Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479830/718-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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-Publisher FASB
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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

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Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Share-based Compensation Stock Incentive Plans - Share-based Compensation Expense and Valuation Information (Details) - USD ($) $ in Millions		3 Months Ended		5 Months Ended	7 Months Ended	12 Months Ended
	Jul. 21, 2023	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Jul. 21, 2023	Dec. 31, 2023	Dec. 31, 2022
Assumptions
Expected volatility						57.00%
Expected volatility, minimum		47.00%	74.00%				47.00%
Expected volatility, maximum		50.00%	80.00%				61.00%
Risk-free interest rate, minimum		4.10%	3.61%			4.10%	1.87%
Risk-free interest rate, maximum		4.30%	3.66%			4.40%	3.92%
Minimum
Assumptions
Expected life (in years)		5 years 3 months 7 days	5 years 6 months			3 years	5 years 9 months
Maximum
Assumptions
Expected life (in years)		6 years 3 months	6 years 3 months			6 years 3 months	6 years 3 months
ABP Sub Inc. 2019 Incentive Award Plan
Share-based Compensation Expense
Share-based compensation expense	$ 1.0
Selling, general and administrative expenses
Share-based Compensation Expense
Share-based compensation expense		$ 1.2	$ 1.2	$ 3.1	$ 2.8		$ 5.9
Selling, general and administrative expenses \| ABP Sub Inc. 2019 Incentive Award Plan
Share-based Compensation Expense
Share-based compensation expense		0.2
Selling, general and administrative expenses \| ABP Sub Inc. 2019 Incentive Award Plan \| Successor period, July 22, 2023, to September 30, 2023
Share-based Compensation Expense
Share-based compensation expense				0.4
Research and development expenses
Share-based Compensation Expense
Share-based compensation expense		$ 0.4	$ 0.2	$ 0.8	$ 0.4		$ 1.3