You and your husband really need to talk with a good immigration attorney. Take some time, call around and find the one that you think will take your husband's case seriously. I wish you and your husband good luck.
Hire a lawyer ASAP. If he's a green card holder he has more chances to stay in the U.S. However, with the ICE detainer and the criminal conduct, he'll likely be detained by ICE upon the completion of his current incarceration. He'll need to begin working to solidify his right to status in the U.S. now rather than waiting.
If ICE has put a hold on him, it is unlikely he'll be going to any halfway house as he has a detainer - a detainer basically says, "Do not release this person until we've dealt with him." If the detainer were from another jail, upon completion of his current sentence, he'd be held until the new jail/county came to pick him up. In this case, he'll be held until ICE decides what to do with him. As the others have said, you need to speak with an Immigration attorney asap.
This response is for general purposes only and does not establish an attorney-client relationship. You should contact an attorney to fully discuss your issues.