Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 28,919	$ 28,924	$ 26,369	$ 30,767
Restricted cash	45,248	23,761
Trade accounts receivable, less allowance for doubtful accounts of $8,971 and $9,111 at June 30, 2014 and December 31, 2013, respectively	63,322	70,811
Inventories	70,902	72,678
Deferred income taxes	40,402	39,999
Prepaid expenses and other current assets	43,886	28,933
Total current assets	292,679	265,106
Property, plant and equipment, net	51,082	54,372
Patents and other intangible assets, net	8,075	9,046
Goodwill	53,565	53,565
Deferred income taxes	22,762	22,394
Other long-term assets	5,834	7,492
Total assets	433,997	411,975
Current liabilities:
Trade accounts payable	15,712	20,674
Other current liabilities	67,382	49,676
Total current liabilities	83,094	70,350
Long-term debt	20,000	20,000
Deferred income taxes	13,325	13,026
Other long-term liabilities	12,367	12,736
Total liabilities	128,786	116,112
Contingencies (Note 16)
Shareholders' equity:
Common shares $0.10 par value; 50,000,000 shares authorized; 18,534,625 and 18,102,335 issued and outstanding as of June 30, 2014 and December 31, 2013, respectively	1,854	1,810
Additional paid-in capital	228,502	216,653
Retained earnings	70,706	73,897
Accumulated other comprehensive income	4,149	3,503
Total shareholders' equity	305,211	295,863
Total liabilities and shareholders' equity	$ 433,997	$ 411,975