Note 6 - Investments Net Gains (Losses) on Investments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Gain (Loss) on Securities [Line Items]
Fixed-maturities available for sale, net realized gain (loss)	[1]	$ 11,262	$ (11,256)	$ (3,014)
Trading securities, net realized gain (loss)		(303)	(1,840)	(5,995)
Equity securities, net realized gain (loss)		(719)	532	368
Realized Gains (Losses) on Investments, Net		10,843	(12,094)	(8,603)
Other than Temporary Impairment Losses, Investments		0	(1,744)	(1,420)
Net unrealized gains (losses) on trading securities	[2]	33,220	(27,287)	13,230
Total net gains (losses) on investments		44,063	(41,125)	3,207
Net unrealized gains (losses) on investments still held		28,078	(24,720)	8,827
Other investments
Gain (Loss) on Securities [Line Items]
Short-term investments, net realized gain (loss)		603	470	38
Other Investments, Change in Unrealized Holding Gain (Loss)		(174)	447	(118)
Fixed-maturities available for sale
Gain (Loss) on Securities [Line Items]
Gross investment gains from sales and redemptions		17,663	1,986	6,052
Gross investment losses from sales and redemptions		(6,401)	(13,242)	(9,066)
Trading securities
Gain (Loss) on Securities [Line Items]
Trading Securities, Change in Unrealized Holding Gain (Loss)		16,346	(16,281)	8,945
Equity securities
Gain (Loss) on Securities [Line Items]
Equity Securities, Change in Unrealized Holding Gain (Loss)	[3]	$ 11,906	$ (8,886)	$ 0

[1] Components of net realized gains (losses) on fixed-maturities available for sale include:   Year Ended December 31, (In thousands) 2019   2018   2017 Gross investment gains from sales and redemptions $ 17,663
  $ 1,986
  $ 6,052
Gross investment losses from sales and redemptions (6,401 )   (13,242 )   (9,066 )

[2] These amounts include unrealized gains (losses) on investment securities other than securities available for sale. For 2017, the unrealized gains (losses) on investments exclude the net change in unrealized gains and losses on equity securities. Prior to the implementation of the update to the standard for the accounting of financial instruments effective January 1, 2018, the unrealized gains (losses) associated with equity securities were classified in accumulated other comprehensive income.

[3] Prior to the implementation of the update to the standard for the accounting of financial instruments effective January 1, 2018, the unrealized gains (losses) associated with equity securities were classified in accumulated other comprehensive income.