Where is the main idea usually found?

Main ideas are often seen in the beginning of the text. It can be found in different spots in the beginning, though.

Explanation:

For example, the thesis statement of an essay such as an argumentative essay is usually the last sentence of the introductory paragraph. Other times in just some sort of paper, it may be the first sentence of a paragraph. Like supporting detail paragraphs.

In the introduction. Usually the first sentence or the second sentence.