Operating Segments and Related Information (Details 4) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
BU assets (accounts receivable, inventory and demo assets, Net)	$ 728,990	$ 737,805
BU assets (accounts receivable, inventory, demo assets and goodwill, Net)	2,057,818	2,102,401
Cash and cash equivalents	308,615	284,592	$ 284,363	$ 512,144
Prepaid expenses and other current assets	92,929	86,337
Property and equipment, net	251,421	255,905
Deferred Income Tax Assets, Net	39,458	39,983
Goodwill	1,328,828	1,364,596
Intangible assets, net	231,953	247,514
Other assets	140,043	120,809
Assets	3,122,237	3,137,541
Defense Technologies
Segment Reporting, Asset Reconciling Item [Line Items]
BU assets (accounts receivable, inventory and demo assets, Net)	360,791	332,639
Goodwill	700,173	728,697
Industrial Technologies
Segment Reporting, Asset Reconciling Item [Line Items]
BU assets (accounts receivable, inventory and demo assets, Net)	368,199	405,166
Goodwill	$ 628,655	$ 635,899