Fair Value Measurements (Carrying and Estimated Fair Values within Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Mar. 31, 2022
Assets
Reinsurance recoverables and trade receivables, net	$ 203,202	$ 229,343
Mortgage loans, net	417,894	450,347
Other investments	123,565	120,592
Total	744,661	800,282
Liabilities
Notes, loans and leases payable, gross	5,930,507	5,875,781
Total	5,930,507	5,875,781
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	6,336,570	6,059,713
Total	6,336,570	6,059,713
Level 3 [Member]
Assets
Reinsurance recoverables and trade receivables, net	203,202	229,343
Mortgage loans, net	424,633	423,163
Other investments	123,565	120,592
Total	751,400	773,098
Liabilities
Notes, loans and leases payable, gross	0	0
Total	0	0
Carrying Value [Member]
Assets
Reinsurance recoverables and trade receivables, net	203,202	229,343
Mortgage loans, net	424,633	423,163
Other investments	123,565	120,592
Total	751,400	773,098
Liabilities
Notes, loans and leases payable, gross	6,336,570	6,059,713
Total	$ 6,336,570	$ 6,059,713