SSRS Tablix - Grouping and summing data by one or more fields WITHOUT showing details?

Question

I have a dataset that I'm using for several Tablix, rather than create another dataset with the same sql + grouping by Dept, user - I was hoping to just use the same original detail dataset and do the grouping in SSRS.

I have data that looks like this:

NAME         DEPT        HOURS     MONTH 
Joe          Acct        2         1/1/2023
Joe          Acct        1         2/1/2023
Joe          Acct        10        3/1/2023
Tim          Acct        5         1/1/2023
Tim          Acct        6         2/1/2023
Tim          Acct        7         3/1/2023
Alex         IT          1         1/1/2023
Alex         IT          2         2/1/2023
Alex         IT          3         3/1/2023

And I want the output to look like this:

                       HOURS
ACCT                    26
Joe                     13
Tim                     13
IT                       6
Alex                     6

I can create a group, but there is still a "Details" row with the 3 lines - do I need to hide that? Or is there a way to create a tablix where I can group/sum the data up by DEPT and NAME?

Help is appreciated thank you!