Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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Net fair value of all derivative instruments designated as fair value hedging instruments.

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Fair value of the amount outstanding under the credit facility.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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DEBT (Senior Notes) (Details) - USD ($) $ in Millions	3 Months Ended
DEBT (Senior Notes) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 19, 2014
Debt Instrument [Line Items]
Senior notes due 2018	$ 500.0	$ 0.0
Convertible Subordinated Debt, Current	1.4	8.7
Short term debt issuance costs	1.5	0.5
Long-term Debt, Excluding Current Maturities	5,495.6	5,990.9
Line of Credit Facility, Maximum Borrowing Capacity				$ 1,000.0
Credit Facility Option to Increase				350.0
Credit Facility, Maximum Swing Line Borrowings				$ 100.0
Fair Value Hedges, Net	$ 0.6
Debt Instrument, Basis Spread on Variable Rate	2.298%
Long term debt issuance costs	$ 37.4	40.2
Notes Payable	1.8	1.8
Debt, Current	501.7	10.0
Foreign Currency Contract, Asset, Fair Value Disclosure	9.0	2.8
Senior notes due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	300.0	300.0
Senior notes due 2024 [Member] [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	600.0	600.0
Senior notes due 2025 [Member] [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount	300.0
Senior notes due 2027 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	600.0	600.0
Senior notes due 2045 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	900.0	900.0
Cross currency swap maturing 2022 [Member]
Debt Instrument [Line Items]
Derivative, Notional Amount	300.0
Senior notes due 2020 [Member]
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	599.4	597.0
Senior Notes, Noncurrent	$ 0.0	500.0
Stated interest rate percentage	4.625%
2017 Term Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Fair Value of Amount Outstanding	$ 527.0	$ 527.0	$ 750.0