ACCOUNTING POLICIES (Details) - USD ($) $ in Thousands	Jun. 30, 2017		Dec. 31, 2016
Cash equivalents
Cash equivalents	$ 40,300		$ 75,200
Assets:
Cash equivalents - Money market mutual funds	40,322		75,177
Trading securities held in a "rabbi trust"	66	[1]	58
Total assets	40,388		75,235
Liabilities:
Derivatives	1,696	[2]	1,816
Deferred compensation accrual "rabbi trust"	68	[3]	61
Total liabilities	1,764		1,877
Level 1
Assets:
Cash equivalents - Money market mutual funds	40,322		75,177
Trading securities held in a "rabbi trust"	66	[1]	58
Total assets	40,388		75,235
Liabilities:
Derivatives	0	[2]	0
Deferred compensation accrual "rabbi trust"	68	[3]	61
Total liabilities	68		61
Level 2
Assets:
Cash equivalents - Money market mutual funds	0		0
Trading securities held in a "rabbi trust"	0	[1]	0
Total assets	0		0
Liabilities:
Derivatives	1,696	[2]	1,816
Deferred compensation accrual "rabbi trust"	0	[3]	0
Total liabilities	1,696		1,816
Level 3
Assets:
Cash equivalents - Money market mutual funds	0		0
Trading securities held in a "rabbi trust"	0	[1]	0
Total assets	0		0
Liabilities:
Derivatives	0	[2]	0
Deferred compensation accrual "rabbi trust"	0	[3]	0
Total liabilities	$ 0		$ 0

[1] Trading securities held in a rabbi trust are included in Prepaids and other current assets and Other long-term assets, net in the consolidated balance sheets.

[2] Derivative financial instruments are included in Other current liabilities, net and Other long-term liabilities in the consolidated balance sheets.

[3] Non qualified deferred compensation in a rabbi trust is included in Accrued liabilities and Other long-term liabilities in the consolidated balance sheets.