Equity Method Investment, Shares

No definition available.

Name:	alrm_EquityMethodInvestmentShares
Namespace Prefix:	alrm_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Notes Receivable, Face Amount

+ References

No definition available.

+ Details

Name:	alrm_NotesReceivableFaceAmount
Namespace Prefix:	alrm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Notes Receivable, Interest Rate, Stated Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	alrm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of interest income earned from interest-bearing assets owed to the entity by related party.

+ References

No definition available.

+ Details

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

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Details

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Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_EquityMethodInvesteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=alrm_SecuredPromissoryNoteMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=alrm_CostofHardwareandOtherRevenueMember
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis=alrm_DistributionPartnerTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions (Details) - USD ($)	3 Months Ended		6 Months Ended
Related Party Transactions (Details) - USD ($)	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 11, 2015	Sep. 30, 2014
Installation Partner
Related Party Transaction [Line Items]
Ownership percentage in equity method investment	48.20%		48.20%
Equity method investment, shares	48,190		48,190					9,290
Equity method investment, cost	$ 1,000,000		$ 1,000,000					$ 200,000
Installation Partner \| Equity Method Investee
Related Party Transaction [Line Items]
Accounts payable to related party	100,000		100,000			$ 100,000
Interest income from related party	100,000	$ 100	100	$ 100
Installation Partner \| Equity Method Investee \| Secured Promissory Note
Related Party Transaction [Line Items]
Related party notes receivable, face amount									$ 300,000
Notes receivable, interest rate									8.00%
Installation Partner \| Equity Method Investee \| Cost of Hardware and Other Revenue
Related Party Transaction [Line Items]
Expenses incurred from related party	$ 200,000	$ 300,000	$ 500,000	$ 700,000
Notes Receivable \| Distribution Partner Two
Related Party Transaction [Line Items]
Notes receivable, interest rate					6.00%		6.00%