Consolidated Condensed Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Net sales	$ 169,184	$ 174,961	$ 528,151	$ 545,052
Cost of sales	75,638	78,547	248,825	245,028
Gross profit	93,546	96,414	279,326	300,024
Selling and administrative expense	72,056	87,055	220,423	243,653
Research and development expense	6,652	6,910	20,695	20,674
Total operating expenses	78,708	93,965	241,118	264,327
Income from operations	14,838	2,449	38,208	35,697
Interest expense	1,504	1,540	4,453	4,572
Income before income taxes	13,334	909	33,755	31,125
Provision (benefit) for income taxes	4,461	(1,063)	11,109	10,272
Net income	8,873	1,972	22,646	20,853
Comprehensive income (loss)	$ 3,741	$ (4,173)	$ 8,656	$ 17,001
Per share data:
Basic (in dollars per share)	$ 0.32	$ 0.07	$ 0.82	$ 0.76
Diluted (in dollars per share)	0.32	0.07	0.81	0.75
Dividends per share of common stock (in dollars per share)	$ 0.20	$ 0.20	$ 0.60	$ 0.60
Weighted average common shares:
Basic (shares)	27,701	27,454	27,636	27,354
Diluted (shares)	27,898	27,688	27,853	27,777