relaxed and unconcerned
insouciance - casualness
The formal word ‘insouciance’ expresses an attitude of not caring or worrying about things. While that can be an advantageous way to be in some situations, demonstrating such a lack of concern can also lead to problems, particularly in a professional environment. As such, the word has both positive and negative connotations.
Allison has a lot on her plate at the moment but she remains cheerful and untroubled. I admire her insouciance.
I asked Adam whether anybody had informed the client of the latest development. He responded with an insouciant shrug which suggested he couldn’t care less.
The laid back attitude that permeates the company has created an insouciance among the staff which negatively impacts productivity.