It's a good thing for Delaware and Idaho that they have powerful neighbors that export power or their lights would be out more than on. Delaware and Idaho generate less than 50% of the electricity that they consume.
See page 31 at: http://www.nrdc.org/air/pollution/benchmarking/files/benchmarking-2013.pdf.
The rest of the top 10 top electricity importers begins with Virginia in the third spot, Maryland, California, Tennessee, New Jersey, Massachusetts, South Dakota, and then Minnesota.
For the residents of these top ten electricity importing states, it is good to be an American, and they should thank the founders for the Interstate Commerce Clause of the United States Constitution. Distant power plants located in other states and the interstate movement of electricity keep the lights on in the top 10 electricity importing states.