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, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	$ 375,366	$ 358,141	$ 1,096,288	$ 1,096,053
Intersegment revenue	0	0	0	0
Earnings (loss) from operations	70,009	63,539	171,824	202,942
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	119,126	126,591	342,105	392,439
Intersegment revenue	2,659	1,942	6,642	5,119
Earnings (loss) from operations	30,070	29,836	69,366	97,810
Instruments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	82,561	77,199	250,583	236,011
Intersegment revenue	74	2,119	548	4,342
Earnings (loss) from operations	23,191	20,433	64,678	63,378
OEM & Emerging Markets
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	56,105	54,782	168,895	153,700
Intersegment revenue	4,721	6,762	15,277	19,601
Earnings (loss) from operations	16,121	16,814	45,445	43,453
Maritime
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	44,728	41,297	152,533	146,437
Intersegment revenue	804	0	2,308	0
Earnings (loss) from operations	4,614	2,966	23,159	20,447
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	48,648	35,409	122,692	99,331
Intersegment revenue	2,971	0	7,361	0
Earnings (loss) from operations	6,988	4,460	14,560	12,097
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue - External Customers	24,198	22,863	59,480	68,135
Intersegment revenue	4	6	64	1,730
Earnings (loss) from operations	4,167	4,102	5,519	10,547
Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue	(11,233)	(10,829)	(32,200)	(30,792)
Earnings (loss) from operations	$ (15,142)	$ (15,072)	$ (50,903)	$ (44,790)