TREASURY STOCK PURCHASE (Details) (USD $) In Millions, except Per Share data	3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Jun. 30, 2010
TREASURY STOCK PURCHASE
Amount of common stock the board of directors authorized to repurchase	$ 200.0
Common stock repurchased (in shares)		0.7	0.6
Average purchase price (in dollars per share)		$ 54.88	$ 37.68
Common stock repurchased	38.9	38.9	23.5
Amount remained available under the plan for the repurchase of common stock		$ 137.6