EARNINGS PER SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Numerator: Basic
Earnings from continuing operations	$ 52,709	$ 31,153
Net loss attributable to noncontrolling interests	1,872	(359)
Earnings from continuing operations attributable to IAC shareholders	54,581	30,794
Loss from discontinued operations attributable to IAC shareholders	(944)	3,684
Net earnings attributable to IAC shareholders	53,637	34,478
Numerator: Diluted
Earnings from continuing operations	52,709	31,153
Net loss attributable to noncontrolling interests	1,872	(359)
Earnings from continuing operations attributable to IAC shareholders	54,581	30,794
Loss from discontinued operations attributable to IAC shareholders	(944)	3,684
Net earnings attributable to IAC shareholders	$ 53,637	$ 34,478
Denominator: Basic
Weighted average basic shares outstanding	84,218	82,801
Denominator: Diluted
Weighted average basic shares outstanding	84,218	82,801
Dilutive securities including stock options, warrants and RSUs (in shares)	3,162	8,917
Denominator for earnings per share-weighted average shares (in shares)	87,380	91,718
Earnings (loss) per share attributable to IAC shareholders: Basic
Earnings per share from continuing operations (in dollars per share)	$ 0.65	$ 0.37
Discontinued operations (in dollars per share)	$ (0.01)	$ 0.05
Earnings per share (in dollars per share)	$ 0.64	$ 0.42
Earnings (loss) per share attributable to IAC shareholders: Diluted
Earnings per share from continuing operations (in dollars per share)	$ 0.62	$ 0.34
Discontinued operations (in dollars per share)	$ (0.01)	$ 0.04
Earnings per share (in dollars per share)	$ 0.61	$ 0.38