CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Revenue:
Commercial real estate	$ 134.7	$ 133.6	$ 125.3
Land operations	61.9	120.2	96.7
Materials and construction	190.9	219.0	234.3
Total operating revenue	387.5	472.8	456.3
Operating Costs and Expenses:
Cost of commercial real estate	79.0	80.4	78.0
Cost of land operations	35.0	71.1	57.4
Cost of materials and construction contracts	154.5	175.7	191.3
Selling, general and administrative	56.2	55.3	52.9
REIT evaluation costs	9.5	0.0	0.0
Impairment of real estate assets	11.7	0.0	0.0
Total operating costs and expenses	345.9	382.5	379.6
Operating Income	41.6	90.3	76.7
Other Income and (Expense):
Income related to joint ventures	19.2	36.8	1.8
Gain (loss) on the sale of improved property, net	8.1	(1.8)	0.0
Reduction in solar investments, net	(9.8)	(2.6)	(14.7)
Interest income and other	2.5	1.2	6.1
Interest expense	(26.3)	(26.8)	(29.0)
Income From Continuing Operations Before Income Taxes	35.3	97.1	40.9
Income tax expense	2.6	36.3	4.1
Income From Continuing Operations	32.7	60.8	36.8
Income (Loss) from discontinued operations, net of income tax	(41.1)	(29.7)	27.7
Net Income (Loss)	(8.4)	31.1	64.5
Income attributable to noncontrolling interest	(1.8)	(1.5)	(3.1)
Net Income (Loss) Attributable to A&B	$ (10.2)	$ 29.6	$ 61.4
Basic Earnings (Loss) per Share of Common Stock:
Continuing operations available to A&B shareholders (in dollars per share)	$ 0.66	$ 1.15	$ 0.69
Discontinued operations available to A&B shareholders (in dollars per share)	(0.84)	(0.61)	0.57
Net income available to A&B shareholders (in dollars per share)	(0.18)	0.54	1.26
Diluted Earnings (Loss) per Share of Common Stock:
Continuing operations available to A&B shareholders (in dollars per share)	0.65	1.14	0.68
Discontinued operations available to A&B shareholders (in dollars per share)	(0.83)	(0.60)	0.57
Net income available to A&B shareholders (in dollars per share)	$ (0.18)	$ 0.54	$ 1.25
Weighted Average Number of Shares Outstanding:
Basic (in shares)	49.0	48.9	48.7
Diluted (in shares)	49.4	49.3	49.3
Amounts Available to A&B Shareholders:
Income from continuing operations available to A&B shareholders, net of tax	$ 32.2	$ 56.2	$ 33.7
Income (Loss) from discontinued operations, net of income tax	(41.1)	(29.7)	27.7
Net Income (Loss) Available to A&B shareholders	$ (8.9)	$ 26.5	$ 61.4