DERIVATIVE INSTRUMENTS - BALANCE SHEET OFFSETTING (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Cash collateral
Cash collateral in margin account	$ 11.8	$ 16.2
Offsetting Derivative Assets
Gross amount recognized on the balance sheet	5.4	12.4
Gross amount not offset on the balance sheet	(2.1)	(4.9)
Net amount	3.3	7.5
Offsetting Derivative Liabilities
Gross amount recognized on the balance sheet	5.1	11.6
Gross amount not offset on the balance sheet	(3.7)	(9.0)
Net amount	1.4	2.6
Collateral posted	1.6	4.1
Credit Risk Related Contingent Features
Aggregate fair value of all derivative instruments with specific credit risk-related contingent fearures in a net liability position	1.1	3.7
Additional collateral that would have been required	$ 1.5	$ 2.7

The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

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Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, and obligation to return cash collateral under master netting arrangements.

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The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

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