Revenue - Schedule of Disaggregates of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue	$ 1,377	$ 1,230	$ 2,704	$ 2,439
PG [Member]
Revenue	1,057	881	2,053	1,767
CP [Member]
Revenue	320	349	651	672
HW [Member]
Revenue	573	573	1,134	1,140
HW [Member] \| PG [Member]
Revenue	311	275	601	568
HW [Member] \| CP [Member]
Revenue	262	298	533	572
Monitoring [Member]
Revenue	804	657	1,570	1,299
Monitoring [Member] \| PG [Member]
Revenue	746	606	1,452	1,199
Monitoring [Member] \| CP [Member]
Revenue	$ 58	$ 51	$ 118	$ 100

Amount, excluding 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 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: 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

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