Issue price of senior notes.

No definition available.

Name:	pri_IssuePriceOfSeniorNotes
Namespace Prefix:	pri_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents disclosure of the total aggregate cash dividends paid to the entity by consolidated subsidiaries, by unconsolidated subsidiaries, and by 50% or less owned persons accounted for using the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(b))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 235
-Section S99
-Paragraph 2
-Subparagraph (SX 210.9-06)
-URI http://asc.fasb.org/extlink&oid=6882215&loc=d3e537971-122884

+ Details

Name:	us-gaap_CashDividendsPaidToParentCompany
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
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-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of when the fee for available but unused credit capacity is required to be paid (for example, annually, quarterly, or monthly).

+ References

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Details

Name:	dei_EntitySectorIndustryClassificationsSectorAxis=pri_NonLifeInsuranceSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_EntitySectorIndustryClassificationsSectorAxis=pri_LifeInsuranceSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ConsolidatedEntitiesAxis=us-gaap_ParentCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Schedule II - Primerica, Inc. (Parent Only) - Notes to Condensed Financial Statements (Details) - USD ($)		12 Months Ended
	Dec. 19, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	May 31, 2017	Jul. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Debt instrument, face amount		$ 375,000,000	$ 375,000,000
Debt instrument, interest rate, stated percentage				4.75%
Debt instrument maturity date				Jul. 15, 2022
Non-life Insurance Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash dividends paid to parent company		96,000,000	72,500,000	$ 86,500,000
Life Insurance Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash dividends paid to parent company		$ 160,900,000	$ 117,000,000	$ 62,600,000
Maximum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, face amount					$ 1,300,000,000
Revolving Credit Facility [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, face amount	$ 200,000,000
New unsecured revolving credit facility	$ 200,000,000
Debt instrument, term	5 years
Debt instrument, frequency of commitment fee payable		quarterly
Debt instrument, outstanding amount		$ 0
Revolving Credit Facility [Member] \| Minimum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, commitment fee percentage	0.125%
Revolving Credit Facility [Member] \| Maximum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, commitment fee percentage	0.225%
Revolving Credit Facility [Member] \| LIBOR Rate [Member] \| Minimum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate margin	1.125%
Revolving Credit Facility [Member] \| LIBOR Rate [Member] \| Maximum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate margin	1.625%
Revolving Credit Facility [Member] \| Base Rate [Member] \| Minimum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate margin	0.125%
Revolving Credit Facility [Member] \| Base Rate [Member] \| Maximum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate margin	0.625%
Letter of Credit [Member] \| LIBOR Rate [Member] \| Minimum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate margin	0.125%
Letter of Credit [Member] \| LIBOR Rate [Member] \| Maximum [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, interest rate margin	0.625%
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Debt instrument, face amount		$ 375,000,000
Issue price of senior notes						99.843%
Debt instrument, interest rate, stated percentage						4.75%
Debt instrument maturity date		Jul. 15, 2022
Guarantor obligations, maximum exposure, undiscounted		$ 20,000,000