INVESTMENTS (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Schedule of Marketable Securities [Line Items]
Money market funds	$ 59.0	$ 82.9	$ 128.8
Corporate bonds	6.5	6.8	6.8
Other investments	9.2	8.5	6.1
Cash equivalents	8.7	12.6	62.3
Short-term investments	52.8	70.6	66.8
Long-term investments	13.2	15.0	12.6
Total marketable securities	74.7	98.2	141.7
Contractual maturities of the held-to-maturity investments: [Abstract]
Less than 1 year	2.1
1-5 Years	6.5
Total	8.6
Restricted investments, including certificates of deposit and bank accounts	2.4	2.0	2.1
Port facility development venture carried at cost	2.4
Trading securities [Member]
Schedule of Marketable Securities [Line Items]
Trading securities	$ 61.3	$ 85.0	$ 130.8