v3.25.2
Shareholder Report
 6 Months Ended
Jun. 30, 2025
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name PLAN INVESTMENT FUND INC
Entity Central Index Key 0000774412
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2025
C000003007  
Shareholder Report [Line Items]  
Fund Name Government Portfolio
Trading Symbol PIFXX
Annual or Semi-Annual Statement [Text Block] This Semi-Annual Shareholder Report contains important information about the Government Portfolio (the "Portfolio") for the period of January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
Additional Information [Text Block] You can find additional information about the Portfolio at www.pif.com/fund/government-portfolio. You can also request this information by contacting us at (800) 621-9215.
Additional Information Phone Number (800) 621-9215
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.pif.com/fund/government-portfolio</span>
Expenses [Text Block]

What were the Portfolio’s costs for the last six months? 

(based on a hypothetical $10,000 investment)

Ticker
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
PIFXX
$5
0.10%
Expenses Paid, Amount $ 5
Expense Ratio, Percent 0.10%
Updated Performance Information Location [Text Block]

Where can I find additional information about the Portfolio?

An image of a QR code that, when scanned, navigates the user to the following URL: https://pif.com/fund/government-portfolio/

If you wish to view additional information about the Portfolio, including the Portfolio's financial statements, month-end holdings, prospectus and statement of additional information, please visit www.pif.com/fund/government-portfolio.
AssetsNet $ 1,595,697,708
Holdings Count | Holding 89
Additional Fund Statistics [Text Block]

Key Portfolio Statistics

June 30, 2025 

Total Net Assets
$1,595,697,708
# of Portfolio Holdings
89
Holdings [Text Block]

Portfolio Composition 

% of Total Investments

Pie Chart showing Grouping By Sector
Value
Value
Repurchase Agreements
39.2%
U.S. Government Sponsored Agency Obligations
31.7%
U.S. Treasury Obligations
29.1%
Updated Prospectus Web Address <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.pif.com/fund/government-portfolio</span>
C000003006  
Shareholder Report [Line Items]  
Fund Name Money Market Portfolio
Trading Symbol PIMXX
Annual or Semi-Annual Statement [Text Block] This Semi-Annual Shareholder Report contains important information about the Money Market Portfolio (the "Portfolio") for the period of January 1, 2025 to June 30, 2025.
Shareholder Report Annual or Semi-Annual Semi-Annual Shareholder Report
Additional Information [Text Block] You can find additional information about the Portfolio at www.pif.com/fund/money-market-portfolio. You can also request this information by contacting us at (800) 621-9215.
Additional Information Phone Number (800) 621-9215
Additional Information Website <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.pif.com/fund/money-market-portfolio</span>
Expenses [Text Block]

What were the Portfolio’s costs for the last six months? 

(based on a hypothetical $10,000 investment)

Ticker
Costs of a $10,000 investment
Costs paid as a percentage of a $10,000 investment
PIMXX
$9
0.18%
Expenses Paid, Amount $ 9
Expense Ratio, Percent 0.18%
Updated Performance Information Location [Text Block]

Where can I find additional information about the Portfolio?

An image of a QR code that, when scanned, navigates the user to the following URL: https://pif.com/fund/money-market-portfolio

If you wish to view additional information about the Portfolio, including the Portfolio's financial statements, month-end holdings, prospectus and statement of additional information, please visit www.pif.com/fund/money-market-portfolio.
AssetsNet $ 171,891,245
Holdings Count | Holding 159
Additional Fund Statistics [Text Block]

Key Portfolio Statistics

June 30, 2025 

Total Net Assets
$171,891,245
# of Portfolio Holdings
159
Holdings [Text Block]

Portfolio Composition 

% of Total Investments

Pie Chart showing Grouping By Sector
Value
Value
Repurchase Agreements
36.5%
Commercial Paper
32.1%
Bank Obligations - Certificate of Deposit
22.2%
Time Deposits
4.7%
Tender Option Bonds
3.1%
Variable Rate Demand Notes
0.6%
U.S. Treasury Obligations
0.5%
Non-U.S. Sub-Sovereign
0.3%
Updated Prospectus Web Address <span style="box-sizing: border-box; color: rgb(0, 0, 0); display: inline; flex-wrap: nowrap; font-size: 13.3333px; font-weight: 400; grid-area: auto; line-height: 20px; margin: 0px; overflow: visible; text-align: left; text-align-last: auto; white-space-collapse: preserve-breaks;">www.pif.com/fund/money-market-portfolio</span>