Description of Business, Basis of Presentation, and Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions				3 Months Ended
	Jul. 01, 2022	Jul. 01, 2021	Jan. 01, 2021	Mar. 31, 2023
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Future policy benefits reserve percentage of net premium ratio				100.00%
Percentage of net premium ratio capped				100.00%
Change in accounting principle, accounting standards update, adopted				true
Change in accounting principle, accounting standards update, adoption date				Jan. 01, 2023
Accounting standards update [extensible enumeration]				us-gaap:AccountingStandardsUpdate201812Member
Reduction to AOCI net of income tax			$ 1,500.0
Cumulative decrease to AOCI upon application of market observable rates				$ 11.7
Adjustment amount necessary at transition date to cap net premium ratio for a cohort				$ 23.0
Separate accounts contract's minimum guaranteed payments, percentage of policyholder's contribution				75.00%
Separate accounts contract minimum maturity, years				10 years
Separate accounts contract maximum maturity, date				Dec. 31, 2070
Separate accounts contract maturity, years				20 years
Separate accounts contracts minimum guaranteed payments, decline in percentage of policyholder's contribution				25.00%
Strategic retirement income fund maturity description				SRIF mature when the policyholder reaches age 100, which is a minimum of 20 years after issue
Term Life Insurance Segment [Member]
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Percentage of net premium ratio capped				100.00%
Accounting standards update [extensible enumeration]				us-gaap:AccountingStandardsUpdate201812Member
Etelequote Bermuda [Member]
Organization Consolidation Basis Of Presentation Business Description And Accounting Policies [Line Items]
Business acquisition, date of acquisition agreement		Jul. 01, 2021
Percentage of interest acquired		80.00%
Remaining percentage of interest acquired	20.00%
Business acquisition, effective date of acquisition	Jul. 01, 2022