Subsequent Event	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Event	Subsequent EventOn November 4, 2020, we and ADT LLC, or ADT, entered into an amendment to our existing master service agreement, the Amendment. The Amendment extends the initial term of the master service agreement through January 1, 2023 and sets forth certain terms relating to the integration of certain Google Nest products and services into the platform we operate on behalf of ADT, and assures that subject to certain conditions and exceptions, ADT will enable its end customers to continue as subscribers on an Alarm.com platform after the initial term expires for the natural lifetime of such end customer account. Concurrently with the Amendment, we entered into a patent license agreement pursuant to which we granted ADT a license to use certain Alarm.com intellectual property following the termination or expiration of the initial term of the master service agreement. Under the terms of the patent license, ADT will pay us a monthly royalty for each subscriber to its branded residential interactive security, automation and video service offerings that is covered by any of our licensed patents and not supported on our platforms.