SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Reconciliation of Deferred Revenue Balances) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
DEFERRED REVENUE [Abstract]
Balance at beginning of year	$ 214,060	$ 219,968	$ 224,743
Cash received and revenue deferred	0	0	187
Amortization of deferred revenue	(7,592)	(5,908)	(4,962)
Balance at end of year	$ 206,468	$ 214,060	$ 219,968