v3.25.2
Expense Example
Sep. 26, 2025
USD ($)
ARBITRAGE FUND | ARBITRAGE FUND | Class R  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year $ 174
Expense Example, with Redemption, 3 Years 539
Expense Example, with Redemption, 5 Years 928
Expense Example, with Redemption, 10 Years 2,019
ARBITRAGE FUND | ARBITRAGE FUND | Class I  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 149
Expense Example, with Redemption, 3 Years 462
Expense Example, with Redemption, 5 Years 797
Expense Example, with Redemption, 10 Years 1,746
ARBITRAGE FUND | ARBITRAGE FUND | Class C  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 349
Expense Example, with Redemption, 3 Years 767
Expense Example, with Redemption, 5 Years 1,311
Expense Example, with Redemption, 10 Years 2,796
ARBITRAGE FUND | ARBITRAGE FUND | Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 444
Expense Example, with Redemption, 3 Years 799
Expense Example, with Redemption, 5 Years 1,178
Expense Example, with Redemption, 10 Years 2,239
WATER ISLAND EVENT-DRIVEN FUND | WATER ISLAND EVENT-DRIVEN FUND | Class R  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 174
Expense Example, with Redemption, 3 Years 574
Expense Example, with Redemption, 5 Years 1,000
Expense Example, with Redemption, 10 Years 2,187
WATER ISLAND EVENT-DRIVEN FUND | WATER ISLAND EVENT-DRIVEN FUND | Class I  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 149
Expense Example, with Redemption, 3 Years 495
Expense Example, with Redemption, 5 Years 866
Expense Example, with Redemption, 10 Years 1,908
WATER ISLAND EVENT-DRIVEN FUND | WATER ISLAND EVENT-DRIVEN FUND | Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 493
Expense Example, with Redemption, 3 Years 881
Expense Example, with Redemption, 5 Years 1,293
Expense Example, with Redemption, 10 Years 2,441
WATER ISLAND CREDIT OPPORTUNITIES FUND | WATER ISLAND CREDIT OPPORTUNITIES FUND | Class R  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 129
Expense Example, with Redemption, 3 Years 481
Expense Example, with Redemption, 5 Years 857
Expense Example, with Redemption, 10 Years 1,913
WATER ISLAND CREDIT OPPORTUNITIES FUND | WATER ISLAND CREDIT OPPORTUNITIES FUND | Class I  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 103
Expense Example, with Redemption, 3 Years 401
Expense Example, with Redemption, 5 Years 720
Expense Example, with Redemption, 10 Years 1,625
WATER ISLAND CREDIT OPPORTUNITIES FUND | WATER ISLAND CREDIT OPPORTUNITIES FUND | Class A  
Prospectus [Line Items]  
Expense Example, with Redemption, 1 Year 450
Expense Example, with Redemption, 3 Years 790
Expense Example, with Redemption, 5 Years 1,154
Expense Example, with Redemption, 10 Years $ 2,175