Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) segment	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			2
Total revenue	$ 141,637	$ 121,660	$ 293,576	$ 233,995
Operating income / (loss)	14,994	14,045	24,861	23,266
Total Assets	662,645		662,645		$ 557,799
Amortization and depreciation	6,723	5,138	13,145	10,366
Additions to property and equipment			7,116	5,708
Alarm.com
Segment Reporting Information [Line Items]
Amortization and depreciation	6,700	5,100	13,100	10,400
Additions to property and equipment	3,900	1,500	6,500	3,800
Other
Segment Reporting Information [Line Items]
Amortization and depreciation	100	100	100	100
Additions to property and equipment	100	100	900	100
Operating Segments | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	133,469	114,625	278,409	220,374
Operating income / (loss)	15,800	14,754	26,618	24,410
Total Assets	692,689		692,689		589,952
Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	11,708	10,144	21,804	19,208
Operating income / (loss)	(609)	(737)	(1,482)	(1,222)
Total Assets	22,677		22,677		17,844
Intersegment Eliminations | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	(703)	(1,078)	(1,564)	(2,077)
Operating income / (loss)	16	44	57	9
Total Assets	(52,736)		(52,736)		(49,997)
Intersegment Eliminations | Other
Segment Reporting Information [Line Items]
Total revenue	(2,837)	(2,031)	(5,073)	(3,510)
Operating income / (loss)	(213)	$ (16)	(332)	$ 69
Total Assets	$ 15		$ 15		$ 0
Segment Concentration Risk | Revenue | Alarm.com
Segment Reporting Information [Line Items]
Concentration risk percentage	94.00%	93.00%	94.00%	93.00%
Software license revenue | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	$ 9,800	$ 11,000	$ 19,500	$ 22,000
Software license revenue | Other
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
SaaS and license revenue
Segment Reporting Information [Line Items]
Total revenue	95,704	82,334	187,654	162,389
SaaS and license revenue | Operating Segments | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	88,922	78,104	176,334	153,506
SaaS and license revenue | Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	6,782	4,230	11,320	8,883
SaaS and license revenue | Intersegment Eliminations | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
SaaS and license revenue | Intersegment Eliminations | Other
Segment Reporting Information [Line Items]
Total revenue	0	0	0	0
Hardware and other revenue
Segment Reporting Information [Line Items]
Total revenue	45,933	39,326	105,922	71,606
Hardware and other revenue | Operating Segments | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	44,547	36,521	102,075	66,868
Hardware and other revenue | Operating Segments | Other
Segment Reporting Information [Line Items]
Total revenue	4,926	5,914	10,484	10,325
Hardware and other revenue | Intersegment Eliminations | Alarm.com
Segment Reporting Information [Line Items]
Total revenue	(703)	(1,078)	(1,564)	(2,077)
Hardware and other revenue | Intersegment Eliminations | Other
Segment Reporting Information [Line Items]
Total revenue	$ (2,837)	$ (2,031)	$ (5,073)	$ (3,510)