Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 157,893	$ 153,029
Product
Disaggregation of Revenue [Line Items]
Net sales	61,925	63,277
Product \| Mobile Connectivity \| Transferred at point in time
Disaggregation of Revenue [Line Items]
Net sales	26,419	26,086
Product \| Mobile Connectivity \| Transferred over time
Disaggregation of Revenue [Line Items]
Net sales	5,204	5,265
Product \| Intertial Navigation
Disaggregation of Revenue [Line Items]
Net sales	30,302	31,926
Service
Disaggregation of Revenue [Line Items]
Net sales	95,968	89,752
Service \| Mobile Connectivity
Disaggregation of Revenue [Line Items]
Net sales	90,392	84,575
Service \| Intertial Navigation
Disaggregation of Revenue [Line Items]
Net sales	$ 5,576	$ 5,177

Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Name:	us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration