"This kind of material, even on a historical basis, has simply not been available,” Steven Aftergood, an expert at the Federation of American Scientists, a Washington, D.C., organization that provides analyses of national security issues, told The Post.

The budget of $52.6 billion — which not include funding for intelligence gathering by the military — is located in the summary of the Office of the Director of National Intelligence's multivolume FY 2013 Congressional Budget Justification.

Barton Gelmman and Greg Miller note that the 178-budget summary "maps a bureaucratic and operational landscape that has never been subject to public scrutiny," adding that it "details the successes, failures and objectives" of the 17 U.S. spy agencies.