GUARANTOR AND NONGUARANTOR FINANCIAL INFORMATION (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,100,444	$ 749,977	$ 704,153	$ 742,099
Marketable securities	6,004	20,604
Accounts receivable	207,408	229,830
Other current assets	161,530	156,339
Property and equipment, net	293,964	270,512
Goodwill	1,675,323	1,616,154	1,358,524
Intangible assets, net	445,336	482,904
Other non-current assets	164,685	118,230
TOTAL ASSETS	4,234,684	3,805,828
Accounts payable, trade	77,653	98,314
Long-term debt, net of current maturities	1,080,000	580,000
Income taxes payable	416,384	479,945
Other long-term liabilities	58,393	31,830
Redeemable noncontrolling interests	42,861	58,126
Total IAC shareholders' equity	1,686,736	1,655,728
Noncontrolling interests	42,665	51,907
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	4,234,684	3,805,828
IAC
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	782,022	501,075	545,222	0
Marketable securities	1,007	20,604
Accounts receivable	38	43
Other current assets	45,111	58,452
Intercompany receivables	0	0
Property and equipment, net	5,316	4,116
Goodwill	0	0
Intangible assets, net	0	0
Investment in subsidiaries	3,833,751	12,913,694
Other non-current assets	83,207	153,155
TOTAL ASSETS	4,750,452	13,651,139
Accounts payable, trade	4,310	4,366
Other current liabilities	41,623	74,214
Long-term debt, net of current maturities	1,000,000	500,000
Income taxes payable	383,926	440,110
Intercompany liabilities	1,416,453	10,759,104
Other long-term liabilities	217,404	217,617
Redeemable noncontrolling interests	0	0
Total IAC shareholders' equity	1,686,736	1,655,728
Noncontrolling interests	0	0
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	4,750,452	13,651,139
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Marketable securities	0	0
Accounts receivable	124,693	142,627
Other current assets	73,343	53,720
Intercompany receivables	556,370	482,926
Property and equipment, net	220,742	194,515
Goodwill	1,179,317	1,190,199
Intangible assets, net	300,845	340,631
Investment in subsidiaries	599,595	611,851
Other non-current assets	15,485	16,509
TOTAL ASSETS	3,070,390	3,032,978
Accounts payable, trade	47,098	64,888
Other current liabilities	248,413	216,010
Long-term debt, net of current maturities	80,000	80,000
Income taxes payable	6,768	26,389
Intercompany liabilities	0	0
Other long-term liabilities	96,114	91,119
Redeemable noncontrolling interests	0	1,388
Total IAC shareholders' equity	2,591,997	2,553,184
Noncontrolling interests	0	0
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	3,070,390	3,032,978
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	318,422	248,902	158,931	742,099
Marketable securities	4,997	0
Accounts receivable	82,677	87,160
Other current assets	43,890	45,204
Intercompany receivables	860,083	10,276,178
Property and equipment, net	67,906	71,881
Goodwill	496,006	425,955
Intangible assets, net	144,491	142,273
Investment in subsidiaries	0	0
Other non-current assets	252,612	109,912
TOTAL ASSETS	2,271,084	11,407,465
Accounts payable, trade	26,245	29,060
Other current liabilities	219,208	238,003
Long-term debt, net of current maturities	0	0
Income taxes payable	25,690	13,446
Intercompany liabilities	0	0
Other long-term liabilities	73,066	45,950
Redeemable noncontrolling interests	42,861	56,738
Total IAC shareholders' equity	1,841,349	10,972,361
Noncontrolling interests	42,665	51,907
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	2,271,084	11,407,465
Total Eliminations
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	0	0	0	0
Marketable securities	0	0
Accounts receivable	0	0
Other current assets	(814)	(1,037)
Intercompany receivables	(1,416,453)	(10,759,104)
Property and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Investment in subsidiaries	(4,433,346)	(13,525,545)
Other non-current assets	(6,629)	(68)
TOTAL ASSETS	(5,857,242)	(24,285,754)
Accounts payable, trade	0	0
Other current liabilities	0	(1,652)
Long-term debt, net of current maturities	0	0
Income taxes payable	0	0
Intercompany liabilities	(1,416,453)	(10,759,104)
Other long-term liabilities	(7,443)	547
Redeemable noncontrolling interests	0	0
Total IAC shareholders' equity	(4,433,346)	(13,525,545)
Noncontrolling interests	0	0
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	(5,857,242)	(24,285,754)
IAC Consolidated
Condensed Financial Statements, Captions [Line Items]
Cash and cash equivalents	1,100,444	749,977	704,153	742,099
Marketable securities	6,004	20,604
Accounts receivable	207,408	229,830
Other current assets	161,530	156,339
Intercompany receivables	0	0
Property and equipment, net	293,964	270,512
Goodwill	1,675,323	1,616,154
Intangible assets, net	445,336	482,904
Investment in subsidiaries	0	0
Other non-current assets	344,675	279,508
TOTAL ASSETS	4,234,684	3,805,828
Accounts payable, trade	77,653	98,314
Other current liabilities	509,244	526,575
Long-term debt, net of current maturities	1,080,000	580,000
Income taxes payable	416,384	479,945
Intercompany liabilities	0	0
Other long-term liabilities	379,141	355,233
Redeemable noncontrolling interests	42,861	58,126
Total IAC shareholders' equity	1,686,736	1,655,728
Noncontrolling interests	42,665	51,907
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 4,234,684	$ 3,805,828