RECENT ACCOUNTING PRONOUNCEMENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
Components of lease expense
Right-of-use assets	$ 21,700	$ 20,600
Financial position	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Total	$ 20,585	$ 20,100
Outstanding lease obligations, current	$ 3,700	$ 3,000
Financial position	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Outstanding lease obligations, noncurrent	$ 16,900	$ 17,100
Financial position	us-gaap:ContractualObligation	us-gaap:ContractualObligation