hardheaded
1. Inflexible; stubborn; overly willful or obstinate. Also written as "hard-headed." Our son is so hardheaded. Once he's made up his mind about something, there's no way anyone can change it! We've got a hard-headed new boss in the office who thinks her way of doing things is the only correct one.
2. Very practical and shrewd; not concerned with or influenced by emotions. Also written as "hard-headed." We've hired a consultant to give us a hardheaded analysis of the company's future.