Annual report pursuant to Section 13 and 15(d)

UNEARNED REVENUE (Details)

v3.10.0.1
UNEARNED REVENUE (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Change in Contract with Customer, Liability [Roll Forward]    
Balance, beginning of period $ 117,614 $ 106,323
Deferral of unearned revenue 166,053 151,139
Recognition of unearned revenue (156,592) (139,848)
Balance, end of period 127,075 117,614
Long-term unearned revenue $ 11,100 $ 8,600
Long-term unearned revenue, recognition period (or less) 5 years