Other Accrued and Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities, Current
Accrued warranty reserve	$ 879	$ 1,466
Adverse purchase commitments	3,263	268
Accrued restructuring	2,774	1,437
Income tax payable	199	152
Other	3,290	4,248
Other accrued liabilities	10,405	7,571
Other Liabilities, Noncurrent
Long-term income tax payable	5,341	3,047
Long-term deferred revenue	1,108	2,380
Accrued warranty reserve	245	355
Other	172	184
Other long-term liabilities	$ 6,866	$ 5,966