STOCK (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			3 Months Ended			1 Months Ended	3 Months Ended		25 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2010	Mar. 31, 2012 Common Stock	Mar. 31, 2011 Common Stock	Dec. 31, 2010 Common Stock	Mar. 31, 2010 Treasury Stock	Mar. 31, 2012 Treasury Stock	Mar. 31, 2011 Treasury Stock	Mar. 31, 2012 Treasury Stock
Changes in common shares and treasury stock
Common stock issued, balance at beginning of period	205.1		204.8	205.1	204.8	204.8
Treasury stock balance at beginning of period								1.4	0.1
Stock-based compensation	$ 13.6
Stock-based compensation (in shares)				0.6				0.2
Treasury stock purchases								0.2	0.4
Common stock issued, balance at end of period	205.7		204.8	205.7	204.8	204.8
Treasury stock balance at end of period								1.8	0.5	1.8
Balance, beginning of period (in dollars )	89.7	26.9	3.2					89.7	3.2
Stock-based compensation (in dollars )								13.6
Treasury stock purchases (in dollars )								17.2	23.7
Balance, end of period (in dollars )	120.5	26.9	3.2					120.5	26.9	120.5
Shares authorized to be repurchased							$ 300.0	$ 1.5
Shares repurchased, average cost per share										$ 66.69