Represents the purchase price of the debt instrument as a percentage of face value.

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Represents a general basket base limit value amount before other items are included.

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Represents the percent of consolidated net income (loss) included in a general basket limitation for determining if restricted payments can be made.

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Represents the percent of consolidated tangible net assets included in a general basket limitation for determining if restricted payments can be made.

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Represents the offering price of the notes issued as a percentage of their face amount.

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Represents the percent of net cash proceeds from qualified equity offerings included in a general basket limitation for determining if restricted payments can be made.

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No definition available.

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

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Face (par) amount of debt instrument at time of issuance.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Face (par) amount of the original debt instrument that was repurchased.

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No definition available.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt premium.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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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.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Note 9 - Senior Notes and Unsecured Revolving Credit Facility (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 07, 2019	Aug. 06, 2019	May 04, 2017	Mar. 17, 2017
Early Repayment of Senior Debt	$ 15,605,000	$ (0)	$ (0)
Gain (Loss) on Extinguishment of Debt, Total	$ 1,164,000	0	$ 0
Revolving Credit Facility [Member]
Debt Instrument, Interest Rate, Effective Percentage	4.76%
Long-term Line of Credit, Total	$ 0	67,500,000
Revolving Credit Facility [Member] \| Minimum [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 130,000,000	$ 200,000,000
Revolving Credit Facility [Member] \| Minimum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	2.25%
Revolving Credit Facility [Member] \| Maximum [Member]
Line of Credit Facility, Maximum Borrowing Capacity				$ 200,000,000	$ 300,000,000
Revolving Credit Facility [Member] \| Maximum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument, Basis Spread on Variable Rate	3.00%
Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 17,500,000
Letters of Credit Outstanding, Amount	$ 0	$ 2,300,000
Senior Notes [Member] \| Senior Notes Due 2022 [Member]
Debt Instrument, Face Amount							$ 250,000,000
Debt Instrument, Interest Rate, Stated Percentage	7.25%	7.25%					7.25%
Percent of Debt Instrument Face Amount, Value Issued							98.961%
Debt Instrument, Interest Rate, Effective Percentage							7.50%
Debt Instrument, Unamortized Discount, Total	$ 1,100,000	$ 1,700,000
Debt Instrument, Unamortized Premium, Total	900,000	1,300,000
Debt Issuance Costs, Net, Total	$ 3,000,000.0	$ 4,500,000
Percent of Consolidated Net Income, General Basket Limitation for Restricted Payments to be Made	50.00%
Percent of Net Cash Proceeds From Qualified Equity Offerings, General Basket Limitation for Restricted Payments to be Made	100.00%
Percent of Consolidated Tangible Net Assets, General Basket Limitation for Restricted Payments to be Made	15.00%
General Basket, Value	$ 15,000,000
Debt Instrument, Repurchased Face Amount	$ 17,000,000.0
Debt Instrument, Percent of Face Value Repurchased	91.88%
Early Repayment of Senior Debt	$ 15,600,000
Gain (Loss) on Extinguishment of Debt, Total	1,200,000
Write off of Deferred Debt Issuance Cost	200,000
Senior Notes [Member] \| Senior Notes Due 2022, Additional [Member]
Debt Instrument, Face Amount						$ 75,000,000
Debt Instrument, Interest Rate, Stated Percentage						7.25%
Percent of Debt Instrument Face Amount, Value Issued						102.75%
Debt Instrument, Interest Rate, Effective Percentage						6.438%
Existing or Future Bank Credit Facilities [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 260,000,000