Today the Supreme Court held that the Defense of Marriage Act is unconstitutional. The bottom line is that if a same-sex couple has a legal marriage under its state laws, the couple is entitled to federal benefits. For example, the particular benefit in Windsor v. Spyer was a tax refund due because of estate tax calculations after one of the partners died.
However, Idaho does not recognize same-sex marriages, so those partnerships are not entitled to federal benefits. Same-sex partners in Idaho should consider arranging their financial and legal affairs through contract.