I'm a resident of washingtion state, i worked in idaho. i already entered my w-2 info, when it asks to enter idaho income amount is it asking for the income from the w-2?

Yes. If you are working on your IA nonresident state income tax return then you will allocate all income related to your work done in IA to your IA nonresident state income tax return. So if the amounts shown on your W-2 relate to IA-source wages, then when asked to allocate your IA-sourced income on your IA nonresident state income tax return, you will include both of these W-2 amounts.