RegEx to Remove Dash

I have the following strings a wish to remove the dash from the 1st example but not the second

Could somebody please help me

Bob Marley -
Bob Marley - The King of Reggae

Result
Bob Marley
Bob Marley - The King of Reggae

Use the function: $trimRight

DD.20140813.1255.CEST

Use an action of the type "Replace with regular expression"
Enter as search string: " -$"
(leave out the " - I needed them to show the blank)
leave Replace string empty.