DEBT (Convertible Subordinated Notes) (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($) shares	Sep. 30, 2018 USD ($) shares	Sep. 30, 2017 USD ($)
Zero Coupon Convertible Subordinated Notes [Line Items]
Number of trading days used to establish contingent cash interest rate on zero-coupon subordinated notes (in days)	five
Principal Amount At Maturity Of Zero Coupon Subordinated Notes Converted		$ 300,000
Value Of Cash And Common Stock In Connection With Conversions Of Zero Coupon Subordinated Notes Settled In Current Period		700,000
Payments On Zero Coupon Subordinated Notes		$ 300,000	$ 25,100,000
Stock Issued During Period, Shares, Conversion of Convertible Securities | shares		0
tax benefit realized upon conversion of zero coupon convertible debt		$ 200,000
Zero-coupon convertible subordinated notes [Member]
Zero Coupon Convertible Subordinated Notes [Line Items]
Minimum contingent cash interest rate on zero-coupon subordinated notes (in hundredths)	0.125%
Stock conversion rate for zero-coupon subordinated notes (per thousand) | shares	13.4108	13.4108
Principal amount of zero-coupon subordinated notes	$ 1,000,000,000	$ 1,000,000,000