Rachel,
I dont think so any direct Report will be available just to get Error IDOCs details. Although you can create a simple report to read the tables. An example is in below link.
http://wiki.scn.sap.com/wiki/display/Snippets/Custom+report+for+IDOC+Monitoring
Also, you can create a Query of EDIDC and EDIDS tables to obatin relevant information.
Thanks,
Ravi