Other Assets (Tables)

12 Months Ended

Dec. 31, 2017

Other Assets [Abstract]

Schedule of Other Assets, Noncurrent [Table Text Block]

	2017		2016
Restricted insurance settlement	$	21,171	$	21,883
Uncertain tax positions		4,543		3,892
Supplemental retirement income program		1,594		1,410
Pension assets		1,184		—
Other		1,557		1,567
Total other assets	$	30,049	$	28,752