XML 37 R3.htm IDEA: XBRL DOCUMENT v3.21.2
Label Element Value
T. Rowe Price New Income Fund, Inc.  
Risk/Return: rr_RiskReturnAbstract  
Risk/Return [Heading] rr_RiskReturnHeading New Income Fund
Objective [Heading] rr_ObjectiveHeading Investment Objective(s)
Objective, Primary [Text Block] rr_ObjectivePrimaryTextBlock

The fund seeks to maximize total return through income and 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, hold, and sell shares of the fund. You may also incur brokerage commissions and other charges when buying or selling shares of the Investor Class or I Class, which are not reflected in the table.
Shareholder Fees Caption [Text] rr_ShareholderFeesCaption Shareholder fees (fees paid directly from your investment)
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 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 the fund’s 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 126.4% of the average value of its portfolio.
Portfolio Turnover, Rate rr_PortfolioTurnoverRate 126.40%
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 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, that your investment has a 5% return each year, and that the fund’s operating expenses remain the same. The example also assumes that any current expense limitation arrangement remains in place for the period noted in the previous table; therefore, the figures have been adjusted to reflect fee waivers or expense reimbursements only in the periods for which the expense limitation arrangement is expected to continue. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Strategy [Heading] rr_StrategyHeading Principal Investment Strategies
Strategy Narrative [Text Block] rr_StrategyNarrativeTextBlock

The fund will invest at least 80% of its net assets in income-producing securities, which may include, but are not limited to, U.S. government and agency obligations, mortgage- and asset-backed securities (including commercial mortgage-backed securities), corporate bonds, foreign bonds, and Treasury Inflation Protected Securities. For purposes of this 80% policy, the fund includes derivative instruments that are linked to, or provide investment exposure to, income-producing securities.

Active management of the portfolio can result in securities being sold at gains or losses. However, over the long term, the fund seeks to achieve its objective by investing primarily in income-producing securities that possess what the fund believes are favorable total return (income plus increases in principal value) characteristics.

Eighty percent (80%) of the debt securities purchased by the fund will be rated investment grade (i.e., rated in one of the four highest rating categories) by each of the major credit rating agencies (S&P Global Ratings, Moody’s, and Fitch) that have assigned a rating to the security or, if unrated, deemed by T. Rowe Price to be of investment-grade quality. Up to 15% of the fund’s net assets may be invested in “split-rated securities,” which are securities that have been rated investment grade by at least one rating agency but below investment grade by another rating agency. The fund may invest up to 20% of its net assets in non-U.S. dollar-denominated foreign debt securities (including securities of issuers in emerging markets) and take currency positions to hedge this exposure as well as to capture appreciation from favorable currency changes. In addition, the fund may maintain a net exposure of up to 5% of its net assets in instruments (through direct holdings and derivatives) that have received below investment-grade ratings from each of the rating agencies that have assigned ratings to the instruments or, if unrated, deemed by T. Rowe Price to be below investment-grade quality (including high yield or “junk” bonds).

The fund has considerable flexibility in seeking high income. There are no maturity restrictions so the fund can purchase long-term bonds, which tend to have higher yields than shorter-term bonds. In addition, when there is a large yield difference between the various quality levels, the fund may move down the credit scale and purchase lower-rated bonds with higher yields. When the difference is small or the outlook warrants, the fund may concentrate investments in higher-rated issues.

The fund may purchase or sell mortgage-backed securities on a delayed delivery or forward commitment basis through the “to-be-announced” (TBA) market. With TBA transactions, the particular securities to be delivered are not identified at the trade date, but the delivered securities must meet specified terms and standards. The fund will generally enter into TBA transactions with the intention of taking possession of the underlying mortgage-backed securities. However, in an effort to obtain underlying mortgage-backed securities on more preferable terms or to enhance returns, the fund may extend the settlement by entering into “dollar roll” transactions in which the fund sells mortgage-backed securities and simultaneously agrees to purchase substantially similar securities on a future date. The fund also expects to engage in short sales of TBA mortgages, including short sales on TBA mortgages the fund does not own, to potentially enhance returns or manage risk.

