485BPOS

Registration Nos. 002-93131

811-04044

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-1A

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933	☒
Pre-Effective Amendment No.	☐
Post-Effective Amendment No. 48	☒

and/or

REGISTRATION STATEMENT

UNDER

THE INVESTMENT COMPANY ACT OF 1940	☒
Amendment No. 50	☒

(Check appropriate box or boxes.)

PARNASSUS FUNDS

(Exact Name of Registrant as Specified in Charter)

1 Market Street Suite 1600 San Francisco, California	94105
(Address of Principal Executive Offices)	(Zip Code)

(415) 778-0200

(Registrant’s Telephone Number, including Area Code)

Copy to:

Jerome L. Dodson Parnassus Investments 1 Market Street Suite 1600 San Francisco, California 94105	Peter D. Fetzer Foley & Lardner LLP 777 East Wisconsin Avenue Milwaukee, Wisconsin 53202
(Name and Address of Agent for Service)

Approximate Date of Proposed Public Offering: As soon as practicable after the Registration Statement becomes effective.

It is proposed that this filing become effective (check appropriate box):

☒ immediately upon filing pursuant to paragraph (b)

☐ on (date) pursuant to paragraph (b)

☐ 60 days after filing pursuant to paragraph (a) (1)

☐ on (date) pursuant to paragraph (a) (1)

☐ 75 days after filing pursuant to paragraph (a) (2)

☐ on (date) pursuant to paragraph (a) (2) of Rule 485

If appropriate, check the following box:

☐ this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

EXPLANATORY NOTE

This Post-Effective Amendment (“PEA”) No. 48 to the Registration Statement of Parnassus Funds (the “Trust”) on Form N-1A hereby incorporates Parts A, B and C from the Trust’s PEA No. 47 on Form N-1A filed April 28, 2017 and effective April 30, 2017. This PEA No. 48 is filed for the sole purpose of submitting the XBRL exhibit for the risk/return summary first provided in PEA No. 47 to the Trust’s Registration Statement.

S-1

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements for effectiveness of this Amended Registration Statement under Rule 485(b) under the Securities Act and has duly caused this Amended Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized in the City and County of San Francisco and the State of California on the 16^th day of May 2017.

PARNASSUS INCOME FUNDS
(Registrant)
By:	/s/ Jerome L. Dodson
	Jerome L. Dodson, President

Pursuant to the requirements of the Securities Act of 1933, this Amended Registration Statement has been signed by the following persons in the capacities and on the date(s) indicated.

Signature	Title	Date
/s/ Jerome L. Dodson Jerome L. Dodson	Principal Executive Officer And Trustee	May 16, 2017
/s/ Marc C. Mahon Marc C. Mahon	Principal Financial and Accounting Officer	May 16, 2017
Donald J. Boteler +	Trustee	*
Alecia A. DeCoudreaux+	Trustee	*

+By:	/s/ Jerome L. Dodson
	Jerome L. Dodson
	Attorney-in-Fact*

* Signature is affixed as of May 16, 2017. Powers of attorney previously filed as an exhibit.

Signature Page

EXHIBIT INDEX

Exhibit	Exhibit No.
Instance Document	EX-101.INS
Schema Document	EX-101.SCH
Calculation Linkbase Document	EX-101.CAL
Definition Linkbase Document	EX-101.DEF
Label Linkbase Document	EX-101.LAB
Presentation Linkbase Document	EX-101.PRE

Exhibit Index

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Document Period End Date	dei_DocumentPeriodEndDate	Dec. 31, 2016
Registrant Name	dei_EntityRegistrantName	PARNASSUS FUNDS
Central Index Key	dei_EntityCentralIndexKey	0000747546
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Apr. 28, 2017
Document Effective Date	dei_DocumentEffectiveDate	Apr. 30, 2017
Prospectus Date	rr_ProspectusDate	May 01, 2017

XML

Parnassus Fund

Parnassus Fund

Investment Objective

The Parnassus Fund has the overall investment objective of capital appreciation.

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Fund.

Annual Fund Operating Expenses (%)
(expenses that you pay each year as a percentage
of the value of your investment)

Annual Fund Operating Expenses - Parnassus Fund	Investor Shares	Institutional Shares
Management Fees	0.62%	0.62%
Distribution (12b-1) Fees	none	none
Other Expenses	0.24%	0.09%
Service Fees	0.12%	none
All remaining other expenses	0.12%	0.09%
Total Annual Fund Operating Expenses	0.86%	0.71%

For additional information about the Parnassus Fund’s expenses, please see “Financial Highlights” in the prospectus.

Example

This example is intended to help you compare the cost of investing in the Parnassus Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, under these assumptions, your costs would be:

Expense Example - Parnassus Fund - USD ($)	1 Year	3 Years	5 Years	10 Years
Investor Shares	88	274	477	1,061
Institutional Shares	73	227	395	883

Portfolio Turnover

The Parnassus Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 41.7% of the average value of its portfolio.

Principal Investment Strategies

The Parnassus Fund invests in undervalued stocks. This Fund follows a “contrarian” strategy of seeking to invest in stocks that are currently out of favor with the financial community and are therefore, in the opinion of the Fund’s investment adviser (Adviser), deeply undervalued. The Adviser expects that if these undervalued companies are financially strong and have good prospects for the future, they will come back into favor and increase in market value. The Parnassus Fund is a “multi-cap” fund in that it can invest in companies of any size, from larger, well-established companies to smaller companies. The Fund invests mainly in domestic stocks of companies that are financially sound and have good prospects for the future, and to a lesser extent may also invest in foreign securities of similar companies. The Fund may purchase foreign securities directly on foreign markets. The Fund avoids investing in companies engaged in the extraction, exploration, production, manufacturing or refining of fossil fuels; the Fund may invest in companies that use fossil fuel-based energy to power their operations or for other purposes. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s sustainable strategic advantage and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.

Principal Risks

All investments involve risk, and investing in the Parnassus Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following:

• Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in the U.S. and abroad. The Fund’s holdings can vary significantly from broad stock market indices.

• Large-Capitalization Company Risk. Large-capitalization companies may be unable to respond quickly to new competitive challenges and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.

• Small- and Mid-Capitalization Company Risk. This is a “multi-cap” fund. In addition to large-capitalization companies, the Fund may invest in small- and/or mid-capitalization companies, which can be particularly sensitive to changing economic conditions since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, small-capitalization companies tend to perform poorly during times of economic stress.

• Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer.

• Foreign Securities Risk. The Fund may invest up to 20% of its assets in foreign securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market.

Performance Information

The bar chart and table that follow contain information that allows you to evaluate the Parnassus Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and the performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.

Annual Total Returns

During the ten-year period shown in the bar chart, the highest return for a quarter was 19.9% (quarter ended September 30, 2009), and the lowest return for a quarter was a loss of 26.6% (quarter ended December 31, 2008).

On the following page is a table comparing the performance of the Parnassus Fund’s two share classes with that of the S&P 500 Index and the Lipper Multi-Cap Core Average. Figures are average annual returns for the one-, five- and ten-year periods ended December 31, 2016. The table is intended to demonstrate the risk of investing in the Parnassus Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the S&P 500 Index, and a group of similar mutual funds, the Lipper Multi-Cap Core Average, and also how the Fund’s performance varies from year to year.

