DEFERRED REVENUE (Tables)

6 Months Ended

Jun. 30, 2017

DEFERRED REVENUE [Abstract]

Reconciliation of Deferred Revenue Balances

	Three Months Ended		Six Months Ended
	June 30		June 30
in thousands	2017	2016	2017	2016
Deferred Revenue
Balance at beginning of period	$     204,819	$     212,292	$     206,468	$     214,060
Amortization of deferred revenue	(1,719)	(2,092)	(3,368)	(3,860)
Balance at end of period	$     203,100	$     210,200	$     203,100	$     210,200