While most assets will typically be invested in bonds, the fund also uses interest rate futures, credit default swaps and forward currency exchange contracts. Interest rate futures would typically be used to manage the fund’s exposure to interest rate changes or to adjust portfolio duration. Credit default swaps are used to protect the value of certain portfolio holdings or to manage the fund’s overall exposure to changes in credit quality. Forward currency exchange contracts would be used to gain exposure to certain currencies expected to increase or decrease

in value relative to other currencies or to protect the fund’s foreign bond holdings from adverse currency movements relative to the U.S. dollar.
Risk [Heading] rr_RiskHeading Principal Risks
Risk Narrative [Text Block] rr_RiskNarrativeTextBlock

As with any fund, there is no guarantee that the fund will achieve its objective(s). The fund’s share price fluctuates, which means you could lose money by investing in the fund. The principal risks of investing in this fund, which may be even greater during periods of market disruption or volatility, are summarized as follows:

Fixed income markets Economic and other market developments can adversely affect the fixed income securities markets. At times, participants in these markets may develop concerns about the ability of certain issuers of debt instruments to make timely principal and interest payments, or they may develop concerns about the ability of financial institutions that make markets in certain debt instruments to facilitate an orderly market. Those concerns could cause increased volatility and reduced liquidity in particular securities or in the overall fixed income markets and the related derivatives markets. A lack of liquidity or other adverse credit market conditions may hamper the fund’s ability to sell the debt instruments in which it invests or to find and purchase suitable debt instruments.

Market conditions The value of the fund’s investments may decrease, sometimes rapidly or unexpectedly, due to factors affecting an issuer held by the fund, particular industries, or the overall securities markets. A variety of factors can increase the volatility of the fund’s holdings and markets generally, including political or regulatory developments, recessions, inflation, rapid interest rate changes, war or acts of terrorism, natural disasters, and outbreaks of infectious illnesses or other widespread public health issues such as the coronavirus pandemic and related governmental and public responses. Certain events may cause instability across global markets, including reduced liquidity and disruptions in trading markets, while some events may affect certain geographic regions, countries, sectors, and industries more significantly than others. Government intervention in markets may impact interest rates, market volatility, and security pricing. These adverse developments may cause broad declines in market value due to short-term market movements or for significantly longer periods during more prolonged market downturns.

Interest rates The prices of, and the income generated by, debt instruments held by the fund may be affected by changes in interest rates. A rise in interest rates typically causes the price of a fixed rate debt instrument to fall and its yield to rise. Conversely, a decline in interest rates typically causes the price of a fixed rate debt instrument to rise and the yield to fall. Generally, funds with longer weighted average maturities and durations carry greater interest rate risk. Changes in monetary policy made by central banks and/or governments, such as the discontinuation and replacement of benchmark rates, are likely to affect the level of interest rates.

Prepayments and extensions The fund is subject to prepayment risks because the principal on mortgage-backed securities, other asset-backed securities, or any debt instrument with an embedded call option may be prepaid at any time, which could reduce the security’s yield and

market value. The rate of prepayments tends to increase as interest rates fall, which could cause the average maturity of the portfolio to shorten. Extension risk may result from a rise in interest rates, which tends to make mortgage-backed securities, asset-backed securities, and other callable debt instruments more volatile.

LIBOR transition Many financial instruments use or may use a floating rate based on the London Interbank Offered Rate, or “LIBOR,” which is the offered rate for short-term Eurodollar deposits between major international banks. There remains uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate. The elimination of LIBOR or changes to other reference rates or any other changes or reforms to the determination or supervision of reference rates could have an adverse impact on the market for, or value of, any securities or payments linked to those reference rates, which may adversely affect the fund’s performance and/or net asset value.

TBAs and dollar rolls Although the securities that are delivered in TBA transactions must meet certain standards, there is a risk that the actual securities received by the fund may be less favorable than what was anticipated when entering into the transaction. TBA transactions are collateralized but they still involve the risk that a counterparty will fail to deliver the security, exposing the fund to potential losses. Whether or not the fund takes delivery of the securities at the termination date of a TBA transaction, it will nonetheless be exposed to changes in the value of the underlying investments during the term of the agreement. Forward settling securities, such as TBAs, involve leverage which may magnify investment risks and can cause losses to be realized more quickly. In addition, the fund’s portfolio turnover rate and transaction costs are increased when the fund enters into dollar roll transactions.

