OTHER INCOME (EXPENSE) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Income and Expenses [Abstract]
Income (Loss) from Equity Method Investments		$ 3,163	$ 5,481	$ 2,742
Defined Benefit Plan, Other (Cost) Credit	[1]	2,787	502	769
Other Nonoperating Income (Expense)	[2]	15,048	4,703	5,215
Total other income (expense)		$ 20,998	$ 10,686	$ 8,726

[1] Other components of net periodic pension (cost) income includes pension settlements and curtailments. Refer to Note 12 to the consolidated financial statements for details.

[2] Includes a gain on change in control related to the acquisition of Askaynak in the year ended December 31, 2019. Refer to Note 4 to the consolidated financial statements for details.