Report of the Select Committee on Intelligence, United States Senate on Russian Active Measures Campaigns and Interference in the 2016 U.S. Election; Volume 4: Review of the Intelligence Community Assessment with Additional Views (Redacted) [open pdf - 26MB]
From the Findings: "[U] The Committee found the ICA [Intelligence Community Assessment] presents a coherent and well-constructed intelligence basis for the case of unprecedented Russian interference in the 2016 U.S. presidential election. On the analytic lines of the ICA, the Committee concludes that all [...] analytic lines are supported with all-source intelligence, although with varying substantiation. The Committee did not discover any significant analytic tradecraft issues in the preparation or final presentation of the ICA."
S. Rept. II6-XX; Senate Report 116-XX
U.S. Senate Select Committee on Intelligence: https://www.intelligence.senate.gov/