MANDATORILY REDEEMABLE NONCONTROLLING INTEREST (ROLLFORWARD TABLE) (DETAILS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Mandatorily redeemable noncontrolling interest [Line Items]
Mandatorily redeemable noncontrolling interest, January 1			$ 2,814
Net income attributable to mandatorily redeemable noncontrolling interest	$ 15,493	$ 18,130	35,528	$ 39,433
Change in redemption value			(903)
Mandatorily redeemable noncontrolling interest, June 30	3,410		3,410
Iknowtion [Member]
Mandatorily redeemable noncontrolling interest [Line Items]
Mandatorily redeemable noncontrolling interest, January 1			2,814	2,509
Net income attributable to mandatorily redeemable noncontrolling interest			325	279
Dividends distributed to mandatorily redeemable noncontrolling interest	(632)	(1,244)	(632)	(1,244)
Change in redemption value			903	1,730
Mandatorily redeemable noncontrolling interest, June 30	$ 3,410	$ 3,274	$ 3,410	$ 3,274