Average Annual Total Returns (%)
(all periods ended December 31, 2016)

Average Annual Total Returns - Parnassus Fund	One Year	Five Years	Ten Years
Investor Shares	13.46%	17.15%	9.66%
Investor Shares | Return after Taxes on Distributions	12.69%	14.36%	8.07%
Investor Shares | Return after Taxes on Distributions and Sale of Fund Shares	7.86%	13.54%	7.71%
Institutional Shares	13.59%	17.21%	9.68%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	11.94%	14.63%	6.93%
Lipper Multi-Cap Core Average	10.25%	13.06%	5.94%

The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.

Parnassus Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Fund—Investor Shares and includes expenses that are not applicable to and are higher than those of the Institutional Shares.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	PARNASSUS FUNDS
Prospectus Date	rr_ProspectusDate	May 01, 2017
Parnassus Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Parnassus Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Parnassus Fund has the overall investment objective of capital appreciation.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Fund.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (%) (expenses that you pay each year as a percentage of the value of your investment)
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Parnassus Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 41.7% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	41.70%
Expense Footnotes [Text Block]	rr_ExpenseFootnotesTextBlock	For additional information about the Parnassus Fund’s expenses, please see “Financial Highlights” in the prospectus.
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Parnassus Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, under these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Parnassus Fund invests in undervalued stocks. This Fund follows a “contrarian” strategy of seeking to invest in stocks that are currently out of favor with the financial community and are therefore, in the opinion of the Fund’s investment adviser (Adviser), deeply undervalued. The Adviser expects that if these undervalued companies are financially strong and have good prospects for the future, they will come back into favor and increase in market value. The Parnassus Fund is a “multi-cap” fund in that it can invest in companies of any size, from larger, well-established companies to smaller companies. The Fund invests mainly in domestic stocks of companies that are financially sound and have good prospects for the future, and to a lesser extent may also invest in foreign securities of similar companies. The Fund may purchase foreign securities directly on foreign markets. The Fund avoids investing in companies engaged in the extraction, exploration, production, manufacturing or refining of fossil fuels; the Fund may invest in companies that use fossil fuel-based energy to power their operations or for other purposes. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s sustainable strategic advantage and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	All investments involve risk, and investing in the Parnassus Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following: Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in the U.S. and abroad. The Fund’s holdings can vary significantly from broad stock market indices. Large-Capitalization Company Risk. Large-capitalization companies may be unable to respond quickly to new competitive challenges and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion. Small- and Mid-Capitalization Company Risk. This is a “multi-cap” fund. In addition to large-capitalization companies, the Fund may invest in small- and/or mid-capitalization companies, which can be particularly sensitive to changing economic conditions since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, small-capitalization companies tend to perform poorly during times of economic stress. Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer. Foreign Securities Risk. The Fund may invest up to 20% of its assets in foreign securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market.
Risk Lose Money [Text]	rr_RiskLoseMoney	You could lose money investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and the performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	(800) 999-3505
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.parnassus.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the ten-year period shown in the bar chart, the highest return for a quarter was 19.9% (quarter ended September 30, 2009), and the lowest return for a quarter was a loss of 26.6% (quarter ended December 31, 2008).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (%) (all periods ended December 31, 2016)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	On the following page is a table comparing the performance of the Parnassus Fund’s two share classes with that of the S&P 500 Index and the Lipper Multi-Cap Core Average. Figures are average annual returns for the one-, five- and ten-year periods ended December 31, 2016. The table is intended to demonstrate the risk of investing in the Parnassus Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the S&P 500 Index, and a group of similar mutual funds, the Lipper Multi-Cap Core Average, and also how the Fund’s performance varies from year to year.
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary. Parnassus Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Fund—Investor Shares and includes expenses that are not applicable to and are higher than those of the Institutional Shares.
Parnassus Fund | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.62%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	0.12%
All remaining other expenses	rr_Component2OtherExpensesOverAssets	0.12%
Other Expenses	rr_OtherExpensesOverAssets	0.24%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.86%
1 Year	rr_ExpenseExampleYear01	$ 88
3 Years	rr_ExpenseExampleYear03	274
5 Years	rr_ExpenseExampleYear05	477
10 Years	rr_ExpenseExampleYear10	$ 1,061
2007	rr_AnnualReturn2007	5.43%
2008	rr_AnnualReturn2008	(34.12%)
2009	rr_AnnualReturn2009	47.94%
2010	rr_AnnualReturn2010	16.71%
2011	rr_AnnualReturn2011	(5.01%)
2012	rr_AnnualReturn2012	26.04%
2013	rr_AnnualReturn2013	34.22%
2014	rr_AnnualReturn2014	14.68%
2015	rr_AnnualReturn2015	0.26%
2016	rr_AnnualReturn2016	13.46%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	19.90%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(26.60%)
One Year	rr_AverageAnnualReturnYear01	13.46%
Five Years	rr_AverageAnnualReturnYear05	17.15%
Ten Years	rr_AverageAnnualReturnYear10	9.66%
Parnassus Fund | Institutional Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.62%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	none
All remaining other expenses	rr_Component2OtherExpensesOverAssets	0.09%
Other Expenses	rr_OtherExpensesOverAssets	0.09%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.71%
1 Year	rr_ExpenseExampleYear01	$ 73
3 Years	rr_ExpenseExampleYear03	227
5 Years	rr_ExpenseExampleYear05	395
10 Years	rr_ExpenseExampleYear10	$ 883
One Year	rr_AverageAnnualReturnYear01	13.59%
Five Years	rr_AverageAnnualReturnYear05	17.21%
Ten Years	rr_AverageAnnualReturnYear10	9.68%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 30, 2015
Parnassus Fund | Return after Taxes on Distributions | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	12.69%
Five Years	rr_AverageAnnualReturnYear05	14.36%
Ten Years	rr_AverageAnnualReturnYear10	8.07%
Parnassus Fund | Return after Taxes on Distributions and Sale of Fund Shares | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	7.86%
Five Years	rr_AverageAnnualReturnYear05	13.54%
Ten Years	rr_AverageAnnualReturnYear10	7.71%
Parnassus Fund | S&P 500 Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	11.94%
Five Years	rr_AverageAnnualReturnYear05	14.63%
Ten Years	rr_AverageAnnualReturnYear10	6.93%
Parnassus Fund | Lipper Multi-Cap Core Average
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	10.25%
Five Years	rr_AverageAnnualReturnYear05	13.06%
Ten Years	rr_AverageAnnualReturnYear10	5.94%

XML

Parnassus Endeavor Fund

Parnassus Endeavor Fund

Investment Objective

The Parnassus Endeavor Fund has the overall investment objective of capital appreciation.

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Endeavor Fund.

Annual Fund Operating Expenses (%)
(expenses that you pay each year as a percentage
of the value of your investment)

Annual Fund Operating Expenses - Parnassus Endeavor Fund		Investor Shares	Institutional Shares
Management Fees		0.69%	0.69%
Distribution (12b-1) Fees		none	none
Other Expenses		0.28%	0.05%
Service Fees		0.20%	none
All remaining other expenses		0.08%	0.05%
Total Annual Fund Operating Expenses		0.97%	0.74%
Expense Reimbursement		0.02%	none
Total Annual Fund Operating Expenses After Expense Reimbursement	[1]	0.95%	0.74%

For additional information about the Parnassus Endeavor Fund’s expenses, please see “Financial Highlights” in the prospectus.

