Form N-CSR Cover
| Form N-CSR Cover | 12 Months Ended |
| May 31, 2024 | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | T. ROWE PRICE NEW INCOME FUND, INC. |
| Entity Central Index Key | 0000080249 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | May 31, 2024 |
Shareholder Report
| Shareholder Report | 12 Months Ended |
| May 31, 2024 USD ($) Holding | |
| Shareholder Report [Line Items] | |
| Document Type | N-CSR |
| Amendment Flag | false |
| Registrant Name | T. ROWE PRICE NEW INCOME FUND, INC. |
| Entity Central Index Key | 0000080249 |
| Entity Investment Company Type | N-1A |
| Document Period End Date | May 31, 2024 |
| C000219349 | |
| Shareholder Report [Line Items] | |
| Fund Name | New Income Fund |
| Class Name | Z Class |
| Trading Symbol | (TRVZX) |
| Annual or Semi-Annual Statement [Text Block] | Annual Shareholder Report |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find the funds prospectus, financial information on Form N-CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information at |
| Expenses [Text Block] | What were the fund costs for the last year? Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment New Income Fund - Z Class $0 0.00% |
| Expenses Paid, Amount | $ 0 |
| Expense Ratio, Percent | 0% |
| Factors Affecting Performance [Text Block] | What drove fund performance during the past 12 months? The U.S. investment-grade (IG) fixed income market generated positive results for the 12-month reporting period. Although U.S. Treasury yields generally moved higher, bond investors benefited from higher coupon payments as well as tighter credit spreads amid a resilient economy. The funds underweight to Treasuries combined with allocations to high yield bonds and loans, Treasury inflation protected securities, and securitized credit contributed to relative performance versus the Bloomberg U.S. Aggregate Bond Index. Security selection within the IG corporate sector was also beneficial. Tactical positioning adjustments on the yield curve detracted from performance versus the benchmark as competing concerns about growth and inflation led to elevated interest rate volatility. Security selection in the agency mortgage-backed securities sector also hurt performance as the funds positions in to-be-announced instruments generally underperformed cash bonds that offered more stable cash flows. The fund seeks to maximize total return through income and capital appreciation by investing in a broadly diversified portfolio of mostly investment-grade debt instruments. After shifting to an underweight position earlier in the period, we moved back to an overweight in IG corporates as recession fears eased, and the sector represented our largest position in absolute and relative terms at period-end. The fund held material exposure to derivatives, which had an overall negative effect on absolute returns. Specifically, the funds positions in interest rate derivatives, which are primarily used to manage exposure to certain parts of the yield curve, weighed on absolute performance. |
| Average Annual Return [Table Text Block] | Average Annual Total Returns 1 Year Since Inception 3/16/2020 New Income Fund (Z Class) 1.30 % - % Bloomberg U.S. Aggregate Bond Index (Regulatory/Strategy Benchmark) 1.31 - The preceding line graph shows the value of a hypothetical $10,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The funds performance information included in the line graph and table above is compared with a regulatory required index that represents an overall securities market (Regulatory Benchmark). In addition, the line graph and table may also include one or more indexes that more closely aligns to the fund's investment strategy (Strategy Benchmark(s)). Due to new SEC Rules on shareholder reporting the fund adopted a new broad-based securities market index, referred to as the Regulatory Benchmark. Market index returns do not include expenses, which are deducted from fund returns. The fund's total return figures reflect the reinvestment of dividends and capital gains, if any. Neither the funds returns nor the index returns reflect the deduction of taxes that a shareholder would pay on fund distributions or redemptions of fund shares. The funds past performance is not a good predictor of the funds future performance. www.troweprice.com |
| AssetsNet | $ 16,586,966,000 |
| Holdings Count | Holding | 1,554 |
| Advisory Fees Paid, Amount | $ 8,917,000 |
| InvestmentCompanyPortfolioTurnover | 179.30% |
