Idaho Code § 2-502: Grand jury — How constituted — Quorum.

Sixteen (16) persons shall constitute a grand jury, twelve (12) of whom shall constitute a quorum, and when of the jurors summoned, no more nor less than sixteen (16) attend they shall constitute the grand jury. If more than sixteen (16) attend the clerk shall call over the list summoned, and the sixteen (16) first answering shall constitute the grand jury. If less than sixteen (16) attend, the panel may be filled to sixteen (16).