Example

This example is intended to help you compare the cost of investing in the Parnassus Endeavor Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s expenses are equal to the net annual fund operating expenses for the first year and the total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, under these assumptions, your costs would be:

Expense Example - Parnassus Endeavor Fund - USD ($)	1 Year	3 Years	5 Years	10 Years
Investor Shares	97	307	534	1,188
Institutional Shares	76	237	411	918

Portfolio Turnover

The Parnassus Endeavor Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 34.1% of the average value of its portfolio.

Principal Investment Strategies

The Parnassus Endeavor Fund normally invests at least 80% of its net assets (plus borrowings for investment purposes) in companies believed by the Fund’s investment adviser (Adviser) to provide good workplaces for their employees. Companies with good workplaces usually are able to recruit and retain better employees, and perform at a higher level than competitors in terms of innovation, productivity, customer loyalty and profitability. While no company is perfect, the Adviser makes a judgment as to which companies have good workplaces based on factors such as respectful and fair treatment of employees, employee satisfaction and engagement, pay and benefits, family-friendly policies, and support for volunteerism and philanthropy. These companies must, in the Adviser’s opinion, be undervalued, but they must also have good prospects for long-term capital appreciation over the course of the expected holding period. The Parnassus Endeavor Fund is primarily a large-cap fund, which means that it normally invests more than half of its net assets in large, well-established companies. The Fund may invest to a lesser extent in small- and mid-capitalization companies. The Fund may purchase foreign securities directly on foreign markets. The Fund invests mainly in domestic stocks of companies that are financially sound and have good prospects for the future, and to a lesser extent may also invest in foreign securities of similar companies. The Fund avoids investing in companies engaged in the extraction, exploration, production, manufacturing or refining of fossil fuels; the Fund may invest in companies that use fossil fuel-based energy to power their operations or for other purposes. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s sustainable strategic advantage and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.

Principal Risks

All investments involve risk, and investing in the Parnassus Endeavor Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following:

• Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in the U.S. and abroad. The Fund’s holdings can vary significantly from broad stock market indices.

• Large-Capitalization Company Risk. Large-capitalization companies may be unable to respond quickly to new competitive challenges and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.

• Small- and Mid-Capitalization Company Risk. In addition to large-capitalization companies, the Fund may invest in small- and/or mid-capitalization companies, which can be particularly sensitive to changing economic conditions since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, small-capitalization companies tend to perform poorly during times of economic stress.

• Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer.

• Foreign Securities Risk. The Fund may invest up to 20% of its assets in foreign securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market.

Performance Information

The bar chart and table that follow contain information that allows you to evaluate the Parnassus Endeavor Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and the performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.

Annual Total Returns

During the ten-year period shown in the bar chart, the highest return for a quarter was 26.7% (quarter ended June 30, 2009), and the lowest return for a quarter was a loss of 24.4% (quarter ended December 31, 2008).

On the following page is a table comparing the performance of the Parnassus Endeavor Fund’s two share classes with that of the S&P 500 Index and the Lipper Multi-Cap Core Average. Figures are average annual returns for the one-, five- and ten- year periods ended December 31, 2016. The table is intended to demonstrate the risk of investing in the Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the S&P 500 Index, and a group of similar mutual funds, the Lipper Multi-Cap Core Average, and also how the Fund’s performance varies from year to year.

Average Annual Total Returns (%)
(all periods ended December 31, 2016)

Average Annual Total Returns - Parnassus Endeavor Fund	One Year	Five Years	Ten Years
Investor Shares	21.42%	18.91%	12.23%
Investor Shares | Return after Taxes on Distributions	20.20%	17.09%	11.10%
Investor Shares | Return after Taxes on Distributions and Sale of Fund Shares	12.60%	15.08%	9.99%
Institutional Shares	21.68%	18.99%	12.27%
S&P 500 Index (reflects no deduction for fees, expenses or taxes)	11.94%	14.63%	6.93%
Lipper Multi-Cap Core Average	10.25%	13.06%	5.94%

The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.

Parnassus Endeavor Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Endeavor Fund—Investor Shares and includes expenses that are not applicable to and are higher than those of the Institutional Shares.