| Additional Fund Statistics [Text Block] | What are some fund statistics? Fund Statistics Total Net Assets (000s) $16,586,966 Number of Portfolio Holdings 1,554 |
| Holdings [Text Block] | Credit Quality Allocation* AAA Rated 6.0 % AA Rated 3.6 A Rated 9.6 BBB Rated 17.3 BB Rated and Below 2.6 Not Rated 0.7 U.S. Government Agency Securities 28.5 U.S. Treasury Securities 30.7 Reserves 1.0 *Credit ratings for the securities held in the Fund are provided by Moodys, Standard & Poors, and Fitch and are converted to the Standard & Poors nomenclature. A rating of AAA represents the highest-rated securities, and a rating of D represents the lowest rated securities. If the ratings agencies differ, the highest rating is applied to the security. If a rating is not available, the security is classified as Not Rated. The rating of the underlying investment vehicle is used to determine the creditworthiness of credit default swaps and sovereign securities. The Fund is not rated by any agency. |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes 18.3 % Federal National Mortgage Assn. 14.8 U.S. Treasury Bonds 8.4 Government National Mortgage Assn. 6.9 Federal Home Loan Mortgage 5.8 U.S. Treasury Inflation-Indexed Notes 4.0 UMBS 1.0 Bank of America 0.7 UnitedHealth Group 0.6 JPMorgan Chase 0.6 |
| Material Fund Change [Text Block] | |
| C000005531 | |
| Shareholder Report [Line Items] | |
| Fund Name | New Income Fund |
| Class Name | R Class |
| Trading Symbol | (RRNIX) |
| Annual or Semi-Annual Statement [Text Block] | Annual Shareholder Report |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find the funds prospectus, financial information on Form N-CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information at |
| Expenses [Text Block] | What were the fund costs for the last year? Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment New Income Fund - R Class $108 1.08% |
| Expenses Paid, Amount | $ 108 |
| Expense Ratio, Percent | 1.08% |
| Factors Affecting Performance [Text Block] | What drove fund performance during the past 12 months? The U.S. investment-grade (IG) fixed income market generated positive results for the 12-month reporting period. Although U.S. Treasury yields generally moved higher, bond investors benefited from higher coupon payments as well as tighter credit spreads amid a resilient economy. The funds underweight to Treasuries combined with allocations to high yield bonds and loans, Treasury inflation protected securities, and securitized credit contributed to relative performance versus the Bloomberg U.S. Aggregate Bond Index. Security selection within the IG corporate sector was also beneficial. Tactical positioning adjustments on the yield curve detracted from performance versus the benchmark as competing concerns about growth and inflation led to elevated interest rate volatility. Security selection in the agency mortgage-backed securities sector also hurt performance as the funds positions in to-be-announced instruments generally underperformed cash bonds that offered more stable cash flows. The fund seeks to maximize total return through income and capital appreciation by investing in a broadly diversified portfolio of mostly investment-grade debt instruments. After shifting to an underweight position earlier in the period, we moved back to an overweight in IG corporates as recession fears eased, and the sector represented our largest position in absolute and relative terms at period-end. The fund held material exposure to derivatives, which had an overall negative effect on absolute returns. Specifically, the funds positions in interest rate derivatives, which are primarily used to manage exposure to certain parts of the yield curve, weighed on absolute performance. |
| Average Annual Return [Table Text Block] | Average Annual Total Returns 1 Year 5 Years 10 Years New Income Fund (R Class) 0.21 % - % 0.29 % Bloomberg U.S. Aggregate Bond Index (Regulatory/Strategy Benchmark) 1.31 - 1.26 The preceding line graph shows the value of a hypothetical $10,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The funds performance information included in the line graph and table above is compared with a regulatory required index that represents an overall securities market (Regulatory Benchmark). In addition, the line graph and table may also include one or more indexes that more closely aligns to the fund's investment strategy (Strategy Benchmark(s)). Due to new SEC Rules on shareholder reporting the fund adopted a new broad-based securities market index, referred to as the Regulatory Benchmark. Market index returns do not include expenses, which are deducted from fund returns. The fund's total return figures reflect the reinvestment of dividends and capital gains, if any. Neither the funds returns nor the index returns reflect the deduction of taxes that a shareholder would pay on fund distributions or redemptions of fund shares. The funds past performance is not a good predictor of the funds future performance. www.troweprice.com |
