Note I - Business Segment Information (Detail) - Components of Customer Sales Determined Based on the Location of Customers (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Sales by Location (in Dollars)	$ 375,691	$ 359,490	$ 296,808
Percentage of Sales	100.00%	100.00%	100.00%
United States [Member]
Sales by Location (in Dollars)	239,153	241,405	180,705
Percentage of Sales	64.00%	67.00%	61.00%
Foreign Countries [Member]
Sales by Location (in Dollars)	$ 136,538	$ 118,085	$ 116,103
Percentage of Sales	36.00%	33.00%	39.00%

Amount of total revenue for the reportable segments, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 280

-SubTopic 10

-Section 50

-Paragraph 22

-Subparagraph (a),(b),(c)

-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8736-108599

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 27

-Subparagraph a, b, c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration