Note 12 - Long-term Debt (Details Textual) - Bank of America [Member] - USD ($)		1 Months Ended
Oct. 31, 2015	Oct. 31, 2015	Dec. 31, 2019
Line of Credit Facility, Maximum Borrowing Capacity	$ 175,000,000	$ 175,000,000	$ 60,000,000
Debt Instrument, Term		5 years
Line of Credit Facility, Remaining Borrowing Capacity			$ 50,000,000
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate		1.40%
Debt Instrument, Basis Spread on Base Rate	1.00%
Base Rate [Member]
Debt Instrument, Basis Spread on Variable Rate		0.40%
Fed Funds Effective Rate Overnight Index Swap Rate [Member]
Debt Instrument, Basis Spread on Base Rate	1.00%

Percentage points added to the reference rate to compute the base rate on the debt instrument.

No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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- Details

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- Details

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- Details

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- Details

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