Learning the identity framework in MVC 5

I have been reviewing the videos and documentation at https://www.asp.net/identity and while the code is easy to understand, I find it lacking as far as providing a solid understanding. This topic does not seem to yield nearly as many resources as other topics for MVC and hence I have not found another resource that is more thorough.

Does anyone by chance know of a good resource or even a book that is thorough? I have read through Pro ASP.NET MVC 5 Platform by Apress, and while again the code is simple, its obfuscated in the authors opinions and not very deep other than "this code does the job" approach.

I'd be grateful for any opinions and recommendations.

Thanks!