Adjective classification in this sentence

In the phrase: "in a good many ways." are good and many adjectives? And if so, are they each descriptor or classifier?

Or is the phrase 'good many' idiomatic? And if so, can 'good' and 'many' be classified seperately or is there a different approach to this?

(I am using the Longman grammar textbook)

Solution 1:

"A good many" is an idiom (Cambridge); therefore, parsing it is irrelevant. One cue that confirms that is that the number of the following noun is plural; "a" is not an article determining the noun, just as "in a few days". In CGEL "a good many" and "a few" are said to "function as a unit"; they are classified as post-determiners of the type of the closed-class quantifiers (a finite unchanging number of quantifiers: many, several, (a) few, a lot of (chiefly in informal style)…).