If you didn't earn/receive any income after the move to Idaho then you don't need to file a part-year return for Idaho. If that's the case then you can, if you like, file a full-year resident Calif return - that's easier than a part-year return and will have the same result if all income was earned while you were in Calif. You should file part-year returns for both states if you received income while in Idaho in 2016.
