Operating Segments and Related Information (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 379,472	$ 344,517
Intersegment revenue	0	0
Earnings (loss) from operations	57,377	65,754
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	124,151	112,901
Intersegment revenue	4,224	3,682
Earnings (loss) from operations	35,240	30,166
Instruments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	79,418	83,821
Intersegment revenue	1,575	842
Earnings (loss) from operations	19,496	28,063
OEM & Emerging Markets
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	47,845	39,834
Intersegment revenue	8,176	8,686
Earnings (loss) from operations	10,032	8,779
Maritime
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	51,720	50,972
Intersegment revenue	615	657
Earnings (loss) from operations	4,998	4,789
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	29,277	18,183
Intersegment revenue	0	0
Earnings (loss) from operations	7,880	2,680
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue	(17,063)	(17,843)
Earnings (loss) from operations	$ (16,624)	$ (12,539)