Fair Value Measurements (Table Text Block)	3 Months Ended	12 Months Ended
	Jun. 30, 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 June 30, 2022   Value   Level 1   Level 2   Level 3   Fair Value     (Unaudited) Assets   (In thousands) Reinsurance recoverables and trade receivables, net $ 219,574 $ – $ – $ 219,574 $ 219,574 Mortgage loans, net   433,385   –   –   433,385   437,604 Other investments   123,739   –   –   123,739   123,739 Total $ 776,698 $ – $ – $ 776,698 $ 780,917                                             Liabilities                     Notes, loans and finance leases payable   6,269,352   –   6,269,352   –   5,973,107 Total$ 6,269,352 $ – $ 6,269,352 $ – $ 5,973,107	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 June 30, 2022   Total   Level 1   Level 2   Level 3     (Unaudited) Assets   (In thousands) Short-term investments $ 2,845,484 $ 2,845,484 $ – $ – Fixed maturities - available for sale   2,598,199   25,456   2,572,651   92 Preferred stock   25,950   25,950   –   – Common stock   45,837   45,837   –   – Derivatives   7,111   6,962   149   – Total $ 5,522,581 $ 2,949,689 $ 2,572,800 $ 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 $ –