Policy Benefits And Losses Claims And Loss Expenses Payable (Sensitive Life Insurance Type Products) (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Liability For Future Policy Benefits [Abstract]
Gross premiums	$ 45,099	$ 50,861	$ 45,099	$ 50,861
Other premiums	0	0	0	0
Gross premiums	45,099	50,861	45,099	50,861
Interest expense	63,943	57,193	124,541	106,992
Expected gross premiums:
Liability For Future Policy Benefits [Abstract]
Undiscounted balance	718,993	861,520	718,993	861,520
Discounted balance at original discount rate	555,819	662,234	555,819	662,234
Discounted balance at current discount rate	536,444	664,757	536,444	664,757
Expected policy benefits:
Liability For Future Policy Benefits [Abstract]
Undiscounted balance	1,034,340	1,150,096	1,034,340	1,150,096
Discounted balance at original discount rate	734,389	812,234	734,389	812,234
Discounted balance at current discount rate	720,578	830,362	720,578	830,362
Oxford
Liability For Future Policy Benefits [Abstract]
Interest expense			7,918	8,006
Life Insurance Segment [Member]
Liability For Future Policy Benefits [Abstract]
Gross premiums	$ 26,667	$ 29,158	$ 26,667	$ 29,158
Expected future lifetime (persistency) of policies in force (years)	6 years 10 months 24 days	7 years 1 month 6 days	6 years 10 months 24 days	7 years 1 month 6 days
Weighted average original interest rate of the liability for future policy benefits	5.00%	5.00%	5.00%	5.00%
Weighted average current interest rate of the liability for future policy benefits	5.00%	1.00%	5.00%	1.00%
Life Insurance Segment [Member] | Expected gross premiums:
Liability For Future Policy Benefits [Abstract]
Undiscounted balance	$ 387,141	$ 427,457	$ 387,141	$ 427,457
Discounted balance at original discount rate	299,161	329,233	299,161	329,233
Discounted balance at current discount rate	296,505	339,434	296,505	339,434
Life Insurance Segment [Member] | Expected policy benefits:
Liability For Future Policy Benefits [Abstract]
Undiscounted balance	761,261	807,725	761,261	807,725
Discounted balance at original discount rate	523,777	551,153	523,777	551,153
Discounted balance at current discount rate	$ 524,726	$ 577,060	$ 524,726	$ 577,060
Life Insurance Segment [Member] | Lapses actual experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0.0502	0.0507	0.0502	0.0507
Life Insurance Segment [Member] | Mortality expected experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0.0506	0.0478	0.0506	0.0478
Life Insurance Segment [Member] | Lapses actual experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0.0187	0.0204	0.0187	0.0204
Life Insurance Segment [Member] | Lapses expected experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0.0265	0.0253	0.0265	0.0253
Life Insurance Segment [Member] | Morbidity actual experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0	0	0	0
Life Insurance Segment [Member] | Morbidity expected experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0	0	0	0
Life Insurance Segment [Member] | Oxford
Liability For Future Policy Benefits [Abstract]
Interest expense			$ 7,612	$ 7,677
Health Insurance Product Line [Member]
Liability For Future Policy Benefits [Abstract]
Gross premiums	$ 18,432	$ 21,703	$ 18,432	$ 21,703
Expected future lifetime (persistency) of policies in force (years)	6 years 6 months	6 years 9 months 18 days	6 years 6 months	6 years 9 months 18 days
Weighted average original interest rate of the liability for future policy benefits	4.00%	4.00%	4.00%	4.00%
Weighted average current interest rate of the liability for future policy benefits	5.00%	1.00%	5.00%	1.00%
Health Insurance Product Line [Member] | Expected gross premiums:
Liability For Future Policy Benefits [Abstract]
Undiscounted balance	$ 331,852	$ 434,063	$ 331,852	$ 434,063
Discounted balance at original discount rate	256,658	333,001	256,658	333,001
Discounted balance at current discount rate	239,939	325,323	239,939	325,323
Health Insurance Product Line [Member] | Expected policy benefits:
Liability For Future Policy Benefits [Abstract]
Undiscounted balance	273,079	342,371	273,079	342,371
Discounted balance at original discount rate	210,612	261,081	210,612	261,081
Discounted balance at current discount rate	$ 195,852	$ 253,302	$ 195,852	$ 253,302
Health Insurance Product Line [Member] | Lapses actual experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0	0	0	0
Health Insurance Product Line [Member] | Mortality expected experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0	0	0	0
Health Insurance Product Line [Member] | Lapses actual experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0	0	0	0
Health Insurance Product Line [Member] | Lapses expected experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0	0	0	0
Health Insurance Product Line [Member] | Morbidity actual experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0.8553	0.7925	0.8553	0.7925
Health Insurance Product Line [Member] | Morbidity expected experience
Liability For Future Policy Benefits [Abstract]
Market Risk Benefit Measurement Input	0.7350	0.7130	0.7350	0.7130
Health Insurance Product Line [Member] | Oxford
Liability For Future Policy Benefits [Abstract]
Interest expense			$ 306	$ 329