I don't think either of Arrius's suggestions is negative. Many people would like to be called meticulous, or fastidious. I see a difference between them, however:
Meticulous applies to detail in work - getting everything exactly right. Mathematicians need to be meticulous.
Fastidious applies to detail in dress or food, for instance. I knew someone who preferred to die of bowel cancer, than to have an operation which would have left him with a colostomy bag. We could describe that decision as showing how fastidious he was, but not say that this showed he was meticulous.
Main Entry:me·tic·u·lous Pronunciation: \mə-ˈti-kyə-ləs\ Function:adjective Etymology:Latin meticulosus fearful, irregular from metus fearDate:1827 : marked by extreme or excessive care in the consideration or treatment of details <a meticulous researcher> synonyms see careful
We quite a long way away from the OP of this thread. A "person who pays attention to details" sounds in no way negative to me. "Meticulous" and "thorough" have already been suggested. A person who pays attention to details in the sense of being extraordinarily aware of detail might be called "perceptive".
I am going to ask this question here as the context is the same on the thread (O.P). My question: Is it natural/correct to use "detail" in the examples I made below, meaning/context (= pay attention to details)?
a. Mary is a detailwoman.
b. John is a detailman.
c. I am a detailperson.
d. I am not a detailperson.
It is possible to say informally "I am an X person" with almost any adjective or noun ("I'm a dog person"), but it would be much better in this case to say "a detail-oriented person." It's clearer and we know that you don't detail cars (clean and polish all the small details of a car) for a living.