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This item represents disclosure of the amount of dividends, returns of capital or other distributions received from or contributions made to unconsolidated subsidiaries accounted for using the equity method of accounting.

No definition available.

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The net cash inflow/outflow associated with the acquisition, sales and disposals of property, plant and equipment, and other productive assets, including intangible assets for software.

No definition available.

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The cash inflow from a segregated fund account during the period.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.

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Amount of cash inflow from realized tax benefit related to deductible compensation cost reported on the entity's tax return for equity instruments in excess of the compensation cost for those instruments recognized for financial reporting purposes.

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The net cash inflow or outflow for the increase (decrease) in the beginning and end of period deposits balances.

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Amount of cash inflow (outflow) of financing activities, excluding discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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The cash outflow for derivative instruments during the period, which are classified as financing activities, excluding those designated as hedging instruments.

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Amount of cash (inflow) outflow from investing activities classified as other.

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The cash outflow to reacquire common stock during the period.

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

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The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity.

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Name:	us-gaap_PaymentsToAcquireAvailableForSaleSecurities
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The cash outflow from the purchase of receivables arising from the mortgage note on real estate.

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The cash outflow associated with the purchase of real estate held for investment purposes.

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Amount of cash outflow to a noncontrolling interest. Includes, but not limited to, reduction of noncontrolling interest ownership. Excludes dividends paid to the noncontrolling interest.

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Name:	us-gaap_PaymentsToMinorityShareholders
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The cash inflow provided by derivative instruments during the period, which are classified as financing activities, excluding those designated as hedging instruments.

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The cash inflow from the additional capital contribution to the entity.

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The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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The cash inflow associated with maturities (principal being due), prepayments and calls (requests of early payments) on securities not classified as either held-to-maturity securities or trading securities which are classified as available-for-sale securities.

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Amount of cash inflow from a noncontrolling interest. Includes, but is not limited to, purchase of additional shares or other increase in noncontrolling interest ownership.

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Amount of cash inflow (outflow) from financing activities classified as other.

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The net cash inflow or outflow for borrowing having initial term of repayment within one year or the normal operating cycle, if longer.

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The cash inflow from proceeds from sale of receivables arising from the mortgage note on real estate; includes collections on mortgage notes receivable that are not classified as operating cash flows.

Name:	us-gaap_ProceedsFromSaleAndCollectionOfMortgageNotesReceivable
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The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

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Cash received from the sale of real estate that is held for investment, that is, it is part of an investing activity during the period.

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The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

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The cash outflow for a segregated fund account during the period.

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Balance Type:	credit
Period Type:	duration

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Name:	pfg_ParentAndSubsidiariesNotesGuarantorAxis=pfg_SubsidiariesPrincipalLifeInsuranceCompanyMember
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