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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

+ Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of voting equity interest acquired in business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-8

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 38
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479303/805-10-55-38

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479328/805-10-50-2

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of convertible debt securities using the if-converted method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-42

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 40
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-40

+ Details

Name:	us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after tax, of interest recognized on convertible debt instrument excluding interest on principal required to be paid in cash.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482662/260-10-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 16
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-16

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 40
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482689/260-10-45-40

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=alrm_ConvertibleSeniorNotesDue2026Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=alrm_ConvertibleSeniorNotesDue2029Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=alrm_OpenEyeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=alrm_NoonlightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=alrm_CHeKTIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Earnings Per Share - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Feb. 10, 2025
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Interest expense and debt issuance cost	$ 2,944	$ 3,234	$ 9,438	$ 5,301
Convertible Senior Notes Due 2026
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive effect of convertible senior notes (in shares)	1,661,552	3,396,950	2,812,127	3,396,950
Convertible Senior Notes Due 2029
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Dilutive effect of convertible senior notes (in shares)	5,728,550	5,728,550	5,728,550	2,571,575
OpenEye
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Percentage of business acquired	86.00%		86.00%
Noonlight
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Percentage of business acquired	87.00%		87.00%
CHeKT, Inc
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Percentage of business acquired	81.00%		81.00%		81.00%