After installing the latest Ubuntu updates, Idea started having issues navigating through and editing strings. The characters would not render correctly and the cursor was not on the character that was displayed (usually off by 1 position). This made editing strings near impossible. After searching for many hours, I could not find anything posted that related to the problem, but after trial and error with many different JDK's and IDEA versions, it appears that switching to JDK 1.6.x fixed the problem.
Not sure if the root cause is something in the JDK, the newer IDEA editor (10.5.x and 11.0.x) or if it is something to do with the latest ubuntu updates that were applied. But, using a native editor like Gedit or Vi worked fine.