Held for Sale and Discontinued Operations - Schedule of Income From Discontinued Operations, Net of Taxes And Noncontrolling Interest Included in Consolidated Statements Of Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of assets	$ (2.2)
Income tax benefit (expense) attributable to discontinued operations		$ 3.2	$ 1.1	$ 0.4
Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]		Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue		$ 201.2	$ 171.2	$ 126.2
Cost of sales		(178.1)	(153.5)	(121.0)
Selling, general and administrative		(15.8)	(14.5)	(15.6)
Impairment of assets		0.0	(89.8)	(26.1)
Gain (loss) on disposal of non-core assets, net		(13.2)	0.1	0.1
Operating income (loss) from discontinued operations		(5.9)	(86.5)	(36.4)
Income (loss) related to joint ventures		(1.5)	(0.4)	(0.4)
Impairment of equity method investments		0.0	0.0	(2.9)
Interest and other income (expense), net		0.1	0.5	0.2
Interest expense		(0.5)	(0.2)	(0.1)
Income (loss) from discontinued operations before income taxes		(7.8)	(86.6)	(39.6)
Income tax benefit (expense) attributable to discontinued operations		0.0	0.0	0.0
Income (loss) from discontinued operations		(7.8)	(86.6)	(39.6)
Loss (income) attributable to discontinued noncontrolling interest		(3.2)	(1.1)	(0.4)
Discontinued operations available to A&B common shareholders		(11.0)	(87.7)	(40.0)
Disposal group, including discontinued operation, resolution of liabilities, costs		$ (0.1)	$ (0.4)	$ (1.1)

Held for Sale and Discontinued Operations - Schedule of Income From Discontinued Operations, Net of Taxes And Noncontrolling Interest Included in Consolidated Statements Of Comprehensive Income (Details) - USD ($)
$ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]

Impairment of assets

$ (2.2)

Income tax benefit (expense) attributable to discontinued operations

$ 3.2

$ 1.1

$ 0.4