Note 6 - Investment (Details) (USD $)	9 Months Ended	3 Months Ended		9 Months Ended	12 Months Ended	0 Months Ended	3 Months Ended				6 Months Ended
	Sep. 30, 2013	Dec. 31, 2013 Korea Line Corporation [Member]	Mar. 31, 2013 Korea Line Corporation [Member]	Sep. 30, 2014 Korea Line Corporation [Member]	Dec. 31, 2013 Korea Line Corporation [Member]	May 09, 2013 Korea Line Corporation [Member]	Sep. 30, 2014 Korea Line Corporation [Member]	Mar. 31, 2014 Korea Line Corporation [Member]	Sep. 30, 2013 Korea Line Corporation [Member]	Mar. 31, 2013 Korea Line Corporation [Member]	Jun. 30, 2014 Korea Line Corporation [Member]
Note 6 - Investment (Details) [Line Items]
Payments for Settlement of Termination Agreement										$ 10,300,000
Bunker Liabilities Released						3,500,000
Deferred Revenue, Period Increase (Decrease)										(3,600,000)
Unamortized Fair Value of Charters, Balance Released										10,100,000
(in Shares)					585,983	538,751				5,900,000
Accounts and Notes Receivable, Net										2,700,000
Contract Termination, Consideration Transferred										36,100,000
Termination Revenue										32,800,000
Gain (Loss) on Contract Termination	29,033,503									3,300,000
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings						25,600,000
Other than Temporary Impairment Losses, Investments		8,200,000	3,000,000	0					7,300,000
Unrealized Gain (Loss) on Investments							$ 300,000	$ (2,100,000)			$ 1,400,000