Significant Accounting Policies - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2016 segment
Significant of Account Policies [Line Items]
Number of operating segments sold | segment				1
Concentration risk percentage	100.00%
Capital called from investment funds	$ 234,000
Investment funds, unfunded commitments	$ 450,000
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%
Agent debit balances	$ 467,000	$ 456,000
Agent debit balances, allowance for credit losses	1,200
Advertising costs charged to earnings and included in other operating	10,000	9,800	$ 9,500
Capitalized advertising costs	1,400,000	1,400,000
Carrying value of investment in low-income housing interests	328,000	306,000
Obligations under future commitments for low-income housing interests	177,000
Original cost of property and equipment	378,000	350,000
Accumulated depreciation	173,000	164,000
Depreciation expense	$ 20,000	17,000	16,000
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	5.70%
Insurance policy charges	$ 14,200	14,700	$ 15,600
Commercial loan participations
Significant of Account Policies [Line Items]
Financing receivable, term	3 years
Financing receivable, extension term	2 years
Commercial loan participations, unfunded loan commitment | Total Assets
Significant of Account Policies [Line Items]
Carrying value, net of valuation allowance	$ 29,000
Commercial mortgage participations
Significant of Account Policies [Line Items]
Carrying value, net of valuation allowance	141,843	$ 160,602
Accrued interest receivable	389
Investment in limited partnerships
Significant of Account Policies [Line Items]
Capital called from investment funds	234,000
Investment funds, unfunded commitments	$ 449,917
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	1.00%
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