Description of Business: (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended			9 Months Ended		1 Months Ended		9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2012 item	Sep. 30, 2012 SSAT	Jun. 30, 2012 Alexander & Baldwin	Dec. 31, 2011 Alexander & Baldwin item	Sep. 30, 2012 Alexander & Baldwin item	Dec. 31, 2012 Alexander & Baldwin	Jun. 29, 2012 Alexander & Baldwin
Description of Business
Number of vessels owned				17
Ownership interest in SSAT (as a percent)					35.00%
Number of terminal facilities on which SSAT provides terminal and stevedoring services to Matnav and numerous international carriers				6
Number of publicly traded companies to be created after separation							2
Jones Act requirement to maintain status as U.S. citizen, maximum ownership interest permitted by non-U.S. citizens (as a percent)								22.00%
Number of shares of common stock of A&B received for each share upon separation										1
Maximum period during which services are to be provided under Transition Services Agreement						24 months
Capital distribution to A&B								$ 155.7
Separation costs	0.3	5.8	2.5	8.6				8.6
Capitalized debt financing costs								1.9
Total cash outflow related to the Separation								166.2
Number of cash outflow components								3
Net distribution in relation to separation	$ 4.3			$ 4.3				$ 3.6	$ 0.7