Actually, you're right. I found this pretty interesting. I thought that detention required disclosure of ID, but apparently not... So I learned something today.
Caselaw is: Dutton v. Hayes-Pupko
I stand corrected.
Apparently LEOs get this wrong too, so be careful if you want to stand your ground.
It's worth noting that this is particular to Texas - it is not the same in other states. It's also worth noting that the US Supreme Court has ruled (Hiibel v Nevada) that a state can prosecute someone who refused to ID while detailed... I guess it's just not on the books in Texas (yet).
I thought that one possible exclusion for this would be if you are a passenger in a car that is stopped for a valid violation, you'd be a witness to a crime and required to ID. And apparently TXDPS thinks this way too, as they've arrested passengers for failure to ID. However, there is an internal memo on that issue, indicating that they should not get upset by passengers who don't comply, unless they have "articulable" suspicion - which isn't supported by Texas state law:
http://libertyfight.com/2013/tx_trooper ... to_id.html" onclick="window.open(this.href);return false;