Nature of Operations and Significant Accounting Policies - Other Various Policies (Details)	12 Months Ended
Dec. 31, 2023
Long-Term Debt
Minimum maturity period at date of issuance for debt to be classified as long-term	1 year

Represents the minimum number of years for the maturity date debt when issued for it to be included in long-term debt.

No definition available.

Name:	pfg_LongTermDebtMinimumMaturityPeriod
Namespace Prefix:	pfg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration