Average Annual Total Returns

12 Months Ended

30 Months Ended

31 Months Ended

60 Months Ended

120 Months Ended

Mar. 31, 2026

Dec. 31, 2025

Dec. 31, 2025

Dec. 31, 2025

Dec. 31, 2025

Dec. 31, 2025

Mercer US Small/Mid Cap Equity Fund | Class I

Prospectus [Line Items]

Average Annual Return, Percent

6.20%

11.52%

Performance Inception Date

Jun. 27, 2023

Mercer US Small/Mid Cap Equity Fund | Class Y-3

Prospectus [Line Items]

Average Annual Return, Percent

6.44%

7.58%

9.46%

Mercer US Small/Mid Cap Equity Fund | Class Y-3 | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

4.63%

5.05%

7.08%

Mercer US Small/Mid Cap Equity Fund | Class Y-3 | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

5.09%

5.52%

7.03%

Mercer US Small/Mid Cap Equity Fund | Russell 2500® Index (reflects no deduction for fees, expenses, or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[1]

11.91%

7.26%

10.40%

Mercer Non-US Core Equity Fund | Class I

Prospectus [Line Items]

Average Annual Return, Percent

36.96%

8.89%

Performance Inception Date

Jul. 22, 2021

Mercer Non-US Core Equity Fund | Class Y-3

Prospectus [Line Items]

Average Annual Return, Percent

37.31%

10.05%

9.76%

Mercer Non-US Core Equity Fund | Class Y-3 | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

33.13%

7.76%

7.92%

Mercer Non-US Core Equity Fund | Class Y-3 | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

24.64%

7.50%

7.49%

Mercer Non-US Core Equity Fund | MSCI World ex USA IMI Index (net dividends) (reflects no deduction for fees, expenses, or taxes (other than assumed dividend tax))

Prospectus [Line Items]

Average Annual Return, Percent

^[2]

32.18%

9.03%

8.47%

Mercer Emerging Markets Equity Fund | Class I

Prospectus [Line Items]

Average Annual Return, Percent

30.76%

12.51%

Performance Inception Date

Jun. 27, 2023

Mercer Emerging Markets Equity Fund | Class Y-3

Prospectus [Line Items]

Average Annual Return, Percent

31.10%

1.65%

6.17%

Mercer Emerging Markets Equity Fund | Class Y-3 | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

30.38%

0.80%

5.17%

Mercer Emerging Markets Equity Fund | Class Y-3 | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

19.19%

1.32%

4.85%

Mercer Emerging Markets Equity Fund | MSCI Emerging Markets Index (net dividends) (reflects no deduction for fees, expenses, or taxes (other than assumed dividend tax))

Prospectus [Line Items]

Average Annual Return, Percent

^[3]

33.57%

4.20%

8.42%

Mercer Core Fixed Income Fund | Class I

Prospectus [Line Items]

Average Annual Return, Percent

7.39%

(0.02%)

Performance Inception Date

Dec. 27, 2021

Mercer Core Fixed Income Fund | Class Y-3

Prospectus [Line Items]

Average Annual Return, Percent

7.79%

(0.03%)

2.57%

Mercer Core Fixed Income Fund | Class Y-3 | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

5.68%

(1.50%)

1.14%

Mercer Core Fixed Income Fund | Class Y-3 | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

4.62%

(0.64%)

1.37%

Mercer Core Fixed Income Fund | Bloomberg U.S. Aggregate Bond Index (reflects no deduction for fees, expenses, or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[4]

7.30%

(0.36%)

2.01%

Mercer Opportunistic Fixed Income Fund | Class I

Prospectus [Line Items]

Average Annual Return, Percent

10.14%

7.05%

Performance Inception Date

Jun. 01, 2023

Mercer Opportunistic Fixed Income Fund | Class Y-3

Prospectus [Line Items]

Average Annual Return, Percent

10.41%

2.02%

4.37%

Mercer Opportunistic Fixed Income Fund | Class Y-3 | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

8.23%

(0.05%)