| AssetsNet | $ 16,586,966,000 |
| Holdings Count | Holding | 1,554 |
| Advisory Fees Paid, Amount | $ 8,917,000 |
| InvestmentCompanyPortfolioTurnover | 179.30% |
| Additional Fund Statistics [Text Block] | What are some fund statistics? Fund Statistics Total Net Assets (000s) $16,586,966 Number of Portfolio Holdings 1,554 |
| Holdings [Text Block] | Credit Quality Allocation* AAA Rated 6.0 % AA Rated 3.6 A Rated 9.6 BBB Rated 17.3 BB Rated and Below 2.6 Not Rated 0.7 U.S. Government Agency Securities 28.5 U.S. Treasury Securities 30.7 Reserves 1.0 *Credit ratings for the securities held in the Fund are provided by Moodys, Standard & Poors, and Fitch and are converted to the Standard & Poors nomenclature. A rating of AAA represents the highest-rated securities, and a rating of D represents the lowest rated securities. If the ratings agencies differ, the highest rating is applied to the security. If a rating is not available, the security is classified as Not Rated. The rating of the underlying investment vehicle is used to determine the creditworthiness of credit default swaps and sovereign securities. The Fund is not rated by any agency. |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes 18.3 % Federal National Mortgage Assn. 14.8 U.S. Treasury Bonds 8.4 Government National Mortgage Assn. 6.9 Federal Home Loan Mortgage 5.8 U.S. Treasury Inflation-Indexed Notes 4.0 UMBS 1.0 Bank of America 0.7 UnitedHealth Group 0.6 JPMorgan Chase 0.6 |
| Material Fund Change [Text Block] | |
| C000005529 | |
| Shareholder Report [Line Items] | |
| Fund Name | New Income Fund |
| Class Name | Investor Class |
| Trading Symbol | (PRCIX) |
| Annual or Semi-Annual Statement [Text Block] | Annual Shareholder Report |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find the funds prospectus, financial information on Form N-CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information at |
| Expenses [Text Block] | What were the fund costs for the last year? Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment New Income Fund - Investor Class $44 0.44% |
| Expenses Paid, Amount | $ 44 |
| Expense Ratio, Percent | 0.44% |
| Factors Affecting Performance [Text Block] | What drove fund performance during the past 12 months? The U.S. investment-grade (IG) fixed income market generated positive results for the 12-month reporting period. Although U.S. Treasury yields generally moved higher, bond investors benefited from higher coupon payments as well as tighter credit spreads amid a resilient economy. The funds underweight to Treasuries combined with allocations to high yield bonds and loans, Treasury inflation protected securities, and securitized credit contributed to relative performance versus the Bloomberg U.S. Aggregate Bond Index. Security selection within the IG corporate sector was also beneficial. Tactical positioning adjustments on the yield curve detracted from performance versus the benchmark as competing concerns about growth and inflation led to elevated interest rate volatility. Security selection in the agency mortgage-backed securities sector also hurt performance as the funds positions in to-be-announced instruments generally underperformed cash bonds that offered more stable cash flows. The fund seeks to maximize total return through income and capital appreciation by investing in a broadly diversified portfolio of mostly investment-grade debt instruments. After shifting to an underweight position earlier in the period, we moved back to an overweight in IG corporates as recession fears eased, and the sector represented our largest position in absolute and relative terms at period-end. The fund held material exposure to derivatives, which had an overall negative effect on absolute returns. Specifically, the funds positions in interest rate derivatives, which are primarily used to manage exposure to certain parts of the yield curve, weighed on absolute performance. |
