Earnings Per Share (“EPS”) - Schedule of Reconciliation of Income from Continuing Operations and Computation of Earnings per Share (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Income from continuing operations, net of tax	$ 7.0	$ 10.8	$ 43.0	$ 22.1
Less: Noncontrolling interest	(0.3)	(0.6)	(1.2)	(2.0)
Income from continuing operations available to A&B shareholders, net of tax	6.7	10.2	41.8	20.1
Less: Undistributed earnings allocated to redeemable noncontrolling interests	(1.3)	0.0	(1.3)	0.0
Income from continuing operations attributable to A&B shareholders, net of tax	5.4	10.2	40.5	20.1
Income from discontinued operations available to A&B shareholders, net of tax	0.0	0.0	0.0	34.3
Net income attributable to A&B	$ 5.4	$ 10.2	$ 40.5	$ 54.4
Shares used to compute basic and diluted earnings per share [Abstract]
Denominator for basic EPS - weighted average shares (in shares)	48.9	48.8	48.8	48.7
Effect of dilutive securities:
Employee/director stock options and restricted stock units (in shares)	0.5	0.5	0.5	0.5
Denominator for diluted EPS - weighted average shares (in shares)	49.4	49.3	49.3	49.2