v3.20.2

Interest, advances and promissory notes payable (Details) - Summary of Interest Payable Activity - USD ($) | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Summary of Interest Payable Activity [Abstract] |  |  |  |
Beginning Balance | $ 5,364,997 | $ 4,836,127 | $ 4,307,256 | $ 3,629,913
Interest incurred on promissory notes payable | 265,834 | 528,870 | 528,871 | 504,873
Transfer from implicit interest to interest payable on promissory note |  |  |  | 172,470
Ending Balance | $ 5,630,831 | $ 5,364,997 | $ 4,836,127 | $ 4,307,256

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- Definition The cost of borrowed funds accounted for as interest that was charged against earnings during the period. + References No definition available. + Details
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Namespace Prefix: | alrt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- References No definition available. + Details
Name: | alrt_SummaryOfInterestPayableActivityAbstract
Namespace Prefix: | alrt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- References No definition available. + Details
Name: | alrt_TransferFromImplicitInterestToInterestPayableOnPromissoryNote
Namespace Prefix: | alrt_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Amount of interest payable on debt, including, but not limited to, trade payables. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15(5)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.15(a)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 + Details
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Namespace Prefix: | us-gaap_
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Balance Type: | credit
Period Type: | instant