ORGANIZATION - Narrative (Details) service_professional in Thousands, project in Millions	12 Months Ended
Dec. 31, 2019 operating_segment service_professional project service_category
Noncontrolling Interest [Line Items]
Number of service categories	500
Number of service professionals \| service_professional	250
Number of projects (more than) \| project	25
Number of operating segments \| operating_segment	2
Angie's List
Noncontrolling Interest [Line Items]
Number of service categories	700
ANGI Homeservices \| Class B Common Stock \| IAC
Noncontrolling Interest [Line Items]
Ownership interest (as a percent)	84.10%
Voting interest (as a percent)	98.10%

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

No definition available.

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration