SEGMENT INFORMATION - SCHEDULE OF RECONCILIATION OF ADJUSTED EBITDA TO OPERATING INCOME (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Other Significant Reconciling Item
Operating income (loss)	$ (33,918)	$ (112,505)	$ (2,836)	$ 1,388	$ 6,216	$ 8,843	$ 9,513	$ (514)	$ (147,871)	$ 24,058	$ (1,568)
Stock-based compensation expense									149,230	8,916	7,853
Depreciation									14,543	8,419	6,593
Amortization of intangibles									23,261	3,153	3,835
Adjusted EBITDA									39,163	44,546	16,713
Interest expense—third party									(1,765)	0	0
Interest Expense, Related Party									5,971	894	272
Other income (expense), net									1,974	(699)	(398)
(Loss) earnings before income taxes									(153,633)	22,465	(2,238)
Taxes									49,106	(11,834)	(1,758)
Net (loss) earnings									(104,527)	10,631	(3,996)
Net loss attributable to noncontrolling interests									1,409	2,497	2,671
Net (loss) earnings attributable to ANGI Homeservices Inc. shareholders	$ (58,224)	$ (71,761)	$ 254	$ 26,613	$ 2,720	$ 5,075	$ 6,010	$ (677)	(103,118)	13,128	(1,325)
North America
Segment Reporting, Other Significant Reconciling Item
Operating income (loss)									(128,483)	32,464	2,311
Stock-based compensation expense									147,574	7,126	6,758
Depreciation									13,243	7,996	5,768
Amortization of intangibles									17,848	2,502	3,347
Adjusted EBITDA									50,182	50,088	18,184
Europe
Segment Reporting, Other Significant Reconciling Item
Operating income (loss)									(19,388)	(8,406)	(3,879)
Stock-based compensation expense									1,656	1,790	1,095
Depreciation									1,300	423	825
Amortization of intangibles									5,413	651	488
Adjusted EBITDA									$ (11,019)	$ (5,542)	$ (1,471)