| Average Annual Return [Table Text Block] | Average Annual Total Returns 1 Year 5 Years 10 Years New Income Fund (Investor Class) 0.86 % - % 0.91 % Bloomberg U.S. Aggregate Bond Index (Regulatory/Strategy Benchmark) 1.31 - 1.26 The preceding line graph shows the value of a hypothetical $10,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The funds performance information included in the line graph and table above is compared with a regulatory required index that represents an overall securities market (Regulatory Benchmark). In addition, the line graph and table may also include one or more indexes that more closely aligns to the fund's investment strategy (Strategy Benchmark(s)). Due to new SEC Rules on shareholder reporting the fund adopted a new broad-based securities market index, referred to as the Regulatory Benchmark. Market index returns do not include expenses, which are deducted from fund returns. The fund's total return figures reflect the reinvestment of dividends and capital gains, if any. Neither the funds returns nor the index returns reflect the deduction of taxes that a shareholder would pay on fund distributions or redemptions of fund shares. The funds past performance is not a good predictor of the funds future performance. www.troweprice.com |
| AssetsNet | $ 16,586,966,000 |
| Holdings Count | Holding | 1,554 |
| Advisory Fees Paid, Amount | $ 8,917,000 |
| InvestmentCompanyPortfolioTurnover | 179.30% |
| Additional Fund Statistics [Text Block] | What are some fund statistics? Fund Statistics Total Net Assets (000s) $16,586,966 Number of Portfolio Holdings 1,554 |
| Holdings [Text Block] | Credit Quality Allocation* AAA Rated 6.0 % AA Rated 3.6 A Rated 9.6 BBB Rated 17.3 BB Rated and Below 2.6 Not Rated 0.7 U.S. Government Agency Securities 28.5 U.S. Treasury Securities 30.7 Reserves 1.0 *Credit ratings for the securities held in the Fund are provided by Moodys, Standard & Poors, and Fitch and are converted to the Standard & Poors nomenclature. A rating of AAA represents the highest-rated securities, and a rating of D represents the lowest rated securities. If the ratings agencies differ, the highest rating is applied to the security. If a rating is not available, the security is classified as Not Rated. The rating of the underlying investment vehicle is used to determine the creditworthiness of credit default swaps and sovereign securities. The Fund is not rated by any agency. |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes 18.3 % Federal National Mortgage Assn. 14.8 U.S. Treasury Bonds 8.4 Government National Mortgage Assn. 6.9 Federal Home Loan Mortgage 5.8 U.S. Treasury Inflation-Indexed Notes 4.0 UMBS 1.0 Bank of America 0.7 UnitedHealth Group 0.6 JPMorgan Chase 0.6 |
| Material Fund Change [Text Block] | |
| C000005530 | |
| Shareholder Report [Line Items] | |
| Fund Name | New Income Fund |
| Class Name | Advisor Class |
| Trading Symbol | (PANIX) |
| Annual or Semi-Annual Statement [Text Block] | Annual Shareholder Report |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find the funds prospectus, financial information on Form N-CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information at |
| Expenses [Text Block] | What were the fund costs for the last year? Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment New Income Fund - Advisor Class $92 0.92% |
| Expenses Paid, Amount | $ 92 |
| Expense Ratio, Percent | 0.92% |
| Factors Affecting Performance [Text Block] | What drove fund performance during the past 12 months? The U.S. investment-grade (IG) fixed income market generated positive results for the 12-month reporting period. Although U.S. Treasury yields generally moved higher, bond investors benefited from higher coupon payments as well as tighter credit spreads amid a resilient economy. The funds underweight to Treasuries combined with allocations to high yield bonds and loans, Treasury inflation protected securities, and securitized credit contributed to relative performance versus the Bloomberg U.S. Aggregate Bond Index. Security selection within the IG corporate sector was also beneficial. Tactical positioning adjustments on the yield curve detracted from performance versus the benchmark as competing concerns about growth and inflation led to elevated interest rate volatility. Security selection in the agency mortgage-backed securities sector also hurt performance as the funds positions in to-be-announced instruments generally underperformed cash bonds that offered more stable cash flows. The fund seeks to maximize total return through income and capital appreciation by investing in a broadly diversified portfolio of mostly investment-grade debt instruments. After shifting to an underweight position earlier in the period, we moved back to an overweight in IG corporates as recession fears eased, and the sector represented our largest position in absolute and relative terms at period-end. The fund held material exposure to derivatives, which had an overall negative effect on absolute returns. Specifically, the funds positions in interest rate derivatives, which are primarily used to manage exposure to certain parts of the yield curve, weighed on absolute performance. |
