DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES (Offsetting of Financial Liabilities and Derivative Liabilities) (Details) - USD ($) $ in Millions		Dec. 31, 2016		Dec. 31, 2015
Derivatives
Gross Amount of Recognized Liabilities		$ (221.0)		$ (221.5)
Gross Amount Offset in the Statement of Financial Position		0.0		0.0
Net Amount of Liabilities Presented in the Statement of Financial Position		(221.0)		(221.5)
Gross Amount Not Offset in the Statement of Financial Position		40.2	[1]	41.5	[2]
Net Amount		$ (180.8)		(180.0)
Cash Collateral for Borrowed Securities	[3]			$ 12.6

[1] Includes $12.6 million held of cash collateral at December 31, 2015.

[2] Includes $12.6 million of cash collateral held at December 31, 2015.

[3] Includes settlement gains of $5.5 million, $26.9 million, and $4.5 million for the years ended December 31, 2016, 2015 and 2014, respectively.