Description of Business: (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended			0 Months Ended		3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 item	Sep. 30, 2012	Sep. 30, 2013 SSAT Ocean Transportation item	Jun. 08, 2012 Alexander & Baldwin	Dec. 01, 2011 Alexander & Baldwin item	Dec. 31, 2012 Alexander & Baldwin item	Sep. 30, 2012 Alexander & Baldwin	Jun. 30, 2012 Alexander & Baldwin	Mar. 31, 2012 Alexander & Baldwin	Sep. 30, 2013 Alexander & Baldwin	Sep. 30, 2012 Alexander & Baldwin	Dec. 31, 2012 Alexander & Baldwin item	Jun. 29, 2012 Alexander & Baldwin
Description of Business
Number of vessels owned			18
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 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
Number of cash outflow components								3						3
Capital distribution to A&B														$ 155.7
Separation costs		0.3		8.6									8.6	8.6
Capitalized debt financing costs														1.9
Total cash outflow related to the Separation														166.2
Net distribution in relation to separation								4.3						4.3
Contribution paid upon Separation				155.0				0.7	3.6
Separation costs, net of tax									0.3	5.8	2.5
Deposits into Capital Construction Fund	111.8		(4.4)	(4.4)
Undivided interest in trade receivables assigned to the capital construction fund	$ 111.8