| Average Annual Return [Table Text Block] | Average Annual Total Returns 1 Year 5 Years 10 Years New Income Fund (Advisor Class) 0.36 % - % 0.57 % Bloomberg U.S. Aggregate Bond Index (Regulatory/Strategy Benchmark) 1.31 - 1.26 The preceding line graph shows the value of a hypothetical $10,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The funds performance information included in the line graph and table above is compared with a regulatory required index that represents an overall securities market (Regulatory Benchmark). In addition, the line graph and table may also include one or more indexes that more closely aligns to the fund's investment strategy (Strategy Benchmark(s)). Due to new SEC Rules on shareholder reporting the fund adopted a new broad-based securities market index, referred to as the Regulatory Benchmark. Market index returns do not include expenses, which are deducted from fund returns. The fund's total return figures reflect the reinvestment of dividends and capital gains, if any. Neither the funds returns nor the index returns reflect the deduction of taxes that a shareholder would pay on fund distributions or redemptions of fund shares. The funds past performance is not a good predictor of the funds future performance. www.troweprice.com |
| AssetsNet | $ 16,586,966,000 |
| Holdings Count | Holding | 1,554 |
| Advisory Fees Paid, Amount | $ 8,917,000 |
| InvestmentCompanyPortfolioTurnover | 179.30% |
| Additional Fund Statistics [Text Block] | What are some fund statistics? Fund Statistics Total Net Assets (000s) $16,586,966 Number of Portfolio Holdings 1,554 |
| Holdings [Text Block] | Credit Quality Allocation* AAA Rated 6.0 % AA Rated 3.6 A Rated 9.6 BBB Rated 17.3 BB Rated and Below 2.6 Not Rated 0.7 U.S. Government Agency Securities 28.5 U.S. Treasury Securities 30.7 Reserves 1.0 *Credit ratings for the securities held in the Fund are provided by Moodys, Standard & Poors, and Fitch and are converted to the Standard & Poors nomenclature. A rating of AAA represents the highest-rated securities, and a rating of D represents the lowest rated securities. If the ratings agencies differ, the highest rating is applied to the security. If a rating is not available, the security is classified as Not Rated. The rating of the underlying investment vehicle is used to determine the creditworthiness of credit default swaps and sovereign securities. The Fund is not rated by any agency. |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes 18.3 % Federal National Mortgage Assn. 14.8 U.S. Treasury Bonds 8.4 Government National Mortgage Assn. 6.9 Federal Home Loan Mortgage 5.8 U.S. Treasury Inflation-Indexed Notes 4.0 UMBS 1.0 Bank of America 0.7 UnitedHealth Group 0.6 JPMorgan Chase 0.6 |
| Material Fund Change [Text Block] | |
| C000159679 | |
| Shareholder Report [Line Items] | |
| Fund Name | New Income Fund |
| Class Name | I Class |
| Trading Symbol | (PRXEX) |
| Annual or Semi-Annual Statement [Text Block] | Annual Shareholder Report |
| Shareholder Report Annual or Semi-Annual | annual shareholder report |
| Additional Information [Text Block] | You can find the funds prospectus, financial information on Form N-CSR (which includes required tax information for dividends), holdings, proxy voting information, and other information at |
| Expenses [Text Block] | What were the fund costs for the last year? Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment New Income Fund - I Class $36 0.36% |
| Expenses Paid, Amount | $ 36 |
| Expense Ratio, Percent | 0.36% |