Derivatives The use of interest rate futures, forward currency exchange contracts, and credit default swaps potentially exposes the fund to additional volatility in comparison to investing directly in bonds and other debt instruments. These instruments can be illiquid and difficult to value, may involve leverage so that small changes produce disproportionate losses for the fund and, if not traded on an exchange, are subject to the risk that a counterparty to the transaction will fail to meet its obligations under the derivatives contract. The fund’s principal use of derivatives involves the risk that anticipated interest rate movements, the creditworthiness of an issuer, or expected changes in currency values and currency exchange rates will not be accurately predicted, which could significantly harm the fund’s performance and impair the fund’s efforts to reduce its overall volatility. Changes in regulations could significantly impact the fund’s ability to invest in specific types of derivatives, which could limit the fund’s ability to employ certain strategies that use derivatives.

Foreign investing Investments in the securities of non-U.S. issuers may be adversely affected by local, political, social, and economic conditions overseas; greater volatility; reduced liquidity; or decreases in foreign currency values relative to the U.S. dollar. The risks of investing outside the U.S. are heightened for any investments in emerging markets, which are susceptible to greater volatility than investments in developed markets.

Credit quality An issuer of a debt instrument could suffer an adverse change in financial condition that results in a payment default (failure to make scheduled interest or principal

payments), rating downgrade, or inability to meet a financial obligation. Securities that are rated below investment grade carry greater risk of default and should be considered speculative.

Liquidity The fund may not be able to meet requests to redeem shares issued by the fund without significant dilution of the remaining shareholders’ interests in the fund. In addition, the fund may not be able to sell a holding in a timely manner at a desired price. Reduced liquidity in the bond markets can result from a number of events, such as limited trading activity, reductions in bond inventory, and rapid or unexpected changes in interest rates. Markets with lower overall liquidity could lead to greater price volatility and limit the fund’s ability to sell a holding at a suitable price.

Active management The fund’s overall investment program and holdings selected by the fund’s investment adviser may underperform the broad markets, relevant indices, or other funds with similar objectives and investment strategies.

Portfolio turnover High portfolio turnover may adversely affect the fund’s performance and increase transaction costs, which could increase the fund’s expenses. High portfolio turnover may also result in the distribution of higher capital gains when compared with a fund with less active trading policies, which could have an adverse tax impact if the fund’s shares are held in a taxable account.

Cybersecurity breaches The fund could be harmed by intentional cyberattacks and other cybersecurity breaches, including unauthorized access to the fund’s assets, customer data and confidential shareholder information, or other proprietary information. In addition, a cybersecurity breach could cause one of the fund’s service providers or financial intermediaries to suffer unauthorized data access, data corruption, or loss of operational functionality.
Risk Lose Money [Text] rr_RiskLoseMoney The fund’s share price fluctuates, which means you could lose money by investing in the fund.
Bar Chart and Performance Table [Heading] rr_BarChartAndPerformanceTableHeading Performance
Performance Narrative [Text Block] rr_PerformanceNarrativeTextBlock

The following performance information provides some indication of the risks of investing in the fund. The fund’s performance information represents only past performance (before and after taxes) and is not necessarily an indication of future results.

The following bar chart illustrates how much returns can differ from year to year by showing calendar year returns and the best and worst calendar quarter returns during those years for the fund’s Investor Class. Returns for other share classes vary since they have different expenses.
Performance Information Illustrates Variability of Returns [Text] rr_PerformanceInformationIllustratesVariabilityOfReturns The following performance information provides some indication of the risks of investing in the fund. The following bar chart illustrates how much returns can differ from year to year by showing calendar year returns and the best and worst calendar quarter returns during those years for the fund’s Investor Class. Returns for other share classes vary since they have different expenses. The following table shows the average annual total returns for each class of the fund that has been in operation for at least one full calendar year, and also compares the returns with the returns of a relevant broad-based market index, as well as with the returns of one or more comparative indexes that have investment characteristics similar to those of the fund, if applicable.
Performance Availability Website Address [Text] rr_PerformanceAvailabilityWebSiteAddress troweprice.com
Performance Past Does Not Indicate Future [Text] rr_PerformancePastDoesNotIndicateFuture The fund’s performance information represents only past performance (before and after taxes) and is not necessarily an indication of future results.
Bar Chart [Heading] rr_BarChartHeading Calendar Year Returns
Bar Chart Footnotes [Text Block] rr_BarChartFootnotesTextBlock

The fund’s return for the six months ended 6/30/21 was -0.79%.
Bar Chart Closing [Text Block] rr_BarChartClosingTextBlock
         
  

Quarter Ended

Total Return

  

Quarter Ended

Total Return

 
 

Best Quarter

6/30/20

5.70%

 

