How do I hide payroll details from my users but still show them the payroll total?

In user permissions you can choose which categories/accounts a user can view, and at which level of detail.

To ensure that a user only sees the total payroll, and not any of the individual employee payroll details, edit their user permissions.

Go to Users > All Users, select the employee you need to work on by clicking the edit toll (pencil icon) at the right of the screen.

There are two drop down menus that allow you to choose which categories the user can see, and at what level of detail.

Accessible Detail Categories allows you to choose the categories which the user will be able to see completely.

Accessible Summary Only Categories allows you to choose categories in which the user will only be able to see the total, and none of the sub category detail. They will not be able to edit these categories.

If you select your payroll accounts in the second menu the user will see something like this in the Data Sheet:

It now says Summary Only next to the name of the account, and the i symbol explains why.