DEBT (Convertible Subordinated Notes) (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2016 USD ($) shares	Sep. 30, 2016 USD ($) shares	Sep. 30, 2015 USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
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
Stock conversion rate for zero-coupon subordinated notes (per thousand) | shares	200,000	200,000
tax benefit realized upon conversion of zero coupon convertible debt		$ 6,600,000
Principal amount of zero-coupon subordinated notes	$ 34,900,000	34,900,000
Noncash conversion of zero-coupon convertible debt		62,900,000
Payments On Zero Coupon Subordinated Notes		$ 31,500,000	$ 0
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	$ 1,000
Revolving Credit Facility [Member]
Zero Coupon Convertible Subordinated Notes [Line Items]
Debt to EBITDA (Leverage) Ratio	0	0
Revolving Credit Facility [Member] | Maximum [Member]
Zero Coupon Convertible Subordinated Notes [Line Items]
Debt to EBITDA (Leverage) Ratio						4.75
Subsequent Event [Member] | Revolving Credit Facility [Member] | Maximum [Member]
Zero Coupon Convertible Subordinated Notes [Line Items]
Debt to EBITDA (Leverage) Ratio				3.75	4.25