Note 6 - Investments - Net Gains (Losses) on Investments (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Gain (Loss) on Securities [Line Items]
Net realized gains (losses) on investments	$ (182)	$ 11,639
Impairment losses due to intent to sell	0	(622)
Net decrease (increase) in expected credit losses	310	0
Net unrealized gain (losses) on investments	(2,519)	(26,845)
Total net gains (losses) on investments	(2,391)	(15,828)
Fixed-maturities available for sale
Gain (Loss) on Securities [Line Items]
Fixed maturities available for sale, net realized gain (loss)	(790)	11,247
Gross investment gains from sales and redemptions	4,117	11,899
Gross investment losses from sales and redemptions	(4,907)	(652)
Trading Securities
Gain (Loss) on Securities [Line Items]
Trading securities, net realized gain (loss)	503	49
Equity securities
Gain (Loss) on Securities [Line Items]
Equity securities, net realized gain (loss)	0	310
Other investments
Gain (Loss) on Securities [Line Items]
Other investments, net realized gain (loss)	$ 105	$ 33

Other Than Temporary Impairment Losses, Investments, Due to Intent to Sell

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Other than Temporary Impairment Losses, Investments, Expected Credit Losses

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