Operating Segments and Related Information (Details 2) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 474,738	$ 405,228	$ 402,729	$ 379,472	$ 437,647	$ 381,928	$ 392,975	$ 344,517	$ 1,662,167	$ 1,557,067	$ 1,530,654
Intersegment revenue									0	0	0
Earnings (loss) from operations									295,718	305,764	259,244
Surveillance
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									532,476	503,045	519,982
Intersegment revenue									18,835	10,761	7,209
Earnings (loss) from operations									144,906	145,637	127,222
Instruments
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									336,141	347,476	354,124
Intersegment revenue									4,343	9,951	1,793
Earnings (loss) from operations									96,691	112,353	98,954
OEM & Emerging Markets
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									243,678	186,722	199,096
Intersegment revenue									33,442	33,059	21,856
Earnings (loss) from operations									59,686	41,065	50,249
Maritime
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									185,726	177,948	192,636
Intersegment revenue									3,450	2,108	2,936
Earnings (loss) from operations									15,428	13,611	24,494
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									240,010	226,575	179,090
Intersegment revenue									13,838	12,033	11,017
Earnings (loss) from operations									10,172	28,140	24,871
Detection
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									124,136	115,301	85,726
Intersegment revenue									31	0	95
Earnings (loss) from operations									33,847	26,904	10,958
Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Intersegment revenue									73,939	67,912	44,906
Other Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Earnings (loss) from operations									$ (65,012)	$ (61,946)	$ (77,504)