I have found differing backgrounds on the name Idell.
When we searched - in Australia (where we came after leaving England - we found that the name originally went to England at the time of the Norman invasion from France.It was originally spelt ydel.It was originally found in England around Northampton.
Then there is the theory that it was related to a place in Yorkshire and was Anglo-Saxon in origin.
Our spelling of Idell has an apostrophe and a capital D - something that happened as a result of a falling out between my great-grandfather and his father - I believe.
As for where most of the Idell's in the US live I did see one report that had something like 23% in Texas - coincidentally where we lived whilst in the States for a time.