Other Current Assets (Tables)

12 Months Ended

Dec. 31, 2016

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]

Schedule of Other Current Assets [Table Text Block]

Other current assets were as follows:

	December 31,
	2016		2015
	(In thousands)
Excise and other taxes receivable	$	4,910	$	3,860
Material and chemical inventories	961		1,252
Exchange and other receivables	532		831
Other current assets	$	6,403	$	5,943