Policy Liabilities - Policyholder Account Balance, Guaranteed Minimum Crediting Rate (Details) - USD ($)	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Interest Sensitive Life
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	$ 737,900,000	$ 739,105,000	$ 744,244,000	$ 745,335,000
Interest Sensitive Life | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	$ 737,900,000		744,244,000
Interest Sensitive Life | Less than 3.00% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates (percent)	3.00%	3.00%
Range of guaranteed minimum crediting rates	$ 0		0
Interest Sensitive Life | 3.00%-3.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	$ 28,956,000		28,684,000
Interest Sensitive Life | 3.00%-3.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Minimum
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates (percent)	3.00%	3.00%
Interest Sensitive Life | 3.00%-3.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Maximum
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates (percent)	3.99%	3.99%
Interest Sensitive Life | 4.00%-4.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	$ 619,411,000		626,179,000
Interest Sensitive Life | 4.00%-4.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Minimum
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates (percent)	4.00%	4.00%
Interest Sensitive Life | 4.00%-4.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate | Maximum
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates (percent)	4.99%	4.99%
Interest Sensitive Life | Greater than 5.00% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates (percent)	5.00%	5.00%
Range of guaranteed minimum crediting rates	$ 89,533,000		89,381,000
Deferred Annuity
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	907,797,000	$ 954,318,000	1,027,087,000	1,033,525,000
Deferred Annuity | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	907,797,000		1,027,087,000
Deferred Annuity | Less than 3.00% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	1,971,000		2,254,000
Deferred Annuity | 3.00%-3.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	698,952,000		811,865,000
Deferred Annuity | 4.00%-4.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	206,874,000		212,968,000
Deferred Annuity | Greater than 5.00% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	0		0
Other
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	142,686,000	$ 123,234,000	100,124,000	$ 99,468,000
Other | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	142,686,000		100,124,000
Other | Less than 3.00% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	43,191,000		0
Other | 3.00%-3.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	4,097,000		2,911,000
Other | 4.00%-4.99% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	57,596,000		58,990,000
Other | Greater than 5.00% | Policyholder Account Balance, at Guaranteed Minimum Crediting Rate
Policyholder Account Balance, Guaranteed Minimum Crediting Rate [Line Items]
Range of guaranteed minimum crediting rates	$ 37,802,000		$ 38,223,000