Significant Accounting Policies - Additional Information (Detail) $ in Thousands			12 Months Ended
	Jan. 01, 2023 USD ($)	Aug. 01, 2021 USD ($)	Dec. 31, 2022 USD ($) segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Significant of Account Policies [Line Items]
Number of reportable segments | segment			4
Concentration risk percentage			100.00%
Capital called from investment funds			$ 201,000
Investment funds, unfunded commitments			$ 487,000
Percentage of investment securities not classified as corporate securities, state and municipal securities, redeemable preferred stocks and U.S. government securities (less than)			1.00%
Fair value determined by third party			97.00%
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]			Accrued investment income
Agent debit balances			$ 460,000	$ 467,000
Agent debit balances, allowance for credit losses			1,000
Advertising costs charged to earnings and included in other operating			9,400	10,000	$ 9,800
Capitalized advertising costs			1,500,000	1,400,000
Carrying value of investment in low-income housing interests			315,000	328,000
Obligations under future commitments for low-income housing interests			137,000
Original cost of property and equipment			406,000	378,000
Accumulated depreciation			194,000	173,000
Depreciation expense			$ 21,000	20,000	17,000
Traditional life and health, interest rate, low end			2.50%
Traditional life and health, interest rate, high end			7.00%
Traditional life and health, weighted average interest rate			5.80%
Insurance policy charges			$ 13,500	14,200	14,700
Amortized during period			$ (624,407)	(603,838)	$ (575,770)
Beazley Insurance Company
Significant of Account Policies [Line Items]
Acquisition consideration		$ 59,200
Commercial loan participations
Significant of Account Policies [Line Items]
Financing receivable, term			3 years
Financing receivable, extension term			2 years
Unfunded loan commitment
Significant of Account Policies [Line Items]
Unfunded commitment balance to commercial loan borrowers			$ 38,000
Commercial mortgage loan participations
Significant of Account Policies [Line Items]
Unfunded commitment balance to commercial loan borrowers			181,305	$ 141,843
Accrued interest receivable			903
Investment in Limited Partnerships
Significant of Account Policies [Line Items]
Capital called from investment funds			201,000
Investment funds, unfunded commitments			$ 486,865
Equity Option | Torchmark Corporation 2018 Incentive Plan
Significant of Account Policies [Line Items]
Term over which monthly data points are used to derive volatility			3 years
Equity Option | Employee | Three Year Vesting Period | Torchmark Corporation 2018 Incentive Plan
Significant of Account Policies [Line Items]
Option grants contractual term			7 years
Vesting period			3 years
Equity Option | Employee | Five Year Vesting Period | Torchmark Corporation 2018 Incentive Plan
Significant of Account Policies [Line Items]
Option grants contractual term			10 years
Vesting period			5 years
Equity Option | Director | Torchmark Corporation 2018 Incentive Plan
Significant of Account Policies [Line Items]
Vesting period			6 months
Low-income housing credits and certain limited partnerships | Total Assets | Investment Type
Significant of Account Policies [Line Items]
Concentration risk percentage			2.00%
Life insurance
Significant of Account Policies [Line Items]
Proportion of future policy reserves which are not universal life type			90.00%
Minimum | Investment in Limited Partnerships
Significant of Account Policies [Line Items]
Investment funds ownership percentage			1.00%
Maximum | Investment in Limited Partnerships
Significant of Account Policies [Line Items]
Investment funds ownership percentage			20.00%
Equipment | Minimum
Significant of Account Policies [Line Items]
Property and equipment, estimated useful life			3 years
Equipment | Maximum
Significant of Account Policies [Line Items]
Property and equipment, estimated useful life			10 years
Building and Improvements | Minimum
Significant of Account Policies [Line Items]
Property and equipment, estimated useful life			15 years
Building and Improvements | Maximum
Significant of Account Policies [Line Items]
Property and equipment, estimated useful life			40 years
Cumulative Effect, Period of Adoption, Adjustment | Minimum | Accounting Standards Update 2018-12 | Forecast
Significant of Account Policies [Line Items]
Decrease in AOCI	$ 7,500,000
Increase in future policy benefits before discount rate change	9,500,000
Decrease in AOCI	1,200,000
Increase in future policy benefits	1,500,000
Amortized during period	105,000
Cumulative Effect, Period of Adoption, Adjustment | Maximum | Accounting Standards Update 2018-12 | Forecast
Significant of Account Policies [Line Items]
Decrease in AOCI	8,500,000
Increase in future policy benefits before discount rate change	11,000,000
Decrease in AOCI	1,800,000
Increase in future policy benefits	2,300,000
Amortized during period	$ 115,000