Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Investments, at fair value:
Amortized cost on fixed maturities trading investments	$ 3,909,780	$ 3,388,418
Cost - equity security trading investments	754,536	695,150
Cost - short-term investments	$ 141,206	$ 376,547
Shareholders’ equity:
Common stock, shares authorized (in shares)	70,000,000	70,000,000
Common stock, shares issued (in shares)	55,371,000	55,358,000
Common stock, shares outstanding (in shares)	55,371,000	55,358,000