Absolute signs are signs that tell the number away from 0. So the absolute number cannot be negative. |x| = x. You don't know if the number was positive or negative. |-x|. |-x| is x since it tells it's x away from 0. -|x| is -x. Since the negative sign isn't in the absolute signs, you keep it as -15.
The negative is outside of the absolute value signs/lines. The absolute value is how far the number is from 0. So, it doesn't matter whether or not there is a negative sign inside of the absolute value lines it will always be positive. But, if it's outside of it, then it will be negative.
