DEFERRED REVENUE (Tables)

9 Months Ended

Sep. 30, 2017

DEFERRED REVENUE [Abstract]

Reconciliation of Deferred Revenue Balances

	Three Months Ended		Nine Months Ended
	September 30		September 30
in thousands	2017	2016	2017	2016
Deferred Revenue
Balance at beginning of period	$     203,100	$     210,200	$     206,468	$     214,060
Amortization of deferred revenue	(1,903)	(2,068)	(5,271)	(5,928)
Balance at end of period	$     201,197	$     208,132	$     201,197	$     208,132