Fair Value Measurements (Carrying and Estimated Fair Values within Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023
Assets
Reinsurance recoverables and trade receivables, net	$ 206,663	$ 189,498
Mortgage loans, net	494,664	444,957
Other investments	109,833	109,009
Total	811,160	743,464
Liabilities
Notes, loans and leases payable, gross	5,743,138	5,710,735
Total	5,743,138	5,710,735
Level 1 [Member]
Assets
Reinsurance recoverables and trade receivables, net	0	0
Mortgage loans, net	0	0
Other investments	0	0
Total	0	0
Liabilities
Notes, loans and leases payable, gross	0	0
Total	0	0
Level 2 [Member]
Assets
Reinsurance recoverables and trade receivables, net	0	0
Mortgage loans, net	0	0
Other investments	0	0
Total	0	0
Liabilities
Notes, loans and leases payable, gross	5,743,138	5,710,735
Total	5,743,138	5,710,735
Level 3 [Member]
Assets
Reinsurance recoverables and trade receivables, net	206,663	189,498
Mortgage loans, net	494,664	444,957
Other investments	109,833	109,009
Total	811,160	743,464
Liabilities
Notes, loans and leases payable, gross	0	0
Total	0	0
Carrying Value [Member]
Assets
Reinsurance recoverables and trade receivables, net	206,663	189,498
Mortgage loans, net	510,307	466,531
Other investments	109,833	109,009
Total	826,803	765,038
Liabilities
Notes, loans and leases payable, gross	6,323,782	6,143,350
Total	$ 6,323,782	$ 6,143,350