SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details) $ / shares in Units, shares in Millions								1 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2015 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares	Mar. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($) $ / shares	Sep. 30, 2014 USD ($) $ / shares	Jun. 30, 2014 USD ($) $ / shares	Mar. 31, 2014 USD ($) $ / shares	Jan. 31, 2015 $ / shares	Apr. 30, 2014 $ / shares	Oct. 31, 2013 Quarter $ / shares	Sep. 30, 2015 USD ($) shares	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) shares	Oct. 28, 2015 USD ($)	Jul. 28, 2015 USD ($)	Oct. 31, 2012 USD ($)
Class of Stock [Line Items]
Net Product Sales to Distributors, Percentage											76.00%		75.00%
Deferred Revenue, Gross	$ 28,400,000			$ 25,000,000							$ 28,400,000		$ 25,000,000
Other Deferred Costs, Net	11,900,000			9,800,000							$ 11,900,000		$ 9,800,000
Stock Repurchased and Retired During Period, Shares | shares											1.3		1.6
Stock Repurchased and Retired During Period, Value											$ 53,700,000		$ 80,800,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	0										0
Common Stock, Dividends, Per Share, Declared (in dollars per share) | $ / shares								$ 0.12	$ 0.12	$ 0.10
Payments of Dividends	$ 3,500,000	$ 3,500,000	$ 3,500,000	$ 3,500,000	$ 3,600,000	$ 3,000,000	$ 3,000,000				$ 10,501,000	$ 9,654,000
Common Stock, Dividends, Per Share, Cash Paid (in dollars per share) | $ / shares	$ 0.12	$ 0.12	$ 0.12	$ 0.12	$ 0.12	$ 0.10	$ 0.10
Common Stock, Dividends, Per Share, Declared, Fiscal 2015, Period Four (in dollars per share) | $ / shares								$ 0.12
Dividends Declared, Number Of Quarters | Quarter										4
Common Stock [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount				$ 75,000,000									$ 75,000,000		$ 30,000,000	$ 50,000,000
Common Stock [Member] | Subsequent Event [Member]
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount														$ 30,000,000