Code-only answers are usually avoided, since the value added does not pertain to a wider audience as much as an explanation would. However, the amount of explanation is varied (as you noticed). For example, some people like an answer structured in the form:
while others tend to enjoy
The former is intended to suit a broad audience (experienced and inexperienced), since the solution is provided without having to wade through "tedious" explanations and reasoning, while still adding value post mortem.
I think your best bet as a questioner is to post a comment to the answered requesting more information. Ultimately you decide where to place your vote (an indication as to the "usefulness" of the answer) and/or select the "most useful" answer. These selections/decision, of course, bestow reputation as a reward. If it isn't useful, then don't vote.
Alternatives could include opening up a chat room and create a discussion around the solution so you can understand it better. This is typically done in the the general chat room since most regulars hang out there and would be willing to help. Or, perhaps as a last resort, ask a follow-up question about the specifics of the solution. However, make sure that you're not just asking for an explanation, because that is best left as an addition to existing answers, in my opinion.
Perhaps some answer(er)s require incentive in order to provide detail. I guess a bounty could be issued for that, usually also garnering more answers from other experienced users. But, posters on this site are usually easy to provide more detail from a comment making this not really necessary.