Debt - Short-Term Debt (Details) - USD ($) $ in Millions	24 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Short-Term Debt
Credit facilities	$ 933.4	$ 936.9
Short-term debt	61.1	80.7
Credit facility maturing in October 2027 \| Principal Life Insurance Company
Short-Term Debt
Credit facilities	800.0	800.0
Unsecured lines of credit \| Principal International Chile
Short-Term Debt
Credit facilities	130.9	136.9
Short-term debt	$ 58.6	80.7
Unsecured lines of credit \| Maximum \| Principal International Chile
Short-Term Debt
Term of credit facility	1 year
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
Weighted-average interest rates on short-term borrowings (as a percent)	15.60%	6.00%
Uncollateralized debt \| Other short-term borrowings
Short-Term Debt
Credit facilities	$ 2.5
Short-term debt	$ 2.5

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

No definition available.

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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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- 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

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- 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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Balance Type:	credit
Period Type:	instant

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481372/852-10-55-10

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
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-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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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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- Definition

Weighted average interest rate of short-term debt outstanding calculated at point in time.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 210
-SubTopic 10
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+ Details

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- Details

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- Details

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- Details

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- Details

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