Operating Segments and Related Information Operating Segments and Related Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 348,452	$ 375,969	[1]
Revenue - Intersegments	0	0	[1]
Earnings (loss) from operations	68,296	76,316	[1]
Thermal Vision and Measurement
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	155,741	144,965	[1]
Revenue - Intersegments	5,048	4,694	[1]
Earnings (loss) from operations	39,341	37,176	[1]
Raymarine
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	46,604	50,536	[1]
Revenue - Intersegments	4	3	[1]
Earnings (loss) from operations	3,841	7,410	[1]
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	114,597	149,857	[1]
Revenue - Intersegments	4,903	10,258	[1]
Earnings (loss) from operations	34,901	51,324	[1]
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	19,352	17,871	[1]
Revenue - Intersegments	451	0	[1]
Earnings (loss) from operations	1,437	(3,861)	[1]
Integrated Systems
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	12,158	12,740	[1]
Revenue - Intersegments	574	681	[1]
Earnings (loss) from operations	(398)	(333)	[1]
Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - Intersegments	(10,980)	(15,636)	[1]
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Earnings (loss) from operations	$ (10,826)	$ (15,400)	[1]

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