CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Balance at beginning of period (shares) at Dec. 31, 2018		25,254
Balance at beginning of period at Dec. 31, 2018	$ 369,275	$ 253	$ 90,851	$ 411,325	$ (42,685)	$ (90,469)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	3,890			3,890
Other comprehensive income (loss), net of tax	(587)				(587)
Stock repurchased	(42)					(42)
Stock issued (canceled) under employee plans (shares)		(26)
Stock issued (canceled) under employee plans	(1)	$ (1)
Stock-based compensation expense	862		862
Balance at end of period (shares) at Mar. 31, 2019		25,228
Balance at end of period at Mar. 31, 2019	373,214	$ 252	91,713	415,032	(43,272)	(90,511)
Balance at beginning of period (shares) at Dec. 31, 2019		25,328
Balance at beginning of period at Dec. 31, 2019	318,420	$ 253	94,140	340,629	(25,979)	(90,623)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(56,421)			(56,421)
Other comprehensive income (loss), net of tax	(9,180)				(9,180)
Stock repurchased	(8)					(8)
Stock issued (canceled) under employee plans (shares)		70
Stock issued (canceled) under employee plans	31	$ 1	30
Stock-based compensation expense	735		735
Stock issued to directors (shares)		3
Balance at end of period (shares) at Mar. 31, 2020		25,401
Balance at end of period at Mar. 31, 2020	$ 253,577	$ 254	$ 94,905	$ 284,208	$ (35,159)	$ (90,631)