[1] The investment adviser has contractually agreed to reduce its investment advisory fee to the extent necessary to limit total operating expenses to 0.95% of net assets for the Parnassus Endeavor Fund—Investor Shares and to 0.83% of net assets for the Parnassus Endeavor Fund—Institutional Shares. This agreement will not be terminated prior to May 1, 2018, and may be continued indefinitely by the investment adviser on a year-to-year basis.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	PARNASSUS FUNDS
Prospectus Date	rr_ProspectusDate	May 01, 2017
Parnassus Endeavor Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Parnassus Endeavor Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Parnassus Endeavor Fund has the overall investment objective of capital appreciation.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Endeavor Fund.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (%) (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	May 1, 2018
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Parnassus Endeavor Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 34.1% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	34.10%
Expense Footnotes [Text Block]	rr_ExpenseFootnotesTextBlock	For additional information about the Parnassus Endeavor Fund’s expenses, please see “Financial Highlights” in the prospectus.
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Parnassus Endeavor Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s expenses are equal to the net annual fund operating expenses for the first year and the total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, under these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Parnassus Endeavor Fund normally invests at least 80% of its net assets (plus borrowings for investment purposes) in companies believed by the Fund’s investment adviser (Adviser) to provide good workplaces for their employees. Companies with good workplaces usually are able to recruit and retain better employees, and perform at a higher level than competitors in terms of innovation, productivity, customer loyalty and profitability. While no company is perfect, the Adviser makes a judgment as to which companies have good workplaces based on factors such as respectful and fair treatment of employees, employee satisfaction and engagement, pay and benefits, family-friendly policies, and support for volunteerism and philanthropy. These companies must, in the Adviser’s opinion, be undervalued, but they must also have good prospects for long-term capital appreciation over the course of the expected holding period. The Parnassus Endeavor Fund is primarily a large-cap fund, which means that it normally invests more than half of its net assets in large, well-established companies. The Fund may invest to a lesser extent in small- and mid-capitalization companies. The Fund may purchase foreign securities directly on foreign markets. The Fund invests mainly in domestic stocks of companies that are financially sound and have good prospects for the future, and to a lesser extent may also invest in foreign securities of similar companies. The Fund avoids investing in companies engaged in the extraction, exploration, production, manufacturing or refining of fossil fuels; the Fund may invest in companies that use fossil fuel-based energy to power their operations or for other purposes. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s sustainable strategic advantage and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	All investments involve risk, and investing in the Parnassus Endeavor Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following: Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in the U.S. and abroad. The Fund’s holdings can vary significantly from broad stock market indices. Large-Capitalization Company Risk. Large-capitalization companies may be unable to respond quickly to new competitive challenges and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion. Small- and Mid-Capitalization Company Risk. In addition to large-capitalization companies, the Fund may invest in small- and/or mid-capitalization companies, which can be particularly sensitive to changing economic conditions since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, small-capitalization companies tend to perform poorly during times of economic stress. Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer. Foreign Securities Risk. The Fund may invest up to 20% of its assets in foreign securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market.
Risk Lose Money [Text]	rr_RiskLoseMoney	You could lose money investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Endeavor Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and the performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Endeavor Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	(800) 999-3505
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.parnassus.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the ten-year period shown in the bar chart, the highest return for a quarter was 26.7% (quarter ended June 30, 2009), and the lowest return for a quarter was a loss of 24.4% (quarter ended December 31, 2008).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (%) (all periods ended December 31, 2016)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	On the following page is a table comparing the performance of the Parnassus Endeavor Fund’s two share classes with that of the S&P 500 Index and the Lipper Multi-Cap Core Average. Figures are average annual returns for the one-, five- and ten- year periods ended December 31, 2016. The table is intended to demonstrate the risk of investing in the Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the S&P 500 Index, and a group of similar mutual funds, the Lipper Multi-Cap Core Average, and also how the Fund’s performance varies from year to year.
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary. Parnassus Endeavor Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Endeavor Fund—Investor Shares and includes expenses that are not applicable to and are higher than those of the Institutional Shares.
Parnassus Endeavor Fund | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.69%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	0.20%
All remaining other expenses	rr_Component2OtherExpensesOverAssets	0.08%
Other Expenses	rr_OtherExpensesOverAssets	0.28%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.97%
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.02%
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	0.95%	[1]
1 Year	rr_ExpenseExampleYear01	$ 97
3 Years	rr_ExpenseExampleYear03	307
5 Years	rr_ExpenseExampleYear05	534
10 Years	rr_ExpenseExampleYear10	$ 1,188
2007	rr_AnnualReturn2007	5.64%
2008	rr_AnnualReturn2008	(29.94%)
2009	rr_AnnualReturn2009	62.13%
2010	rr_AnnualReturn2010	12.96%
2011	rr_AnnualReturn2011	(1.62%)
2012	rr_AnnualReturn2012	22.03%
2013	rr_AnnualReturn2013	31.15%
2014	rr_AnnualReturn2014	18.51%
2015	rr_AnnualReturn2015	3.25%
2016	rr_AnnualReturn2016	21.42%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	26.70%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(24.40%)
One Year	rr_AverageAnnualReturnYear01	21.42%
Five Years	rr_AverageAnnualReturnYear05	18.91%
Ten Years	rr_AverageAnnualReturnYear10	12.23%
Parnassus Endeavor Fund | Institutional Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.69%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	none
All remaining other expenses	rr_Component2OtherExpensesOverAssets	0.05%
Other Expenses	rr_OtherExpensesOverAssets	0.05%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.74%
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	0.74%	[1]
1 Year	rr_ExpenseExampleYear01	$ 76
3 Years	rr_ExpenseExampleYear03	237
5 Years	rr_ExpenseExampleYear05	411
10 Years	rr_ExpenseExampleYear10	$ 918
One Year	rr_AverageAnnualReturnYear01	21.68%
Five Years	rr_AverageAnnualReturnYear05	18.99%
Ten Years	rr_AverageAnnualReturnYear10	12.27%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 30, 2015
Parnassus Endeavor Fund | Return after Taxes on Distributions | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	20.20%
Five Years	rr_AverageAnnualReturnYear05	17.09%
Ten Years	rr_AverageAnnualReturnYear10	11.10%
Parnassus Endeavor Fund | Return after Taxes on Distributions and Sale of Fund Shares | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	12.60%
Five Years	rr_AverageAnnualReturnYear05	15.08%
Ten Years	rr_AverageAnnualReturnYear10	9.99%
Parnassus Endeavor Fund | S&P 500 Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	11.94%
Five Years	rr_AverageAnnualReturnYear05	14.63%
Ten Years	rr_AverageAnnualReturnYear10	6.93%
Parnassus Endeavor Fund | Lipper Multi-Cap Core Average
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	10.25%
Five Years	rr_AverageAnnualReturnYear05	13.06%
Ten Years	rr_AverageAnnualReturnYear10	5.94%

[1] The investment adviser has contractually agreed to reduce its investment advisory fee to the extent necessary to limit total operating expenses to 0.95% of net assets for the Parnassus Endeavor Fund—Investor Shares and to 0.83% of net assets for the Parnassus Endeavor Fund—Institutional Shares. This agreement will not be terminated prior to May 1, 2018, and may be continued indefinitely by the investment adviser on a year-to-year basis.

XML

Parnassus Mid Cap Fund

Parnassus Mid Cap Fund

Investment Objective

The Parnassus Mid Cap Fund has the overall investment objective of capital appreciation.

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Mid Cap Fund.

Annual Fund Operating Expenses (%)
(expenses that you pay each year as a percentage
of the value of your investment)

Annual Fund Operating Expenses - Parnassus Mid Cap Fund		Investor Shares	Institutional Shares
Management Fees		0.74%	0.74%
Distribution (12b-1) Fees		none	none
Other Expenses		0.27%	0.06%
Service Fees		0.19%	none
All remaining other expenses		0.08%	0.06%
Total Annual Fund Operating Expenses		1.01%	0.80%
Expense Reimbursement		0.02%	none
Total Annual Fund Operating Expenses After Expense Reimbursement	[1]	0.99%	0.80%

For additional information about the Parnassus Mid Cap Fund’s expenses, please see “Financial Highlights” in the prospectus.

Example

This example is intended to help you compare the cost of investing in the Parnassus Mid Cap Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s expenses are equal to the net annual fund operating expenses for the first year and the total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, under these assumptions, your costs would be:

Expense Example - Parnassus Mid Cap Fund - USD ($)	1 Year	3 Years	5 Years	10 Years
Investor Shares	101	320	556	1,235
Institutional Shares	82	255	444	989

Portfolio Turnover

The Parnassus Mid Cap Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 18.8% of the average value of its portfolio.

Principal Investment Strategies

The Parnassus Mid Cap Fund normally invests at least 80% of its net assets in mid-sized companies. The Fund considers a mid-sized company to be one that has a market capitalization between that of the smallest and largest constituents of the Russell Midcap Index (which was between $2.9 billion and $24.5 billion as of May 27, 2016) measured at the time of purchase. The Russell Midcap Index includes approximately 800 of the smallest companies in the Russell 1000 Index. The Fund will not automatically sell or cease to purchase stock of a company it already owns just because the company’s market capitalization grows or falls outside the ranges of the Russell Midcap Index, which are subject to change. The Fund may normally invest up to 20% of its net assets in smaller- and larger-capitalization companies. The Fund invests mainly in domestic stocks of companies that are financially sound and have good prospects for the future, and may invest up to 20% of its assets in foreign securities of similar companies. The Fund may purchase foreign securities directly on foreign markets. Using a value-oriented investment process, the Fund seeks to invest in equity securities that have the potential for long-term capital appreciation. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s sustainable strategic advantage and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.

Principal Risks

All investments involve risk, and investing in the Parnassus Mid Cap Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following:

• Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in the U.S. and abroad. The Fund’s holdings can vary significantly from broad stock market indices.

• Small- and Mid-Capitalization Company Risk. The Fund invests primarily in mid-capitalization companies and may also invest in small-capitalization companies, both of which can be particularly sensitive to changing economic conditions since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, smaller capitalization companies tend to perform poorly during times of economic stress.

• Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer.

• Foreign Securities Risk. The Fund may invest up to 20% of its assets in foreign securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market.

Performance Information

The bar chart and table that follow contain information that allows you to evaluate the Parnassus Mid Cap Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and the performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.

