Obtain AutoIncrement Field Data after Insert operation in Oracle

Question

I have a master table in Oracle with the primary key is an autoincrement field, so the question is how can I obtain the autoincrement field after I performed an insert operation in the table? Because I need it to insert into my detail table too... I knew in MSSQL Server, I Can use @@IDENTITY to get the identity value after insertion for my session, is that any similiar command in Oracle ?? Thank you