ASSETS CONSTRUCTED FOR OTHERS (TERMINAL 6 AT LAX) (DETAILS) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Sale Leaseback Transaction [Line Items]
Other liabilities	$ 204.8	$ 176.7
LAX airport project proprietary assets [Member]
Sale Leaseback Transaction [Line Items]
Other property and equipment	16.3	8.7
LAX airport project assets constructed for other [Member]
Sale Leaseback Transaction [Line Items]
Other property and equipment	219.2	143.4
LAX airport project total cost [Member]
Sale Leaseback Transaction [Line Items]
Other property and equipment	235.5	152.1
LAX airport project reimbursement [Member]
Sale Leaseback Transaction [Line Items]
Other liabilities	46.3	17.7
LAX airport project capitalized interest [Member]
Sale Leaseback Transaction [Line Items]
Other property and equipment	$ 6.0	$ 4.5