UNAUDITED CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of new accounting standard (Note C), net of tax of $63	$ (179)				$ (179)
Shares at beginning of period (in shares) at Dec. 31, 2017		71,494				45,167
Balance at beginning of period at Dec. 31, 2017	134,277	$ 715	$ 437,394	$ 100	195,143	$ (499,075)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,175				9,175
Issuance for stock-based compensation and dividends, net of forfeitures (in shares)		63
Issuance for stock-based compensation and dividends, net of forfeitures	0	$ 1	166		(167)
Exercise of stock options (in shares)		5				1
Exercise of stock options	0	$ 0	46			$ (46)
Stock-based compensation expense	2,260		2,260
Employee stock purchase plan	132		71			$ 61
Employee stock purchase plan (in shares)						(6)
Dividends ($0.12 per share)	(2,973)				(2,973)
Change in fair value of interest rate swap, net of tax of $176	517			517
Repurchases of common stock (in shares)						319
Repurchases of common stock	(8,715)					$ (8,715)
Shares at end of period (in shares) at Mar. 31, 2018		71,562				45,481
Balance at end of period at Mar. 31, 2018	$ 134,494	$ 716	$ 439,937	$ 617	$ 200,999	$ (507,775)