CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Net sales	$ 151,778	$ 184,163
Cost of sales	108,837	144,289
Gross profit	42,941	39,874
Research and development expenses	7,898	6,791
Selling, general and administrative expenses	26,997	31,420
Operating income	8,046	1,663
Interest income (expense), net	(632)	(1,206)
Other income (expense), net	(348)	(466)
Income (loss) before provision for income taxes	7,066	(9)
Provision for income taxes	1,220	996
Net income (loss)	$ 5,846	$ (1,005)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.42	$ (0.07)
Diluted (in dollars per share)	$ 0.41	$ (0.07)
Shares used in computing earnings (loss) per share:
Basic (in shares)	13,960	13,827
Diluted (in shares)	14,211	13,827