STOCK-BASED PLANS - Restricted Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jun. 30, 2014
Stock-based plans
Restricted stock and stock option amortization		$ 3,232	$ 3,818
Weighted Average Grant Date Fair Value
Stock based compensation expense		3,232	$ 3,818
Restricted Stock
Stock-based plans
Restricted stock and stock option amortization	$ 1,200	$ 2,100
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)		(4,002)
Restricted stock outstanding at the end of the period (in shares)	242,055	242,055
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
Forfeited (in dollars per share)		147.56
Restricted stock outstanding at the end of the period (in dollars per share)	$ 100.05	$ 100.05
Stock based compensation expense	$ 1,200	$ 2,100