Note 2 - Supplemental Cash Flow Disclosure (Details) - Supplemental Disclosures of Cash Flow Information and Non-Cash Investing (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash paid for:
Interest, net of interest capitalized	$ 1,843us-gaap_InterestPaidNet		$ 1,083us-gaap_InterestPaidNet
Income taxes	2,793us-gaap_IncomeTaxesPaidNet	5,161us-gaap_IncomeTaxesPaidNet	577us-gaap_IncomeTaxesPaidNet
Non-cash investing and financing activities:
Unrealized holding gains (losses) on marketable securities	$ (1,120)	$ 6,737	$ 12,078

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- Definition

Amount of unrealized gain (loss) on investments in debt and equity securities classified as available-for-sale securities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

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- Definition

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

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- Definition

The amount of cash paid for interest during the period net of cash paid for interest that is capitalized.

+ References

+ Details

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