CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net earnings	$ 325,991	$ 95,635	$ 340,619	$ 204,872
Other comprehensive (loss) income, net of tax:
Change in foreign currency translation adjustment	(36,759)	16,724	(31,569)	3,703
Changes in fair value of available-for-sale securities (net of tax benefit of $245 and $1,683 for the three and nine months ended September 30, 2014, respectively, and tax provision of $1,732 and $1,648 for the three and nine months ended September 30, 2013, respectively)	(389)	12,182	(2,639)	24,393
Net current period other comprehensive loss	(37,148)	28,906	(34,208)	28,096
Comprehensive income	288,843	124,541	306,411	232,968
Comprehensive loss (income) attributable to noncontrolling interests	1,107	(2,039)	4,568	1,443
Comprehensive income attributable to IAC shareholders	$ 289,950	$ 122,502	$ 310,979	$ 234,411