Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 26,747	$ 30,486
Restricted cash	19,270	23,761
Trade accounts receivable, less allowance for doubtful accounts of $12,593 and $11,969 at March 31, 2014 and December 31, 2013, respectively	76,917	75,567
Inventories	92,753	90,577
Deferred income taxes	33,956	33,947
Prepaid expenses and other current assets	28,781	25,906
Total current assets	278,424	280,244
Property, plant and equipment, net	52,532	54,606
Patents and other intangible assets, net	8,518	9,046
Goodwill	53,565	53,565
Deferred income taxes	18,758	18,336
Other long-term assets	6,743	7,385
Total assets	418,540	423,182
Current liabilities:
Trade accounts payable	14,022	20,674
Other current liabilities	41,467	46,146
Total current liabilities	55,489	66,820
Long-term debt	20,000	20,000
Deferred income taxes	13,307	13,132
Other long-term liabilities	12,487	12,736
Total liabilities	101,283	112,688
Contingencies (Note 15)
Shareholders' equity:
Common shares $0.10 par value; 50,000,000 shares authorized; 18,365,910 and 18,102,335 issued and outstanding as of March 31, 2014 and December 31, 2013, respectively	1,836	1,810
Additional paid-in capital	223,630	216,653
Retained earnings	88,550	89,332
Accumulated other comprehensive income	3,241	2,699
Total shareholders' equity	317,257	310,494
Total liabilities and shareholders' equity	$ 418,540	$ 423,182