Policyholders' Liabilities - Guaranteed Minimum Crediting Rate (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 205,799	$ 193,291
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 39,117	$ 41,584
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149 | Minimum [Member]
Policyholder Account Balance [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	0.00%	0.00%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149 | Maximum [Member]
Policyholder Account Balance [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	1.49%	1.49%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 30,994	$ 23,003
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299 | Minimum [Member]
Policyholder Account Balance [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	1.50%	1.50%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299 | Maximum [Member]
Policyholder Account Balance [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	2.99%	2.99%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449
Policyholder Account Balance [Line Items]
Policyholder Account Balance	$ 104,314	$ 96,942
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449 | Minimum [Member]
Policyholder Account Balance [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	3.00%	3.00%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449 | Maximum [Member]
Policyholder Account Balance [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	4.49%	4.49%
Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From Greater Than Or Equal To 0450
Policyholder Account Balance [Line Items]
Policyholder Account Balance, Guaranteed Minimum Credit Rating	4.50%	4.50%
Policyholder Account Balance	$ 31,374	$ 31,762
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance [Line Items]
Policyholder Account Balance	166,680	151,766
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0000 To 0149
Policyholder Account Balance [Line Items]
Policyholder Account Balance	746	702
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0150 To 0299
Policyholder Account Balance [Line Items]
Policyholder Account Balance	30,256	22,370
Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Policyholder Account Balance, Guaranteed Minimum Crediting Rate, Range From 0300 To 0449
Policyholder Account Balance [Line Items]
Policyholder Account Balance	104,304	96,932
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 [Line Items]
Policyholder Account Balance	31,374	31,762
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0001 to 0050
Policyholder Account Balance [Line Items]
Policyholder Account Balance	685	613
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 [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 [Line Items]
Policyholder Account Balance	675	603
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 [Line Items]
Policyholder Account Balance	10	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 [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0051 to 0150
Policyholder Account Balance [Line Items]
Policyholder Account Balance	1,201	857
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 [Line Items]
Policyholder Account Balance	1,138	827
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 [Line Items]
Policyholder Account Balance	63	30
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 [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, Range From Greater Than Or Equal To 0450
Policyholder Account Balance [Line Items]
Policyholder Account Balance	0	0
Policyholder Account Balance, above Guaranteed Minimum Crediting Rate, Range from 0151 and Greater
Policyholder Account Balance [Line Items]
Policyholder Account Balance	37,233	40,055
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 [Line Items]
Policyholder Account Balance	37,233	40,055
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 [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 0300 To 0449
Policyholder Account Balance [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 [Line Items]
Policyholder Account Balance	$ 0	$ 0