OTHER INCOME (EXPENSE) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other Income and Expenses [Abstract]
Equity earnings in affiliates	$ 1,559	$ 440	$ 2,759	$ 1,235
Other income	1,070	936	2,313	1,892
Other components of net periodic pension income	1,812	2,069	2,820	4,148
Total Other income (expense)	$ 4,441	$ 3,445	$ 7,892	$ 7,275