| Factors Affecting Performance [Text Block] | What drove fund performance during the past 12 months? The U.S. investment-grade (IG) fixed income market generated positive results for the 12-month reporting period. Although U.S. Treasury yields generally moved higher, bond investors benefited from higher coupon payments as well as tighter credit spreads amid a resilient economy. The funds underweight to Treasuries combined with allocations to high yield bonds and loans, Treasury inflation protected securities, and securitized credit contributed to relative performance versus the Bloomberg U.S. Aggregate Bond Index. Security selection within the IG corporate sector was also beneficial. Tactical positioning adjustments on the yield curve detracted from performance versus the benchmark as competing concerns about growth and inflation led to elevated interest rate volatility. Security selection in the agency mortgage-backed securities sector also hurt performance as the funds positions in to-be-announced instruments generally underperformed cash bonds that offered more stable cash flows. The fund seeks to maximize total return through income and capital appreciation by investing in a broadly diversified portfolio of mostly investment-grade debt instruments. After shifting to an underweight position earlier in the period, we moved back to an overweight in IG corporates as recession fears eased, and the sector represented our largest position in absolute and relative terms at period-end. The fund held material exposure to derivatives, which had an overall negative effect on absolute returns. Specifically, the funds positions in interest rate derivatives, which are primarily used to manage exposure to certain parts of the yield curve, weighed on absolute performance. |
| Average Annual Return [Table Text Block] | Average Annual Total Returns 1 Year 5 Years Since Inception 8/28/2015 New Income Fund (I Class) 0.81 % - % 0.94 % Bloomberg U.S. Aggregate Bond Index (Regulatory/Strategy Benchmark) 1.31 - 1.15 The preceding line graph shows the value of a hypothetical $500,000 investment in the fund over the past 10 fiscal year periods or since inception (for funds lacking 10-year records). The funds performance information included in the line graph and table above is compared with a regulatory required index that represents an overall securities market (Regulatory Benchmark). In addition, the line graph and table may also include one or more indexes that more closely aligns to the fund's investment strategy (Strategy Benchmark(s)). Due to new SEC Rules on shareholder reporting the fund adopted a new broad-based securities market index, referred to as the Regulatory Benchmark. Market index returns do not include expenses, which are deducted from fund returns. The fund's total return figures reflect the reinvestment of dividends and capital gains, if any. Neither the funds returns nor the index returns reflect the deduction of taxes that a shareholder would pay on fund distributions or redemptions of fund shares. The funds past performance is not a good predictor of the funds future performance. www.troweprice.com |
| AssetsNet | $ 16,586,966,000 |
| Holdings Count | Holding | 1,554 |
| Advisory Fees Paid, Amount | $ 8,917,000 |
| InvestmentCompanyPortfolioTurnover | 179.30% |
| Additional Fund Statistics [Text Block] | What are some fund statistics? Fund Statistics Total Net Assets (000s) $16,586,966 Number of Portfolio Holdings 1,554 |
| Holdings [Text Block] | Credit Quality Allocation* AAA Rated 6.0 % AA Rated 3.6 A Rated 9.6 BBB Rated 17.3 BB Rated and Below 2.6 Not Rated 0.7 U.S. Government Agency Securities 28.5 U.S. Treasury Securities 30.7 Reserves 1.0 *Credit ratings for the securities held in the Fund are provided by Moodys, Standard & Poors, and Fitch and are converted to the Standard & Poors nomenclature. A rating of AAA represents the highest-rated securities, and a rating of D represents the lowest rated securities. If the ratings agencies differ, the highest rating is applied to the security. If a rating is not available, the security is classified as Not Rated. The rating of the underlying investment vehicle is used to determine the creditworthiness of credit default swaps and sovereign securities. The Fund is not rated by any agency. |
| Largest Holdings [Text Block] | Top Ten Holdings U.S. Treasury Notes 18.3 % Federal National Mortgage Assn. 14.8 U.S. Treasury Bonds 8.4 Government National Mortgage Assn. 6.9 Federal Home Loan Mortgage 5.8 U.S. Treasury Inflation-Indexed Notes 4.0 UMBS 1.0 Bank of America 0.7 UnitedHealth Group 0.6 JPMorgan Chase 0.6 |
| Material Fund Change [Text Block] |
Shareholder Report, Average Ann
| Shareholder Report, Average Annual Return (Details) | 12 Months Ended | 51 Months Ended | 60 Months Ended | 105 Months Ended | 120 Months Ended |
