STOCK-BASED PLANS (Details) (USD $)	6 Months Ended	3 Months Ended
	Jun. 30, 2012 Options	Jun. 30, 2012 Restricted common stock	Jun. 30, 2012 Restricted common stock Certain non-employee directors	Jun. 30, 2011 Restricted common stock Certain non-employee directors
Stock-based plans
Vesting period (in years)	5 years
Expiration period (in years)	10 years
Shares granted		14,900
Shares granted, weighted-average grant date fair value (in dollars per share)		$ 67.11
Stock Options
Stock Options Outstanding at the beginning of the period (in shares)	712,640
Granted (in shares)	157,000		13,033	8,953
Forfeited (in shares)	(24,200)
Stock Options Outstanding at the end of the period (in shares)	845,440
Weighted Average Exercise Price
Stock Options Outstanding at the beginning of the period (in dollars per share)	$ 57.72
Granted (in dollars per share)	$ 63.34		$ 60.15	$ 65.04
Forfeited (in dollars per share)	$ 60.09
Stock Options Outstanding at the end of the period (in dollars per share)	$ 58.70
Shares of restricted stock outstanding		57,933