CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY [Abstract]
Dividends	$ 1.26	$ 1.26	$ 1.26
Deferred taxes related to net gain/prior service cost	$ (10)	$ (10)	$ 5
Deferred taxes related to amortization of net loss/prior service cost	$ 5	$ 6	$ 5

For each annual statement of income presented, the tax effect of the net gain (loss) recognized in other comprehensive income that is a reclassification adjustment of other comprehensive income as a result of being recognized as a component of net periodic benefit cost for the period, and the tax effect on adjustment out of other comprehensive income for prior service costs recognized as a component of net period benefit cost during the period.

No definition available.

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Namespace Prefix:	alex_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration