Well I would say it's good to think sometimes but not overthinking per say. I happen to have this friend that over thinks, when I mean over things I mean he practically over things everything; just a little thing to decide or act on, he just keep thinking about many other possibilities in his head and sometimes find himself being into a state of confusion, emotional and stressed just because of thinking.
Overthinking can actually cause someone to be in a state of dilemma you know sometimes even confused about the decisions you are to make. it's better you just think out what you need to do on a minimal level like give it a thought, probably do researches and make a good decision instead of burdening yourself with thinking too much.