Policyholders' Liabilities - Guaranteed Minimum Crediting Rate (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 222,009	$ 205,799
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 36,314	$ 39,117
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149 | Minimum [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of Guaranteed Minimum Crediting Rates:	0.00%	0.00%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149 | Maximum [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of Guaranteed Minimum Crediting Rates:	1.49%	1.49%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 36,145	$ 30,994
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299 | Minimum [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of Guaranteed Minimum Crediting Rates:	1.50%	1.50%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299 | Maximum [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of Guaranteed Minimum Crediting Rates:	2.99%	2.99%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 118,031	$ 104,314
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449 | Minimum [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of Guaranteed Minimum Crediting Rates:	3.00%	3.00%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449 | Maximum [Member]
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of Guaranteed Minimum Crediting Rates:	4.49%	4.49%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From Greater Than Or Equal To 0450
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of Guaranteed Minimum Crediting Rates:	4.50%	4.50%
Policyholder Account Balance	$ 31,519	$ 31,374
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	142,821	166,680
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	816	746
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	8,840	30,256
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	101,646	104,304
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From Greater Than Or Equal To 0450
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	31,519	31,374
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	522	685
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	176	675
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	346	10
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From Greater Than Or Equal To 0450
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	16,802	1,201
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	726	1,138
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	37	63
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	16,039	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150 | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From Greater Than Or Equal To 0450
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	61,864	37,233
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	34,772	37,233
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	27,092	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From Greater Than Or Equal To 0450
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Policyholder Account Balance	$ 0	$ 0