Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Prospectus Date	rr_ProspectusDate	Mar. 01, 2011
Global Div Inc Fund (Prospectus Summary): \| Global Div Inc Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return, Heading	rr_RiskReturnHeading	GLOBAL DIVERSIFIED INCOME FUND
Supplement Text	ck0000898745_SupplementTextBlock	Supplement dated December 16, 2011 to the Institutional Class Prospectus for Principal Funds, Inc. dated March 1, 2011 (as supplemented on March 14, 2011, June 16, 2011, July 20, 2011, August 29, 2011, September 16, 2011 and October 31, 2011) This supplement updates information currently in the Prospectus. Retain this supplement with the Prospectus.
Bar Chart and Performance Table, Heading	rr_BarChartAndPerformanceTableHeading	In the Performance section, delete the paragraph immediately above the Total Returns as of December 31 heading and substitute:
Performance, Narrative	rr_PerformanceNarrativeTextBlock	Effective September 30, 2011, the weightings for the Global Diversified Income Custom Index changed to the following: 38% Barclays Capital U.S. Corporate High Yield 2% Issuer Capped Index, 20% blend of 50% BofA Merrill Lynch Fixed Rate Preferred Securities Index and 50% Barclays Capital U.S. Tier I Capital Securities Index, 14% Barclays Capital U.S. Dollar Emerging Markets Bond Index, 5% MSCI All Country World Value Index, 6% Tortoise Midstream MLP Index, 7% blend of 65% S&P 500 Utilities Index, 25% S&P 500 Telecom Services Index and 10% S&P 500 Energy Index, 5% FTSE EPRA/NAREIT Developed Index and 5% Barclays Capital Investment Grade CMBS Index.
Annual Return Heading	ck0000898745_AnnualReturnHeading	In the Average Annual Total Returns table, add:
Annual Return, Caption	rr_AnnualReturnCaption	Average Annual Total Returns For the periods ended December 31, 2010
Performance Table, Market Index Changed	rr_PerformanceTableMarketIndexChanged	Effective September 30, 2011, the weightings for the Global Diversified Income Custom Index changed to the following: 38% Barclays Capital U.S. Corporate High Yield 2% Issuer Capped Index, 20% blend of 50% BofA Merrill Lynch Fixed Rate Preferred Securities Index and 50% Barclays Capital U.S. Tier I Capital Securities Index, 14% Barclays Capital U.S. Dollar Emerging Markets Bond Index, 5% MSCI All Country World Value Index, 6% Tortoise Midstream MLP Index, 7% blend of 65% S&P 500 Utilities Index, 25% S&P 500 Telecom Services Index and 10% S&P 500 Energy Index, 5% FTSE EPRA/NAREIT Developed Index and 5% Barclays Capital Investment Grade CMBS Index.
Global Div Inc Fund \| Institutional Class
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	PGDIX
Global Div Inc Fund \| S&P 500 Energy Index
Risk/Return:	rr_RiskReturnAbstract
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	20.46%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	16.63%
Global Div Inc Fund \| S&P 50 Telecom Services Index
Risk/Return:	rr_RiskReturnAbstract
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	18.97%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	16.83%
Global Div Inc Fund \| S&P 500 Utilities Index
Risk/Return:	rr_RiskReturnAbstract
Average Annual Returns, 1 Year	rr_AverageAnnualReturnYear01	5.46%
Average Annual Returns, Since Inception	rr_AverageAnnualReturnSinceInception	10.48%

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No definition available.

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Trading symbol of an instrument as listed on an exchange.

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If the Fund has annual returns for at least one calendar year, provide a bar chart showing the Fund's annual total returns for each of the last 10 calendar years (or for the life of the Fund if less than 10 years), but only for periods subsequent to the effective date of the Fund's registration statement. Present the corresponding numerical return adjacent to each bar. If the Fund's fiscal year is other than a calendar year, include the year-to-date return information as of the end of the most recent quarter in a footnote to the bar chart. Following the bar chart, disclose the Fund's highest and lowest return for a quarter during the 10 years or other period of the bar chart. Provide annual total returns beginning with the earliest calendar year. Calculate annual returns using the Instructions to Item 8(a), except that the calculations should be based on calendar years. If a Fund's shares are sold subject to a sales load or account fees, state that sales loads or account fees are not reflected in the bar chart and that, if these amounts were reflected, returns would be less than those shown. When a Multiple Class Fund offers more than one Class in the prospectus, provide annual total returns in the bar chart for only one of those Classes. The Fund can select which Class to include (e.g., the oldest Class, the Class with the greatest net assets). When a Multiple Class Fund offering one or more Classes offers a new Class in a prospectus that does not offer the shares of any other Class, include the bar chart with annual total returns for any other existing Class for the first year that the Class is offered. Explain in a footnote that the returns are for a Class that is not offered in the prospectus that would have substantially similar annual returns because the shares are invested in the same portfolio of securities and the annual returns would differ only to the extent that the Classes do not have the same expenses. Include return information for the other Class reflected in the bar chart in the performance table.

+ References

Reference 1: 1

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

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Return Before Taxes.

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Reference 1: 1

-Publisher SEC

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-Number N-1A

-Chapter A

-Section 4

-Paragraph 2

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-Clause 1

-Exhibit 2

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Return Before Taxes.

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Reference 1: 1

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-Paragraph 2

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-Clause 1

-Exhibit 2

-Subsection b

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- Definition

Risk/Return Bar Chart and Table.

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Risk/Return Bar Chart and Table.

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If the Fund selects an index that is different from the index used in a table for the immediately preceding period, explain the reason(s) for the selection of a different index and provide information for both the newly selected and the former index.

+ References

Reference 1: 1

-Publisher SEC

-Name Form

-Number N-1A

-Chapter A

-Section 4

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The date of the prospectus.

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Risk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicated

+ References

Reference 1: 1

-Publisher SEC

-Name Form

-Number N-1A

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-Section 2

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