Operating Segments and Related Information (Details 2) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 392,975	$ 369,380	$ 737,492	$ 720,923
Intersegment revenue	0	0	0	0
Earnings (loss) from operations	70,531	59,364	136,285	101,814
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	107,814	113,641	220,715	236,729
Intersegment revenue	2,065	1,568	5,747	3,983
Earnings (loss) from operations	26,378	22,634	56,546	45,900
Instruments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	90,260	83,968	174,080	168,023
Intersegment revenue	1,068	173	1,910	474
Earnings (loss) from operations	28,341	21,037	56,404	41,486
OEM & Emerging Markets
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	46,285	51,124	86,120	99,039
Intersegment revenue	9,072	5,390	17,758	10,556
Earnings (loss) from operations	10,495	13,914	19,274	22,720
Maritime
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	52,030	55,230	103,002	107,805
Intersegment revenue	925	836	1,582	1,504
Earnings (loss) from operations	6,421	9,714	11,210	18,544
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	60,048	44,735	98,854	74,045
Intersegment revenue	4,032	2,735	8,007	4,390
Earnings (loss) from operations	7,874	5,886	11,689	7,572
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	36,538	20,682	54,721	35,282
Intersegment revenue	0	39	0	59
Earnings (loss) from operations	9,380	3,152	12,059	1,353
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue	(17,162)	(10,741)	(35,004)	(20,966)
Earnings (loss) from operations	$ (18,358)	$ (16,973)	$ (30,897)	$ (35,761)