I have no idea, and neither do you.
The documents were created by the Deep State. They were created by Comey's FBI and Lynch's DOJ. And Deep State Rosenstein still controls the documents. They already know what's in them. Giving the documents to Congress won't give the bad guys any more information than they already have.
Giving the documents to Congress, gives information about the Deep State to the number of folks on the committees who are the good guys.
And Congress has the Constitutional authority to get the documents.