Jun. 30, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 338,291	$ 391,555	[1]	$ 686,743	$ 767,524	[1]
Revenue - Intersegments	0	0	[1]	0	0	[1]
Earnings (loss) from operations	60,721	41,803	[1]	129,017	118,118	[1]
Thermal Vision and Measurement
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	142,641	164,838	[1]	298,381	309,803	[1]
Revenue - Intersegments	4,403	5,705	[1]	9,451	10,398	[1]
Earnings (loss) from operations	27,394	47,109	[1]	66,736	84,285	[1]
Raymarine
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	47,181	50,190	[1]	93,785	100,726	[1]
Revenue - Intersegments	0	4	[1]	4	7	[1]
Earnings (loss) from operations	5,728	7,243	[1]	9,569	14,653	[1]
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	119,493	141,479	[1]	234,090	291,336	[1]
Revenue - Intersegments	7,083	6,764	[1]	11,986	17,021	[1]
Earnings (loss) from operations	40,821	46,475	[1]	75,722	97,799	[1]
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	15,713	17,221	[1]	35,066	35,092	[1]
Revenue - Intersegments	326	1,478	[1]	776	1,478	[1]
Earnings (loss) from operations	(1,767)	(3,014)	[1]	(330)	(6,875)	[1]
Integrated Systems
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	13,263	17,827	[1]	25,421	30,567	[1]
Revenue - Intersegments	473	1,221	[1]	1,047	1,902	[1]
Earnings (loss) from operations	331	161	[1]	(66)	(172)	[1]
Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - Intersegments	(12,285)	(15,172)	[1]	(23,264)	(30,806)	[1]
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Earnings (loss) from operations	$ (11,786)	$ (56,171)	[1]	$ (22,614)	$ (71,572)	[1]

[1] Amounts have been adjusted for the reclassification of certain discontinued operations to continuing operations.