MANDATORILY REDEEMABLE NONCONTROLLING INTEREST (ROLLFORWARD TABLE) (DETAILS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Mandatorily redeemable noncontrolling interest [Line Items]
Mandatorily redeemable noncontrolling interest, January 1	$ 4,131
Net income attributable to mandatorily redeemable noncontrolling interest	37,435	$ 65,885	$ 77,417
Change in redemption value	(466)	(1,113)	(936)
Purchase of mandatorily redeemable noncontrolling interest	(4,105)	0	0
Mandatorily redeemable noncontrolling interest, December 31		4,131
Iknowtion [Member]
Mandatorily redeemable noncontrolling interest [Line Items]
Mandatorily redeemable noncontrolling interest, January 1	4,131	2,814
Net income attributable to mandatorily redeemable noncontrolling interest		837
Working capital distributed to mandatorily redeemable noncontrolling interest	(492)	(633)
Change in redemption value	466	1,113
Purchase of mandatorily redeemable noncontrolling interest	$ (4,105)
Mandatorily redeemable noncontrolling interest, December 31		$ 4,131	$ 2,814