Annual Total Returns

During the ten-year period shown in the bar chart, the highest return for a quarter was 18.3% (quarter ended June 30, 2009), and the lowest return for a quarter was a loss of 22.0% (quarter ended December 31, 2008).

On the following page is a table comparing the performance of the Parnassus Mid Cap Fund’s two share classes with that of the Russell Midcap Index and the Lipper Mid-Cap Core Average. Figures are average annual returns for one-, five- and ten-year periods ended December 31, 2016. The table is intended to demonstrate the risk of investing in the Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the Russell Midcap Index, and a group of similar mutual funds, the Lipper Mid-Cap Core Average, and also how the Fund’s performance varies from year to year.

Average Annual Total Returns (%)
(all periods ended December 31, 2016)

Average Annual Total Returns - Parnassus Mid Cap Fund	One Year	Five Years	Ten Years
Investor Shares	16.07%	14.25%	8.87%
Investor Shares | Return after Taxes on Distributions	15.20%	13.34%	8.15%
Investor Shares | Return after Taxes on Distributions and Sale of Fund Shares	9.60%	11.37%	7.17%
Institutional Shares	16.28%	14.34%	8.91%
Russell Midcap Index (reflects no deduction for fees, expenses or taxes)	13.80%	14.72%	7.86%
Lipper Mid-Cap Core Average	15.46%	13.40%	6.98%

The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.

Parnassus Mid Cap Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Mid Cap Fund—Investor Shares and includes expenses that are not applicable to and are higher than those of the Institutional Shares.

[1] The investment adviser has contractually agreed to reduce its investment advisory fee to the extent necessary to limit total operating expenses to 0.99% of net assets for the Parnassus Mid Cap Fund—Investor Shares and to 0.85% of net assets for the Parnassus Mid Cap Fund—Institutional Shares. This agreement will not be terminated prior to May 1, 2018, and may be continued indefinitely by the investment adviser on a year-to-year basis.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	PARNASSUS FUNDS
Prospectus Date	rr_ProspectusDate	May 01, 2017
Parnassus Mid Cap Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Parnassus Mid Cap Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Parnassus Mid Cap Fund has the overall investment objective of capital appreciation.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Mid Cap Fund.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (%) (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	May 1, 2018
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Parnassus Mid Cap Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 18.8% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	18.80%
Expense Footnotes [Text Block]	rr_ExpenseFootnotesTextBlock	For additional information about the Parnassus Mid Cap Fund’s expenses, please see “Financial Highlights” in the prospectus.
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Parnassus Mid Cap Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s expenses are equal to the net annual fund operating expenses for the first year and the total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, under these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	The Parnassus Mid Cap Fund normally invests at least 80% of its net assets in mid-sized companies. The Fund considers a mid-sized company to be one that has a market capitalization between that of the smallest and largest constituents of the Russell Midcap Index (which was between $2.9 billion and $24.5 billion as of May 27, 2016) measured at the time of purchase. The Russell Midcap Index includes approximately 800 of the smallest companies in the Russell 1000 Index. The Fund will not automatically sell or cease to purchase stock of a company it already owns just because the company’s market capitalization grows or falls outside the ranges of the Russell Midcap Index, which are subject to change. The Fund may normally invest up to 20% of its net assets in smaller- and larger-capitalization companies. The Fund invests mainly in domestic stocks of companies that are financially sound and have good prospects for the future, and may invest up to 20% of its assets in foreign securities of similar companies. The Fund may purchase foreign securities directly on foreign markets. Using a value-oriented investment process, the Fund seeks to invest in equity securities that have the potential for long-term capital appreciation. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s sustainable strategic advantage and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	All investments involve risk, and investing in the Parnassus Mid Cap Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following: Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in the U.S. and abroad. The Fund’s holdings can vary significantly from broad stock market indices. Small- and Mid-Capitalization Company Risk. The Fund invests primarily in mid-capitalization companies and may also invest in small-capitalization companies, both of which can be particularly sensitive to changing economic conditions since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, smaller capitalization companies tend to perform poorly during times of economic stress. Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer. Foreign Securities Risk. The Fund may invest up to 20% of its assets in foreign securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market.
Risk Lose Money [Text]	rr_RiskLoseMoney	You could lose money investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Mid Cap Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and the performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Mid Cap Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	(800) 999-3505
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.parnassus.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the ten-year period shown in the bar chart, the highest return for a quarter was 18.3% (quarter ended June 30, 2009), and the lowest return for a quarter was a loss of 22.0% (quarter ended December 31, 2008).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (%) (all periods ended December 31, 2016)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	On the following page is a table comparing the performance of the Parnassus Mid Cap Fund’s two share classes with that of the Russell Midcap Index and the Lipper Mid-Cap Core Average. Figures are average annual returns for one-, five- and ten-year periods ended December 31, 2016. The table is intended to demonstrate the risk of investing in the Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the Russell Midcap Index, and a group of similar mutual funds, the Lipper Mid-Cap Core Average, and also how the Fund’s performance varies from year to year.
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary. Parnassus Mid Cap Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Mid Cap Fund—Investor Shares and includes expenses that are not applicable to and are higher than those of the Institutional Shares.
Parnassus Mid Cap Fund | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.74%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	0.19%
All remaining other expenses	rr_Component2OtherExpensesOverAssets	0.08%
Other Expenses	rr_OtherExpensesOverAssets	0.27%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.01%
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.02%
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	0.99%	[1]
1 Year	rr_ExpenseExampleYear01	$ 101
3 Years	rr_ExpenseExampleYear03	320
5 Years	rr_ExpenseExampleYear05	556
10 Years	rr_ExpenseExampleYear10	$ 1,235
2007	rr_AnnualReturn2007	1.81%
2008	rr_AnnualReturn2008	(29.38%)
2009	rr_AnnualReturn2009	36.26%
2010	rr_AnnualReturn2010	18.70%
2011	rr_AnnualReturn2011	3.33%
2012	rr_AnnualReturn2012	18.58%
2013	rr_AnnualReturn2013	28.27%
2014	rr_AnnualReturn2014	11.24%
2015	rr_AnnualReturn2015	(0.87%)
2016	rr_AnnualReturn2016	16.07%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Jun. 30, 2009
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	18.30%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Dec. 31, 2008
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(22.00%)
One Year	rr_AverageAnnualReturnYear01	16.07%
Five Years	rr_AverageAnnualReturnYear05	14.25%
Ten Years	rr_AverageAnnualReturnYear10	8.87%
Parnassus Mid Cap Fund | Institutional Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	0.74%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	none
All remaining other expenses	rr_Component2OtherExpensesOverAssets	0.06%
Other Expenses	rr_OtherExpensesOverAssets	0.06%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	0.80%
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	none
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	0.80%	[1]
1 Year	rr_ExpenseExampleYear01	$ 82
3 Years	rr_ExpenseExampleYear03	255
5 Years	rr_ExpenseExampleYear05	444
10 Years	rr_ExpenseExampleYear10	$ 989
One Year	rr_AverageAnnualReturnYear01	16.28%
Five Years	rr_AverageAnnualReturnYear05	14.34%
Ten Years	rr_AverageAnnualReturnYear10	8.91%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 30, 2015
Parnassus Mid Cap Fund | Return after Taxes on Distributions | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	15.20%
Five Years	rr_AverageAnnualReturnYear05	13.34%
Ten Years	rr_AverageAnnualReturnYear10	8.15%
Parnassus Mid Cap Fund | Return after Taxes on Distributions and Sale of Fund Shares | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	9.60%
Five Years	rr_AverageAnnualReturnYear05	11.37%
Ten Years	rr_AverageAnnualReturnYear10	7.17%
Parnassus Mid Cap Fund | Russell Midcap Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.80%
Five Years	rr_AverageAnnualReturnYear05	14.72%
Ten Years	rr_AverageAnnualReturnYear10	7.86%
Parnassus Mid Cap Fund | Lipper Mid-Cap Core Average
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	15.46%
Five Years	rr_AverageAnnualReturnYear05	13.40%
Ten Years	rr_AverageAnnualReturnYear10	6.98%

[1] The investment adviser has contractually agreed to reduce its investment advisory fee to the extent necessary to limit total operating expenses to 0.99% of net assets for the Parnassus Mid Cap Fund—Investor Shares and to 0.85% of net assets for the Parnassus Mid Cap Fund—Institutional Shares. This agreement will not be terminated prior to May 1, 2018, and may be continued indefinitely by the investment adviser on a year-to-year basis.

