STOCK-BASED PLANS (Details 2)-K (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock-based plans
Recognized compensation expense	$ 8.2	$ 5.7	$ 4.3
Restricted Stock [Member]
Stock-based plans
Recognized compensation expense	3.9	2.2	1.3
Fair value of restricted stock vested	1.7
Unamortized restricted stock expense	10.4
Weighted-average period for recognition of unamortized restricted stock expense	3 years 3 months 29 days
Restricted stock activity
Restricted stock outstanding at the beginning of the period (in shares)	122,334	57,933	42,553
Granted (in shares)	61,750	77,434	27,933
Vested (in shares)	(11,394)	(13,033)	(12,553)
Restricted stock outstanding at the end of the period (in shares)	172,690	122,334	57,933
Weighted Average Grant Date Fair Value
Restricted stock outstanding at the beginning of the period (in dollars per share)	$ 75.21	$ 65.72	$ 65.18
Granted (in dollars per share)	$ 126.38	$ 79.77	$ 63.86
Vested (in dollars per share)	$ 97.72	$ 60.15	$ 59.77
Restricted stock outstanding at the end of the period (in dollars per share)	$ 92.02	$ 75.21	$ 65.72
Restricted Stock [Member] | General and Administrative Expense [Member]
Stock-based plans
Recognized compensation expense	$ 3.9