CONSOLIDATED STATEMENT OF COMPREHENSIVE OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net (loss) earnings	$ (182,643)	$ 112,985
Other comprehensive (loss) income, net of income taxes:
Change in foreign currency translation adjustment	(26,093)	1,309
Change in unrealized gains and losses of available-for-sale securities	(12)	1
Total other comprehensive (loss) income, net of income taxes	(26,105)	1,310
Comprehensive (loss) income, net of income taxes	(208,748)	114,295
Components of comprehensive (income) loss attributable to noncontrolling interests:
Net income attributable to noncontrolling interests	(28,397)	(24,290)
Change in foreign currency translation adjustment attributable to noncontrolling interests	4,766	(316)
Change in unrealized gains and losses of available-for-sale debt securities attributable to noncontrolling interests	0	1
Comprehensive income attributable to noncontrolling interests	(23,631)	(24,605)
Comprehensive (loss) income attributable to IAC shareholders	$ (232,379)	$ 89,690