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Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021
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Statement of Financial Position [Abstract] |  |
Fixed income securities, held-to-maturity, fair value | $ 32,625 | $ 29,460
Fixed Income Securities, Available-for-sale, Allowance for Credit Loss | (37,599) | (9,724)
Fixed income securities, available-for-sale, amortized cost | 6,717,907 | 6,490,753
Commercial mortgage loan, fair value | 113,106 | 97,598
Equity Securities, cost | 320,040 | 308,840
Property and equipment, accumulated depreciation and amortization | $ 259,522 | $ 253,427
Preferred stock, Par or Stated Value (in dollars per share) | $ 0 | $ 0
Preferred stock, shares authorized | 5,000,000 | 5,000,000
Preferred stock, shares issued | 8,000 | 8,000
Preferred Stock, Shares Outstanding | 8,000 | 8,000
Preferred Stock, Liquidation Preference (in dollars per share) | $ 25,000 | $ 25,000
Common stock, Par or Stated Value (in dollars per share) | $ 2 | $ 2
Common stock, shares authorized | 360,000,000 | 360,000,000
Common stock, shares issued | 104,674,999 | 104,450,916
Treasury stock, shares | 44,339,527 | 44,266,534

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