DEBT - CREDIT FACILITIES (Details) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016 Quarters	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($)	Dec. 19, 2014 USD ($)
Line of Credit Facility [Line Items]
Long-term debt, less current portion		$ 6,344.6	$ 5,300.0
Line of Credit Facility, Maximum Borrowing Capacity				$ 1,000.0
Debt covenant, requirement for number of consecutive fiscal quarters | Quarters	4
Credit Facility Option to Increase				350.0
Credit Facility, Maximum Swing Line Borrowings				100.0
Long-term Debt, Maturities, Repayment Terms		P5Y
Debt Covenant Requirement [Member]
Line of Credit Facility [Line Items]
Debt to EBITDA (leverage) ratio			3.0
Debt Covenant Actual [Member]
Line of Credit Facility [Line Items]
Debt to EBITDA (leverage) ratio			2.5
60-Day Debt Bridge Traunche [Domain]
Line of Credit Facility [Line Items]
Bridge Term Credit Facility Agreement, Maximum Borrowing Amount				400.0
Short-term Debt, Terms	P60D
Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate at Period End		2.80%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Credit Facility, Maximum Letters of Credit				$ 150.0
Debt to EBITDA (leverage) ratio			3,200,000
Line of Credit Facility, Interest Rate at Period End		2.70%
Prime Rate [Member] | Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.125% to 1.00%	0.0% to 0.50%
Prime Rate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.00% to 0.25%
London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Description	0.10% to 0.25%
London Interbank Offered Rate (LIBOR) [Member] | Term Loan [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	1.125% to 2.00%	0.875% to 1.50%
London Interbank Offered Rate (LIBOR) [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate Description	0.775% to 1.25%
Zero-coupon convertible subordinated notes [Member]
Line of Credit Facility [Line Items]
Zero Coupon Convertible Subordinated Notes Conversion Trigger Price | $ / shares		$ 77.45