STOCK-BASED PLANS - Restricted Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Stock-based plans
Restricted stock and stock option amortization			$ 5,269	$ 5,940
Weighted Average Grant Date Fair Value
Stock based compensation expense			5,269	5,940
Restricted Stock
Stock-based plans
Restricted stock and stock option amortization	$ 1,300	$ 1,100	$ 3,400	2,900
Restricted stock activity
Restricted stock outstanding at the beginning of the period (in shares)			172,690
Granted (in shares)			80,913
Vested (in shares)			(7,546)
Forfeited (in shares)			(4,169)
Restricted stock outstanding at the end of the period (in shares)	241,888		241,888
Weighted Average Grant Date Fair Value
Restricted stock outstanding at the beginning of the period (in dollars per share)			$ 92.02
Granted (in dollars per share)			121.59
Vested (in dollars per share)			147.56
Forfeited (in dollars per share)			101.33
Restricted stock outstanding at the end of the period (in dollars per share)	$ 100.02		$ 100.02
Stock based compensation expense	$ 1,300	$ 1,100	$ 3,400	$ 2,900