Note 3 - Long-Term Debt (Details) - Long-Term Debt (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Total long-term debt	$ 500,000	$ 500,000
Debt Premium	898	999
Total	500,898	500,999
Senior Notes Due Two Thousand Twenty Two [Member]
Debt Instrument [Line Items]
Total long-term debt	500,000	500,000
Multicurrency Credit Facility [Member]
Debt Instrument [Line Items]
Total long-term debt
Norweigan Facility Agreement [Member]
Debt Instrument [Line Items]
Total long-term debt