SEGMENT INFORMATION - Schedule of Revenue Disaggregated by Service (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 1,059,122	$ 767,387	$ 2,054,197	$ 1,528,220
Operating segments | Match Group
Segment Reporting Information [Line Items]
Revenue	421,196	309,572	828,563	608,336
Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	294,822	180,711	550,133	331,456
Operating segments | Video
Segment Reporting Information [Line Items]
Revenue	62,757	55,182	128,919	105,759
Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	143,074	143,969	275,061	302,866
Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	137,355	78,124	271,677	156,204
North America | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	277,505	165,491	513,531	303,563
International
Segment Reporting Information [Line Items]
Revenue	350,551	222,367	688,046	434,602
Europe | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	17,317	15,220	36,602	27,893
Direct revenue | Operating segments | Match Group
Segment Reporting Information [Line Items]
Revenue	407,727	299,423	800,464	587,175
Direct revenue | North America | Operating segments | Match Group
Segment Reporting Information [Line Items]
Revenue	222,163	178,505	433,520	353,833
Direct revenue | International | Operating segments | Match Group
Segment Reporting Information [Line Items]
Revenue	185,564	120,918	366,944	233,342
Indirect revenue | Operating segments | Match Group
Segment Reporting Information [Line Items]
Revenue	13,469	10,149	28,099	21,161
Marketplace revenue | North America | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	204,735	155,755	370,343	285,399
Consumer connection revenue | North America | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	187,172	141,163	336,232	257,163
Membership subscription revenue | North America | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	16,565	13,704	32,192	26,456
Other revenue | North America | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	998	888	1,919	1,780
Other revenue | Operating segments | Video
Segment Reporting Information [Line Items]
Revenue	13,766	4,656	25,537	9,483
Other revenue | North America | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	72,770	9,736	143,188	18,164
Other revenue | Europe | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	304	178	551	380
Consumer connection revenue | Europe | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	12,496	11,170	26,863	19,635
Membership subscription revenue | Europe | Operating segments | ANGI Homeservices
Segment Reporting Information [Line Items]
Revenue	4,517	3,872	9,188	7,878
Subscription revenue | Operating segments | Video
Segment Reporting Information [Line Items]
Revenue	32,724	26,782	67,067	51,599
Media production and distribution revenue | Operating segments | Video
Segment Reporting Information [Line Items]
Revenue	16,267	23,744	36,315	44,677
Consumer | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	123,565	117,883	233,639	248,215
Advertising revenue | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	95,303	102,808	189,088	214,219
Google advertising revenue | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	88,821	94,130	176,252	199,228
Other | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	6,482	8,678	12,836	14,991
Subscription and other revenue | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	28,262	15,075	44,551	33,996
Partnerships | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	19,509	26,086	41,422	54,651
Advertising revenue | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	19,487	26,024	41,364	54,516
Google advertising revenue | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	18,746	25,329	39,892	53,038
Other | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	741	695	1,472	1,478
Other revenue | Operating segments | Applications
Segment Reporting Information [Line Items]
Revenue	22	62	58	135
Premium Brands | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	39,759	28,346	78,567	54,346
Advertising revenue | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	38,576	28,042	76,161	53,697
Google advertising revenue | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	12,353	10,808	25,991	20,597
Other | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	26,223	17,234	50,170	33,100
Other revenue | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	1,183	304	2,406	649
Ask & Other | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	97,596	49,778	193,110	101,858
Advertising revenue | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	94,225	49,580	189,530	101,472
Google advertising revenue | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	84,563	43,794	173,255	88,481
Other | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	9,662	5,786	16,275	12,991
Other revenue | Operating segments | Publishing
Segment Reporting Information [Line Items]
Revenue	$ 3,371	$ 198	$ 3,580	$ 386