| May 31, 2024 | May 31, 2024 | May 31, 2024 | May 31, 2024 | May 31, 2024 | |
| Without Sales Load [Member] | C000219349 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.30% | (1.16%) | |||
| Without Sales Load [Member] | C000005531 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 0.21% | (1.35%) | 0.29% | ||
| Without Sales Load [Member] | C000005529 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 0.86% | (0.73%) | 0.91% | ||
| Without Sales Load [Member] | C000005530 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 0.36% | (1.15%) | 0.57% | ||
| Without Sales Load [Member] | C000159679 | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 0.81% | (0.64%) | 0.94% | ||
| Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.31% | (1.82%) | |||
| Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.31% | (0.17%) | 1.26% | ||
| Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.31% | (0.17%) | 1.26% | ||
| Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.31% | (0.17%) | 1.26% | ||
| Bloomberg U.S. Aggregate Bond Index | |||||
| Average Annual Return [Line Items] | |||||
| Average Annual Return, Percent | 1.31% | (0.17%) | 1.15% |
Shareholder Report, Holdings (D
| Shareholder Report, Holdings (Details) | May 31, 2024 |
| C000219349 | AAA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000219349 | AA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000219349 | A Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.60% |
| C000219349 | BBB Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.30% |
| C000219349 | BB Rated and Below | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000219349 | Not Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000219349 | U.S. Government Agency Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.50% |
| C000219349 | U.S. Treasury Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.70% |
| C000005531 | AAA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000005531 | AA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000005531 | A Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.60% |
| C000005531 | BBB Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.30% |
| C000005531 | BB Rated and Below | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000005531 | Not Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000005531 | U.S. Government Agency Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.50% |
| C000005531 | U.S. Treasury Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.70% |
| C000005529 | AAA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000005529 | AA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000005529 | A Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.60% |
| C000005529 | BBB Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.30% |
| C000005529 | BB Rated and Below | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000005529 | Not Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000005529 | U.S. Government Agency Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.50% |
| C000005529 | U.S. Treasury Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.70% |
| C000005530 | AAA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000005530 | AA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000005530 | A Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.60% |
| C000005530 | BBB Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.30% |
| C000005530 | BB Rated and Below | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000005530 | Not Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000005530 | U.S. Government Agency Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.50% |
| C000005530 | U.S. Treasury Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.70% |
| C000159679 | AAA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 6% |
| C000159679 | AA Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 3.60% |
| C000159679 | A Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 9.60% |
| C000159679 | BBB Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 17.30% |
| C000159679 | BB Rated and Below | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 2.60% |
| C000159679 | Not Rated | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 0.70% |
| C000159679 | U.S. Government Agency Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 28.50% |
| C000159679 | U.S. Treasury Securities | |
| Holdings [Line Items] | |
| Percent of Net Asset Value | 30.70% |