See https://ttlc.intuit.com/community/income/help/how-do-i-allocate-split-income-for-a-part-year-state-r...
I'm not specifically familiar with the ID software. But generally, it goes like this: once you tell TT, in the personal info section that your were part year residents of two states, you will get allocation screens in the state software. It will either ask you to allocate your ID income or your non ID income (read carefully).
Some (most) times the allocation screens will not allocate W-2 income. Instead, you allocate at the W-2 screen (in the federal section) by state abbreviation in box 15. Because TX does not have an income tax, the employer may not show this on the actual paper W-2. You have to type in info for boxes 15 and 16. Put TX in box 15 and the amount of wages allocated to TX in box 16. Use a 2nd line at the W-2 screen to show ID in box 15, the portion of wages, for the time in ID, in box 16 and ID withholding in box 17.
