v3.25.2
Shareholder Fees
Sep. 26, 2025
ARBITRAGE FUND | ARBITRAGE FUND | Class R  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
ARBITRAGE FUND | ARBITRAGE FUND | Class I  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
ARBITRAGE FUND | ARBITRAGE FUND | Class C  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 1.00% [1]
ARBITRAGE FUND | ARBITRAGE FUND | Class A  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 2.75%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 1.00% [2]
WATER ISLAND EVENT-DRIVEN FUND | WATER ISLAND EVENT-DRIVEN FUND | Class R  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
WATER ISLAND EVENT-DRIVEN FUND | WATER ISLAND EVENT-DRIVEN FUND | Class I  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
WATER ISLAND EVENT-DRIVEN FUND | WATER ISLAND EVENT-DRIVEN FUND | Class A  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 3.25%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 1.00% [3]
WATER ISLAND CREDIT OPPORTUNITIES FUND | WATER ISLAND CREDIT OPPORTUNITIES FUND | Class R  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
WATER ISLAND CREDIT OPPORTUNITIES FUND | WATER ISLAND CREDIT OPPORTUNITIES FUND | Class I  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 0.00%
WATER ISLAND CREDIT OPPORTUNITIES FUND | WATER ISLAND CREDIT OPPORTUNITIES FUND | Class A  
Prospectus [Line Items]  
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price) 3.25%
Maximum Deferred Sales Charge (as a percentage of Offering Price) 1.00% [4]
[1] This contingent deferred sales charge applies to Class C shares redeemed within 12 months of purchase.
[2] A deferred sales charge of up to 1.00% may be imposed on purchases of $250,000 or more of Class A shares purchased without a front-end sales charge that are redeemed within 18 months of purchase.
[3] A deferred sales charge of up to 1.00% may be imposed on purchases of $250,000 or more of Class A shares purchased without a front-end sales charge that are redeemed within 18 months of purchase.
[4] A deferred sales charge of up to 1.00% may be imposed on purchases of $250,000 or more of Class A shares purchased without a front-end sales charge that are redeemed within 18 months of purchase.