EARNINGS (LOSS) PER SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Numerator: Basic
Earnings from continuing operations	$ 45,630	$ 15,421	$ 65,798	$ 824
Net (earnings) loss attributable to noncontrolling interests	(718)	756	(868)	1,375
Earnings from continuing operations attributable to IAC shareholders	44,912	16,177	64,930	2,199
Loss from discontinued operations, net of tax	(2,488)	(2,586)	(4,436)	(7,313)
Net earnings (loss) attributable to IAC shareholders	42,424	13,591	60,494	(5,114)
Numerator: Diluted
Earnings from continuing operations	45,630	15,421	65,798	824
Net (earnings) loss attributable to noncontrolling interests	(718)	756	(868)	1,375
Earnings from continuing operations attributable to IAC shareholders	44,912	16,177	64,930	2,199
Loss from discontinued operations, net of tax	(2,488)	(2,586)	(4,436)	(7,313)
Net earnings (loss) attributable to IAC shareholders	$ 42,424	$ 13,591	$ 60,494	$ (5,114)
Denominator: Basic
Weighted average basic shares outstanding (in shares)	90,050	109,287	89,568	112,847
Denominator: Diluted
Weighted average basic shares outstanding (in shares)	90,050	109,287	89,568	112,847
Dilutive securities including stock options, warrants and RSUs (in shares)	7,252	3,320	5,923	3,394
Denominator for earnings per share-weighted average shares (in shares)	97,302	112,607	95,491	116,241
Earnings per share attributable to IAC shareholders: Basic
Earnings per share from continuing operations (in dollars per share)	$ 0.50	$ 0.15	$ 0.72	$ 0.02
Discontinued operations, net of tax (in dollars per share)	$ (0.03)	$ (0.03)	$ (0.04)	$ (0.07)
Earnings (loss) per share (in dollars per share)	$ 0.47	$ 0.12	$ 0.68	$ (0.05)
Earnings (loss) per share attributable to IAC shareholders: Diluted
Earnings per share from continuing operations (in dollars per share)	$ 0.46	$ 0.14	$ 0.68	$ 0.02
Discontinued operations, net of tax (in dollars per share)	$ (0.02)	$ (0.02)	$ (0.05)	$ (0.06)
Earnings (loss) per share (in dollars per share)	$ 0.44	$ 0.12	$ 0.63	$ (0.04)