Worst Quarter

12/31/16

-3.09%

 
Performance Table Heading rr_PerformanceTableHeading Average Annual Total Returns Periods ended December 31, 2020
Performance Table Uses Highest Federal Rate rr_PerformanceTableUsesHighestFederalRate 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 Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as a 401(k) account or an IRA.
Performance Table One Class of after Tax Shown [Text] rr_PerformanceTableOneClassOfAfterTaxShown After-tax returns are shown only for the Investor Class and will differ for other share classes.
Performance Table Narrative rr_PerformanceTableNarrativeTextBlock

The following table shows the average annual total returns for each class of the fund that has been in operation for at least one full calendar year, and also compares the returns with the returns of a relevant broad-based market index, as well as with the returns of one or more comparative indexes that have investment characteristics similar to those of the fund, if applicable.

In addition, the table shows hypothetical after-tax returns to demonstrate how taxes paid by a shareholder may influence returns. 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 shown are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as a 401(k) account or an IRA. After-tax returns are shown only for the Investor Class and will differ for other share classes.
Performance Table Closing [Text Block] rr_PerformanceTableClosingTextBlock

Updated performance information is available through troweprice.com.
T. Rowe Price New Income Fund, Inc. | Bloomberg U.S. Aggregate Bond Index  
Risk/Return: rr_RiskReturnAbstract  
Index No Deduction for Fees, Expenses, Taxes [Text] rr_IndexNoDeductionForFeesExpensesTaxes reflects no deduction for fees, expenses, or taxes
Label rr_AverageAnnualReturnLabel Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)
T. Rowe Price New Income Fund, Inc. | Bloomberg U.S. Aggregate Bond Index  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 7.51%
5 Years rr_AverageAnnualReturnYear05 4.44%
10 Years rr_AverageAnnualReturnYear10 3.84%
Since Inception rr_AverageAnnualReturnSinceInception 4.15% [1]
T. Rowe Price New Income Fund, Inc. | Lipper Core Bond Funds Average  
Risk/Return: rr_RiskReturnAbstract  
Label rr_AverageAnnualReturnLabel Lipper Core Bond Funds Average
T. Rowe Price New Income Fund, Inc. | Lipper Core Bond Funds Average  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 8.24%
5 Years rr_AverageAnnualReturnYear05 4.59%
10 Years rr_AverageAnnualReturnYear10 3.90%
Since Inception rr_AverageAnnualReturnSinceInception 4.24% [2]
T. Rowe Price New Income Fund, Inc. | Investor Class  
Risk/Return: rr_RiskReturnAbstract  
Maximum account fee rr_MaximumAccountFee $ 20 [3]
Management fees rr_ManagementFeesOverAssets 0.31% [4],[5]
Distribution and service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.10%
Total annual fund operating expenses rr_ExpensesOverAssets 0.41% [4]
Fee waiver/expense reimbursement rr_FeeWaiverOrReimbursementOverAssets none
Total annual fund operating expenses after fee waiver/expense reimbursement rr_NetExpensesOverAssets 0.41% [4],[5]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination September 30, 2022
Expenses Restated to Reflect Current [Text] rr_ExpensesRestatedToReflectCurrent Restated to reflect current fees.
1 Year rr_ExpenseExampleYear01 $ 42
3 Years rr_ExpenseExampleYear03 132
5 Years rr_ExpenseExampleYear05 230
10 Years rr_ExpenseExampleYear10 $ 518
Annual Return 2011 rr_AnnualReturn2011 6.25%
Annual Return 2012 rr_AnnualReturn2012 5.86%
Annual Return 2013 rr_AnnualReturn2013 (2.26%)
Annual Return 2014 rr_AnnualReturn2014 5.74%
Annual Return 2015 rr_AnnualReturn2015 0.18%
Annual Return 2016 rr_AnnualReturn2016 2.64%
Annual Return 2017 rr_AnnualReturn2017 4.01%
Annual Return 2018 rr_AnnualReturn2018 (0.63%)
Annual Return 2019 rr_AnnualReturn2019 9.26%
Annual Return 2020 rr_AnnualReturn2020 5.74%
Year to Date Return, Label rr_YearToDateReturnLabel The fund’s return for the six months ended
Bar Chart, Year to Date Return, Date rr_BarChartYearToDateReturnDate Jun. 30, 2021
