Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

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The net result for the period of deducting operating expenses from operating revenues.

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The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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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.

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Segment Information (Details)	3 Months Ended		9 Months Ended
Segment Information (Details)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) segment	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Total revenue	$ 127,880,000	$ 111,848,000	$ 361,875,000	$ 309,092,000
Number of reportable segments \| segment			2
Operating income / (loss)	12,195,000	(16,694,000)	$ 35,461,000	3,809,000
Total Assets	501,006,000		501,006,000		$ 440,985,000
Amortization and depreciation	5,467,000	5,891,000	15,833,000	16,154,000
Additions to property and equipment			10,660,000	9,317,000
Alarm.com
Segment Reporting Information [Line Items]
Amortization and depreciation	5,500,000	5,800,000	15,800,000	15,900,000
Additions to property and equipment	4,700,000	3,900,000	8,500,000	10,100,000
Other
Segment Reporting Information [Line Items]
Amortization and depreciation	100,000	100,000	100,000	200,000
Additions to property and equipment	100,000	100,000	100,000	100,000
Operating Segments \| Alarm.com
Segment Reporting Information [Line Items]
Total revenue	120,970,000	105,526,000	341,343,000	292,867,000
Operating income / (loss)	12,772,000	(15,593,000)	37,182,000	8,335,000
Total Assets	534,948,000		534,948,000		482,666,000
Operating Segments \| Other
Segment Reporting Information [Line Items]
Total revenue	10,454,000	9,386,000	29,664,000	23,769,000
Operating income / (loss)	(561,000)	(1,084,000)	(1,782,000)	(4,548,000)
Total Assets	18,144,000		18,144,000		19,629,000
Intersegment Eliminations \| Alarm.com
Segment Reporting Information [Line Items]
Total revenue	(1,287,000)	(1,343,000)	(3,364,000)	(3,585,000)
Operating income / (loss)	62,000	26,000	71,000	(211,000)
Total Assets	(52,086,000)		(52,086,000)		(61,309,000)
Intersegment Eliminations \| Other
Segment Reporting Information [Line Items]
Total revenue	(2,257,000)	(1,721,000)	(5,768,000)	(3,959,000)
Operating income / (loss)	(78,000)	$ (43,000)	(10,000)	$ 233,000
Total Assets	$ 0		$ 0		$ (1,000)
Segment Concentration Risk \| Revenue \| Alarm.com
Segment Reporting Information [Line Items]
Concentration risk percentage	94.00%	93.00%	93.00%	94.00%
Software license revenue \| Alarm.com
Segment Reporting Information [Line Items]
Total revenue	$ 10,800,000	$ 10,500,000	$ 32,800,000	$ 30,600,000
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	84,924,000	74,292,000	247,313,000	213,248,000
SaaS and license revenue \| Operating Segments \| Alarm.com
Segment Reporting Information [Line Items]
Total revenue	79,954,000	70,884,000	233,459,000	204,622,000
SaaS and license revenue \| Operating Segments \| Other
Segment Reporting Information [Line Items]
Total revenue	4,970,000	3,408,000	13,854,000	8,626,000
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	42,956,000	37,556,000	114,562,000	95,844,000
Hardware and other revenue \| Operating Segments \| Alarm.com
Segment Reporting Information [Line Items]
Total revenue	41,016,000	34,642,000	107,884,000	88,245,000
Hardware and other revenue \| Operating Segments \| Other
Segment Reporting Information [Line Items]
Total revenue	5,484,000	5,978,000	15,810,000	15,143,000
Hardware and other revenue \| Intersegment Eliminations \| Alarm.com
Segment Reporting Information [Line Items]
Total revenue	(1,287,000)	(1,343,000)	(3,364,000)	(3,585,000)
Hardware and other revenue \| Intersegment Eliminations \| Other
Segment Reporting Information [Line Items]
Total revenue	$ (2,257,000)	$ (1,721,000)	$ (5,768,000)	$ (3,959,000)