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Parnassus Asia Fund

Parnassus Asia Fund

Investment Objective

The Parnassus Asia Fund has the overall investment objective of capital appreciation.

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Asia Fund.

Annual Fund Operating Expenses (%)
(expenses that you pay each year as a percentage
of the value of your investment)

Annual Fund Operating Expenses - Parnassus Asia Fund		Investor Shares	Institutional Shares
Management Fees		1.10%	1.10%
Distribution (12b-1) Fees		none	none
Other Expenses		2.03%	none
Service Fees		0.14%	none
All remaining other expenses		1.89%	none
Total Annual Fund Operating Expenses		3.13%	1.10%
Expense Reimbursement		1.88%	0.14%
Total Annual Fund Operating Expenses After Expense Reimbursement	[1]	1.25%	0.96%

For additional information about the Parnassus Asia Fund’s expenses, please see “Financial Highlights” in the prospectus.

Example

This example is intended to help you compare the cost of investing in the Parnassus Asia Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s expenses are equal to the net annual fund operating expenses for the first year and the total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, under these assumptions, your costs would be:

Expense Example - Parnassus Asia Fund - USD ($)	1 Year	3 Years	5 Years	10 Years
Investor Shares	127	789	1,476	3,308
Institutional Shares	98	336	593	1,328

Portfolio Turnover

The Parnassus Asia Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46.0% of the average value of its portfolio.

Principal Investment Strategies

Under normal market conditions, the Parnassus Asia Fund seeks to achieve its investment objective by investing at least 80% of its net assets (plus borrowings for investment purposes) in equity securities of Asian companies. Asian companies are companies domiciled or headquartered in Asia, companies that have a substantial amount of business in Asia, or companies whose primary trading markets for their securities are located in Asia. Sometimes these companies are traded in the U.S. on a national securities exchange, or through American Depositary Receipts (“ADRs”) or American Depositary Shares (“ADSs”). The Fund invests in common stocks and other equity securities, including ADRs and ADSs. The Fund may purchase securities directly on foreign markets. Asia consists of all countries and markets in Asia, and includes developed, emerging, and frontier countries and markets in the Asian region. Many Asian markets are considered to be emerging markets. The Parnassus Asia Fund is a “multi-cap” fund in that it can invest in companies of any size, from larger, well-established companies to smaller companies with market capitalizations below $1 billion. The Fund invests principally in stocks of Asian companies that the Fund’s investment adviser (Adviser) believes are financially sound and have good prospects for the future. The companies in which the Fund invests must, in the opinion of the Adviser, be undervalued, but they must also have good prospects for long-term capital appreciation over the course of the expected holding period. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s competitive position and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.

Principal Risks

All investments involve risk, and investing in the Parnassus Asia Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following:

• Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in Asia and other parts of the world. The Fund’s holdings can vary significantly from broad stock market indices.

• Foreign Securities Risk. The Fund invests primarily in non-U.S. securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market.

• Emerging Markets Risk. Many Asian countries are considered to be emerging markets. There may be less publicly available information about companies in emerging markets, and the stock exchanges and brokerage industries of emerging markets do not have the same level of government oversight as do those in the U.S. The securities markets of such countries are substantially smaller, less liquid and more volatile than securities markets in the U.S.

• Geographic Concentration Risk. The Fund’s investments are concentrated in a specific geographical region and thus, may be more adversely affected by events in that region than investments of a fund that does not have such a regional focus. For example, economic, political and social instability and foreign investment and exchange controls may disproportionately and adversely impact Asia.

• Foreign Currency Risk. When the Fund conducts securities transactions in a foreign currency, there is the risk of the value of the foreign currency increasing or decreasing against the value of the U.S. dollar. The value of an investment denominated in a foreign currency will decline in dollar terms if that currency weakens against the dollar.

• Large-Capitalization Company Risk. Large-capitalization companies may be unable to respond quickly to new competitive challenges and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion.

• Small- and Mid-Capitalization Company Risk. This is a “multi-cap” fund. In addition to large-capitalization companies, the Fund may invest in small- and/or mid-capitalization companies, which can be particularly sensitive to changing economic conditions, since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, small-capitalization companies tend to perform poorly during times of economic stress.

• Depositary Receipts Risk. Depositary receipts involve many of the same risks as those associated with direct investment in foreign securities. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts or to pass through to them any voting rights with respect to the deposited securities.

• Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer.

Performance Information

The bar chart and table that follow contain information that allows you to evaluate the Parnassus Asia Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.

Annual Total Returns

During the period shown in the bar chart, the highest return for a quarter was 15.1% (quarter ended September 30, 2016), and the lowest return for a quarter was a loss of 18.1% (quarter ended September 30, 2015).

On the following page is a table comparing the performance of the Parnassus Asia Fund’s two share classes with that of the MSCI AC Asia Pacific Index and the Lipper Asia Pacific Region Average. Figures are average annual returns for the one-year period ended December 31, 2016 and since inception (Investor Shares incepted on April 30, 2013 and Institutional Shares incepted on April 30, 2015). The table is intended to demonstrate the risk of investing in the Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the MSCI AC Asia Pacific Index, and a group of similar mutual funds, the Lipper Asia Pacific Region Average, and also how the Fund’s performance varies from year to year.

Average Annual Total Returns (%)
(all periods ended December 31, 2016)

Average Annual Total Returns - Parnassus Asia Fund	One Year	Since Inception
Investor Shares	13.98%	3.44%
Investor Shares | Return after Taxes on Distributions	13.93%	3.36%
Investor Shares | Return after Taxes on Distributions and Sale of Fund Shares	7.89%	2.64%
Institutional Shares	14.21%	3.58%
MSCI AC Asia Pacific Index (reflects no deduction for fees, expenses or taxes)	5.21%	1.37%
Lipper Asia Pacific Region Average	4.28%	0.26%

The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.

Parnassus Asia Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Asia Fund—Investor Shares, which were incepted on April 30, 2013, and includes expenses that are not applicable to and are higher than those of the Institutional Shares.