2.82%

Mercer Opportunistic Fixed Income Fund | Class Y-3 | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

6.17%

0.63%

2.73%

Mercer Opportunistic Fixed Income Fund | Bloomberg U.S. Aggregate Index (reflects no deduction for fees, expenses, or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[5]

7.30%

(0.36%)

2.01%

Mercer Opportunistic Fixed Income Fund | Secondary Index (reflects no deduction for fees, expenses, or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[6]

9.57%

4.26%

5.62%

Mercer Short Duration Fixed Income Fund | Class I

Prospectus [Line Items]

Performance Inception Date

Dec. 01, 2023

Mercer Short Duration Fixed Income Fund | Class Y-3

Prospectus [Line Items]

Average Annual Return, Percent

5.97%

5.77%

Mercer Short Duration Fixed Income Fund | Class Y-3 | After Taxes on Distributions

Prospectus [Line Items]

Average Annual Return, Percent

3.73%

3.70%

Mercer Short Duration Fixed Income Fund | Class Y-3 | After Taxes on Distributions and Sales

Prospectus [Line Items]

Average Annual Return, Percent

3.61%

3.41%

Mercer Short Duration Fixed Income Fund | Bloomberg U.S. 1-3 Year Government/Credit Index (reflects no deduction for fees, expenses, or taxes)

Prospectus [Line Items]

Average Annual Return, Percent

^[7]

5.25%

5.35%

[1]	The Russell 2500^® Index measures the performance of the small-to mid-cap segment of the U.S. equity universe. The Russell 2500^®Index is a subset of the Russell 3000^® Index. It includes approximately 2,500 of the smallest securities based on a combination of their market cap and current index membership. The index is unmanaged and cannot be invested in directly.
[2]	The Fund’s primary benchmark index, the MSCI World ex USA IMI Index, measures the performance of equity securities in developed markets in North America, Europe, and the Asia/Pacific region, excluding the United States.
[3]	The MSCI Emerging Markets Index measures the performance of equity securities in global emerging markets. The index is unmanaged and cannot be invested in directly.
[4]	The Bloomberg U.S. Aggregate Bond Index is an index that measures the performance of securities from the Bloomberg U.S. Government/Corporate Bond Index, Mortgage-Backed Securities Index, Asset-Backed Securities Index, and Commercial Mortgage-Backed Securities Index. The Bloomberg U.S. Aggregate Bond Index is a broad representation of the investment-grade fixed-income market in the United States and includes U.S. government and corporate debt securities, mortgage- and asset-backed securities, and international U.S. dollar-denominated bonds. All securities contained in the Bloomberg U.S. Aggregate Bond Index have a minimum term to maturity of one year. The index is unmanaged and cannot be invested in directly.
[5]	The Bloomberg U.S. Aggregate Bond Index measures the performance of securities from the Bloomberg U.S. Government/Corporate Bond Index, Mortgage-Backed Securities Index, Asset-Backed Securities Index, and Commercial Mortgage-Backed Securities Index. The Bloomberg U.S. Aggregate Bond Index is a broad representation of the investment-grade fixed-income market in the United States and includes U.S. government and corporate debt securities, mortgage- and asset-backed securities, and international U.S. dollar-denominated bonds. All securities contained in the Bloomberg U.S. Aggregate Bond Index have a minimum term to maturity of one year. The index is unmanaged and cannot be invested in directly.
[6]	The Fund has selected a secondary index that is a blended benchmark consisting of 33.3% Bloomberg US Corporate High Yield Index (USD), 33.3% Morningstar LSTA US Leveraged Loan Index and 33.3% JP Morgan EMBI Global Diversified Index (USD). The index is unmanaged and cannot be invested in directly.
[7]	The Bloomberg U.S. 1-3 Year Government/Credit Index is an index that measures the performance of investment grade, U.S.-dollar-denominated, fixed-rate Treasury securities and government-related and corporate securities with 1 to 3 year maturities. The index is unmanaged and cannot be invested in directly