CHANGE IN WORKING CAPITAL (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CHANGE IN WORKING CAPITAL
(Increase)/decrease in accounts receivable and other	$ (0.1)	$ (0.1)	$ 2.8
(Decrease)/increase in accounts payable and accrued liabilities	(2.7)	3.2	(0.8)
Decrease in accrued interest	(0.2)		(2.4)
Change in working capital	(3.0)	3.1	(0.4)
Increase in investing working capital			(2.9)
(Increase)/decrease in operating working capital	$ (3.0)	$ 3.1	$ 2.5