Bar Chart, Year to Date Return rr_BarChartYearToDateReturn (0.79%)
Label rr_HighestQuarterlyReturnLabel Best Quarter
Highest Quarterly Return, Date rr_BarChartHighestQuarterlyReturnDate Jun. 30, 2020
Highest Quarterly Return rr_BarChartHighestQuarterlyReturn 5.70%
Label rr_LowestQuarterlyReturnLabel Worst Quarter
Lowest Quarterly Return, Date rr_BarChartLowestQuarterlyReturnDate Dec. 31, 2016
Lowest Quarterly Return rr_BarChartLowestQuarterlyReturn (3.09%)
1 Year rr_AverageAnnualReturnYear01 5.74%
5 Years rr_AverageAnnualReturnYear05 4.15%
10 Years rr_AverageAnnualReturnYear10 3.62%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 31, 1973
T. Rowe Price New Income Fund, Inc. | Investor Class | After Taxes on Distributions  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 4.44%
5 Years rr_AverageAnnualReturnYear05 2.93%
10 Years rr_AverageAnnualReturnYear10 2.38%
T. Rowe Price New Income Fund, Inc. | Investor Class | After Taxes on Distributions and Sales  
Risk/Return: rr_RiskReturnAbstract  
1 Year rr_AverageAnnualReturnYear01 3.50%
5 Years rr_AverageAnnualReturnYear05 2.66%
10 Years rr_AverageAnnualReturnYear10 2.27%
T. Rowe Price New Income Fund, Inc. | I Class  
Risk/Return: rr_RiskReturnAbstract  
Maximum account fee rr_MaximumAccountFee none
Management fees rr_ManagementFeesOverAssets 0.31% [4],[5]
Distribution and service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.02%
Total annual fund operating expenses rr_ExpensesOverAssets 0.33% [4]
Fee waiver/expense reimbursement rr_FeeWaiverOrReimbursementOverAssets none
Total annual fund operating expenses after fee waiver/expense reimbursement rr_NetExpensesOverAssets 0.33% [4],[5]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination September 30, 2022
Expenses Restated to Reflect Current [Text] rr_ExpensesRestatedToReflectCurrent Restated to reflect current fees.
1 Year rr_ExpenseExampleYear01 $ 34
3 Years rr_ExpenseExampleYear03 106
5 Years rr_ExpenseExampleYear05 185
10 Years rr_ExpenseExampleYear10 $ 418
1 Year rr_AverageAnnualReturnYear01 5.85%
5 Years rr_AverageAnnualReturnYear05 4.29%
Since Inception rr_AverageAnnualReturnSinceInception 4.01%
Inception Date rr_AverageAnnualReturnInceptionDate Aug. 28, 2015
T. Rowe Price New Income Fund, Inc. | Advisor Class  
Risk/Return: rr_RiskReturnAbstract  
Maximum account fee rr_MaximumAccountFee none
Management fees rr_ManagementFeesOverAssets 0.31% [4],[5]
Distribution and service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.25%
Other expenses rr_OtherExpensesOverAssets 0.18%
Total annual fund operating expenses rr_ExpensesOverAssets 0.74% [4]
Fee waiver/expense reimbursement rr_FeeWaiverOrReimbursementOverAssets none
Total annual fund operating expenses after fee waiver/expense reimbursement rr_NetExpensesOverAssets 0.74% [4],[5]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination September 30, 2022
Expenses Restated to Reflect Current [Text] rr_ExpensesRestatedToReflectCurrent Restated to reflect current fees.
1 Year rr_ExpenseExampleYear01 $ 76
3 Years rr_ExpenseExampleYear03 237
5 Years rr_ExpenseExampleYear05 411
10 Years rr_ExpenseExampleYear10 $ 918
1 Year rr_AverageAnnualReturnYear01 5.41%
5 Years rr_AverageAnnualReturnYear05 3.86%
10 Years rr_AverageAnnualReturnYear10 3.34%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2002
T. Rowe Price New Income Fund, Inc. | R Class  
Risk/Return: rr_RiskReturnAbstract  
Maximum account fee rr_MaximumAccountFee none
Management fees rr_ManagementFeesOverAssets 0.31% [4],[5]
Distribution and service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets 0.50% [6]
Other expenses rr_OtherExpensesOverAssets 0.43%
Total annual fund operating expenses rr_ExpensesOverAssets 1.24% [4]
Fee waiver/expense reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.16%) [4],[5],[7]
Total annual fund operating expenses after fee waiver/expense reimbursement rr_NetExpensesOverAssets 1.08% [4],[5],[7]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination September 30, 2022 - September 30, 2023
Expenses Restated to Reflect Current [Text] rr_ExpensesRestatedToReflectCurrent Restated to reflect current fees.
