SHAREHOLDERS' EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
	Jul. 12, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	May. 12, 2015	May. 11, 2015
Option Exercises
Options exercised during period (in shares)		304,308	279,544	1,089,032	1,248,117
Net proceeds from options exercised during the period		$ 1.9	$ 1.7	$ 7.5	$ 6.5
Common Stock
Increase in authorized shares of common stock						100,000,000
Authorized shares of common stock						200,000,000	100,000,000
Series B Junior Participating Preferred Stock
Shareholders' equity
Number of shares that each right entitles the holder to purchase	1
Rights Plan
Dividends declared as rights per share	1
Number of shares that each right entitles the holder to purchase	1
Purchase price per fractional share	$ 105.00
Number of days on which beneficial ownership is ten percent or more of outstanding share.	10 years
Beneficial ownership (as a percent)	10.00%
Number of business days from commencement of tender or exchange offer	10 years