Share-based Compensation - Stock Option Activity Under 2019 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	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
ABP Sub Inc. 2019 Incentive Award Plan
Options, Number of Shares
Outstanding, beginning of period						3,515,219
Options granted							0
Options forfeited						(63,748)
Outstanding, end of period				3,451,471		3,451,471	3,515,219
Exercisable, end of period				2,815,063		2,815,063
Options, Weighted Average Exercise Price
Outstanding, beginning of period						$ 10.00
Options granted	$ 10.00
Options forfeited						10.00
Outstanding, end of period				$ 10.00		10.00	$ 10.00
Exercisable, end of period				$ 10.00		$ 10.00
Weighted average remaining contractual life of options outstanding						6 years 3 months 18 days	7 years 1 month 6 days
Share-based compensation expense	$ 1.0
Unrecognized compensation expense related to non-vested stock options				$ 2.5		$ 2.5	$ 4.9
Weighted-average remaining requisite service period for which unrecognized compensation expense						5 months	10 months
ABP Sub Inc. 2019 Incentive Award Plan | Stock options
Options, Weighted Average Exercise Price
Share-based compensation expense		$ 0.2	$ 1.6	$ 0.7	$ 2.7	$ 2.3