1 Year rr_ExpenseExampleYear01 $ 110
3 Years rr_ExpenseExampleYear03 361
5 Years rr_ExpenseExampleYear05 649
10 Years rr_ExpenseExampleYear10 $ 1,471
1 Year rr_AverageAnnualReturnYear01 5.05%
5 Years rr_AverageAnnualReturnYear05 3.51%
10 Years rr_AverageAnnualReturnYear10 3.02%
Inception Date rr_AverageAnnualReturnInceptionDate Sep. 30, 2002
T. Rowe Price New Income Fund, Inc. | Z Class  
Risk/Return: rr_RiskReturnAbstract  
Maximum account fee rr_MaximumAccountFee none
Management fees rr_ManagementFeesOverAssets 0.31% [4],[5]
Distribution and service (12b-1) fees rr_DistributionAndService12b1FeesOverAssets none
Other expenses rr_OtherExpensesOverAssets 0.01%
Total annual fund operating expenses rr_ExpensesOverAssets 0.32% [4]
Fee waiver/expense reimbursement rr_FeeWaiverOrReimbursementOverAssets (0.32%) [4],[5],[8]
Total annual fund operating expenses after fee waiver/expense reimbursement rr_NetExpensesOverAssets none [5],[8]
Fee Waiver or Reimbursement over Assets, Date of Termination rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination September 30, 2022
Expenses Restated to Reflect Current [Text] rr_ExpensesRestatedToReflectCurrent Restated to reflect current fees.
1 Year rr_ExpenseExampleYear01 none
3 Years rr_ExpenseExampleYear03 none
5 Years rr_ExpenseExampleYear05 none
10 Years rr_ExpenseExampleYear10 none
1 Year rr_AverageAnnualReturnYear01 7.51%
5 Years rr_AverageAnnualReturnYear05 4.44%
10 Years rr_AverageAnnualReturnYear10 3.84%
Since Inception rr_AverageAnnualReturnSinceInception 4.15% [1]
Inception Date rr_AverageAnnualReturnInceptionDate Mar. 16, 2020
[1] Return since 8/28/15.
[2] Return since 8/31/15.
[3] Subject to certain exceptions, accounts with a balance of less than $10,000 are charged an annual $20 fee.
[4] Restated to reflect current fees.
[5] T. Rowe Price Associates, Inc., has contractually agreed (at least through September 30, 2022) to waive a portion of the fund’s management fees so that an individual fund fee of 0.0255% is applied to the fund’s average daily net assets that are equal to or greater than $20 billion. Thereafter, this agreement will automatically renew for one-year terms unless terminated by the fund’s Board of Directors. Any fees waived under this agreement are not subject to reimbursement to T. Rowe Price Associates, Inc., by the fund.
[6] Restated to show maximum 12b-1 fee rate of 0.50%. Actual rate for the prior fiscal year was 0.49%.
[7] T. Rowe Price Associates, Inc., has contractually agreed (through September 30, 2023) to waive its fees and/or bear any expenses (excluding interest; expenses related to borrowings, taxes, and brokerage; nonrecurring, extraordinary expenses; and acquired fund fees and expenses) that would cause the class’ ratio of expenses to average daily net assets to exceed 1.08%. The agreement may only be terminated at any time after September 30, 2023, with approval by the fund’s Board of Directors. Fees waived and expenses paid under this agreement (and a previous limitation of 1.15%) are subject to reimbursement to T. Rowe Price Associates, Inc., by the fund whenever the class’ expense ratio is below 1.08%. However, no reimbursement will be made more than three years from the date such amounts were initially waived or reimbursed. The fund may only make repayments to T. Rowe Price Associates, Inc., if such repayment does not cause the class’ expense ratio (after the repayment is taken into account) to exceed the lesser of: (1) the expense limitation in place at the time such amounts were waived or (2) the class’ current expense limitation.
[8] T. Rowe Price Associates, Inc., has contractually agreed to waive and/or bear all the Z Class’ expenses (excluding interest; expenses related to borrowings, taxes, and brokerage; nonrecurring, extraordinary expenses; and acquired fund fees and expenses) in their entirety. T. Rowe Price Associates, Inc., expects this fee waiver and/or expense reimbursement arrangement to remain in place indefinitely, and the agreement may only be amended or terminated with approval by the fund’s Board of Directors.