Fair Value Measurements (Table Text Block)	3 Months Ended	12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020
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, 2020   Value   Level 1   Level 2   Level 3   Fair Value     (Unaudited) Assets   (In thousands) Reinsurance recoverables and trade receivables, net $ 208,371 $ - $ - $ 208,371 $ 208,371 Mortgage loans, net   294,551   -   -   294,551   294,551 Other investments   100,572   -   -   100,572   100,572 Total $ 603,494 $ - $ - $ 603,494 $ 603,494                                             Liabilities                     Notes, loans and finance/capital leases payable   4,808,147   -   4,808,147   -   4,510,021 Total $ 4,808,147 $ - $ 4,808,147 $ - $ 4,510,021	Fair Value Hierarchy     Carrying               Total Estimated As of March 31, 2020   Value   Level 1   Level 2   Level 3   Fair Value     (In thousands) Assets                     Reinsurance recoverables and trade receivables, net $ 186,672 $ - $ - $ 186,672 $ 186,672 Mortgage loans, net   262,688   -   -   262,688   262,688 Other investments   97,685   -   -   97,685   97,685 Total $ 547,045 $ - $ - $ 547,045 $ 547,045                                             Liabilities                     Notes, loans and leases payable   4,651,068   -   4,651,068   -   4,342,308 Total $ 4,651,068 $ - $ 4,651,068 $ - $ 4,342,308
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis	As of June 30, 2020   Total   Level 1   Level 2   Level 3     (Unaudited) Assets   (In thousands) Short-term investments $ 629,550 $ 629,265 $ 285 $ - Fixed maturities - available for sale   2,370,821   7,614   2,363,047   160 Preferred stock   6,106   6,106   -   - Common stock   16,595   16,595   -   - Derivatives   1,763   1,763   -   - Total $ 3,024,835 $ 661,343 $ 2,363,332 $ 160                                     Liabilities                 Derivatives   8,170   -   8,170   - Total $ 8,170 $ - $ 8,170 $ -	As of March 31, 2020   Total   Level 1   Level 2   Level 3     (In thousands) Assets                 Short-term investments $ 369,279 $ 368,968 $ 311 $ - Fixed maturities - available for sale   2,466,048   7,156   2,458,731   161 Preferred stock   6,675   6,675   -   - Common stock   20,015   20,015   -   - Derivatives   5,944   5,944   -   - Total $ 2,867,961 $ 408,758 $ 2,459,042 $ 161                                     Liabilities                 Derivatives   8,214   -   8,214   - Total $ 8,214 $ - $ 8,214 $ -