Operating Segments and Related Information (Details 2) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 405,228	$ 381,928	$ 1,187,429	$ 1,119,420
Intersegment revenue	0	0	0	0
Earnings (loss) from operations	80,849	75,982	203,438	212,267
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	136,402	131,598	373,993	352,312
Intersegment revenue	5,001	2,653	13,980	8,400
Earnings (loss) from operations	38,427	39,918	99,801	96,464
Instruments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	82,673	74,796	240,160	248,877
Intersegment revenue	709	777	3,498	2,687
Earnings (loss) from operations	27,010	21,555	65,640	77,959
Security [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	56,431	59,331	166,872	158,185
Intersegment revenue	4,267	2,386	10,575	10,393
Earnings (loss) from operations	2,958	7,222	2,527	18,911
OEM & Emerging Markets
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	62,719	51,448	167,544	137,568
Intersegment revenue	7,518	8,020	24,528	25,778
Earnings (loss) from operations	19,936	14,233	46,063	33,507
Maritime
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	40,586	38,920	147,469	141,922
Intersegment revenue	656	85	2,728	1,667
Earnings (loss) from operations	2,391	1,848	14,110	13,058
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	26,417	25,835	91,391	80,556
Intersegment revenue	0	0	31	0
Earnings (loss) from operations	6,641	5,290	24,484	17,349
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue	(18,151)	(13,921)	(55,340)	(48,925)
Earnings (loss) from operations	$ (16,514)	$ (14,084)	$ (49,187)	$ (44,981)