TREASURY STOCK PURCHASE (Details) (USD $) In Millions, except Per Share data	1 Months Ended		9 Months Ended
	Oct. 31, 2011	Mar. 31, 2010	Sep. 30, 2011	Sep. 30, 2010
TREASURY STOCK PURCHASE
Amount of common stock the board of directors authorized to repurchase		$ 200.0
Common stock repurchased (in shares)			2.1	0.6
Average purchase price (in dollars per share)			$ 69.92	$ 37.68
Common stock repurchased			149.0	23.6
Additional shares purchased, subequent to period			0.3
Average purchase price, subequent to period (in dollars per share)			$ 79.56
Amount of shares the board of directors authorized to repurchase, subequent to period	$ 250.0