Segment Information (Details)	3 Months Ended
	Mar. 31, 2022 USD ($) segment	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	2
Total revenue	$ 205,437,000	$ 172,498,000
Operating income / (loss)	8,913,000	15,003,000
Total Assets	1,224,790,000		$ 1,232,015,000
Amortization and depreciation	7,761,000	7,385,000
Additions to property and equipment	2,171,000	4,069,000
Alarm.com
Segment Reporting Information [Line Items]
Amortization and depreciation	7,500,000	7,300,000
Additions to property and equipment	1,600,000	3,500,000
Other
Segment Reporting Information [Line Items]
Amortization and depreciation	300,000	100,000
Additions to property and equipment	100,000	100,000
Operating Segments | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	196,569,000	165,532,000
Operating income / (loss)	12,754,000	17,707,000
Total Assets	1,265,081,000		1,264,416,000
Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	10,181,000	8,137,000
Operating income / (loss)	(4,004,000)	(2,853,000)
Total Assets	35,395,000		37,198,000
Intersegment Eliminations | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	(899,000)	(905,000)
Operating income / (loss)	185,000	153,000
Total Assets	(75,719,000)		(69,595,000)
Intersegment Eliminations | Other
Segment Reporting Information [Line Items]
Total revenue	(414,000)	(266,000)
Operating income / (loss)	(22,000)	$ (4,000)
Total Assets	$ 33,000		$ (4,000)
Segment Concentration Risk | Revenue | Alarm.com
Segment Reporting Information [Line Items]
Concentration risk percentage	95.00%	95.00%
SaaS and license revenue
Segment Reporting Information [Line Items]
Total revenue	$ 123,225,000	$ 107,383,000
SaaS and license revenue | Operating Segments | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	115,348,000	101,263,000
SaaS and license revenue | Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	7,877,000	6,120,000
SaaS and license revenue | Intersegment Eliminations | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	0	0
SaaS and license revenue | Intersegment Eliminations | Other
Segment Reporting Information [Line Items]
Total revenue	0	0
Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	82,212,000	65,115,000
Hardware and other revenue | Operating Segments | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	81,221,000	64,269,000
Hardware and other revenue | Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	2,304,000	2,017,000
Hardware and other revenue | Intersegment Eliminations | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	(899,000)	(905,000)
Hardware and other revenue | Intersegment Eliminations | Other
Segment Reporting Information [Line Items]
Total revenue	(414,000)	(266,000)
Software license revenue | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	7,100,000	8,700,000
Software license revenue | Other
Segment Reporting Information [Line Items]
Total revenue	$ 0	$ 0