Note 5 - Fair Values of Financial Instruments (Details) - Changes in Fair Value of Level 3 Financial Instruments (USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended							3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Corporate Debt Securities [Member]	Sep. 30, 2012 Corporate Debt Securities [Member]	Sep. 30, 2013 Corporate Debt Securities [Member]	Sep. 30, 2012 Corporate Debt Securities [Member]	Sep. 30, 2013 Foreign [Member]	Sep. 30, 2013 Foreign [Member]	Sep. 30, 2013 Common Stock [Member]	Jun. 30, 2013 Common Stock [Member]	Dec. 31, 2012 Common Stock [Member]	Sep. 30, 2012 Common Stock [Member]	Jun. 30, 2012 Common Stock [Member]	Dec. 31, 2011 Common Stock [Member]	Sep. 30, 2013 Derivative [Member]	Sep. 30, 2012 Derivative [Member]	Sep. 30, 2013 Derivative [Member]	Sep. 30, 2012 Derivative [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 5,154,600	$ 3,121,451	$ 4,861,070	$ 3,237,779	$ 1,890,000	$ 2,089,651	$ 3,834,470	$ 2,133,079	$ 1,995,000		$ 384,000	$ 384,000	$ 384,000	$ 352,000	$ 352,000	$ 352,000	$ 885,600	$ 679,800	$ 642,600	$ 752,700
Transfers out of Level 3	(1,887,820)		(5,722,290)		(1,887,820)		(5,722,290)
Purchases	2,001,500		6,026,500		2,001,500		4,001,500			2,025,000
Sales	(645,488)	(52,974)	(645,823)	(102,008)	(13)	(52,974)	(13)	(102,008)	(475)	(810)							(645,000)		(645,000)
Included in earnings	(240,600)	4,800	2,400	(68,100)													(240,600)	4,800	2,400	(68,100)
Included in other comprehensive income (loss)	(160,692)	45,366	(300,357)	50,972	(48,667)	45,366	(158,667)	50,972	(112,025)	(141,690)
Ending balance	$ 4,221,500	$ 3,118,643	$ 4,221,500	$ 3,118,643	$ 1,955,000	$ 2,082,043	$ 1,955,000	$ 2,082,043	$ 1,882,500	$ 1,882,500	$ 384,000	$ 384,000	$ 384,000	$ 352,000	$ 352,000	$ 352,000		$ 684,600		$ 684,600