out on bail
Released from custody on the basis of bail being posted, as in The lawyer promised to get him out on bail. This expression alludes to a payment made to the court as surety that the accused will appear for trial.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.