Though technically not "congressional documents" these are included as they often requested and sometimes confused as being such.
"The Code of Federal Regulations (CFR) annual edition is the codification of the general and permanent rules published in the Federal Register by the departments and agencies of the Federal Government. It is divided into 50 titles that represent broad areas subject to Federal regulation. The 50 subject matter titles contain one or more individual volumes, which are updated once each calendar year, on a staggered basis." [source]
Beginning in 1936, the Federal Register (FR),"published by the Office of the Federal Register, National Archives and Records Administration (NARA), the Federal Register is the official daily publication for rules, proposed rules, and notices of Federal agencies and organizations, as well as executive orders and other presidential documents. It is updated daily by 6 a.m. and is published Monday through Friday, except Federal holidays." [source]
"The List of CFR Sections Affected (LSA) lists proposed, new, and amended Federal regulations that have been published in the Federal Register since the most recent revision date of a Code of Federal Regulations (CFR) title." [source]