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DEBT - Schedule of Long-Term Debt Instruments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Long-Term Debt
Interest Income (Expense), Net	$ (26.3)	$ (14.8)	$ (78.9)	$ (42.5)
Unamortized Basis Adj for Terminated Interest Rate Swaps	5.6		5.6		$ 7.0
Debt Instrument, Unamortized Discount	(4.4)		(4.4)		(4.8)
Unamortized debt issuance costs	(20.0)		(20.0)		(21.6)
Fair-value interest rate swaps	27.2		27.2		0.4
Long-term Debt	3,008.4		3,008.4		2,981.0
Senior Notes
Long-Term Debt
Long-term Debt, Gross	3,000.0		3,000.0		3,000.0
Notes 4.90 Percent Due 2019 \| Senior Notes
Long-Term Debt
Long-term Debt, Gross	$ 700.0		$ 700.0		$ 700.0
Debt Instrument, Interest Rate, Stated Percentage	4.90%		4.90%		4.90%
Notes 3.00 Percent Due 2020 \| Senior Notes
Long-Term Debt
Long-term Debt, Gross	$ 750.0		$ 750.0		$ 750.0
Debt Instrument, Interest Rate, Stated Percentage	3.00%		3.00%		3.00%
Notes 4.125 Percent Due 2025 \| Senior Notes
Long-Term Debt
Long-term Debt, Gross	$ 750.0		$ 750.0		$ 750.0
Debt Instrument, Interest Rate, Stated Percentage	4.125%		4.125%		4.125%
Notes 5.90 Percent Due 2039 \| Senior Notes
Long-Term Debt
Long-term Debt, Gross	$ 300.0		$ 300.0		$ 300.0
Debt Instrument, Interest Rate, Stated Percentage	5.90%		5.90%		5.90%
Notes 4.600 Percent due 2044 \| Senior Notes
Long-Term Debt
Long-term Debt, Gross	$ 500.0		$ 500.0		$ 500.0
Debt Instrument, Interest Rate, Stated Percentage	4.60%		4.60%		4.60%