EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Numerator: Basic
Earnings (loss) from continuing operations	$ 57,885	$ (17,995)	$ 79,748	$ 16,310
Net loss attributable to noncontrolling interests	1,573	867	5,990	3,261
Earnings (loss) from continuing operations attributable to IAC shareholders	59,458	(17,128)	85,738	19,571
Earnings (loss) from discontinued operations attributable to IAC shareholders	(153)	(868)	(28)	(1,682)
Net earnings (loss) attributable to IAC shareholders	59,305	(17,996)	85,710	17,889
Numerator: Diluted
Earnings (loss) from continuing operations	57,885	(17,995)	79,748	16,310
Net loss attributable to noncontrolling interests	1,573	867	5,990	3,261
Earnings (loss) from continuing operations attributable to IAC shareholders	59,458	(17,128)	85,738	19,571
Earnings (loss) from discontinued operations attributable to IAC shareholders	(153)	(868)	(28)	(1,682)
Net earnings (loss) attributable to IAC shareholders	$ 59,305	$ (17,996)	$ 85,710	$ 17,889
Denominator: Basic
Weighted average basic shares outstanding	82,416	83,178	82,932	82,833
Denominator: Diluted
Weighted average basic shares outstanding	82,416	83,178	82,932	82,833
Dilutive securities including stock options and RSUs (in shares)	4,674	0	4,989	5,150
Denominator for earnings per share-weighted average shares (in shares)	87,090	83,178	87,921	87,983
Earnings (loss) per share attributable to IAC shareholders: Basic
Earnings per share from continuing operations (in dollars per share)	$ 0.72	$ (0.21)	$ 1.03	$ 0.24
Discontinued operations (in dollars per share)	0.00	(0.01)	0.00	(0.02)
Earnings per share (in dollars per share)	0.72	(0.22)	1.03	0.22
Earnings (loss) per share attributable to IAC shareholders: Diluted
Earnings per share from continuing operations (in dollars per share)	0.68	(0.21)	0.98	0.22
Discontinued operations (in dollars per share)	0.00	(0.01)	(0.01)	(0.02)
Earnings per share (in dollars per share)	$ 0.68	$ (0.22)	$ 0.97	$ 0.20