Note 3 - Long-term Debt - Long-term Debt Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
2014 Senior Credit Facility [Member]
Long-term debt including current portion:
Long-term Debt, Gross	$ 556,438	$ 556,438
Unamortized deferred loan costs	(12,857)	(6,136)
2020 Notes [Member]
Long-term debt including current portion:
Unsecured Debt		675,000
Unamortized deferred loan costs		(9,317)
Unamortized premium		4,099
2024 Notes [Member]
Long-term debt including current portion:
Unsecured Debt	525,000
Unamortized deferred loan costs	(7,971)
2026 Notes [Member]
Long-term debt including current portion:
Unsecured Debt	700,000
Unamortized deferred loan costs	(10,834)
Unamortized premium	5,949
2014 Revolving Credit Facility [Member]
Long-term debt including current portion:
Borrowing availability under the Revolving Credit Facility	60,000	50,000
Total outstanding principal	1,781,438	1,231,438
Net carrying value	$ 1,755,725	$ 1,220,084

Total Long term debt including current portion and before unamortized premium or discount.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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