Share-based Compensation - Stock Option Activity Under 2023 Incentive Award Plan (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	7 Months Ended	9 Months Ended	12 Months Ended
	Jul. 21, 2023	Sep. 30, 2023	Sep. 30, 2024	Jul. 21, 2023	Sep. 30, 2024	Dec. 31, 2023
Options, Weighted Average Exercise Price
Share-based compensation expense	$ 0.7	$ 2.2	$ 1.6	$ 3.2	$ 4.9
AEON Biopharma Inc 2023 Incentive Award Plan | Stock options
Options, Number of Shares
Outstanding, beginning of period					331,753
Options granted					3,428,692
Options forfeited					(88,229)
Outstanding, end of period			3,672,216		3,672,216	331,753
Exercisable, end of period			254,238		254,238
Options, Weighted Average Exercise Price
Outstanding, beginning of period					$ 5.47
Options granted					3.36
Options forfeited					11.26
Outstanding, end of period			$ 3.36		3.36	$ 5.47
Exercisable, end of period			$ 2.70		2.70
Weighted average fair value of options granted per share					$ 2.00	$ 3.18
Weighted average remaining contractual life of options exercisable					9 years 8 months 12 days	9 years 7 months 6 days
Share-based compensation expense		$ 0.1	$ 0.5		$ 1.0
Unrecognized compensation expense related to non-vested stock options			$ 5.9		$ 5.9	$ 0.9
Weighted-average remaining requisite service period for which unrecognized compensation expense					22 months	35 months