Operating Segments and Related Information (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 402,729	$ 392,975	$ 782,201	$ 737,492
Intersegment revenue	0	0	0	0
Earnings (loss) from operations	65,212	70,531	122,589	136,285
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	113,440	107,814	237,591	220,715
Intersegment revenue	4,755	2,065	8,979	5,747
Earnings (loss) from operations	26,135	26,378	61,374	56,546
Instruments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	78,068	90,260	157,487	174,080
Intersegment revenue	1,213	1,068	2,788	1,910
Earnings (loss) from operations	19,133	28,341	38,629	56,404
Security [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	63,380	60,048	110,441	98,854
Intersegment revenue	3,836	4,032	6,308	8,007
Earnings (loss) from operations	3,214	7,874	(430)	11,689
OEM & Emerging Markets
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	56,980	46,285	104,825	86,120
Intersegment revenue	8,833	9,072	17,010	17,758
Earnings (loss) from operations	16,094	10,495	26,127	19,274
Maritime
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	55,163	52,030	106,883	103,002
Intersegment revenue	1,458	925	2,072	1,582
Earnings (loss) from operations	6,721	6,421	11,719	11,210
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	35,698	36,538	64,974	54,721
Intersegment revenue	31	0	31	0
Earnings (loss) from operations	9,963	9,380	17,843	12,059
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue	(20,126)	(17,162)	(37,188)	(35,004)
Earnings (loss) from operations	$ (16,048)	$ (18,358)	$ (32,673)	$ (30,897)