Debt - Short-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Short-Term Debt
Credit facilities	$ 800.0	$ 800.0
Credit facility maturing in October 2027 \| PLIC
Short-Term Debt
Credit facilities	$ 800.0	800.0
Commercial paper
Short-Term Debt
Support provided by back-stop facility for commercial paper program (as a percent)	100.00%
Back-stop facility outstanding balances	$ 0.0	$ 0.0

Amount of outstanding back-stop facilities as of the balance sheet date.

No definition available.

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Namespace Prefix:	plic_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage of support provided by back-stop facility for commercial paper program.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
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Period Type:	instant

- 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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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

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- Details

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Namespace Prefix:
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- Details

Name:	plic_ParentAndSubsidiariesShelfRegistrationDebtGuarantorAxis=plic_PrincipalLifeInsuranceCompanyMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
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Balance Type:
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