Expanding upon or elaborating on a topic are antonyms for the phrase "putting in a nutshell." When we "put something in a nutshell," we convey a concise and condensed version of a larger idea or concept. Antonyms, therefore, are words or phrases that imply taking up more space, time, or explanation. Some synonyms for expanding on an idea include "delving deeper," "exploring thoroughly," and "going into detail." These antonyms are often used when we want to provide a thorough and complete understanding of something rather than simply summarizing it. While "putting in a nutshell" can be useful in certain contexts, reckoning with the complexity and nuance of a subject sometimes requires more substantial explanations.