Fair Value of Financial Instruments - Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	$ 2,495,456	$ 2,702,567
Equity securities	35,404	42,551
Cash and cash equivalents	489,240	392,501
Separate account assets	2,305,717	2,799,992
Separate account liabilities	2,305,717	2,799,992
Fair Value, Recurring Measurements [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	2,495,456	2,702,567
Equity securities	35,404	42,551
Trading securities	3,698	24,355
Cash and cash equivalents	489,240	392,501
Separate account assets	2,305,717	2,799,992
Assets, fair value disclosure	5,398,921	6,047,209
Separate account liabilities	2,305,717	2,799,992
Liabilities, fair value disclosure	2,305,717	2,799,992
Fair Value, Recurring Measurements [Member] | Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	3,586	5,898
Equity securities	32,727	37,912
Cash and cash equivalents	489,240	351,508
Assets, fair value disclosure	525,553	395,318
Fair Value, Recurring Measurements [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	2,491,870	2,696,642
Equity securities	967	1,070
Trading securities	3,698	24,355
Cash and cash equivalents		40,993
Separate account assets	2,305,717	2,799,992
Assets, fair value disclosure	4,871,658	5,648,295
Separate account liabilities	2,305,717	2,799,992
Liabilities, fair value disclosure	2,305,717	2,799,992
Fair Value, Recurring Measurements [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities		27
Equity securities	1,710	3,569
Assets, fair value disclosure	1,710	3,596
Fair Value, Recurring Measurements [Member] | U.S. Government and Agencies [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	30,468	32,400
Fair Value, Recurring Measurements [Member] | U.S. Government and Agencies [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	30,468	32,400
Fair Value, Recurring Measurements [Member] | Foreign Government [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	152,915	152,976
Fair Value, Recurring Measurements [Member] | Foreign Government [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	152,915	152,976
Fair Value, Recurring Measurements [Member] | States and Political Subdivisions [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	122,245	153,527
Fair Value, Recurring Measurements [Member] | States and Political Subdivisions [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	122,245	153,527
Fair Value, Recurring Measurements [Member] | Corporates [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	1,496,849	1,713,684
Fair Value, Recurring Measurements [Member] | Corporates [Member] | Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	3,586	5,898
Fair Value, Recurring Measurements [Member] | Corporates [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	1,493,263	1,707,786
Fair Value, Recurring Measurements [Member] | Residential Mortgage-backed Securities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	401,730	375,631
Fair Value, Recurring Measurements [Member] | Residential Mortgage-backed Securities [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	401,730	375,604
Fair Value, Recurring Measurements [Member] | Residential Mortgage-backed Securities [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities		27
Fair Value, Recurring Measurements [Member] | Commercial Mortgage-backed Securities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	122,967	145,525
Fair Value, Recurring Measurements [Member] | Commercial Mortgage-backed Securities [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	122,967	145,525
Fair Value, Recurring Measurements [Member] | Other Asset-backed Securities [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	168,282	128,824
Fair Value, Recurring Measurements [Member] | Other Asset-backed Securities [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	168,282	128,824
Fair Value, Recurring Measurements [Member] | Fixed-Maturity Securities and Short-term Investments [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	2,564,862	2,787,810
Fair Value, Recurring Measurements [Member] | Fixed-Maturity Securities and Short-term Investments [Member] | Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	3,586	5,898
Fair Value, Recurring Measurements [Member] | Fixed-Maturity Securities and Short-term Investments [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	2,561,276	2,781,885
Fair Value, Recurring Measurements [Member] | Fixed-Maturity Securities and Short-term Investments [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities		27
Fair Value, Recurring Measurements [Member] | Short-Term Investments
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	69,406	85,243
Fair Value, Recurring Measurements [Member] | Short-Term Investments | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total available-for-sale fixed-maturity securities	$ 69,406	$ 85,243