Acquisitions (GD NG-911 Business) (Details) - GD NG-911 business	Apr. 29, 2019 USD ($) employee
Business Acquisition [Line Items]
Aggregate purchase price \| $	$ 11,013,000
Development contract term	5 years
Number of employees hired \| employee	60

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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