Operating Segments and Related Information Operating Segments and Related Information (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 332,230	$ 371,327	$ 1,018,973	$ 1,138,850
Revenue - Intersegments	0	0	0	0
Earnings (loss) from operations	74,237	85,409	203,253	203,527
Thermal Vision and Measurement
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	149,540	160,998	447,922	470,799
Revenue - Intersegments	3,076	3,799	12,527	14,197
Earnings (loss) from operations	42,916	47,162	109,651	131,447
Raymarine
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	31,659	35,442	125,443	136,169
Revenue - Intersegments	0	0	4	7
Earnings (loss) from operations	374	(2,824)	9,944	11,829
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	115,915	139,827	350,005	431,164
Revenue - Intersegments	5,260	5,982	17,246	23,003
Earnings (loss) from operations	39,243	51,872	114,965	149,672
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	15,401	21,193	50,467	56,284
Revenue - Intersegments	1,027	1,913	1,803	3,391
Earnings (loss) from operations	1,131	1,997	801	(4,878)
Integrated Systems
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	19,715	13,867	45,136	44,434
Revenue - Intersegments	295	0	1,342	1,811
Earnings (loss) from operations	1,333	298	1,267	126
Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - Intersegments	(9,658)	(11,694)	(32,922)	(42,409)
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Earnings (loss) from operations	$ (10,760)	$ (13,096)	$ (33,375)	$ (84,669)