Investments - Summary of Fixed Maturities Available for Sale by Component (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 21,305,287	$ 21,213,509
Fixed maturities available for sale
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	17,805,309	17,197,145
Allowance for Credit Losses	(387)	(3,346)
Gross Unrealized Gains	3,534,404	4,067,243
Gross Unrealized Losses	(34,039)	(47,533)
Fair Value	$ 21,305,287	$ 21,213,509
Percentage of Fixed Maturities at Fair Value	100.00%	100.00%
Fixed maturities available for sale \| U.S. Government direct, guaranteed, and government-sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 383,083	$ 380,602
Allowance for Credit Losses	0	0
Gross Unrealized Gains	64,513	87,272
Gross Unrealized Losses	(164)	(43)
Fair Value	$ 447,432	$ 467,831
Percentage of Fixed Maturities at Fair Value	2.00%	2.00%
Fixed maturities available for sale \| States, municipalities, and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 2,252,997	$ 1,880,607
Allowance for Credit Losses	0	0
Gross Unrealized Gains	239,135	251,291
Gross Unrealized Losses	(2,907)	(315)
Fair Value	$ 2,489,225	$ 2,131,583
Percentage of Fixed Maturities at Fair Value	12.00%	10.00%
Fixed maturities available for sale \| Foreign governments
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 59,861	$ 52,913
Allowance for Credit Losses	0	0
Gross Unrealized Gains	900	2,635
Gross Unrealized Losses	(5,132)	(898)
Fair Value	$ 55,629	$ 54,650
Percentage of Fixed Maturities at Fair Value	0.00%	0.00%
Fixed maturities available for sale \| Corporates
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 14,967,902	$ 14,691,277
Allowance for Credit Losses	(387)	(3,346)
Gross Unrealized Gains	3,199,104	3,698,971
Gross Unrealized Losses	(25,406)	(33,630)
Fair Value	$ 18,141,213	$ 18,353,272
Percentage of Fixed Maturities at Fair Value	85.00%	87.00%
Fixed maturities available for sale \| Corporates \| Financial
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 4,569,160	$ 4,404,203
Allowance for Credit Losses	(387)	0
Gross Unrealized Gains	907,741	1,016,813
Gross Unrealized Losses	(9,349)	(24,221)
Fair Value	$ 5,467,165	$ 5,396,795
Percentage of Fixed Maturities at Fair Value	26.00%	26.00%
Fixed maturities available for sale \| Corporates \| Utilities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,931,391	$ 1,975,460
Allowance for Credit Losses	0	0
Gross Unrealized Gains	490,119	608,595
Gross Unrealized Losses	(1,012)	(108)
Fair Value	$ 2,420,498	$ 2,583,947
Percentage of Fixed Maturities at Fair Value	11.00%	12.00%
Fixed maturities available for sale \| Corporates \| Energy
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,587,892	$ 1,623,970
Allowance for Credit Losses	0	(3,346)
Gross Unrealized Gains	346,780	346,197
Gross Unrealized Losses	(1,683)	(3,083)
Fair Value	$ 1,932,989	$ 1,963,738
Percentage of Fixed Maturities at Fair Value	9.00%	9.00%
Fixed maturities available for sale \| Corporates \| Other corporate sectors
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 6,879,459	$ 6,687,644
Allowance for Credit Losses	0	0
Gross Unrealized Gains	1,454,464	1,727,366
Gross Unrealized Losses	(13,362)	(6,218)
Fair Value	$ 8,320,561	$ 8,408,792
Percentage of Fixed Maturities at Fair Value	39.00%	40.00%
Fixed maturities available for sale \| Collateralized debt obligations
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 36,468	$ 57,007
Allowance for Credit Losses	0	0
Gross Unrealized Gains	27,037	23,460
Gross Unrealized Losses	0	(8,869)
Fair Value	$ 63,505	$ 71,598
Percentage of Fixed Maturities at Fair Value	0.00%	0.00%
Fixed maturities available for sale \| Other asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 104,998	$ 134,739
Allowance for Credit Losses	0	0
Gross Unrealized Gains	3,715	3,614
Gross Unrealized Losses	(430)	(3,778)
Fair Value	$ 108,283	$ 134,575
Percentage of Fixed Maturities at Fair Value	1.00%	1.00%

Percentage of fixed maturities by component at fair value.

No definition available.

Name:	gl_PercentageOfFixedMaturitiesAtFairValue
Namespace Prefix:	gl_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563

+ Details

Name:	us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount excluding accrued interest, of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

+ Details

Name:	us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_FixedMaturitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=gl_USGovernmentDirectGuaranteedAndGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gl_FinancialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gl_UtilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gl_EnergyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=gl_OtherCorporateSectorsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CollateralizedDebtObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=gl_OtherAssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: