Description of Business: (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended		3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 08, 2012	Dec. 01, 2011 item	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012 item	Jun. 29, 2012
Description of Business
Number of vessels owned						18
Separation costs				$ 5.8			$ 8.3
SSAT | Ocean Transportation
Description of Business
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
Alexander & Baldwin
Description of Business
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
Capital distribution to A&B								155.7
Separation costs							8.3	8.6
Capitalized debt financing costs								1.9
Total cash outflow related to the Separation				161.6				166.2
Net distribution in relation to separation								4.3
Separation costs, net of tax			$ 0.3	$ 5.8	$ 2.5