[1] The investment adviser has contractually agreed to reduce its investment advisory fee to the extent necessary to limit total operating expenses to 1.25% of net assets for the Parnassus Asia Fund—Investor Shares and to 1.22% of net assets for the Parnassus Asia Fund—Institutional Shares. This agreement will not be terminated prior to May 1, 2018, and may be continued indefinitely by the investment adviser on a year-to-year basis.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	PARNASSUS FUNDS
Prospectus Date	rr_ProspectusDate	May 01, 2017
Parnassus Asia Fund
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Parnassus Asia Fund
Objective [Heading]	rr_ObjectiveHeading	Investment Objective
Objective, Primary [Text Block]	rr_ObjectivePrimaryTextBlock	The Parnassus Asia Fund has the overall investment objective of capital appreciation.
Expense [Heading]	rr_ExpenseHeading	Fees and Expenses
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	This table describes the fees and expenses that you may pay if you buy and hold shares of the Parnassus Asia Fund.
Operating Expenses Caption [Text]	rr_OperatingExpensesCaption	Annual Fund Operating Expenses (%) (expenses that you pay each year as a percentage of the value of your investment)
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	May 1, 2018
Portfolio Turnover [Heading]	rr_PortfolioTurnoverHeading	Portfolio Turnover
Portfolio Turnover [Text Block]	rr_PortfolioTurnoverTextBlock	The Parnassus Asia Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 46.0% of the average value of its portfolio.
Portfolio Turnover, Rate	rr_PortfolioTurnoverRate	46.00%
Expense Footnotes [Text Block]	rr_ExpenseFootnotesTextBlock	For additional information about the Parnassus Asia Fund’s expenses, please see “Financial Highlights” in the prospectus.
Expense Example [Heading]	rr_ExpenseExampleHeading	Example
Expense Example Narrative [Text Block]	rr_ExpenseExampleNarrativeTextBlock	This example is intended to help you compare the cost of investing in the Parnassus Asia Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year, and that the Fund’s expenses are equal to the net annual fund operating expenses for the first year and the total annual fund operating expenses for the remaining years. Although your actual costs may be higher or lower, under these assumptions, your costs would be:
Strategy [Heading]	rr_StrategyHeading	Principal Investment Strategies
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Under normal market conditions, the Parnassus Asia Fund seeks to achieve its investment objective by investing at least 80% of its net assets (plus borrowings for investment purposes) in equity securities of Asian companies. Asian companies are companies domiciled or headquartered in Asia, companies that have a substantial amount of business in Asia, or companies whose primary trading markets for their securities are located in Asia. Sometimes these companies are traded in the U.S. on a national securities exchange, or through American Depositary Receipts (“ADRs”) or American Depositary Shares (“ADSs”). The Fund invests in common stocks and other equity securities, including ADRs and ADSs. The Fund may purchase securities directly on foreign markets. Asia consists of all countries and markets in Asia, and includes developed, emerging, and frontier countries and markets in the Asian region. Many Asian markets are considered to be emerging markets. The Parnassus Asia Fund is a “multi-cap” fund in that it can invest in companies of any size, from larger, well-established companies to smaller companies with market capitalizations below $1 billion. The Fund invests principally in stocks of Asian companies that the Fund’s investment adviser (Adviser) believes are financially sound and have good prospects for the future. The companies in which the Fund invests must, in the opinion of the Adviser, be undervalued, but they must also have good prospects for long-term capital appreciation over the course of the expected holding period. To determine a company’s prospects, the Adviser reviews the company’s income statement, cash flow statement and balance sheet, and analyzes the company’s competitive position and management team. Upon initial investment, a company’s stock must be trading below its intrinsic value, which means that the Adviser seeks to purchase stock trading at a discount to the Adviser’s assessment of the company’s estimated value. The Adviser also takes environmental, social and governance (“ESG”) factors into account in making investment decisions. The Fund will sell a security if the Adviser believes a company’s fundamentals will deteriorate, if it believes a company’s stock has little potential for appreciation or if the company no longer meets the Adviser’s ESG criteria.
Risk [Heading]	rr_RiskHeading	Principal Risks
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	All investments involve risk, and investing in the Parnassus Asia Fund is no exception. You could lose money investing in the Fund. The likelihood of loss may be greater if you invest for a shorter period of time. The Fund is intended for investors who can accept that there will be fluctuations in value. Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s principal risks include the following: Stock Market Risk. The Fund invests in common stocks, whose prices fluctuate in response to the fortunes of individual companies and in response to general market and economic conditions both in Asia and other parts of the world. The Fund’s holdings can vary significantly from broad stock market indices. Foreign Securities Risk. The Fund invests primarily in non-U.S. securities. Foreign markets can be more volatile than the U.S. market due to increased risks of adverse issuer, political, regulatory, market or economic developments and can perform differently from the U.S. market. Emerging Markets Risk. Many Asian countries are considered to be emerging markets. There may be less publicly available information about companies in emerging markets, and the stock exchanges and brokerage industries of emerging markets do not have the same level of government oversight as do those in the U.S. The securities markets of such countries are substantially smaller, less liquid and more volatile than securities markets in the U.S. Geographic Concentration Risk. The Fund’s investments are concentrated in a specific geographical region and thus, may be more adversely affected by events in that region than investments of a fund that does not have such a regional focus. For example, economic, political and social instability and foreign investment and exchange controls may disproportionately and adversely impact Asia. Foreign Currency Risk. When the Fund conducts securities transactions in a foreign currency, there is the risk of the value of the foreign currency increasing or decreasing against the value of the U.S. dollar. The value of an investment denominated in a foreign currency will decline in dollar terms if that currency weakens against the dollar. Large-Capitalization Company Risk. Large-capitalization companies may be unable to respond quickly to new competitive challenges and also may not be able to attain the high growth rate of successful smaller companies, especially during extended periods of economic expansion. Small- and Mid-Capitalization Company Risk. This is a “multi-cap” fund. In addition to large-capitalization companies, the Fund may invest in small- and/or mid-capitalization companies, which can be particularly sensitive to changing economic conditions, since they do not have the financial resources or the well-established businesses of large-capitalization companies. Relative to the stocks of large-capitalization companies, the stocks of small- and mid-capitalization companies are often thinly traded, and purchases and sales may result in higher transaction costs. Also, small-capitalization companies tend to perform poorly during times of economic stress. Depositary Receipts Risk. Depositary receipts involve many of the same risks as those associated with direct investment in foreign securities. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts or to pass through to them any voting rights with respect to the deposited securities. Management Risk. The Adviser may be wrong in its assessment of a company’s value and/or the stocks the Fund holds may not reach what the Adviser believes are their full values. From time to time, “value” investing falls out of favor with investors, and during those periods the Fund’s relative performance may suffer.
