Fair Value Measurements (Table Text Block)	9 Months Ended	12 Months Ended
	Dec. 31, 2022	Mar. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Financial Instruments, Carrying and Estimated fair values	Fair Value Hierarchy     Carrying               Total Estimated As of December 31, 2022   Value   Level 1   Level 2   Level 3   Fair Value     (Unaudited) Assets   (In thousands) Reinsurance recoverables and trade receivables, net $ 208,182 $ – $ – $ 208,182 $ 208,182 Mortgage loans, net   414,886   –   –   414,886   393,980 Other investments   103,569   –   –   103,569   103,569 Total $ 726,637 $ – $ – $ 726,637 $ 705,731                                             Liabilities                     Notes, loans and finance leases payable $ 6,236,822 $ – $ 6,236,822 $ – $ 5,813,962 Total$ 6,236,822 $ – $ 6,236,822 $ – $ 5,813,962	Fair Value Hierarchy     Carrying               Total Estimated As of March 31, 2022   Value   Level 1   Level 2   Level 3   Fair Value     (In thousands) Assets                     Reinsurance recoverables and trade receivables, net $ 229,343 $ – $ – $ 229,343 $ 229,343 Mortgage loans, net   423,163   –   –   423,163   450,347 Other investments   120,592   –   –   120,592   120,592 Total $ 773,098 $ – $ – $ 773,098 $ 800,282                                             Liabilities                     Notes, loans and finance leases payable $ 6,059,713 $ – $ 6,059,713 $ – $ 5,875,781 Total$ 6,059,713 $ – $ 6,059,713 $ – $ 5,875,781
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis	As of December 31, 2022   Total   Level 1   Level 2   Level 3     (Unaudited) Assets   (In thousands) Short-term investments $ 2,193,606 $ 2,193,606 $ – $ – Fixed maturities - available for sale   2,663,528   249,161   2,414,275   92 Preferred stock   22,054   22,054   –   – Common stock   37,619   37,619   –   – Derivatives   10,388   2,182   8,206   – Total $ 4,927,195 $ 2,504,622 $ 2,422,481 $ 92                                     Liabilities                 Derivatives $ – $ – $ – $ – Total$ – $ – $ – $ –	As of March 31, 2022   Total   Level 1   Level 2   Level 3     (In thousands) Assets                 Short-term investments $ 2,482,154 $ 2,482,154 $ – $ – Fixed maturities - available for sale   2,821,092   26,914   2,794,086   92 Preferred stock   26,095   26,095   –   – Common stock   46,212   46,212   –   – Derivatives   7,474   7,474   –   – Total $ 5,383,027 $ 2,588,849 $ 2,794,086 $ 92                                     Liabilities                 Derivatives $ 587 $ – $ 587 $ – Total$ 587 $ – $ 587 $ –