CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Net loss	$ (5,924)	$ (21,035)	$ (82,955)
Other comprehensive income (loss), before tax:
Unrealized loss, net	0	0	(658)
Loss reclassified into earnings	0	0	384
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Tax	0	0	(274)
Adjustment to pension benefit plan	(206)	202	528
Unrealized foreign exchange gain (loss), net on intercompany long-term loans	291	667	(1,705)
Translation gain (loss)	(1,728)	(5,100)	11,471
Loss reclassified into earnings	56	11	106
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	(1,672)	(5,089)	11,577
Other comprehensive income (loss) before tax	(1,587)	(4,220)	10,126
Provision for (benefit from) income taxes	262	378	(526)
Other comprehensive income (loss), net of tax	(1,849)	(4,598)	10,652
Total comprehensive loss	$ (7,773)	$ (25,633)	$ (72,303)