Risk Lose Money [Text]	rr_RiskLoseMoney	You could lose money investing in the Fund.
Risk Not Insured Depository Institution [Text]	rr_RiskNotInsuredDepositoryInstitution	Investments in the Fund are not deposits, endorsements or guarantees of any bank and are not insured by the Federal Deposit Insurance Corporation or any other government agency.
Bar Chart and Performance Table [Heading]	rr_BarChartAndPerformanceTableHeading	Performance Information
Performance Narrative [Text Block]	rr_PerformanceNarrativeTextBlock	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Asia Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance. The bar chart shows the performance of the Fund’s Investor Shares, and performance of the Fund’s Institutional Shares will differ from those shown to the extent that the classes of shares do not have the same expenses or inception date. How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future. Updated performance information is available on the Fund’s website, www.parnassus.com, or by calling toll-free at (800) 999-3505.
Performance Information Illustrates Variability of Returns [Text]	rr_PerformanceInformationIllustratesVariabilityOfReturns	The bar chart and table that follow contain information that allows you to evaluate the Parnassus Asia Fund’s performance using several measures, such as yearly changes in performance, best and worst quarterly returns, and average annual total returns before and after taxes compared to a broad measure of market performance.
Performance Availability Phone [Text]	rr_PerformanceAvailabilityPhone	(800) 999-3505
Performance Availability Website Address [Text]	rr_PerformanceAvailabilityWebSiteAddress	www.parnassus.com
Performance Past Does Not Indicate Future [Text]	rr_PerformancePastDoesNotIndicateFuture	How the Fund performed in the past (before and after taxes) is not necessarily an indication of how it will perform in the future.
Bar Chart [Heading]	rr_BarChartHeading	Annual Total Returns
Bar Chart Closing [Text Block]	rr_BarChartClosingTextBlock	During the period shown in the bar chart, the highest return for a quarter was 15.1% (quarter ended September 30, 2016), and the lowest return for a quarter was a loss of 18.1% (quarter ended September 30, 2015).
Performance Table Heading	rr_PerformanceTableHeading	Average Annual Total Returns (%) (all periods ended December 31, 2016)
Performance Table Uses Highest Federal Rate	rr_PerformanceTableUsesHighestFederalRate	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes.
Performance Table Not Relevant to Tax Deferred	rr_PerformanceTableNotRelevantToTaxDeferred	After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts.
Performance Table One Class of after Tax Shown [Text]	rr_PerformanceTableOneClassOfAfterTaxShown	After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary.
Performance Table Explanation after Tax Higher	rr_PerformanceTableExplanationAfterTaxHigher	Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares.
Performance Table Narrative	rr_PerformanceTableNarrativeTextBlock	On the following page is a table comparing the performance of the Parnassus Asia Fund’s two share classes with that of the MSCI AC Asia Pacific Index and the Lipper Asia Pacific Region Average. Figures are average annual returns for the one-year period ended December 31, 2016 and since inception (Investor Shares incepted on April 30, 2013 and Institutional Shares incepted on April 30, 2015). The table is intended to demonstrate the risk of investing in the Fund by showing how the Fund’s average annual total returns, before and after taxes, compare with a broad measure of market performance, the MSCI AC Asia Pacific Index, and a group of similar mutual funds, the Lipper Asia Pacific Region Average, and also how the Fund’s performance varies from year to year.
Performance Table Closing [Text Block]	rr_PerformanceTableClosingTextBlock	The after-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Return After Taxes on Distributions and Sale of Fund Shares may be higher than other returns for the same period due to a tax benefit of realizing a capital loss upon the sale of Fund shares. After-tax returns are shown for Investor Shares only. After-tax returns for Institutional Shares will vary. Parnassus Asia Fund—Institutional Shares were incepted on April 30, 2015. Performance shown prior to the inception of the Institutional Shares reflects the performance of the Parnassus Asia Fund—Investor Shares, which were incepted on April 30, 2013, and includes expenses that are not applicable to and are higher than those of the Institutional Shares.
Parnassus Asia Fund | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	1.10%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	0.14%
All remaining other expenses	rr_Component2OtherExpensesOverAssets	1.89%
Other Expenses	rr_OtherExpensesOverAssets	2.03%
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	3.13%
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	1.88%
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	1.25%	[1]
1 Year	rr_ExpenseExampleYear01	$ 127
3 Years	rr_ExpenseExampleYear03	789
5 Years	rr_ExpenseExampleYear05	1,476
10 Years	rr_ExpenseExampleYear10	$ 3,308
2014	rr_AnnualReturn2014	7.84%
2015	rr_AnnualReturn2015	(11.84%)
2016	rr_AnnualReturn2016	13.98%
Highest Quarterly Return, Label	rr_HighestQuarterlyReturnLabel	highest return
Highest Quarterly Return, Date	rr_BarChartHighestQuarterlyReturnDate	Sep. 30, 2016
Highest Quarterly Return	rr_BarChartHighestQuarterlyReturn	15.10%
Lowest Quarterly Return, Label	rr_LowestQuarterlyReturnLabel	lowest return
Lowest Quarterly Return, Date	rr_BarChartLowestQuarterlyReturnDate	Sep. 30, 2015
Lowest Quarterly Return	rr_BarChartLowestQuarterlyReturn	(18.10%)
One Year	rr_AverageAnnualReturnYear01	13.98%
Since Inception	rr_AverageAnnualReturnSinceInception	3.44%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 30, 2013
Parnassus Asia Fund | Institutional Shares
Risk/Return:	rr_RiskReturnAbstract
Management Fees	rr_ManagementFeesOverAssets	1.10%
Distribution (12b-1) Fees	rr_DistributionAndService12b1FeesOverAssets	none
Service Fees	rr_Component1OtherExpensesOverAssets	none
All remaining other expenses	rr_Component2OtherExpensesOverAssets	none
Other Expenses	rr_OtherExpensesOverAssets	none
Total Annual Fund Operating Expenses	rr_ExpensesOverAssets	1.10%
Expense Reimbursement	rr_FeeWaiverOrReimbursementOverAssets	0.14%
Total Annual Fund Operating Expenses After Expense Reimbursement	rr_NetExpensesOverAssets	0.96%	[1]
1 Year	rr_ExpenseExampleYear01	$ 98
3 Years	rr_ExpenseExampleYear03	336
5 Years	rr_ExpenseExampleYear05	593
10 Years	rr_ExpenseExampleYear10	$ 1,328
One Year	rr_AverageAnnualReturnYear01	14.21%
Since Inception	rr_AverageAnnualReturnSinceInception	3.58%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 30, 2015
Parnassus Asia Fund | Return after Taxes on Distributions | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	13.93%
Since Inception	rr_AverageAnnualReturnSinceInception	3.36%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 30, 2013
Parnassus Asia Fund | Return after Taxes on Distributions and Sale of Fund Shares | Investor Shares
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	7.89%
Since Inception	rr_AverageAnnualReturnSinceInception	2.64%
Inception Date	rr_AverageAnnualReturnInceptionDate	Apr. 30, 2013
Parnassus Asia Fund | MSCI AC Asia Pacific Index (reflects no deduction for fees, expenses or taxes)
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	5.21%
Since Inception	rr_AverageAnnualReturnSinceInception	1.37%
Parnassus Asia Fund | Lipper Asia Pacific Region Average
Risk/Return:	rr_RiskReturnAbstract
One Year	rr_AverageAnnualReturnYear01	4.28%
Since Inception	rr_AverageAnnualReturnSinceInception	0.26%

[1] The investment adviser has contractually agreed to reduce its investment advisory fee to the extent necessary to limit total operating expenses to 1.25% of net assets for the Parnassus Asia Fund—Investor Shares and to 1.22% of net assets for the Parnassus Asia Fund—Institutional Shares. This agreement will not be terminated prior to May 1, 2018, and may be continued indefinitely by the investment adviser on a year-to-year basis.

XML

Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Registrant Name	dei_EntityRegistrantName	PARNASSUS FUNDS
Prospectus Date	rr_ProspectusDate	May 01, 2017
Document Creation Date	dei_DocumentCreationDate	Apr. 28, 2017